Facile coupling of synthetic peptides and peptide-polymer conjugates to cartilage via transglutaminase enzyme.

Covalent attachment of synthetic and biological molecules to tissue surfaces can be used to enhance local drug delivery, reduce adhesions after surgery, and attach reconstructive biomaterials and tissue-engineered matrices to tissues. We present here a mild approach to coupling polymers to tissue surfaces through an enzyme catalyzed reaction between peptide modified polymer and native protein components of the tissue extracellular matrix (ECM). Tissue transglutaminase (tTG), a Ca2+-dependent enzyme that catalyzes the reaction between lysine and glutamine residues to form a epsilon(gamma-glutaminyl) lysine isopeptide bond, was incubated with cartilage in the presence of lysine (FKG-NH2) and glutamine (GQQQLG-NH2) peptides as well as peptide functionalized poly(ethylene glycol) (PEG).