Navidea Biopharmaceuticals (NAVB) 10-Q 13 May 21 2021 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2021	May 07, 2021
Document Information [Line Items]
Entity Registrant Name	NAVIDEA BIOPHARMACEUTICALS, INC.
Entity Central Index Key	0000810509
Trading Symbol	navb
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Current Reporting Status	Yes
Entity Emerging Growth Company	false
Entity Small Business	true
Entity Interactive Data Current	Yes
Entity Common Stock, Shares Outstanding (in shares)		29,025,412
Entity Shell Company	false
Document Type	10-Q
Document Period End Date	Mar. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Amendment Flag	false
Title of 12(b) Security	Common Stock

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 7,507,319	$ 2,670,495
Stock subscriptions and other receivables	583,733	2,987,319
Inventory	166,242	169,798
Prepaid expenses and other	570,745	700,716
Total current assets	8,828,039	6,528,328
Property and equipment	845,379	845,379
Less accumulated depreciation and amortization	722,297	713,217
Property and equipment, net	123,082	132,162
Right-of-use lease assets	458,280	458,280
Less accumulated amortization	238,563	208,185
Right-of-use lease assets, net	219,717	250,095
License agreements, patents and trademarks	815,335	747,863
Less accumulated amortization	136,290	127,622
License agreements, patents and trademarks, net	679,045	620,241
Other assets	227,192	227,192
Total assets	10,077,075	7,758,018
Current liabilities:
Accounts payable	1,234,120	1,161,717
Accrued liabilities and other	2,429,822	2,512,994
Notes payable	190,550	745,443
Lease liabilities, current	304,262	294,951
Total current liabilities	4,158,754	4,715,105
Lease liabilities	209,439	296,006
Deferred revenue	700,000	700,000
Total liabilities	5,068,193	5,711,111
Commitments and contingencies (Note 11)
Stockholders’ equity:
Series D preferred stock subscribed; $.001 par value, 100,500 and 103,000 shares subscribed as of March 31, 2021 and December 31, 2020, respectively	101	132
Series D preferred stock subscriptions receivable	(9,550,000)	(10,300,000)
Common stock; $.001 par value; 300,000,000 shares authorized; 28,706,187 and 27,149,691 shares issued and outstanding as of March 31, 2021 and December 31, 2020, respectively	219,703	218,146
Common stock subscribed; $.001 par value, 995,000 shares subscribed as of March 31, 2021 and December 31, 2020, respectively	995	995
Common stock subscriptions receivable	(4,975,000)	(4,975,000)
Additional paid-in capital	380,605,305	375,428,014
Accumulated deficit	(362,023,573)	(359,056,683)
Total Navidea stockholders' equity	4,277,581	1,315,604
Noncontrolling interest	731,301	731,303
Total stockholders’ equity	5,008,882	2,046,907
Total liabilities and stockholders’ equity	10,077,075	7,758,018
Non-Series Preferred Stock [Member]
Stockholders’ equity:
Preferred stock, par value, authorized, issued and outstanding as of March 31, 2021 and December 31, 2020, respectively
Series E Preferred Stock [Member]
Stockholders’ equity:
Preferred stock, par value, authorized, issued and outstanding as of March 31, 2021 and December 31, 2020, respectively	$ 50

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - $ / shares	Mar. 31, 2021	Dec. 31, 2020
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock subscriptions, subscribed (in shares)	100,500	103,000
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	300,000,000	300,000,000
Common stock, shares issued (in shares)	28,706,187	27,149,691
Common stock, shares outstanding (in shares)	28,706,187	27,149,691
Common stock subscription, shares authorized (in shares)	995,000	995,000
Non-Series Preferred Stock [Member]
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Series E Preferred Stock [Member]
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	50,000	50,000
Preferred stock, shares outstanding (in shares)	50,000	0

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($)		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
Revenue:
Revenue from contract with customer		$ 22,000	$ 15,000
Grant and other revenue		101,251	141,051
Total revenue		123,737	156,272
Cost of revenue			609
Gross profit		123,737	155,663
Operating expenses:
Research and development		1,222,754	999,269
Selling, general and administrative		2,230,745	1,827,754
Total operating expenses		3,453,499	2,827,023
Loss from operations	[1]	(3,329,762)	(2,671,360)
Other income (expense):
Interest expense, net		(2,875)	(2,372)
Gain on extinguishment of debt		366,000
Other, net		(255)	124
Total other income (expense), net	[2]	362,870	(2,248)
Net loss		(2,966,892)	(2,673,608)
Less (loss) income attributable to noncontrolling interest		(2)	2
Net loss attributable to common stockholders		$ (2,966,890)	$ (2,673,610)
Loss attributable to common stockholders per common share (basic and diluted) (in dollars per share)		$ (0.11)	$ (0.13)
Weighted average shares outstanding (in shares)		28,066,296	20,203,636
Royalty [Member]
Revenue:
Revenue from contract with customer			$ 15,221
License [Member]
Revenue:
Revenue from contract with customer		$ 22,486
[1]	Income (loss) from operations does not reflect the allocation of certain selling, general and administrative expenses, excluding depreciation and amortization, to our individual reportable segments, other than those expenses directly incurred by Navidea Europe, Navidea UK and MT.
[2]	Amounts consist primarily of interest income and interest expense, which are not currently allocated to our individual reportable segments.

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($)	Preferred Stock [Member]Series D Preferred Stock [Member]	Preferred Stock [Member]Series E Preferred Stock [Member]	Preferred Stock [Member]	Preferred Stock Subscription [Member]Series D Preferred Stock [Member]	Preferred Stock Subscription [Member]Series E Preferred Stock [Member]	Preferred Stock Subscription [Member]	Preferred Stock Subscriptions Receivable [Member]Series D Preferred Stock [Member]	Preferred Stock Subscriptions Receivable [Member]Series E Preferred Stock [Member]	Preferred Stock Subscriptions Receivable [Member]	Common Stock [Member]Series D Preferred Stock [Member]	Common Stock [Member]Series E Preferred Stock [Member]	Common Stock [Member]Private Placement [Member]	Common Stock [Member]Registered Direct Offering [Member]	Common Stock [Member]	Common Stock Subscription [Member]Series D Preferred Stock [Member]	Common Stock Subscription [Member]Series E Preferred Stock [Member]	Common Stock Subscription [Member]Private Placement [Member]	Common Stock Subscription [Member]Registered Direct Offering [Member]	Common Stock Subscription [Member]	Common Stock Subscriptions Receivable [Member]Series D Preferred Stock [Member]	Common Stock Subscriptions Receivable [Member]Series E Preferred Stock [Member]	Common Stock Subscriptions Receivable [Member]Private Placement [Member]	Common Stock Subscriptions Receivable [Member]Registered Direct Offering [Member]	Common Stock Subscriptions Receivable [Member]	Additional Paid-in Capital [Member]Series D Preferred Stock [Member]	Additional Paid-in Capital [Member]Series E Preferred Stock [Member]	Additional Paid-in Capital [Member]Private Placement [Member]	Additional Paid-in Capital [Member]Registered Direct Offering [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]Series D Preferred Stock [Member]	Retained Earnings [Member]Series E Preferred Stock [Member]	Retained Earnings [Member]Private Placement [Member]	Retained Earnings [Member]Registered Direct Offering [Member]	Retained Earnings [Member]	Noncontrolling Interest [Member]Series D Preferred Stock [Member]	Noncontrolling Interest [Member]Series E Preferred Stock [Member]	Noncontrolling Interest [Member]Private Placement [Member]	Noncontrolling Interest [Member]Registered Direct Offering [Member]	Noncontrolling Interest [Member]	Series D Preferred Stock [Member]	Series E Preferred Stock [Member]	Private Placement [Member]	Registered Direct Offering [Member]	Total
Balance (in shares) at Dec. 31, 2019														19,234,960					902,162
Balance at Dec. 31, 2019														$ 210,232					$ 902										$ 345,847,676					$ (347,671,102)					$ 731,303					$ (880,989)
Issued stock (in shares)												902,162		1,000,001			(902,162)
Issued stock												$ 902		$ 1,000			$ (902)												699,000															700,000
Series D Preferred Stock subscribed (in shares)																	2,373,529	647,058
Series D Preferred Stock subscribed																	$ 2,374	$ 647				$ (912,500)					$ 2,015,126	$ 549,353														$ 1,105,000	$ 550,000
Stock compensation expense																													39,246															39,246
Net loss																																		(2,673,610)					2					(2,673,608)
Total comprehensive income (loss)																																												(2,673,608)
Issued stock in payment of services (in shares)														3,810
Issued stock in payment of services														$ 4															4,797															4,801
Issued stock in payment of employee bonuses (in shares)														53,315
Issued stock in payment of employee bonuses														$ 53															64,458															64,511
Balance (in shares) at Mar. 31, 2020														21,194,248					3,020,587
Balance at Mar. 31, 2020														$ 212,191					$ 3,021					(912,500)					349,219,656					(350,344,712)					731,305					(1,091,039)
Balance (in shares) at Dec. 31, 2020						132,250								27,149,691					995,000
Balance at Dec. 31, 2020						$ 132			$ (10,300,000)					$ 218,146					$ 995					(4,975,000)					375,428,014					(359,056,683)					731,303					2,046,907
Issued restricted stock (in shares)														12,500
Issued restricted stock														$ 13																														$ 13
Issued stock to 401(k) plan (in shares)														30,018																														30,018
Issued stock to 401(k) plan														$ 30															76,816															$ 76,846
Issued stock (in shares)	31,750	50,000		(31,750)
Issued stock	$ 32	$ 50		$ (31)			$ 250,000																			$ 4,980,659														$ 250,001	$ 4,980,709
Issued stock upon conversion of Series D Preferred Stock (in shares)	(31,750)									1,513,978
Issued stock upon conversion of Series D Preferred Stock	$ (32)									$ 1,514															$ (1,482)
Series D Preferred Stock subscribed (in shares)
Series D Preferred Stock subscribed									500,000																																			500,000
Stock compensation expense																													121,298															121,298
Net loss																																		(2,966,890)					(2)					(2,966,892)
Total comprehensive income (loss)																																												(2,966,892)
Balance (in shares) at Mar. 31, 2021			50,000			100,500								28,706,187					995,000
Balance at Mar. 31, 2021			$ 50			$ 101			$ (9,550,000)					$ 219,703					$ 995					$ (4,975,000)					$ 380,605,305					$ (362,023,573)					$ 731,301					$ 5,008,882

