Genipin Attachment of Conjugated Gold Nanoparticles to a Decellularized Tissue Scaffold

Decellularized allograft tissue is used for a wide array of tissue injuries and repair with tenons and ligament repair being among the most common. However, despite their frequent use there is concern over the lengthy inflammatory period and slow healing associated with allografts. One promising solution has been the use of nanoparticles. There is currently no easy, fast method to achieve consistent conjugation of nanoparticles to tissue. The available conjugation methods can be time-consuming and/or may create numerous cytotoxic byproducts. Genipin, a naturally derived crosslinking agent isolated from the fruits of Gardenia jasminoides was investigated as a conjugation agent to achieve fast, consistent crosslinking without cytotoxic byproducts. The rational of utilizing genipin is that is reacts spontaneously with amino-group-containing compounds such as proteins, collagens, and gelatins, and does not require extensive washing after conjugation. Porcine diaphragm tendons were decellularized and then immersed in cysteamine functionalized gold nanoparticles and genipin for various time points. Tissue scaffolds were tested for the degree of crosslinking, gold nanoparticle concentrations, and fibroblast attachment and biocompatibility. Results demonstrated that genipin can successfully and reproducibly attach gold nanoparticles to tissue in as little as 15 min. The genipin had no cytotoxic effects and improved fibroblast attachment and proliferation. Genipin can be used to attach gold nanoparticles to tissue in a fast, cell safe manner.