10.Notes Receivable

​

Notes receivable consists of the following for the periods presented:

​

​

In December 2022, the Company entered into a senior convertible promissory note (also referred as debt security) arrangement with Monarch Medical Technologies, LLC (“Monarch”) providing Monarch with up to $5,000 in available funding, of which $5,000, in principal was drawn. The Monarch debt security accrued interest at 10% per annum, payable monthly, and the principal balance was originally due December 6, 2024, with such due date extended to January 17, 2025. On January 15, 2025, Monarch repaid $3,500, along with the transaction fees and accrued interest. At the same time, the Company entered into an Amended and Restated Secured Convertible Promissory Note (“New Note”) and related subordination agreement for the outstanding principal balance of $1,500. The New Note carries an interest rate of 15% payable monthly. Unless earlier repaid or converted, the New Note will mature and the outstanding principal amount, together with accrued and unpaid interest thereon and transaction expenses, will be due and payable on the first to occur of (i) the occurrence of an Event of Default (as defined in the New Note), (ii) a Change of Control (as defined in the New Note) unless converted as set forth in the New Note or (iii) February 15, 2028. 

The Company recognized interest income of $57 and $104 on the Monarch debt securities for the three and six months ended June 30, 2025, respectively, which is included in interest (expense) income, net in the Unaudited Condensed Consolidated Statement of Operations. The Company recognized interest income of $133 and $258 for the three and six months ended June 30, 2024, respectively, which is included in interest (expense) income, net in the Unaudited Condensed Statement of Operations.

​

In June 2022, the Company loaned Mellitus Health, Inc. (“Mellitus”) an aggregate of $1,000 through the purchase of two senior secured promissory notes that bear interest at a rate of 5% per annum, which mature on the third anniversary of issuance unless accelerated due to an event of default as provided in the notes. Repayment of the Mellitus notes is secured by a first priority interest in all of Mellitus’ assets. As of June 30, 2025, the Company recorded an impairment charge on the entire note principal balance of $1,000 and accrued interest of $135 as the Company believed it was unlikely to be recovered.