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	1 Months Ended		3 Months Ended			12 Months Ended
	Jan. 31, 2020	Dec. 31, 2019	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net loss			$ (2,966,892)		$ (2,673,608)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization			17,748		16,843
Non-cash lease expense			30,378		30,223
Stock compensation expense			121,298		39,246
Gain on extinguishment of debt			(366,000)
Value of stock issued to 401(k) plan for employer matching contributions			76,846
Value of stock issued in payment of employee bonuses					64,511
Value of stock issued in payment of services					4,801
Changes in operating assets and liabilities:
Receivables			(21,414)		860,917
Inventory			3,556
Prepaid expenses and other assets			129,970		127,922
Accounts payable			72,403		342,214
Accrued and other liabilities			(83,171)		305,375
Lease liabilities			(77,256)		(69,768)
Net cash used in operating activities			(3,062,534)		(951,324)
Cash flows from investing activities:
Payments for purchases of equipment					(6,460)
Patent and trademark costs			(67,472)		(57,984)
Net cash used in investing activities			(67,472)		(64,444)
Cash flows from financing activities:
Proceeds from issuance of preferred stock, including stock subscriptions receivable			8,175,000
Proceeds from issuance of common stock	$ 812,000	$ 1,900,000	13	$ 1,700,000	850,000		$ 1,100,000
Principal payments on notes payable			(188,893)		(130,036)
Net cash provided by financing activities			7,966,830		569,964
Net increase (decrease) in cash and cash equivalents			4,836,824		(445,804)
Cash and cash equivalents, beginning of period	$ 1,047,159		2,670,495	$ 601,355	1,047,159	$ 1,047,159
Cash and cash equivalents, end of period		$ 1,047,159	7,507,319		601,355	$ 2,670,495	$ 1,047,159
Preferred Stock Issuance Costs [Member]
Cash flows from financing activities:
Payment of stock issuance costs			(19,290)
Common Stock Issuance Costs [Member]
Cash flows from financing activities:
Payment of stock issuance costs					$ (150,000)

Note 1 - Summary of Significant

Note 1 - Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Significant Accounting Policies [Text Block]	1. Summary of Significant Accounting Policies a. Basis of Presentation: March 31, 2021 three March 31, 2021 2020 March 31, 2021 not December 31, 2020, 10 Our consolidated financial statements include the accounts of Navidea and our wholly owned subsidiaries, Navidea Biopharmaceuticals Europe Limited (“Navidea Europe”) and Navidea Biopharmaceuticals Limited (“Navidea UK”), as well as those of our majority-owned subsidiary, Macrophage Therapeutics, Inc. (“MT”). All significant inter-company accounts were eliminated in consolidation. During the ongoing COVID- 19 not 19. 19 NAV3 32 19 19 not b. Financial Instruments and Fair Value: ( 1 Cash and cash equivalents, stock subscriptions and other receivables, and accounts payable: ( 2 Notes payable: March 31, 2021 December 31, 2020 March 31, 2021 December 31, 2020, $191,000 $745,000, 9. c. Revenue Recognition: We also earn revenues related to our licensing and distribution agreements. The consideration we are eligible to receive under our licensing and distribution agreements typically includes upfront payments, reimbursement for research and development costs, milestone payments, and royalties. Each licensing and distribution agreement is unique and requires separate assessment in accordance with current accounting standards. See Note 3. d. Leases: 2018. 12 not 10. e. Series D and Series E Convertible Preferred Stock: 480, Distinguishing Liabilities from Equity 815, Derivatives and Hedging 470, Debt 268, Presentation in Financial Statements of Redeemable Preferred Stocks not not No. 2020 06, Accounting for Convertible Instruments and Contracts in an Entity s Own Equity January 1, 2021, not not 12. f. Recently Adopted Accounting Standards: December 2019, No. 2019 12, Income Taxes (Topic 740 2019 12 2019 12 740 2019 12 December 12, 2020, 2019 12 not In August 2020, No. 2020 06, Accounting for Convertible Instruments and Contracts in an Entity s Own Equity 2020 06 2020 06 2020 06 2020 06 December 15, 2021, December 15, 2023 2020 06 January 1, 2021 2020 06 not g. Recently Issued Accounting Standards: May 2021, No. 2021 04, Issuer s Accounting for Certain Modifications or Exchanges of Freestanding Equity-Classified Written Call Options 2021 04 ASU2 021 04 ASU2021 04 2021 04 December 15, 2021, not 2021 04

Note 2 - Liquidity

Note 2 - Liquidity	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Substantial Doubt about Going Concern [Text Block]	2. Liquidity As disclosed in the notes to the financial statements included in the Company's Annual Report on Form 10 $1.9 11. In addition, the Company is engaged in ongoing litigation with our former President and Chief Executive Officer, Dr. Michael Goldberg. See Notes 7 11. The Company has also been engaged in ongoing litigation with Capital Royalty Partners II L.P. (“CRG”) and pursuing recovery of approximately $4.3 11. On August 30, 2020, $25.0 $0.001 10 $25,000 $5.0 12. On August 31, 2020, 150,000 $15.0 one 5,147,000 10 $5.5 12 17. On March 2, 2021, 50,000 $5.0 2,173,913 10 none 12. Navidea intends to use the net proceeds from these transactions to fund its research and development programs, including continued advancement of its two 2b 3 Tc99m The Coronavirus Aid, Relief, and Economic Security Act (the “CARES Act”) was enacted on March 27, 2020. 7 May 18, 2020, $366,000 February 23, 2021, $366,000 9. During the ongoing COVID- 19 not 19. 19 NAV3 32 19 The Company has experienced recurring net losses and has used significant cash to fund its operations. The Company has considerable discretion over the extent of development project expenditures and has the ability to curtail the related cash flows as needed. The Company also has funds remaining under outstanding grant awards, and continues working to establish new sources of funding, including collaborations, potential equity investments, and additional grant funding that can augment the balance sheet. Based on our committed equity investments, current working capital, and our projected cash burn, management believes that the Company will be able to continue as a going concern for a period of one 10

