Consolidated Balance Sheets - USD ($)	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 28,979,969	$ 18,676,663
Contracts and grants receivable	117,680	203,774
Research and development incentives receivable	106,598	361,096
Prepaid expenses and other current assets	148,594	225,473
Total current assets	29,352,841	19,467,006
Security deposit	22,777	22,777
Office furniture and equipment, net of accumulated depreciation of $161,037 and $154,769	17,242	23,510
Deferred issuance cost	5,796	53,523
Right-of-use lease assets	167,608	228,027
Research and development incentive receivable	28,525	73,142
Other assets	15,500	23,250
Total assets	29,610,289	19,891,235
Current liabilities:
Accounts payable	1,482,359	2,129,844
Accrued expenses	2,461,630	2,638,308
Accrued compensation	67,053	875,096
Paycheck Protection Program loan		324,979
Lease liabilities - current	113,664	112,294
Total current liabilities	4,124,706	6,080,521
Non-current liabilities:
Convertible debt, net of debt discount of $164,787 and $140,261	9,835,213	9,859,739
Paycheck Protection Program loan, net of current		92,851
Lease liabilities, net of current	54,180	116,296
Total liabilities	14,014,099	16,149,407
Commitments and contingencies
Shareholders' equity:
Preferred stock, 350,000 shares authorized, none issued or outstanding
Common stock, $.001 par value; 75,000,000 shares authorized; 40,078,760 shares and 30,643,656 shares issued and outstanding at March 31, 2021 and December 31, 2020, respectively	40,079	30,644
Additional paid-in capital	213,061,849	196,949,655
Accumulated other comprehensive loss	(32,058)	(24,337)
Accumulated deficit	(197,473,680)	(193,214,134)
Total shareholders' equity	15,596,190	3,741,828
Total liabilities and shareholders' equity	$ 29,610,289	$ 19,891,235