Segment Information - Schedule of Financial Information by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Segment Reporting Information [Line Items]
Net revenues	$ 12,111	$ 2,938	$ 26,792	$ 6,873
Cost of revenues	2,123	802	3,763	2,805
Direct expenses	19,707	21,683	39,578	76,353
Segment contribution	(9,719)	(19,547)	(16,549)	(72,285)
Indirect expenses	456	22,929	1,002	34,061
Loss from operations	(10,175)	(42,476)	(17,551)	(106,346)
Components of other
Change in fair value of contingent consideration liability	0	(85,407)	0	(104,339)
Change in fair value of contingent stock consideration				(120)
Goodwill impairment	0	0	0	29,633
IPR&D impairment	0	107,800	0	107,800
Cell Therapy
Segment Reporting Information [Line Items]
Direct expenses	3,422	8,456	8,887	48,618
Segment contribution	(3,422)	(8,456)	(8,887)	(48,618)
Biobanking
Segment Reporting Information [Line Items]
Net revenues	1,278	1,278	2,565	2,635
Cost of revenues	537	485	714	957
Direct expenses	447	86	863	430
Segment contribution	294	707	988	1,248
Degenerative Disease
Segment Reporting Information [Line Items]
Net revenues	10,833	1,660	24,227	4,238
Cost of revenues	1,586	317	3,049	1,848
Direct expenses	5,784	1,889	10,198	4,898
Segment contribution	3,463	(546)	10,980	(2,508)
Other
Segment Reporting Information [Line Items]
Direct expenses	10,054	11,252	19,630	22,407
Segment contribution	(10,054)	(11,252)	(19,630)	(22,407)
Indirect expenses	456	22,929	1,002	34,061
Components of other
Change in fair value of contingent consideration liability		(85,407)		(104,339)
Change in fair value of contingent stock consideration		(10)		(120)
Goodwill impairment				29,633
IPR&D impairment		107,800		107,800
Amortization	456	546	1,002	1,087
Total other	$ 456	$ 22,929	$ 1,002	$ 34,061