Note 3 - Revenue From Contracts

Note 3 - Revenue From Contracts With Customers	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Revenue from Contract with Customer [Text Block]	3. Revenue from Contracts with Customers Navidea is focused on the development and commercialization of precision immunodiagnostic agents and immunotherapeutics. We manage our business based on two Tc99m Tc99m one Tc99 not May 11, 2020, The Company also has an agreement in place to provide Meilleur Technologies, Inc., (“Meilleur”), a wholly-owned subsidiary of Cerveau Technologies, Inc. (“Cerveau”), worldwide rights to conduct research using NAV4694, NAV4694 Currently, the Company recognizes revenue from up-front license fees and pre-market milestones after the cash has been received from its customers and the performance obligations have been met. Payments for sales-based royalties and milestones are generally received after the related revenue has been recognized and invoiced. Normal payment terms generally range from 15 90 Up-front and milestone payments received related to our license and distribution agreements in India and China are deferred until Tc99m not Tc99m not no not eight ten The transaction price of a contract is the amount of consideration to which the Company expects to be entitled in exchange for transferring promised goods or services to a customer. Transaction prices do not third not When estimating a contract's transaction price, the Company considers all the information (historical, current, and forecasted) that is reasonably available to it and identifies possible consideration amounts. Most of the Company's contracts with customers include both fixed and variable components of the transaction price. Under those contracts, some or all of the consideration for satisfied performance obligations is contingent on events over which the Company has no Tc99m The milestone payments have a binary outcome (that is, the Company will either receive all or none not Royalties are estimated based on the expected value method because they are based on a variable amount of sales representing a range of possible outcomes. However, when taking into account the constraint on variable consideration, the estimate of future royalties included in the transaction price is generally $0. Tc99m not no no The sublicense of NAV4694 No. 606, Revenue from Contracts with Customers 606” Up-front fees, milestones and royalties are generally non-refundable. Therefore, the Company does not During the three March 31, 2021 2020, $22,000 $15,000, three March 31, 2021 2020, not The following table disaggregates the Company's revenue from contracts with customers for the three March 31, 2021 2020. Three Months Ended March 31, 2021 2020 Royalty revenue: Tc99m tilmanocept - Europe $ — $ 15,221 License revenue: Tc99m tilmanocept - Europe $ 22,486 $ — The following economic factors affect the nature, amount, timing and uncertainty of the Company's revenue and cash flows as indicated: Geographical Location of Customers: may may Tc99m Status of Regulatory Approval: Tc99m Tc99m Tc99m not may NAV4694 not Through March 31, 2021, not The following table summarizes the changes in contract liabilities, the current portion of which is included in accrued liabilities and other in the consolidated balance sheets, during the three March 31, 2021 2020. Three Months Ended March 31, 2021 2020 Total deferred revenue, beginning of period $ 700,000 $ 700,000 Revenue recognized from satisfaction of performance obligations — — Total deferred revenue, end of period $ 700,000 $ 700,000 The Company had license revenue receivable of approximately $82,000 $59,000 March 31, 2021 December 31, 2020, In addition to revenue from contracts from customers, we also generate revenue from National Institutes of Health (“NIH”) grants to support various product development initiatives. The revenue recognition standard applies to revenue from contracts with customers. A customer is defined as a party that has contracted with an entity to obtain goods or services that are an output of the entity's ongoing major or central operations in exchange for consideration. The Company's ongoing major or central operations consist of the development and commercialization of precision immunodiagnostic agents and immunotherapeutics. The NIH and its various institutes are responsible for biomedical and public health research and provide major biomedical research funding to non-NIH research facilities and entities such as Navidea. While the Company will directly benefit from any knowledge gained from the project, there is also a public health benefit provided, which justifies the use of public funds in the form of the grants. Based on the nature of the Company's operations and the terms of the grant awards, Navidea does not not three March 31, 2021 2020, $1,000 $141,000, On May 11, 2020 ( March 5, 2015 ( Tc99m Pursuant to the Termination Agreement, the parties agreed that neither owed the other any payments due under the License Agreement as of the Termination Date and that, among other things, SpePharm no six ninety

Note 4 - Stock-based Compensati

Note 4 - Stock-based Compensation	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Share-based Payment Arrangement [Text Block]	4. Stock-Based Compensation For the three March 31, 2021 2020, $121,000 $39,000, not three March 31, 2021 2020. A summary of the status of our stock options as of March 31, 2021, three Three Months Ended March 31, 2021 Number of Options Weighted Average Exercise Price Weighted Average Remaining Contractual Life (years) Aggregate Intrinsic Value Outstanding, January 1, 2021 549,970 $ 8.81 8.0 $ 209,280 Granted 229,500 2.54 Outstanding, March 31, 2021 779,470 $ 6.97 8.4 $ 184,320 Exercisable, March 31, 2021 201,438 $ 15.21 6.4 $ 67,841 The weighted average grant date fair value per stock option granted during the three March 31, 2021 $1.87. three March 31, 2021 90.14%, 0.67%, 5.97 A summary of the status of our unvested restricted stock as of March 31, 2021, three Three Months Ended March 31, 2021 Number of Shares Weighted Average Grant-Date Fair Value Unvested, January 1, 2021 60,000 $ 2.90 Granted 12,500 2.28 Vested (10,000 ) 1.06 Unvested, March 31, 2021 62,500 $ 3.07 As of March 31, 2021, $595,000 1.6

Note 5 - Loss Per Share

Note 5 - Loss Per Share	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Earnings Per Share [Text Block]	5. Loss Per Share Basic loss per share is calculated by dividing net loss attributable to common stockholders by the weighted average number of common shares. Diluted loss per share reflects additional common shares that would have been outstanding if dilutive potential common shares had been issued. Potential common shares that may Diluted loss per common share for the three March 31, 2021 2020 1,173,762 1,515,164 The Company's unvested restricted stock awards contain nonforfeitable rights to dividends or dividend equivalents, whether paid or unpaid (referred to as “participating securities”). Therefore, the unvested restricted stock awards are required to be included in the number of shares outstanding for both basic and diluted earnings per share calculations. However, due to our loss from continuing operations, 62,500 10,000 three March 31, 2021 2020,

Note 6 - Inventory

Note 6 - Inventory	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Inventory Disclosure [Text Block]	6. Inventory The components of inventory as of March 31, 2021 December 31, 2020 March 31, 2021 December 31, 2020 Materials $ 77,750 $ 77,750 Finished goods 88,492 92,048 Total inventory $ 166,242 $ 169,798 During the three March 31, 2021, $4,000

Note 7 - Investment in Macropha

Note 7 - Investment in Macrophage Therapeutics, Inc.	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Investments in and Advances to Affiliates, Schedule of Investments [Text Block]	7. Investment in Macrophage Therapeutics, Inc. In August 2018, one February 2019, may December 18, 2020 no New York Litigation Involving Dr. Goldberg On February 20, 2019, April 26, 2019, June 13, 2019, third On December 26, 2019, third not The District Court also rejected Dr. Goldberg's claim for wrongful termination as Chief Executive Officer of MT. In addition, the District Court found that Dr. Goldberg lacked standing to seek injunctive relief to force the removal of Dr. Claudine Bruck and Michael Rice from MT's Board of Directors, to invalidate all actions taken by the MT Board on or after November 29, 2018 ( In addition, the District Court found Navidea's breach of fiduciary duty claim against Dr. Goldberg for conduct occurring more than three On January 31, 2020, April 1, 2020, On January 27, 2020, July 9, 2020, 1 2 3 4 On August 24, 2020, not third On April 21, 2021, 1 $14,955 2 $1,237.50 3 not 4 not third 5 6 not May 5, 2021, May 19, 2021. Fact discovery in the New York Action has been completed and the parties and the Court anticipate meeting in the future to address remaining case deadlines. Delaware Litigation Involving Dr. Goldberg On February 20, 2019, June 12, 2019, not May 23, 2019 December 1 December 3, 2020. two one one March 16, 2021 Derivative Action Involving Dr. Goldberg On July 26, 2019, November 20, 2019, April 3, 2020, not 2 11.

Note 8 - Accounts Payable, Accr

Note 8 - Accounts Payable, Accrued Liabilities and Other	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Current [Text Block]	8. Accounts Payable, Accrued Liabilities and Other Accounts payable as of March 31, 2021 December 31, 2020 $78,000 $66,000, March 31, 2021 December 31, 2020 $457,000 $755,000,

Note 9 - Notes Payable

Note 9 - Notes Payable	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Debt Disclosure [Text Block]	9. Notes Payable First Insurance Funding In November 2019, $349,000 5.0%. eight $44,000, July 2020. Interest expense related to the FIF note payable totaled $3,000 three March 31, 2020. IPFS Corporation In November 2020, $442,000 3.5%. seven $64,000, June 2021. Interest expense related to the IPFS note payable totaled $3,000 three March 31, 2021. $191,000 March 31, 2021, Paycheck Protection Program The CARES Act was enacted on March 27, 2020. May 18, 2020, $366,000. February 23, 2021, $366,000 2. Summary During the three March 31, 2021 2020, $3,000

Note 10 - Leases

Note 10 - Leases	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Leases of Lessee Disclosure [Text Block]	10. Leases We currently lease approximately 5,000 4995 $3,000. June 2023. In addition, we currently lease approximately 25,000 5600 $27,000 2021. October 2022 five not June 2017, $39,000 October 2022. We also currently lease a vehicle at a monthly payment of approximately $300, September 2021, $100, October 2024. Total operating lease expense was $46,000 $51,000 three March 31, 2021 2020, The following table presents information about the amount, timing and uncertainty of cash flows arising from the Company's operating leases as of March 31, 2021. Maturity of Lease Liabilities Operating Lease Payments 2021 (remaining) $ 251,842 2022 291,111 2023 19,699 2024 1,355 Total undiscounted operating lease payments 564,007 Less imputed interest 50,306 Present value of operating lease liabilities $ 513,701 Balance Sheet Classification Current lease liabilities $ 304,262 Noncurrent lease liabilities 209,439 Total operating lease liabilities $ 513,701 Other Information Weighted-average remaining lease term for operating leases (years) 1.6 Weighted-average discount rate for operating leases 10.9 % Cash paid for amounts included in the present value of operating lease liabilities was $93,000 $91,000 three March 31, 2021 2020,

