At December 31, 2011 and December 31, 2010, we had $0 and $85,000, respectively, of convertible promissory notes (“Senior Convertible Secured Notes-2007”) bearing the greater of 8% or LIBOR plus 3% interest per annum, convertible into shares of our common stock at an original conversion price of $87.50 per share. The Senior Convertible Secured Notes – 2007 were originally due August 26, 2010. On September 22, 2010, we entered into a debt modification agreement with the two holders of an aggregate of $126,362 of convertible promissory notes that were due on August 26, 2010. Based on the terms of the modification, this transaction qualified as a debt extinguishment under the relevant accounting guidance. As part of the debt extinguishment, the maturity date of the convertible promissory notes was extended until April 26, 2011. We entered into a debt-for-equity repayment plan whereby we retired the convertible promissory notes in equal installments by issuing our common stock priced at a 15% discount from the average market closing price for the five days ending on the 25th of each month over the eight month period beginning September 26, 2010 ending on April 26, 2011. The holders of the notes had the right to convert the outstanding balance priced at $2.25 per share if the market value of our common stock was greater than $2.50 per share for five consecutive days.

During the period from August 25, 2009 through December 15, 2009, we completed a private placement of convertible notes totaling $987,000 that were converted, at the holder’s option, into shares of our common stock at a conversion price of $0.50 per share (the “Convertible Notes - 2009”). The convertible note holders had the right to have the conversion price adjusted to equal the lower stock price if we issued common stock or convertible notes at a lower conversion price than $0.50 per share during the period that the notes were outstanding. The Convertible Notes - 2009 that were originally due on December 31, 2010 were extended to June 30, 2011 (see below under Warrant Repricing and Debt Extension Financing Transaction – 2010) and bore an annual interest rate of 7%, payable on June 30 and December 31 of each year that the convertible notes were outstanding. In addition, we issued 986,983 three-year warrants to the convertible note holders with an exercise price of $1.00 per share. The warrants may be exercised and converted to common stock, at the warrant holder’s option, beginning on the six-month anniversary of the date of issuance until the warrant expiration date. We are not obligated to register the common stock related to the convertible debt or the warrants. During the year ended December 31, 2011 we issued 1,851,486 shares of our common stock to holders of Convertible Notes – 2009 who converted principal of $912,036 and $13,707 of related accrued interest. On June 30, 2011, we paid in cash the remaining outstanding principal balance of $25,000 of Convertible Notes – 2009. As of December 31, 2011, all of the Convertible Notes – 2009 have been paid in full with cash or have been converted to shares of our common stock.

The embedded conversion feature of the Convertible Notes – 2009 met the definition of a derivative financial instrument and was classified as a liability in accordance with relevant accounting guidance. The note holders had the right to convert the debt into shares of our common stock, and the notes included price protection whereby these notes were protected for as long as the notes remained outstanding against future private placements made at lower share prices, and therefore, the total number of shares of our common stock that the convertible notes could be convertible into was not fixed. The embedded conversion features were revalued on each balance sheet date and marked-to-market with the change recorded to non-cash items related to debt discounts, deferred financing fees and the valuation of conversion features and warrants in the consolidated statements of operations. As a result of the conversions and repayments during the year ended December 31, 2011, the Company reclassified approximately $4.6 million of the related derivative liabilities to additional paid-in capital. As of December 31, 2011, the fair value of the remaining embedded conversion features was $0 due to the repayment or conversion of all the Convertible Notes - 2009. The Company recorded a loss of $2.3 million due to the change in the fair value of the embedded conversion features of these Convertible Notes – 2009 during the year ended December 31, 2011.

During the period from January 2010 through June 30, 2010, we received $1,597,000 in cash proceeds and converted $163,000 of accounts payable related to a private placement of convertible notes (“Convertible Notes – 2010”) and stock purchase warrants that were convertible, at the holder’s option, into shares of our common stock at a conversion price of $0.50 per share and we issued 1,760,712 stock purchase warrants that had an exercise price of $1.00 per share. The convertible note holders had the right to have the conversion price adjusted to equal the lower stock price if we issued stock or convertible notes at a lower conversion price than $0.50 during the period that the notes were outstanding. These convertible notes were originally due on December 31, 2010 and were extended to June 30, 2011 (see below under Warrant Repricing and Debt Extension Financing Transaction – 2010) and bore an annual interest rate of 7%, payable on June 30 and December 31 of each year that the convertible notes were outstanding. The warrants may be exercised and converted to common stock, at the warrant holder’s option, beginning on the six-month anniversary date of issuance until the warrant expiration date. We are not obligated to register the common stock related to the convertible debt or the warrants. During the year ended December 31, 2011, we issued 3,557,171 shares of our common stock to holders of Convertible Notes – 2010 who converted principal of $1,750,143 and $28,442 of related accrued interest. As of December 31, 2011, all of the Convertible Notes – 2010 have been converted to shares of our common stock.

The embedded conversion feature of the Convertible Notes – 2010 met the definition of a derivative financial instrument and was classified as a liability in accordance with accounting guidance. The note holders had the right to convert the debt into shares of our common stock, and the notes include price protection whereby these notes were protected for as long as the notes remained outstanding against future private placements made at lower share prices, and therefore, the total number of shares of our common stock that the convertible notes could be convertible into was not fixed. The embedded conversion features was revalued on each balance sheet date and marked to market with the increase or decrease in fair value to non-cash items related to debt discounts and deferred financing fees and the valuation of conversion features and warrants in the consolidated statements of operations. As a result of the conversions during the year ended December 31, 2011, the Company reclassified approximately $8.7 million of the related derivative liabilities to additional paid-in capital. As of December 31, 2011, the fair value of the remaining embedded conversion features is $0 as all the Convertible Notes – 2010 were converted. The Company recorded a loss of approximately $4.4 million due to the change in the fair value of the embedded conversion feature of these Convertible Notes – 2010 during the year ended December 31, 2011.

