Summary of significant accounting policies - Potentially dilutive securities (Details) - shares	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Potentially dilutive securities
Total shares of common stock equivalents	2,968,232	648,448
March 2024 Private Placement | Pre-funded Warrants
Potentially dilutive securities
Warrants to purchase of shares	507,076
Convertible preferred stock (as converted)
Potentially dilutive securities
Total shares of common stock equivalents	28,112	28,112
Employee Stock Option
Potentially dilutive securities
Total shares of common stock equivalents	715,620	596,466
Warrants to purchase common stock
Potentially dilutive securities
Total shares of common stock equivalents	2,194,788
Unvested restricted stock units
Potentially dilutive securities
Total shares of common stock equivalents	29,712	23,870