Consolidated Balance Sheets - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 4,921,545	$ 5,525,094
Contracts and grants receivable	1,985,212	794,767
Prepaid expenses	244,267	172,928
Total current assets	7,151,024	6,492,789
Office furniture and equipment, net	47,366	51,510
Intangible assets, net	188,732	409,949
Total assets	7,387,122	6,954,248
Current liabilities:
Accounts payable	4,379,936	$ 3,003,545
Notes payable	292,719
Warrant liability	2,434,101	$ 3,789,562
Accrued compensation	298,675	315,030
Total current liabilities	$ 7,405,431	$ 7,108,137
Commitments and contingencies
Shareholders' deficiency:
Preferred stock, 350,000 shares authorized; none issued or outstanding
Common stock, $.001 par value; 50,000,000 shares authorized; 31,269,522 and 23,936,568 shares issued and outstanding in 2015 and 2014, respectively	$ 31,270	$ 23,937
Additional paid-in capital	146,828,000	138,868,523
Accumulated deficit	(146,877,579)	(139,046,349)
Total shareholders' deficiency	(18,309)	(153,889)
Total liabilities and shareholders' deficiency	$ 7,387,122	$ 6,954,248

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

Name:	us-gaap_AccountsPayableCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Excess of issue price over par or stated value of the entity's capital stock and amounts received from other transactions involving the entity's stock or stockholders. Includes adjustments to additional paid in capital. Some examples of such adjustments include recording the issuance of debt with a beneficial conversion feature and certain tax consequences of equity instruments awarded to employees. Use this element for the aggregate amount of additional paid-in capital associated with common and preferred stock. For additional paid-in capital associated with only common stock, use the element additional paid in capital, common stock. For additional paid-in capital associated with only preferred stock, use the element additional paid in capital, preferred stock.