During September and October 2010, all of the holders of the convertible notes and the holders of the stock purchase warrants issued in the 2009 and 2010 Senior Secured Convertible Debt Financing Transactions agreed to extend the maturity date of their convertible debt from December 31, 2010 to June 30, 2011 under the same terms and conditions as the original notes. Holders of 2,766,857 stock purchase warrants also agreed to exercise their previously granted three-year warrants with an exercise price of $1.00 for a discounted exercise price of $0.88 per share. They received 2,766,857 shares of our common stock and 2,766,857 replacement three-year warrants with an exercise price of $1.38 for each warrant exercised. We raised a total of $2.4 million by these warrant exercises. In accordance with relevant accounting guidance, we noted that the transaction qualified for debt extinguishment accounting. As a result, the remaining debt discounts were written off and charged to interest expense and fair value of the replacement warrants were recorded to loss on extinguishment of debt, which was deemed to be the date that the convertible debt holder signed the modification agreement. As the Company did not have sufficient unissued authorized shares to cover all dilutive instruments until the increase in authorized shares on December 13, 2010, these replacement warrants were initially recorded as derivative liabilities at their grant date fair value. On December 13, 2010, the Company increased its authorized shares and then had sufficient authorized shares to cover all dilutive instruments and as such the replacement warrants were re-valued on that date (totaling $4,335,785) and the Company reclassified the replacement warrants to additional paid-in-capital in accordance with relevant accounting guidance.

During March and April 2011, we received approximately $4.2 million in cash proceeds related to a private placement of convertible notes (“Senior Convertible Secured Notes – 2011”), bearing interest at a rate of seven percent (7%) per annum, that was scheduled to mature on March 1, 2014 and that were convertible at the holder’s option into 1,691,320 shares of our common stock at a conversion price of $2.50 per share. The notes were automatically convertible into shares of the Company’s common stock in the event that on or before the note due date either (a) the Company’s common stock was traded at a price per share of $6.25 or higher for five (5) consecutive trading days, or (b) the Company consummated a financing in the amount of at least $5 million. The accrued interest was payable in stock, using the $2.50 conversion price, or cash, at the holder’s option, on June 30 and December 31 of each year.

In connection with the March and April 2011 financing transactions the Company valued the warrants issued to the convertible note holders on a relative fair value basis using the Black-Scholes option pricing model, totaling $937,000. This relative fair value of the warrants was recorded as a debt discount. The embedded conversion features to the notes has been determined to meet the definition of a derivative liability and as of the date of issuance was valued at $4.8 million. In accordance with relevant accounting guidance, the Company recorded an additional debt discount up to the full amount of the notes, recorded the derivative liability for the embedded conversion feature at $4.8 million and recorded the fair value in excess of face amount of debt as interest expense on the issuance date of $1.5 million. The debt discount was amortized in full upon the conversion of the notes to common stock on December 14, 2011. As of December 31, 2011, the fair value of the embedded conversion feature was $0 due to the conversion of all the Senior Convertible Secure Notes – 2011. The Company recorded a loss of $1.9 million due to the change in fair value of the embedded conversion feature for the year ended December 31, 2011 which is included in the accompanying consolidated statement of operations as a component of the non-cash items related to debt discounts and deferred financing fees and the valuation of conversion features and warrants.

During the year ended December 31, 2011, the Company issued 27,851 shares of unregistered common stock to note holders of the Senior Convertible Secured Notes – 2011 private placement financing transaction in lieu of cash for their $69,628 accrued interest payment that was due June 30, 2011. In addition, the Company paid $10,277 of the accrued interest in cash to note holders who declined to convert their interest payment to stock.

During the year ended December 31 2011, the Company issued 422,830 new five-year common stock purchase warrants to the investors, with an exercise price of $3.13 per share (the “March 2011 Warrants”), with each investor receiving a number of March 2011 Warrants that is equal to twenty-five percent (25%) of the investor’s note to the Company. The March 2011 Warrants may be exercised by cash payment or through cashless exercise by the surrender of warrant shares having a value equal to the exercise price of the portion of the warrants being exercised.

On December 13, 2011, following a public offering pursuant to a Registration Statement on Form S-3, the Company received gross proceeds in excess of $5 million. Pursuant to the terms, as defined, in the Senior Convertible Secure Notes – 2011 agreements, the remaining outstanding principal balance immediately following such date, plus accrued interest, was automatically convertible into shares of common stock at a conversion price of $2.50 per share. In accordance with the terms of the agreement, the Company automatically converted approximately $3.7 million of remaining principal and approximately $130,000 of accrued interest into 1,513,237 shares of the Company’s common stock. In addition, the Company issued 99,461 shares of common stock related to the bonus interest feature associated with the mandatory conversion of the debt. The fair value of the shares issued were computed based on the stock price of the Company’s common stock on December 14, 2011 and were valued at $397,845 and recorded as additional interest expense in non-cash items related to debt discounts and deferred financing fees and the valuation of conversion features and warrants in the consolidated statement of operations. As a result of the conversions and repayments of the Senior Convertible Secure Notes - 2011 during the year ended December 31, 2011, the Company reclassified approximately $6.7 million of derivative liabilities to additional paid-in capital. The Company recorded a loss of $1.9 million for the year ended December 31, 2011 due to the change in fair value of the embedded conversion features. As of December 31, 2011, the fair value of the embedded conversion features was $0. As of December 31, 2011, all of the Senior Convertible Secure Notes - 2011 plus accrued interest was paid or converted into shares of common stock.