Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Operating activities:
Net loss	$ (4,824)	$ (3,665)
Adjustments to reconcile net loss to net cash used in operating activities:
Compensation related to restricted stock, stock options and employee stock purchase plan	229	294
Depreciation and amortization	228	361
Non-cash research and development expense		30
Non-cash amortization of discount on notes payable and debt issuance costs	878
Non-cash restructuring expense	35	203
Accretion of restructuring liability		25
Change in fair value of price adjustable warrants and subscription investment units	(270)	(1,602)
Loss on retirement of assets	17
Changes in assets and liabilities:
Restricted cash	(81)
Accounts receivable		59
Prepaid expenses and other assets	251	97
Accounts payable	720	(607)
Deferred revenue	(51)	313
Accrued expenses and deferred rent and other liabilities	(391)	56
Accrued restructuring		(73)
Net cash used in operating activities	(3,259)	(4,509)
Investing activities:
Change in restricted cash		(140)
Proceeds from sales of property and equipment	107
Net cash (used in) provided by investing activities	107	(140)
Financing activities:
Proceeds from issuance of notes payable and warrants	1,500
Proceeds from sales of common shares and warrants, net	1,111	4,520
Proceeds from exercise of warrants, subscription investment units, stock options and employee stock purchase plan purchases	2	187
Net cash provided by financing activities	2,613	4,707
Net increase (decrease) in cash	(539)	58
Cash - beginning of year	976	1,066
Cash - end of period	437	1,124
Non-cash financing activities:
Issuance of common stock to settle liabilities		80
Issuance of common stock in connection with license agreement	107
Supplemental disclosure:
Cash paid for interest	$ 2