Peptide-mediated surface coatings for the release of wound-healing cytokines.

Supporting the wound healing process by sending the appropriate cytokine signals can shorten healing time and overcome chronic inflammation syndromes. Even though adhesion peptides consisting of Arg-Gly-Asp (RGD) are commonly used to enhance cell-surface interactions, peptide-mediated cytokine delivery has not been widely exploited so far. Cytokines interact with high affinity with their cognitive receptors but also with sulfated glycosaminoglycans (GAGs), both of which form a base for incorporation of cytokines into functional biomaterials. Here, we report on a mussel-derived surface coating as a prospective cytokine delivery system using covalently bound heparin-mimetics, receptor derived chemokine binding peptides (RDP) and heparin binding peptides (HBP). The latter enabled non-covalent immobilization of heparin on the surface followed by chemokine binding and release, while the former allowed direct non-covalent chemokine immobilization The peptide displayed excellent binding to custom-made polystyrene 96-well plates, enabling convenient testing of several compounds. Released chemokine successfully induced migration in Jurkat cells especially for the non-covalent heparin immobilization approach using HBPs as evaluated in a transwell assay. In comparison, heparin-mimetic coatings, comprised of sulfated peptides and GAG derivatives, proved less efficient with respect to amount of immobilized chemokine and migratory response. Thus, our study provides a roadmap for further rational optimization and translation into clinics.