For the three months ended September 30, 2021 and 2020, we incurred $685,079 and $448,442, respectively, of general and administrative expenses. We attribute the increase of $200,637 primarily to a greater level of business activities being conducted in the three months ended September 30, 2021 as compared to the same period in 2020, including costs related to the hiring of additional personnel and increased fees for outside consultants, and an increase in rent expense of over $100,000.
For the nine months ended September 30, 2021 and 2020, we incurred $2,678,689 and $625,812, respectively, of general and administrative expenses. We attribute the increase of $2,052,877 primarily to a greater level of business activities being conducted in the nine months ended September 30, 2021 as compared to the same period in 2020, including costs related to the hiring of additional personnel (increase of over $350,000), increased fees for outside consultants (over $900,000) and rent expense (increase of almost $300,000).
Research and Development Expenses
Since our inception, we have focused our resources on our research and development activities. We expense research and development costs as they are incurred. Our research and development expenses primarily consist of outsourced engineering, product development and manufacturing design costs. For the three months ended September 30, 2021 and 2020, we incurred $956,499 and $812,950, respectively, in research and development costs. For the nine months ended September 30, 2021 and 2020, we incurred $3,617,101 and $1,057,265, respectively, in research and development costs. Research and development expenses were relatively flat for three months ended September 30, 2021 as compared to the prior year period while they increased $2,559,836 for the nine months ended September 30, 2021 as compared to the prior year period. We began to ramp up research and development activities in May of 2020 resulting in a lower rate of expenditures in the nine month September 30, 2020 period as compared to the current year period. The three month periods were relatively flat as we had reached a normalized run rate of expenditures by the third quarter of fiscal 2020.
Net Losses
Our net losses were $1,528,012 and $1,297,392 for the three months ended September 30, 2021 and 2020, respectively. Our net losses were $6,182,224 and $1,683,077 for the nine months ended September 30, 2021 and 2020, respectively. Losses increased in fiscal 2021 as compared to fiscal 2020 for the reasons set forth above.
Liquidity and Capital Resources
Sources of Liquidity
As of September 30, 2021, we had cash of $655,780 compared to cash of $2,333,117 as of December 31, 2020. From January 1, 2021 through September 30, 2021, we raised an additional approximately $5,100,000 in gross proceeds from the sale of our Class A units and we issued an additional approximately $900,000 of our Class A units to our independent contractors and Board members for services rendered. On September 30, 2021, we borrowed $500,000, and on November 5, 2021, we borrowed an additional $500,000 pursuant to bridge loans (collectively, the “Bridge Loans”) from our Chairman at an interest rate of the prime rate plus 3.0% per annum, 6.25% for the life of the Bridge Loans, with the principal and accrued interest due upon demand. On November 29, 2021, the Company completed a public offering (the “Public Offering”) of 2,514,000 shares of its common stock, which included the partial exercise of the underwriters’ overallotment option, at a public offering price of $10.00 per share for aggregate gross proceeds of $25,140,000 and net proceeds of approximately $22,000,000 after deducting underwriting fees and closing costs of approximately $3,100,000. We repaid the Bridge Loans and accrued interest on December 1, 2021 with a portion of the net proceeds from the Public Offering.
Prior to the Public Offering, we funded our operations principally with approximately $15 million in gross proceeds from the sale of Class A units. As of September 30, 2021, we had an accumulated deficit of $14,405,631. The Company’s net cash used in operating activities was $5,524,098 for the nine months ended September 30, 2021 as compared to $1,280,449 used in operating activities for the prior year period.
We have incurred operating losses since our inception. While the Company began producing and selling its Pūrgo device in July 2021, these losses are expected to continue through the end of 2022 as we continue to make significant investments to develop and market our products and to establish our consumables and service business.