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

12 Months Ended

Dec. 31, 2015

Equity Incentive Plan [Member]

Share-based Compensation Arrangement by Share-based Payment Award

Summary of option and warrant activity

	December 31,
	2015			2014
Shares available for grant at plan approval		300,000			-
Options granted		(47,700	)		-
Shares available for grant at end of year		252,300			-

Share - based Compensation [Member]

Share-based Compensation Arrangement by Share-based Payment Award

Summary of option and warrant activity

Share-based Compensation	2015		2014
Research and Development	$	260,204	$	308,847
General and Administrative		394,277		411,303
Total	$	654,481	$	720,150

Stock options [Member]

Share-based Compensation Arrangement by Share-based Payment Award

Summary of option and warrant activity

	Options			Weighted Average Options Exercise Price
Balance at December 31, 2013		205,151		$	26.30
Granted		63,750			17.90
Exercised		(3,667	)		7.70
Forfeited		(16,406	)		31.30
Balance at December 31, 2014		248,828		$	24.00
Granted		60,534			11.90
Exercised		(3,312	)		5.80
Forfeited		(29,189	)		31.30
Balance at December 31, 2015		276,861		$	21.30

Weighted-average range of exercise prices for options and warrants outstanding and exercisable

Price Range	Weighted Average Remaining Contractual Life in Years		Outstanding Options		Exercisable Options
$3.00-$22.00		8.03		217,084		148,443
$22.60-$41.00		5.36		17,477		17,477
$46.40-$94.00		3.22		42,300		42,300
Total		7.28		276,861		208,220

Warrant [Member]

Share-based Compensation Arrangement by Share-based Payment Award

Summary of option and warrant activity

	Warrants			Weighted Average Warrant Exercise Price
Balance at December 31, 2013		815,653		$	21.70
Granted		116,932			14.80
Exercised		(58,608	)		16.50
Expired		(147,027	)		34.90
Balance at December 31, 2014		726,950		$	11.50
Exercised		(174,643	)		6.40
Expired		(59,695	)		55.90
Balance at December 31, 2015		492,612		$	7.40

Weighted-average range of exercise prices for options and warrants outstanding and exercisable

Price  Range	Weighted Average Remaining Contractual Life in Years		Outstanding Warrants		Exercisable Warrants
$5.10-$5.30		2.4		381,180		381,180
$14.80-$20.50		4.0		111,432		111,432
Total		2.7		492,612		492,612