Note 10 - Share-based Compensation (Tables)

9 Months Ended

Jun. 30, 2025

Notes Tables

Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]

	Three Months Ended				Nine Months Ended
	June 30,				June 30,
	2025		2024		2025			2024
Selling, general and administrative	$	1,290,912	$	2,310,153	$	4,914,586		$	7,005,004
Research and development		378,516		758,532		1,662,839			2,077,235
Discontinued operations		—		307,721		(10,049	)		1,335,287
Share-based compensation	$	1,669,428	$	3,376,406	$	6,567,376		$	10,417,526

Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	Three Months Ended						Nine Months Ended
	June 30,						June 30,
	2025			2024			2025			2024
Weighted Average Assumptions:
Expected volatility		115.3	%		109.6	%		114.6	%		108.9	%
Expected dividend yield		0.0	%		0.0	%		0.0	%		0.0	%
Risk-free interest rate		4.0	%		4.5	%		4.0	%		4.5	%
Expected term (in years)		6.0			6.0			6.0			6.0
Fair value of options granted	$	4.32		$	13.74		$	4.59		$	12.16

Share-Based Payment Arrangement, Option, Activity [Table Text Block]

				Weighted Average
						Remaining		Aggregate
	Number of			Exercise Price		Contractual Term		Intrinsic
	Shares			Per Share		(years)		Value
Outstanding at September 30, 2024		1,846,243		$	45.92
Granted		184,000		$	5.36
Exercised		—		$	—
Forfeited and expired		(78,175	)	$	48.70
Outstanding at June 30, 2025		1,952,068		$	41.98		5.49	$	136,465
Exercisable at June 30, 2025		1,553,904		$	46.88		4.61	$	8,180