Segments and Geographic Information - Revenues, Expenses and Operating Income (Loss) by Market Segment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Revenues:
Total revenues	$ 7,176	$ 7,128
Operating expenses:
Total operating expenses	9,097	9,946
Operating income (loss)
Total operating income (loss)	(1,921)	(2,818)
Anti-aging Market [Member]
Revenues:
Total revenues	1,240	1,534
Operating expenses:
Total operating expenses	1,484	1,751
Operating income (loss)
Total operating income (loss)	(244)	(217)
Biomedical Market [Member]
Revenues:
Total revenues	5,936	5,594
Operating expenses:
Total operating expenses	4,346	4,785
Operating income (loss)
Total operating income (loss)	1,590	809
Therapeutics Market [Member]
Operating expenses:
Total operating expenses	3,267	3,410
Operating income (loss)
Total operating income (loss)	$ (3,267)	$ (3,410)