Note 11 - Commitments and Conti

Note 11 - Commitments and Contingencies	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Commitments and Contingencies Disclosure [Text Block]	11. Commitments and Contingencies We are subject to legal proceedings and claims that arise in the ordinary course of business. In accordance with ASC Topic 450, Contingencies not CRG Litigation As disclosed in the notes to the financial statements included in the Company's Annual Report on Form 10 December 2017, $66.0 $66.0 March 3, 2017. $59.0 March 2017, $7.0 not June 2016 $4.1 $66.0 $4.1 $4.1 $7.0 On April 9, 2018, $7.1 414, 414” $4.1 $59.0 The Company has also been engaged in ongoing litigation with CRG in the Court of Common Pleas of Franklin County, Ohio related to Navidea's claims that the CRG Lenders fraudulently induced Navidea to enter into a settlement agreement and breached the terms of the same through certain actions taken by the CRG Lenders in connection with the Global Settlement Agreement, pursuant to which Navidea agreed to pay up to $66.0 $66.0 $4.1 June 2016 $66.0 $66.0 $7.1 414 May 7, 2019, June 28, 2019. November 27, 2019, $66.0 $4.3 April 9, 2018, 414 no December 5, 2019, 10th March 27, 2020, September 23, 2020. March 16, 2021, 10th November 27, 2019 $4.3 not not April 30, 2021, not CRG filed another lawsuit in the Texas Court in April 2018. not $7.1 414 August 28, 2020. December 18, 2020, February 1, 2021. 2. Platinum Litigation In November 2017, $1.9 March 3, 2017, October 31, 2018, no On November 30, 2018, January 22, 2019, September 5, 2019. November 25, 2019, not April 28, 2020 19 not June 4, 2020. September 2, 2020, September 23, 2020 not 2. Goldberg Agreement and Litigation In August 2018, one 1,175,000 1,175,000 18 5% November 2018, 925,000 250,000 On February 11, 2019, February 19, 2019, March 1, 2019, February 20, 2019, may December 18, 2020 no New York Litigation Involving Dr. Goldberg On February 20, 2019, April 26, 2019, June 13, 2019, third On December 26, 2019, third not The District Court also rejected Dr. Goldberg's claim for wrongful termination as Chief Executive Officer of MT. In addition, the District Court found that Dr. Goldberg lacked standing to seek injunctive relief to force the removal of Dr. Claudine Bruck and Michael Rice from MT's Board of Directors, to invalidate all actions taken by the MT Board on or after November 29, 2018 ( In addition, the District Court found Navidea's breach of fiduciary duty claim against Dr. Goldberg for conduct occurring more than three On January 31, 2020, April 1, 2020, On January 27, 2020, July 9, 2020, 1 2 3 4 On August 24, 2020, not third On April 21, 2021, 1 $14,955 2 $1,237.50 3 not 4 not third 5 6 not May 5, 2021, May 19, 2021. Fact discovery in the New York Action has been completed and the parties and the Court anticipate meeting in the future to address remaining case deadlines. Delaware Litigation Involving Dr. Goldberg On February 20, 2019, June 12, 2019, not May 23, 2019 December 1 December 3, 2020. two one one March 16, 2021 Derivative Action Involving Dr. Goldberg On July 26, 2019, November 20, 2019, April 3, 2020, not 2 7. NYSE American Continued Listing Standards Navidea must maintain compliance with NYSE American continued listing standards, including those relating to stockholders' equity. Specifically, Sections 1003 $6.0 five March 31, 2021, $4.3 Even if an issuer does not 1003 not 1 $50,000,000; $50,000,000 two three 2 1,100,000 $15,000,000 400 March 31, 2021, $57.7 March 31, 2021 $50.0 not may

Note 12 - Equity

Note 12 - Equity	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Stockholders' Equity Note Disclosure [Text Block]	12. Equity In December 2019, 2.1 $1.9 $1.1 2019, $812,000 December 31, 2019. $812,000 January 2020. In February 2020, two 4.0 $3.4 $850,000 first 2020. $1.7 second 2020. On August 30, 2020, $25.0 10 $25,000 $4.975 March 31, 2021. 2. On August 31, 2020, 150,000 $15.0 one 5,147,000 Of the $15.0 $5.0 49,500 March 31, 2021. 49,500 2,341,258 March 31, 2021. $5.0 March 31, 2021, $3.2 first 2021, $2.925 10 December 31, 2020. $2.925 December 31, 2020. $500,000 5,000 April 1, 2021 10 5,000 316,725 April 1, 2021 10 $500,000 $9.6 March 31, 2021. 2 17. On March 2, 2021, 50,000 $5.0 Under the Series E Preferred Stock Purchase Agreement, Mr. Scott was granted a right of first no 33.33% 13 1934, not third not no 33.33% no may December 31, 2021 In connection with the private placement, the Company entered into a registration rights agreement (the “Registration Rights Agreement”), pursuant to which, among other things, the Company will prepare and file with the Securities and Exchange Commission (the “SEC”) one 20% 13 144 not 1933, not may not Except with respect to transactions which may no one may $2.30 not $110 one 2. Navidea intends to use the net proceeds from these transactions to fund its research and development programs, including continued advancement of its two 2b 3 Tc99m 2. During the three March 31, 2021, 30,018 $77,000 401 During the three March 31, 2020, 53,315 $65,000 2019

Note 13 - Stock Warrants

Note 13 - Stock Warrants	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Stock Warrants Disclosure [Text Block]	13. Stock Warrants At March 31, 2021, 972,324 $0.20 $49.80 $17.97 one 14.4

Note 14 - Income Taxes

Note 14 - Income Taxes	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Income Tax Disclosure [Text Block]	14. Income Taxes Income taxes are accounted for under the asset and liability method in accordance with Accounting Standards Codification 740, Income Taxes Current accounting standards require a valuation allowance against DTAs if, based on the weight of available evidence, it is more likely than not may not March 31, 2021 December 31, 2020. In assessing the realizability of DTAs, management considers whether it is more likely than not not not not March 31, 2021. Current accounting standards include guidance on the accounting for uncertainty in income taxes recognized in the financial statements. Such standards also prescribe a recognition threshold and measurement model for the financial statement recognition of a tax position taken, or expected to be taken, and provides guidance on derecognition, classification, interest and penalties, accounting in interim periods, disclosure and transition. The Company believes that the ultimate deductibility of all tax positions is highly certain, although there is uncertainty about the timing of such deductibility. As a result, no March 31, 2021 December 31, 2020 not twelve March 31, 2021, 2017 2020 As of March 31, 2021, $153.3 $20.1 $8.9 2021 2040.

Note 15 - Segments

Note 15 - Segments	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Segment Reporting Disclosure [Text Block]	15. Segments We report information about our operating segments using the “management approach” in accordance with current accounting standards. This information is based on the way management organizes and reports the segments within the enterprise for making operating decisions and assessing performance. Our reportable segments are identified based on differences in products, services and markets served. There were no two Tc99m The information in the following tables is derived directly from each reportable segment's financial reporting. Three Months Ended March 31, 2021 Diagnostics Therapeutics Corporate Total License revenue $ 22,486 $ — $ — $ 22,486 Grant and other revenue 101,251 — — 101,251 Total revenue 123,737 — — 123,737 Cost of revenue — — — — Research and development expenses 1,094,390 128,364 — 1,222,754 Selling, general and administrative expenses, excluding depreciation and amortization (1) — 2,006 2,210,991 2,212,997 Depreciation and amortization (2) 6,040 — 11,708 17,748 Loss from operations (3) (976,693 ) (130,370 ) (2,222,699 ) (3,329,762 ) Other income (4) — — 362,870 362,870 Net loss (976,693 ) (130,370 ) (1,859,829 ) (2,966,892 ) Total assets, net of depreciation and amortization: United States $ 160,669 $ — $ 9,723,212 $ 9,883,881 International 193,194 — — 193,194 Capital expenditures — — — — Three Months Ended March 31, 2020 Diagnostics Therapeutics Corporate Total Royalty revenue $ 15,221 $ — $ — $ 15,221 Grant and other revenue 58,916 82,135 — 141,051 Total revenue 74,137 82,135 — 156,272 Cost of revenue 609 — — 609 Research and development expenses 957,626 41,643 — 999,269 Selling, general and administrative expenses, excluding depreciation and amortization (1) — (1,522 ) 1,812,433 1,810,911 Depreciation and amortization (2) — — 16,843 16,843 (Loss) income from operations (3) (884,098 ) 42,014 (1,829,276 ) (2,671,360 ) Other expense (4) — — (2,248 ) (2,248 ) Net loss (884,098 ) 42,014 (1,831,524 ) (2,673,608 ) Total assets, net of depreciation and amortization: United States $ 36,671 $ 2,494 $ 4,438,066 $ 4,477,231 International — — — — Capital expenditures — — 6,459 6,459 ( 1 General and administrative expenses, excluding depreciation and amortization, represent costs that relate to the general administration of the Company and as such are not ( 2 Depreciation and amortization are reflected in selling, general and administrative expenses ( $17,748 $16,843 three March 31, 2021 2020, ( 3 Income (loss) from operations does not ( 4 Amounts consist primarily of interest income and interest expense, which are not

Note 16 - Supplemental Disclosu

Note 16 - Supplemental Disclosure for Statements of Cash Flows	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Cash Flow, Supplemental Disclosures [Text Block]	16. Supplemental Disclosure for Statements of Cash Flows During the three March 31, 2021 2020, $3,000 three March 31, 2021, $2.925 10 December 31, 2020 December 31, 2020. February 2020, $100,432. three March 31, 2021, 30,018 $77,000 401 three March 31, 2020, 53,315 $65,000 2019

Note 17 - Subsequent Events

Note 17 - Subsequent Events	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Subsequent Events [Text Block]	17. Subsequent Events The Company has evaluated events and transactions subsequent to March 31, 2021 10 As discussed previously, the Company entered into a Series D Preferred Stock Purchase Agreement with Keystone for a total commitment of $15.0 $5.0 49,500 March 31, 2021. $500,000 5,000 April 1, 2021 10 5,000 316,725 April 1, 2021 10 $500,000 $9.6 March 31, 2021. 2 12.

