Share-Based Compensation - Share-based compensation expenses (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total share-based compensation		$ 70,000
Biostage2013 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total share-based compensation	$ 980,000	1,144,000
Research and development [Member] | Biostage2013 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total share-based compensation	495,000	311,000
General and administrative [Member] | Biostage2013 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total share-based compensation	$ 485,000	$ 833,000