Consolidated Balance Sheets - USD ($)	Jun. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 3,183,289	$ 4,921,545
Contracts and grants receivable	1,805,871	1,985,212
Prepaid expenses	229,064	244,267
Total current assets	5,218,224	7,151,024
Office furniture and equipment, net	39,927	47,366
Intangible assets, net	157,896	188,732
Total assets	5,416,047	7,387,122
Current liabilities:
Accounts payable	4,177,376	4,379,936
Notes payable		292,719
Warrant liability	1,148,616	2,434,101
Accrued compensation	56,169	298,675
Total current liabilities	5,382,161	7,405,431
Commitments and contingencies
Shareholders' equity (deficiency):
Preferred stock, 350,000 shares authorized; none issued or outstanding
Common stock, $.001 par value; 100,000,000 shares and 50,000,000 shares authorized at June 30, 2016 and December 31, 2015 respectively; 32,859,631 shares and 31,269,522 shares issued and outstanding at June 30, 2016 and December 31, 2015, respectively	32,860	31,270
Additional paid-in capital	148,120,813	146,828,000
Accumulated deficit	(148,119,787)	(146,877,579)
Total shareholders' equity (deficiency)	33,886	(18,309)
Total liabilities and shareholders' equity (deficiency)	$ 5,416,047	$ 7,387,122

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.