Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current Assets
Cash and cash equivalents	$ 15,045	$ 23,906
Accounts receivable, net	21	24
Inventories	986	877
Prepaid expenses and other current assets	1,037	1,100
Current assets of discontinued operations		1,713
Total current assets	17,089	27,620
Property and equipment, net	1,809	2,527
Operating lease right-of-use assets	2,110	2,484
Other non-current assets	36	45
Long-term assets of discontinued operations		762
TOTAL ASSETS	21,044	33,438
Current Liabilities
Accounts payable	988	471
Accrued expenses	4,119	4,147
Current portion of operating lease liabilities	283	356
Current portion of PPP promissory note		421
Current portion of equipment financing		265
Current liabilities of discontinued operations		2,102
Total current liabilities	5,390	7,762
Operating lease liabilities	1,981	2,264
PPP promissory note		1,579
Long-term liabilities of discontinued operations		686
Total liabilities	7,371	12,291
Commitments and contingencies (Note 16)
Stockholders’ Equity
Preferred stock, $0.0001 par value, 10,000 shares authorized; no shares issued
Common stock, $0.0001 par value, 300,000 shares authorized; 7,010 and 3,189 shares issued and outstanding at December 31, 2021 and 2020, respectively	8	7
Additional paid-in capital	191,937	174,342
Accumulated deficit	(178,272)	(153,202)
Total stockholders’ equity	13,673	21,147
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 21,044	$ 33,438