4. Term Loan

On February 5, 2016, we entered into a loan and security agreement with Hercules Technology Growth Capital, Inc. ("HTGC"), as administrative agent and lender, and Hercules Technology III, L.P., as lender ("Hercules"), pursuant to which the lenders made term loans to us on February 8, 2016 in the aggregate principal amount of $25 million (the "Term Loans").

The Term Loans bear interest at the daily variable rate per annum equal to 6.0% plus the prime rate, or 10.25%, whichever is greater. We are required to make interest-only payments on the Term Loans through February 28, 2017, and beginning on March 1, 2017 blended equal monthly installments of principal amortization and accrued interest until the maturity date of the Term Loans on February 1, 2020. Under the terms of the loan, we are required to maintain a minimum cash balance equal to the greater of (i) $10 million or (ii) forward three months projected cash burn. As security under our obligations, we issued to the lenders warrants to purchase a total of 634,146 shares of our common stock at an exercise price of $2.05. These warrants are classified as equity warrants with a fair value of $633,749. All outstanding principal and accrued interest on the term loans will be due and payable in full on the maturity date of February 1, 2020.

As security for our obligations under the loan and securities agreement, we granted HTGC, as administrative agent, a security interest in substantially all of our existing and after-acquired assets except for our intellectual property and certain other excluded assets. The loan and security agreement contains customary representations, warranties and covenants.

	June 30, 2017			December 31, 2016
Term Loan Principal – Current	$	7,737,492		$	6,214,057
Issuance Cost/Loan Discount – Current		(1,036,452	)		(732,401	)
Term Loan, Net – Current	$	6,701,040		$	5,481,656

Long Term Loan Principal	$	14,835,146		$	18,785,943
End Fee Payable		1,771,250			1,771,250
Long Term Loan Discount/Issuance Cost		(792,889	)		(2,072,683	)
Long Term Loan, Net	$	15,813,507		$	18,484,510

On July 28, 2017, we entererd into an Amended Loan Services Agreement with the lenders of the Term Loans whereby we agreed to make an immediate payment of $5 million of principal and unpaid interest, a further $5 million payment of principal and unpaid interest by September 30, 2017, and agreed to an updated schedule of monthly payments and a new maturity date of August 1, 2018.

The interest expense on the loan for the three-month and six-month periods ended June 30, 2017 was $848,395 and $2,171,110, respectively, as compared to $741,346 and $1,158,148 for comparative 2016 periods.