Significant Accounting Policies

Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	a. Basis of Presentation: March 31, 2021 three March 31, 2021 2020 March 31, 2021 not December 31, 2020, 10 Our consolidated financial statements include the accounts of Navidea and our wholly owned subsidiaries, Navidea Biopharmaceuticals Europe Limited (“Navidea Europe”) and Navidea Biopharmaceuticals Limited (“Navidea UK”), as well as those of our majority-owned subsidiary, Macrophage Therapeutics, Inc. (“MT”). All significant inter-company accounts were eliminated in consolidation. During the ongoing COVID- 19 not 19. 19 NAV3 32 19 19 not
Fair Value of Financial Instruments, Policy [Policy Text Block]	b. Financial Instruments and Fair Value: ( 1 Cash and cash equivalents, stock subscriptions and other receivables, and accounts payable: ( 2 Notes payable: March 31, 2021 December 31, 2020 March 31, 2021 December 31, 2020, $191,000 $745,000, 9.
Revenue [Policy Text Block]	c. Revenue Recognition: We also earn revenues related to our licensing and distribution agreements. The consideration we are eligible to receive under our licensing and distribution agreements typically includes upfront payments, reimbursement for research and development costs, milestone payments, and royalties. Each licensing and distribution agreement is unique and requires separate assessment in accordance with current accounting standards. See Note 3.
Lessee, Leases [Policy Text Block]	d. Leases: 2018. 12 not 10.
Stockholders' Equity Note, Redeemable Preferred Stock, Issue, Policy [Policy Text Block]	e. Series D and Series E Convertible Preferred Stock: 480, Distinguishing Liabilities from Equity 815, Derivatives and Hedging 470, Debt 268, Presentation in Financial Statements of Redeemable Preferred Stocks not not No. 2020 06, Accounting for Convertible Instruments and Contracts in an Entity s Own Equity January 1, 2021, not not 12.
New Accounting Pronouncements, Policy [Policy Text Block]	f. Recently Adopted Accounting Standards: December 2019, No. 2019 12, Income Taxes (Topic 740 2019 12 2019 12 740 2019 12 December 12, 2020, 2019 12 not In August 2020, No. 2020 06, Accounting for Convertible Instruments and Contracts in an Entity s Own Equity 2020 06 2020 06 2020 06 2020 06 December 15, 2021, December 15, 2023 2020 06 January 1, 2021 2020 06 not g. Recently Issued Accounting Standards: May 2021, No. 2021 04, Issuer s Accounting for Certain Modifications or Exchanges of Freestanding Equity-Classified Written Call Options 2021 04 ASU2 021 04 ASU2021 04 2021 04 December 15, 2021, not 2021 04

Note 3 - Revenue From Contrac_2

Note 3 - Revenue From Contracts With Customers (Tables)	3 Months Ended
	Mar. 31, 2021
Notes Tables
Disaggregation of Revenue [Table Text Block]	Three Months Ended March 31, 2021 2020 Royalty revenue: Tc99m tilmanocept - Europe $ — $ 15,221 License revenue: Tc99m tilmanocept - Europe $ 22,486 $ —
Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block]	Three Months Ended March 31, 2021 2020 Total deferred revenue, beginning of period $ 700,000 $ 700,000 Revenue recognized from satisfaction of performance obligations — — Total deferred revenue, end of period $ 700,000 $ 700,000

Note 4 - Stock-based Compensa_2

Note 4 - Stock-based Compensation (Tables)	3 Months Ended
	Mar. 31, 2021
Notes Tables
Share-based Payment Arrangement, Option, Activity [Table Text Block]	Three Months Ended March 31, 2021 Number of Options Weighted Average Exercise Price Weighted Average Remaining Contractual Life (years) Aggregate Intrinsic Value Outstanding, January 1, 2021 549,970 $ 8.81 8.0 $ 209,280 Granted 229,500 2.54 Outstanding, March 31, 2021 779,470 $ 6.97 8.4 $ 184,320 Exercisable, March 31, 2021 201,438 $ 15.21 6.4 $ 67,841
Schedule of Nonvested Restricted Stock Units Activity [Table Text Block]	Three Months Ended March 31, 2021 Number of Shares Weighted Average Grant-Date Fair Value Unvested, January 1, 2021 60,000 $ 2.90 Granted 12,500 2.28 Vested (10,000 ) 1.06 Unvested, March 31, 2021 62,500 $ 3.07

Note 6 - Inventory (Tables)

Note 6 - Inventory (Tables)	3 Months Ended
	Mar. 31, 2021
Notes Tables
Schedule of Inventory, Current [Table Text Block]	March 31, 2021 December 31, 2020 Materials $ 77,750 $ 77,750 Finished goods 88,492 92,048 Total inventory $ 166,242 $ 169,798

Note 10 - Leases (Tables)

Note 10 - Leases (Tables)	3 Months Ended
	Mar. 31, 2021
Notes Tables
Lessee, Operating Lease, Liability, Maturity [Table Text Block]	Maturity of Lease Liabilities Operating Lease Payments 2021 (remaining) $ 251,842 2022 291,111 2023 19,699 2024 1,355 Total undiscounted operating lease payments 564,007 Less imputed interest 50,306 Present value of operating lease liabilities $ 513,701
Lessee, Operating Lease, Assets and Liabilities [Table Text Block]	Balance Sheet Classification Current lease liabilities $ 304,262 Noncurrent lease liabilities 209,439 Total operating lease liabilities $ 513,701
Lease, Cost [Table Text Block]	Other Information Weighted-average remaining lease term for operating leases (years) 1.6 Weighted-average discount rate for operating leases 10.9 %

Note 15 - Segments (Tables)

Note 15 - Segments (Tables)	3 Months Ended
	Mar. 31, 2021
Notes Tables
Schedule of Segment Reporting Information, by Segment [Table Text Block]	Three Months Ended March 31, 2021 Diagnostics Therapeutics Corporate Total License revenue $ 22,486 $ — $ — $ 22,486 Grant and other revenue 101,251 — — 101,251 Total revenue 123,737 — — 123,737 Cost of revenue — — — — Research and development expenses 1,094,390 128,364 — 1,222,754 Selling, general and administrative expenses, excluding depreciation and amortization (1) — 2,006 2,210,991 2,212,997 Depreciation and amortization (2) 6,040 — 11,708 17,748 Loss from operations (3) (976,693 ) (130,370 ) (2,222,699 ) (3,329,762 ) Other income (4) — — 362,870 362,870 Net loss (976,693 ) (130,370 ) (1,859,829 ) (2,966,892 ) Total assets, net of depreciation and amortization: United States $ 160,669 $ — $ 9,723,212 $ 9,883,881 International 193,194 — — 193,194 Capital expenditures — — — — Three Months Ended March 31, 2020 Diagnostics Therapeutics Corporate Total Royalty revenue $ 15,221 $ — $ — $ 15,221 Grant and other revenue 58,916 82,135 — 141,051 Total revenue 74,137 82,135 — 156,272 Cost of revenue 609 — — 609 Research and development expenses 957,626 41,643 — 999,269 Selling, general and administrative expenses, excluding depreciation and amortization (1) — (1,522 ) 1,812,433 1,810,911 Depreciation and amortization (2) — — 16,843 16,843 (Loss) income from operations (3) (884,098 ) 42,014 (1,829,276 ) (2,671,360 ) Other expense (4) — — (2,248 ) (2,248 ) Net loss (884,098 ) 42,014 (1,831,524 ) (2,673,608 ) Total assets, net of depreciation and amortization: United States $ 36,671 $ 2,494 $ 4,438,066 $ 4,477,231 International — — — — Capital expenditures — — 6,459 6,459

Note 1 - Summary of Significa_2

Note 1 - Summary of Significant Accounting Policies (Details Textual) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Notes Payable, Fair Value Disclosure	$ 191,000	$ 745,000

