License and Collaboration Agreements (Details) - USD ($) shares in Millions		12 Months Ended
	Sep. 27, 2019	Dec. 31, 2022	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2014
License agreements:
Research and development			$ 8,085,522	$ 10,321,397
Collaboration Agreement with CanSino Biologics
License agreements:
Term (in years)	10 years
Period within with Cansino to provide development cost statement	45 days
Period within which to reimburse Cansino of development costs	1 year
Schepens Eye Research Institute
License agreements:
License fee paid					$ 100,000
Potential development and regulatory milestone payments					6,000,000.0
Potential commercial milestone payment					$ 10,100,000
Milestone payment			0
Royalty payments			0
Cancellation period, written notice					180 days
Research and development			600,000	500,000
Collaboration agreement with University of Illinois, Chicago
License agreements:
Potential development and regulatory milestone payments						$ 1,300,000
Milestone payment				$ 300,000
Cancellation period, written notice				90 days
Signing fee paid						$ 15,000
Minimum annual royalty payment			$ 20,000
Collaboration agreement with University of Illinois, Chicago | Forecast
License agreements:
Minimum annual royalty payment		$ 50,000
Collaboration agreement with University of Colorado
License agreements:
Potential development and regulatory milestone payments					$ 1,500,000
Cancellation period, written notice							60 days
Minimum annual royalty payment					$ 20,000
Shares issued (in shares)							0.1