Goodwill and other intangible assets (Details) - USD ($)			1 Months Ended		3 Months Ended			12 Months Ended
	Apr. 01, 2023	Apr. 18, 2022	Sep. 30, 2023	Apr. 30, 2023	Jun. 30, 2023	Sep. 30, 2022	Dec. 31, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2017
Goodwill and other intangible assets
In-process research and development impairment									$ 3,500,000
Goodwill impairment loss								$ 3,873,079
Intangible asset impairment loss								2,277,921
Increase in deferred tax liability								(571,120)	(3,288,937)
IPRD
Goodwill and other intangible assets
Balance of finite-lived intangible assets							$ 3,500,000	0	0
Intangible asset impairment loss									3,500,000
Pelican Therapeutics, Inc.
Goodwill and other intangible assets
Goodwill acquired										$ 2,200,000
Goodwill impairment loss							1,500,000
Pelican Therapeutics, Inc. | IPRD
Goodwill and other intangible assets
Finite-lived intangible assets acquired										$ 5,900,000
Carrying value written down							5,900,000
Intangible assets fair value							3,500,000
In-process research and development impairment						$ 3,500,000	$ 2,400,000
Elusys Therapeutics
Goodwill and other intangible assets
Goodwill acquired		$ 3,300,000							5,067,748
Finite-lived intangible assets acquired		$ 9,700,000
In-process research and development impairment	$ 0								0
Goodwill impairment loss			$ 3,900,000					3,873,079
Remaining amortization period		80 months
Goodwill		$ 3,873,080			$ 3,900,000				3,301,959
Acquisition fair value adjustments					$ 600,000			571,120	1,765,789
Intangible asset impairment loss			2,300,000
Amount of impairment charges			$ 0
Increase in goodwill				$ 600,000
Increase in other assets				1,000,000.0
Increase in liability for uncertain tax positions				1,000,000.0
Increase in deferred tax liability				$ 600,000
Elusys Therapeutics | Intangible Assets
Goodwill and other intangible assets
Finite-lived intangible assets acquired									11,200,000
Balance of finite-lived intangible assets									$ 8,669,375
Intangible asset impairment loss								$ 2,277,921