Stock Option Plans and Warrants to Purchase Common Stock (Tables)

12 Months Ended

Dec. 31, 2023

Grant 2015 Plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of shares available for grant under the 2015 plan

Shares available for grant at January 1, 2023	5,812,991
Options granted	(731,544)
Options forfeited	15,000
Options exercised	—
Shares available for grant at December 31, 2023	5,096,447

Stock options

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of activity under the 2005 plan and the 2015 plan

		Weighted
		Average
		Exercise
	Options	Price
Balance outstanding at December 31, 2021	140,996	$	37.12
Granted	55,730		8.85
Forfeited	(3,908)		107.83
Cancelled	(545)		11.70
Exercised	—		—
Balance outstanding at December 31, 2022	192,273	$	27.56
Granted	731,544		0.65
Forfeited	(16,925)		34.71
Cancelled	—		—
Exercised	—		—
Balance outstanding at December 31, 2023	906,892	$	5.73

Schedule of weighted-average exercise price, by price range, for outstanding options to purchase common stock

	Weighted
	Average
	Remaining
	Contractual	Outstanding	Exercisable
Price Range	Life in Years	Options	Options
$0.59 - $40.05	9.31	899,794	299,490
$111.00- $328.50	1.52	7,098	7,098
Total	9.25	906,892	306,588

Share-based Payment Arrangement

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of share-based compensation expense

Share-based compensation	2023		2022
Research and development	$	150,466	$	142,879
General and administrative		219,716		190,510
Total	$	370,182	$	333,389

Warrants

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of warrant activity

			Weighted
			Average
			Exercise
	Warrants		Price
Balance at December 31, 2021		221,872	$	33.79
Granted		—		—
Exercised		—		—
Expired		(221,205)		33.81
Balance at December 31, 2022		667	$	29.25
Granted		10,775,073		0.91
Exercised		(4,237,000)		0.001
Expired		(667)		29.25
Balance at December 31, 2023		6,538,073	$	1.50

Schedule of remaining life, by grant date, for outstanding warrants

			Remaining
	Exercise		Contractual	Outstanding	Exercisable
Grant Date	Price		Life in Years	Warrants	Warrants
May 09, 2023	$	1.50	4.36	6,538,073	6,538,073