Consolidated Balance Sheets (USD $)	Dec. 31, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 13,980,321	$ 12,825,090
Restricted cash	601,471	601,351
Prepaid expenses and other current assets	20,087	143,867
Total current assets	14,601,879	13,570,308
Property and equipment, net	2,337,210	2,311,942
Other assets	157,355	179,415
Total assets	17,096,444	16,061,665
Current liabilities:
Accounts payable	899,260	1,152,550
Note payable-current portion	73,987
Capital lease payable-current portion	2,799	32,606
Derivative warrant liability	0	14,584,818
Accrued expenses	1,292,185	1,021,275
Total current liabilities	2,268,231	16,791,249
Loan payable	1,920,000	1,578,000
Note payable-less current portion	18,497
Capital lease payable-less current portion		2,799
Total liabilities	4,206,728	18,372,048
Commitments and contingencies
Stockholders' equity (deficit):
Common stock, $0.00001 par value, authorized 200,000,000 shares; issued and outstanding 78,773,736 and 65,881,122 shares at December 31 2013 and 2012, respectively	788	659
Additional paid-in capital	94,798,231	40,842,339
Deficit accumulated during the development stage	(81,909,303)	(43,153,381)
Total stockholders' equity (deficit)	12,889,716	(2,310,383)
Total liabilities and stockholders' equity (deficit)	$ 17,096,444	$ 16,061,665