Note 2 - Liquidity (Details Tex

Note 2 - Liquidity (Details Textual) - USD ($)	Mar. 02, 2021	Feb. 23, 2021	Aug. 31, 2020	May 18, 2020	May 13, 2021	Aug. 31, 2020	Jan. 31, 2020	Dec. 31, 2019	Nov. 30, 2017	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Mar. 31, 2021	May 13, 2021	Dec. 31, 2020	Dec. 31, 2019	Aug. 30, 2020
Common Stock, Par or Stated Value Per Share (in dollars per share)										$ 0.001			$ 0.001		$ 0.001
Proceeds from Issuance of Common Stock							$ 812,000	$ 1,900,000		$ 13	$ 1,700,000	$ 850,000				$ 1,100,000
Stock Issued During Period, Shares, New Issues (in shares)								2,100,000
Stock Issued During Period, Value, New Issues												700,000
Proceeds from Issuance of Preferred Stock and Preference Stock										8,175,000
Paycheck Protection Program CARES Act [Member]
Proceeds from Notes Payable, Total				$ 366,000
Forgiveness of Notes Payable		$ 366,000
Series D Preferred Stock [Member]
Stock Issued During Period, Value, New Issues										250,001
Series E Preferred Stock [Member]
Stock Issued During Period, Value, New Issues										4,980,709
Keystone Capital Partners, LLC [Member] | Series D Preferred Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares)			150,000			150,000							49,500
Stock Issued During Period, Value, New Issues			$ 15,000,000
Proceeds from Issuance of Preferred Stock and Preference Stock										3,200,000			$ 5,000,000		$ 2,925,000
Keystone Capital Partners, LLC [Member] | Series D Preferred Stock [Member] | Maximum [Member]
Convertible Preferred Stock, Shares Issued upon Conversion (in shares)			5,147,000			5,147,000
Keystone Capital Partners, LLC [Member] | Subsequent Event [Member] | Series D Preferred Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares)					5,000
Proceeds from Issuance of Preferred Stock and Preference Stock					$ 500,000									$ 5,500,000
John K. Scott, Jr. [Member] | Series E Preferred Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares)	50,000
Stock Issued During Period, Value, New Issues	$ 5,000,000
Preferred Stock Convertible Shares, Issuable (in shares)	2,173,913
Private Placement [Member]
Stock Issued During Period, Value, New Issues
Private Placement [Member] | Mastiff Group LLC [Member]
Sale of Stock, Commitment Amount										4,975,000			$ 4,975,000				$ 25,000,000
Common Stock, Par or Stated Value Per Share (in dollars per share)																	$ 0.001
Private Placement [Member] | Mastiff Group LLC [Member] | Subsequent Event [Member]
Proceeds from Issuance of Common Stock					$ 25,000
Platinum-Montaur Life Sciences LLC Litigation [Member]
Loss Contingency, Damages Sought, Value									$ 1,900,000
CRG Loan Agreement, Ohio Case [Member]
Loss Contingency, Damages Sought, Value										$ 4,300,000

Note 3 - Revenue From Contrac_3

Note 3 - Revenue From Contracts With Customers (Details Textual) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Contract with Customer, Payment Term, Minimum (Day)	15 days
Contract with Customer, Payment Term, Maximum (Day)	90 days
Contract with Customer, Transaction Price of Royalties Using Expected Value Method	$ 0
Revenue from Contract with Customer, Including Assessed Tax	22,000	$ 15,000
Contract with Customer, Asset, Impairment Loss	0	0
Capitalized Contract Cost, Net, Total	0
Contract with Customer, Asset, after Allowance for Credit Loss, Total	82,000		$ 59,000
Grant [Member]
Revenue Not from Contract with Customer	$ 1,000	$ 141,000
INDIA
Contract with Customer, Term of Contract (Year)	8 years
CHINA
Contract with Customer, Term of Contract (Year)	10 years

Note 3 - Revenue From Contrac_4

Note 3 - Revenue From Contracts With Customers - Disaggregation of Revenue (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenue from contract with customer	$ 22,000	$ 15,000
Royalty [Member]
Revenue from contract with customer		15,221
Diagnostics Segment [Member] | Royalty [Member]
Revenue from contract with customer		15,221
Diagnostics Segment [Member] | Royalty [Member] | Europe [Member]
Revenue from contract with customer		15,221
Diagnostics Segment [Member] | Expanded Tc99m Tilmanocept License Agreement [Member] | Europe [Member]
Revenue from contract with customer	$ 22,486

Note 3 - Revenue From Contrac_5

Note 3 - Revenue From Contracts With Customers - Changes in Contract Liabilities (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Total deferred revenue, beginning of period	$ 700,000	$ 700,000
Revenue recognized from satisfaction of performance obligations
Total deferred revenue, end of period	$ 700,000	$ 700,000

Note 4 - Stock-based Compensa_3

Note 4 - Stock-based Compensation (Details Textual) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share-based Payment Arrangement, Expense	$ 121,000	$ 39,000
Share-based Payment Arrangement, Expense, Tax Benefit	$ 0	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share)	$ 1.87
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum	90.14%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate	0.67%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term (Year)	5 years 354 days
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total	$ 595,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)	1 year 219 days

Note 4 - Stock-based Compensa_4

Note 4 - Stock-based Compensation - Summary of Stock Option Activity (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Outstanding at beginning of period (in shares)	549,970
Outstanding at beginning of period, weighted average exercise price (in dollars per share)	$ 8.81
Outstanding, weighted average remaining contractual life (Year)	8 years 146 days	8 years
Outstanding, aggregate intrinsic value	$ 184,320	$ 209,280
Granted (in shares)	229,500
Granted, weighted average exercise price (in dollars per share)	$ 2.54
Outstanding at end of period (in shares)	779,470	549,970
Outstanding at end of period, weighted average exercise price (in dollars per share)	$ 6.97	$ 8.81
Exercisable at end of period (in shares)	201,438
Exercisable at end of period, weighted average exercise price (in dollars per share)	$ 15.21
Exercisable, weighted average remaining contractual life (Year)	6 years 146 days
Exercisable, aggregate intrinsic value	$ 67,841

Note 4 - Stock-based Compensa_5

Note 4 - Stock-based Compensation - Summary of Unvested Restricted Stock (Details) - Restricted Stock [Member]	3 Months Ended
	Mar. 31, 2021$ / sharesshares
Unvested at beginning of period (in shares) | shares	60,000
Unvested at beginning of period, weighted average grant-date fair value (in dollars per share) | $ / shares	$ 2.90
Granted (in shares) | shares	12,500
Granted, weighted average grant-date fair value (in dollars per share) | $ / shares	$ 2.28
Vested (in shares) | shares	(10,000)
Vested, weighted average grant-date fair value (in dollars per share) | $ / shares	$ 1.06
Unvested at end of period (in shares) | shares	62,500
Unvested at end of period, weighted average grant-date fair value (in dollars per share) | $ / shares	$ 3.07

Note 5 - Loss Per Share (Detail

Note 5 - Loss Per Share (Details Textual) - shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Stock Options and Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares)	1,173,762	1,515,164
Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares)	62,500	10,000

Note 6 - Inventory (Details Tex

Note 6 - Inventory (Details Textual) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Inventory, Finished Goods, Gross, Total	$ 88,492	$ 92,048
Clinical Trials [Member]
Inventory, Finished Goods, Gross, Total	$ 4,000

Note 6 - Inventory - Net Invent

Note 6 - Inventory - Net Inventory (Details) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Materials	$ 77,750	$ 77,750
Finished goods	88,492	92,048
Total inventory	$ 166,242	$ 169,798

Note 7 - Investment in Macrop_2

Note 7 - Investment in Macrophage Therapeutics, Inc. (Details Textual) - New York Litigation Involving Former CEO and President [Member] - Judicial Ruling [Member]	Apr. 21, 2021USD ($)
Litigation Settlement, Amount Can Be Awarded to Other Party for Indemnification for Attorneys’ Fees	$ 14,955
Litigation Settlement, Amount Can Be Advanced to Other Party for Attorneys’ Fees Subject to Repayment	$ 1,237.50

Note 8 - Accounts Payable, Ac_2

Note 8 - Accounts Payable, Accrued Liabilities and Other (Details Textual) - Director Fees [Member] - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Accounts Payable [Member]
Due to Related Parties, Current, Total	$ 78,000	$ 66,000
Accrued Liabilities and Other [Member]
Due to Related Parties, Current, Total	$ 457,000	$ 755,000

Note 9 - Notes Payable (Details

Note 9 - Notes Payable (Details Textual) - USD ($)	Feb. 23, 2021	May 18, 2020	Nov. 30, 2020	Nov. 30, 2019	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Interest Expense, Debt, Total					$ 3,000	$ 3,000
Notes Payable, Current, Total					190,550		$ 745,443
Notes Payable Issued for Prepayment of Insurance Premiums [Member] | FIF [Member]
Debt Instrument, Face Amount			$ 442,000	$ 349,000
Debt Instrument, Interest Rate, Stated Percentage			3.50%	5.00%
Debt Instrument, Term (Month)			210 days	240 days
Debt Instrument, Periodic Payment, Total			$ 64,000	$ 44,000
Interest Expense, Debt, Total					3,000	$ 3,000
Notes Payable, Current, Total					$ 191,000
Paycheck Protection Program CARES Act [Member]
Proceeds from Notes Payable, Total		$ 366,000
Forgiveness of Notes Payable	$ 366,000

Note 10 - Leases (Details Textu

Note 10 - Leases (Details Textual)	1 Months Ended	3 Months Ended
	Jun. 30, 2017USD ($)	Mar. 31, 2021USD ($)ft²	Mar. 31, 2020USD ($)
Operating Lease, Expense		$ 46,000	$ 51,000
Operating Lease, Payments		$ 93,000	$ 91,000
Office Space at 4995 Bradenton Avenue, Dublin Ohio [Member]
Area of Real Estate Property (Square Foot) | ft²		5,000
Operating Lease, Monthly Base Rent		$ 3,000
Office Space at 5600 Blazer Parkway, Dublin, Ohio [Member]
Area of Real Estate Property (Square Foot) | ft²		25,000
Operating Lease, Monthly Base Rent	$ 39,000	$ 27,000
Lessee, Operating Lease, Renewal Term (Year)		5 years
Vehicle Lease [Member]
Operating Lease, Monthly Base Rent		$ 300
Office Equipment [Member]
Operating Lease, Monthly Base Rent		$ 100

