Share-based compensation - Options - Activity (Details) - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Number of Options
Number of options, beginning of period (in shares)	462,340
Granted (in shares)	697,629
Forfeited (in shares)	0
Exercised (in shares)	0
Expired (in shares)	0
Number of options, end of period (in shares)	1,159,969	462,340
Number of options, vested and exercisable (in shares)	373,824
Weighted Average Exercise Price
Weighted average exercise price, beginning of period (in dollars per share)	$ 2.37
Granted (in dollars per share)	1.46
Weighted average exercise price, end of period (in dollars per share)	1.82	$ 2.37
Weighted Average Grant Date Fair Value
Weighted average grant date fair value, beginning of period (in dollars per share)	1.20
Weighted average grant date fair value, granted (in dollars per share)	0.82
Weighted average grant date fair value, end of period (in dollars per share)	$ 0.96	$ 1.20
Weighted Average Remaining Contractual Term
Weighted average remaining contractual term, outstanding	8 years 6 months 21 days	9 years 4 months 6 days
Weighted average remaining contractual term, granted	10 years
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest [Abstract]
Weighted average exercise price, vested and exercisable (in dollars per share)	$ 2.43
Weighted average grant date fair value - vested and exercisable (in dollars per share)	$ 1.18
Weighted average remaining contractual term, vested and exercisable	7 years 5 months 8 days
Average Intrinsic Value
Aggregate intrinsic value, beginning balance	$ 0
Aggregate intrinsic value, granted	0
Aggregate intrinsic value, ending balance	0	$ 0
Aggregate intrinsic value, vested and exercisable	$ 0