Face value about $35 million, except Implant has agreed not to prepay $2.0 million in principal of the note that converts at $0.08 per share.
Still, for a substantial premium, I think DMRJ would agree to be bought out rather that the uncertainty of waiting to sell shares.
From the 10-K:
As of June 30, 2014, the outstanding balance due under the senior secured convertible promissory notes issued to DMRJ and accrued and unpaid interest was $34,552,000, of which a $3,184,000 senior secured promissory and $2,175,288 of accrued and unpaid interest are convertible into shares of our common stock at $0.08 per share; a $12,000,000 senior convertible promissory note and $3,320,000 of accrued and unpaid interest is convertible into shares of Series H Convertible Preferred Stock, which preferred stock is convertible into shares of our common stock at $1.09 per share; and a $12,000,000 senior secured promissory note and $1,873,000 of accrued and unpaid interest is convertible into shares of Series I Convertible Preferred Stock, which preferred stock is convertible into shares of our common stock at $1.18 per share.