Note 10 - Leases - Maturity of

Note 10 - Leases - Maturity of Lease Liabilities (Details)	Mar. 31, 2021USD ($)
2021 (remaining)	$ 251,842
2022	291,111
2023	19,699
2024	1,355
Total undiscounted operating lease payments	564,007
Less imputed interest	50,306
Present value of operating lease liabilities	$ 513,701

Note 10 - Leases - Balance Shee

Note 10 - Leases - Balance Sheet Classification (Details) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Current lease liabilities	$ 304,262	$ 294,951
Noncurrent lease liabilities	209,439	$ 296,006
Present value of operating lease liabilities	513,701
Other Current Liabilities [Member]
Current lease liabilities	304,262
Other Noncurrent Liabilities [Member]
Noncurrent lease liabilities	$ 209,439

Note 10 - Leases - Other Inform

Note 10 - Leases - Other Information (Details)	Mar. 31, 2021
Weighted-average remaining lease term for operating leases (years) (Year)	1 year 219 days
Weighted-average discount rate for operating leases	10.90%

Note 11 - Commitments and Con_2

Note 11 - Commitments and Contingencies (Details Textual) - USD ($)

Apr. 21, 2021

Mar. 16, 2021

Nov. 27, 2019

Apr. 09, 2018

Nov. 02, 2017

Mar. 03, 2017

Dec. 31, 2019

Nov. 30, 2018

Aug. 31, 2018

Nov. 30, 2017

Jun. 30, 2016

Mar. 31, 2020

Mar. 31, 2021

Dec. 31, 2020

Stock Issued During Period, Shares, New Issues (in shares)

2,100,000

Stockholders' Equity Attributable to Parent, Ending Balance

$ 4,277,581

$ 1,315,604

Market Capitalization, Fair Value

$ 57,700,000

Common Stock [Member]

Stock Issued During Period, Shares, New Issues (in shares)

1,000,001

Former Chief Executive Officer and President [Member]

Common Stock Shares Provided by Agreement (in shares)

1,175,000

Common Stock Shares Provided by Agreement, Escrow Period (Month)

1 year 180 days

Former Chief Executive Officer and President [Member] | Common Stock [Member]

Stock Issued During Period, Shares, New Issues (in shares)

925,000

Stock Issued During Period, Shares, New Issues Placed in Escrow (in shares)

250,000

Former Chief Executive Officer and President [Member] | MT [Member] | Common Stock [Member] | Dr. Michael Goldberg [Member]

Ownership Percentage

5.00%

CRG [Member]

Draws on Letter of Credit

$ 7,100,000

CRG Loan Agreement, Texas Case [Member] | Judicial Ruling [Member]

Loss Contingency, Damages Awarded, Value, Additional Amount

$ 7,000,000

Loss Contingency, Damages Awarded, Value, Amount not Taken into Consideration

$ 4,100,000

Ohio Court of Common Pleas [Member]

Litigation Settlement, Amount Awarded from Other Party

$ 4,300,000

Litigation Settlement, Reversal of Amount Awarded from Other Party

$ 4,300,000

Platinum-Montaur Life Sciences LLC Litigation [Member]

Loss Contingency, Damages Sought, Value

$ 1,900,000

Platinum-Montaur Life Sciences LLC Litigation [Member] | Pending Litigation [Member]

Loss Contingency, Damages Sought, Value

$ 1,900,000

New York Litigation Involving Former CEO and President [Member] | Judicial Ruling [Member]

Litigation Settlement, Amount Can Be Awarded to Other Party for Indemnification for Attorneys’ Fees

$ 14,955

Litigation Settlement, Amount Can Be Advanced to Other Party for Attorneys’ Fees Subject to Repayment

$ 1,237.50

CRG [Member] | Term Loan Agreement [Member] | CRG Loan Agreement, Texas Case [Member] | Judicial Ruling [Member]

Repayments of Debt

59,000,000

CRG [Member] | Term Loan Agreement [Member] | Maximum [Member]

Debt Instrument, Agreed-upon Final Payoff Amount

$ 66,000,000

Note 12 - Equity (Details Textu

Note 12 - Equity (Details Textual) - USD ($)	Mar. 02, 2021	Aug. 31, 2020	May 13, 2021	Aug. 31, 2020	Feb. 29, 2020	Jan. 31, 2020	Dec. 31, 2019	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Mar. 31, 2021	May 13, 2021	Dec. 31, 2020	Dec. 31, 2019	Aug. 30, 2020
Stock Issued During Period, Shares, New Issues (in shares)							2,100,000
Proceeds from Issuance of Common Stock						$ 812,000	$ 1,900,000	$ 13	$ 1,700,000	$ 850,000				$ 1,100,000
Common Stock, Share Subscribed but Unissued, Subscriptions Receivable								4,975,000			$ 4,975,000		$ 4,975,000
Proceeds from Issuance of Preferred Stock and Preference Stock								8,175,000
Preferred Stock, Shares Subscribed but Unissued, Subscriptions Receivable								$ 9,550,000			9,550,000		10,300,000
Stock Issued During Period, Value, New Issues										700,000
Stock Issued During Period, Shares, Employee Benefit Plan (in shares)								30,018
Stock Issued During Period, Value, Employee Benefit Plan								$ 76,846
Issuance of Stock to Defined Contribution Plan for Employer Matching Contribution								$ 76,846
Common Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares)										1,000,001
Stock Issued During Period, Value, New Issues										$ 1,000
Stock Issued During Period, Shares, Employee Benefit Plan (in shares)								30,018
Stock Issued During Period, Value, Employee Benefit Plan								$ 30
Stock Issued During Period, Shares, Issued for Employee Bonuses (in shares)										53,315
Conversion from Series D Preferred Stock To Common Stock [Member]
Conversion of Stock, Shares Issued (in shares)								2,341,258
Series D Preferred Stock [Member]
Stock Subscriptions Receivable								$ 500,000			500,000
Preferred Stock, Shares Subscribed but Unissued, Subscriptions Receivable								9,600,000			$ 9,600,000
Stock Issued During Period, Value, New Issues								$ 250,001
Series D Preferred Stock [Member] | Common Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares)
Stock Issued During Period, Value, New Issues
Series C Preferred Stock [Member]
Conversion of Stock, Shares Converted (in shares)								49,500
Series E Preferred Stock [Member]
Stock Issued During Period, Value, New Issues								$ 4,980,709
Convertible Stock, Fixed Price Per Share (in dollars per share)								$ 2.30			$ 2.30
Preferred Stock, Redemption Price Per Share (in dollars per share)								$ 110			$ 110
Series E Preferred Stock [Member] | Common Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares)
Stock Issued During Period, Value, New Issues
Subsequent Event [Member] | Conversion from Series D Preferred Stock To Common Stock [Member]
Conversion of Stock, Shares Converted (in shares)			5,000
Conversion of Stock, Shares Issued (in shares)			316,725
Keystone Capital Partners, LLC [Member] | Series D Preferred Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares)		150,000		150,000							49,500
Stock Issued During Period, Value, Other				$ 15,000,000
Proceeds from Issuance of Preferred Stock and Preference Stock								3,200,000			$ 5,000,000		$ 2,925,000
Stock Issued During Period, Value, New Issues		$ 15,000,000
Keystone Capital Partners, LLC [Member] | Series D Preferred Stock [Member] | Maximum [Member]
Convertible Preferred Stock, Shares Issued upon Conversion (in shares)		5,147,000		5,147,000
Keystone Capital Partners, LLC [Member] | Subsequent Event [Member] | Series D Preferred Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares)			5,000
Proceeds from Issuance of Preferred Stock and Preference Stock			$ 500,000									$ 5,500,000
John K. Scott, Jr. [Member] | Series E Preferred Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares)	50,000
Stock Issued During Period, Value, New Issues	$ 5,000,000
Percentage of Securities Allowed to be Purchased in Third-Party Offering, Maximum	33.33%
Private Placement [Member]
Stock Issued During Period, Value, New Issues
Private Placement [Member] | Common Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares)										902,162
Stock Issued During Period, Value, New Issues										$ 902
Private Placement [Member] | Mastiff Group LLC [Member]
Sale of Stock, Commitment Amount								$ 4,975,000			$ 4,975,000				$ 25,000,000
Private Placement [Member] | Mastiff Group LLC [Member] | Subsequent Event [Member]
Proceeds from Issuance of Common Stock			$ 25,000
Investor [Member]
Stock Issued During Period, Shares, New Issues (in shares)					4,000,000
Proceeds from Issuance of Common Stock					$ 3,400,000
Employees [Member] | Common Stock [Member]
Stock Issued During Period, Shares, Issued for Employee Bonuses (in shares)										53,315
Issuance of Stock to Defined Contribution Plan for Employer Matching Contribution										$ 65,000
Prepaid Expenses and Other Current Assets [Member]
Common Stock, Share Subscribed but Unissued, Subscriptions Receivable							$ 812,000							$ 812,000

Note 13 - Stock Warrants (Detai

Note 13 - Stock Warrants (Details Textual)	Mar. 31, 2021$ / sharesshares
Class of Warrant or Right, Outstanding (in shares) | shares	972,324
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 17.97
Minimum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 0.20
Warrants and Rights Outstanding, Term (Year)	1 year
Maximum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 49.80
Warrants and Rights Outstanding, Term (Year)	14 years 146 days

