Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2017

Stockholders' Equity Note [Abstract]

Common Stock Warrants Outstanding

The Company has a total of 310,397 warrants outstanding at a weighted average exercise price of $14.60 to purchase its common stock as of December 31, 2017. These warrants are summarized as follows:

Issuance Date	Number of Shares	Exercise Price	Expiration Date
3/10/2011	1,738	$    4.80	3/10/2021
7/23/2013	12,500	$125.00	7/23/2018
3/23/2016	296,159	$  10.00	3/23/2021

Summary of Common Stock Warrants by Exercise Price Range

The following table summarizes the warrant activity of the Company’s common stock warrants:

	Common Stock Warrants
Outstanding, December 31, 2015		14,238
March 23, 2016 public offering		682,500
Exercised		(386,341	)
Expired		—
Outstanding, December 31, 2016		310,397
Exercised		—
Expired		—
Outstanding, December 31, 2017		310,397

Schedule of Components of Stock-based Compensation Included in Net Loss

There are 553,196 stock options remaining available for grant under the Plans. The following table summarizes the components of the Company’s stock-based compensation included in net loss:

	For the years ended
	December 31,
	2017		2016
Employee stock options	$	474,251	$	527,697
Non-employee stock options		14,362		2,664
Employee stock awards		169,517		24,276
Non-employee stock awards		31,000		27,993
	$	689,130	$	582,630

Schedule of Stock Option Valuation Assumptions

The fair value of each stock option is estimated on the date of grant using the Black-Scholes-Merton option pricing model with the following assumptions for stock options granted during the years ended:

	December 31,
	2017			2016
Dividend yield		0.0	%		0.0	%
Expected volatility		76.35-79.08	%		72.95-78.54	%
Risk-free interest rate		1.86-2.26	%		1.36-2.25	%
Expected term (years)		5.8-7.8			5.4 - 6.3

Schedule of Stock Option Activity

The following tables summarize the stock option activity for the year ended December 31, 2017:

	Shares			Weighted Average Exercise Price
Outstanding, December 31, 2016		113,672		$	39.32
Granted		190,151		$	7.88
Exercised		—		$	—
Forfeited/Expired		(37,013	)	$	20.18
Outstanding, December 31, 2017		266,810		$	19.57

Schedule of Options Outstanding, Vested and Exercisable

The following table summarizes information about stock options outstanding at December 31, 2017:

Options Outstanding			Options Vested and Exercisable
Balance as of 12/31/2017	Weighted Average Remaining Contractual Life (Years)	Weighted Average Exercise Price	Balance as of 12/31/2017	Weighted Average Remaining Contractual Life (Years)	Weighted Average Exercise Price
266,810	7.97	$19.57	105,102	6.07	$36.28