Note 14 - Income Taxes (Details

Note 14 - Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Unrecognized Tax Benefits, Ending Balance	$ 0	$ 0
Domestic Tax Authority [Member]
Operating Loss Carryforwards, Total	$ 153,300
Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Open Tax Year	2017 2018 2019 2020
Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Research Tax Credit Carryforward [Member]
Tax Credit Carryforward, Amount	$ 8,900
State and Local Jurisdiction [Member]
Open Tax Year	2017 2018 2019 2020
Operating Loss Carryforwards, Total	$ 20,100

Note 15 - Segments (Details Tex

Note 15 - Segments (Details Textual)		3 Months Ended
		Mar. 31, 2021USD ($)	Mar. 31, 2020USD ($)
Revenues, Total		$ 123,737	$ 156,272
Number of Primary Types of Products Sold		2
Depreciation, Depletion and Amortization, Nonproduction, Total	[1]	$ 17,748	16,843
Selling, General and Administrative Expenses [Member]
Depreciation, Depletion and Amortization, Nonproduction, Total		17,748	$ 16,843
Intersegment Eliminations [Member]
Revenues, Total		$ 0
[1]	Depreciation and amortization are reflected in selling, general and administrative expenses ($17,748 and $16,843 for the three-month periods ended March 31, 2021 and 2020, respectively).

Note 15 - Segments - Segment In

Note 15 - Segments - Segment Information (Details) - USD ($)		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Revenue from contract with customer		$ 22,000	$ 15,000
Grant and other revenue		101,251	141,051
Revenues, Total		123,737	156,272
Cost of revenue			609
Research and development expenses		1,222,754	999,269
Selling, general and administrative expenses, excluding depreciation and amortization	[1]	2,212,997	1,810,911
Depreciation, Depletion and Amortization, Nonproduction, Total	[2]	17,748	16,843
Loss from operations	[3]	(3,329,762)	(2,671,360)
Other income (4)	[4]	362,870	(2,248)
Net loss		(2,966,892)	(2,673,608)
Total assets, net of depreciation and amortization		10,077,075		$ 7,758,018
Capital expenditures			6,459
UNITED STATES
Total assets, net of depreciation and amortization		9,883,881	4,477,231
Non-US [Member]
Total assets, net of depreciation and amortization		193,194
License [Member]
Revenue from contract with customer		22,486
Royalty [Member]
Revenue from contract with customer			15,221
Diagnostics Segment [Member]
Grant and other revenue		101,251	58,916
Revenues, Total		123,737	74,137
Cost of revenue			609
Research and development expenses		1,094,390	957,626
Selling, general and administrative expenses, excluding depreciation and amortization	[1]
Depreciation, Depletion and Amortization, Nonproduction, Total	[2]	6,040
Loss from operations	[3]	(976,693)	(884,098)
Other income (4)	[4]
Net loss		(976,693)	(884,098)
Capital expenditures
Diagnostics Segment [Member] | UNITED STATES
Total assets, net of depreciation and amortization		160,669	36,671
Diagnostics Segment [Member] | Non-US [Member]
Total assets, net of depreciation and amortization		193,194
Diagnostics Segment [Member] | License [Member]
Revenue from contract with customer		22,486
Diagnostics Segment [Member] | Royalty [Member]
Revenue from contract with customer			15,221
Therapeutics Segment [Member]
Grant and other revenue			82,135
Revenues, Total			82,135
Cost of revenue
Research and development expenses		128,364	41,643
Selling, general and administrative expenses, excluding depreciation and amortization	[1]	2,006	(1,522)
Depreciation, Depletion and Amortization, Nonproduction, Total	[2]
Loss from operations	[3]	(130,370)	42,014
Other income (4)	[4]
Net loss		(130,370)	42,014
Capital expenditures
Therapeutics Segment [Member] | UNITED STATES
Total assets, net of depreciation and amortization			2,494
Therapeutics Segment [Member] | Non-US [Member]
Total assets, net of depreciation and amortization
Therapeutics Segment [Member] | License [Member]
Revenue from contract with customer
Therapeutics Segment [Member] | Royalty [Member]
Revenue from contract with customer
Corporate Segment [Member]
Grant and other revenue
Revenues, Total
Cost of revenue
Research and development expenses
Selling, general and administrative expenses, excluding depreciation and amortization	[1]	2,210,991	1,812,433
Depreciation, Depletion and Amortization, Nonproduction, Total	[2]	11,708	16,843
Loss from operations	[3]	(2,222,699)	(1,829,276)
Other income (4)	[4]	362,870	(2,248)
Net loss		(1,859,829)	(1,831,524)
Capital expenditures			6,459
Corporate Segment [Member] | UNITED STATES
Total assets, net of depreciation and amortization		9,723,212	4,438,066
Corporate Segment [Member] | Non-US [Member]
Total assets, net of depreciation and amortization
Corporate Segment [Member] | License [Member]
Revenue from contract with customer
Corporate Segment [Member] | Royalty [Member]
Revenue from contract with customer
[1]	General and administrative expenses, excluding depreciation and amortization, represent costs that relate to the general administration of the Company and as such are not currently allocated to our individual reportable segments, other than those expenses directly incurred by Navidea Europe, Navidea UK and MT.
[2]	Depreciation and amortization are reflected in selling, general and administrative expenses ($17,748 and $16,843 for the three-month periods ended March 31, 2021 and 2020, respectively).
[3]	Income (loss) from operations does not reflect the allocation of certain selling, general and administrative expenses, excluding depreciation and amortization, to our individual reportable segments, other than those expenses directly incurred by Navidea Europe, Navidea UK and MT.
[4]	Amounts consist primarily of interest income and interest expense, which are not currently allocated to our individual reportable segments.

Note 16 - Supplemental Disclo_2

Note 16 - Supplemental Disclosure for Statements of Cash Flows (Details Textual) - USD ($)	1 Months Ended	3 Months Ended		7 Months Ended	12 Months Ended
	Feb. 29, 2020	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Dec. 31, 2020
Interest Paid, Excluding Capitalized Interest, Operating Activities		$ 3,000	$ 3,000
Proceeds from Issuance of Preferred Stock and Preference Stock		$ 8,175,000
Stock Issued During Period, Shares, Employee Benefit Plan (in shares)		30,018
Stock Issued During Period, Value, Employee Benefit Plan		$ 76,846
Issuance of Stock to Defined Contribution Plan for Employer Matching Contribution		$ 76,846
Common Stock [Member]
Stock Issued During Period, Shares, Employee Benefit Plan (in shares)		30,018
Stock Issued During Period, Value, Employee Benefit Plan		$ 30
Stock Issued During Period, Shares, Issued for Employee Bonuses (in shares)			53,315
Employees [Member] | Common Stock [Member]
Stock Issued During Period, Shares, Issued for Employee Bonuses (in shares)			53,315
Issuance of Stock to Defined Contribution Plan for Employer Matching Contribution			$ 65,000
Office Lease [Member]
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 100,432
Series D Preferred Stock [Member] | Keystone Capital Partners, LLC [Member]
Proceeds from Issuance of Preferred Stock and Preference Stock		$ 3,200,000		$ 5,000,000	$ 2,925,000

Note 17 - Subsequent Events (De

Note 17 - Subsequent Events (Details Textual) - USD ($)	Aug. 31, 2020	May 13, 2021	Aug. 31, 2020	Dec. 31, 2019	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	May 13, 2021	Dec. 31, 2020
Stock Issued During Period, Value, New Issues						$ 700,000
Proceeds from Issuance of Preferred Stock and Preference Stock					$ 8,175,000
Stock Issued During Period, Shares, New Issues (in shares)				2,100,000
Preferred Stock, Shares Subscribed but Unissued, Subscriptions Receivable					$ 9,550,000		$ 9,550,000		$ 10,300,000
Conversion from Series D Preferred Stock To Common Stock [Member]
Conversion of Stock, Shares Issued (in shares)					2,341,258
Subsequent Event [Member] | Conversion from Series D Preferred Stock To Common Stock [Member]
Conversion of Stock, Shares Converted (in shares)		5,000
Conversion of Stock, Shares Issued (in shares)		316,725
Series D Preferred Stock [Member]
Stock Issued During Period, Value, New Issues					$ 250,001
Stock Subscriptions Receivable					500,000		500,000
Preferred Stock, Shares Subscribed but Unissued, Subscriptions Receivable					9,600,000		9,600,000
Keystone Capital Partners, LLC [Member] | Series D Preferred Stock [Member]
Stock Issued During Period, Value, New Issues	$ 15,000,000
Proceeds from Issuance of Preferred Stock and Preference Stock					$ 3,200,000		$ 5,000,000		$ 2,925,000
Stock Issued During Period, Shares, New Issues (in shares)	150,000		150,000				49,500
Keystone Capital Partners, LLC [Member] | Series D Preferred Stock [Member] | Subsequent Event [Member]
Proceeds from Issuance of Preferred Stock and Preference Stock		$ 500,000						$ 5,500,000
Stock Issued During Period, Shares, New Issues (in shares)		5,000