title: Effects of ultraviolet irradiation on bonding strength between Co-Cr alloy and citric acid-crosslinked gelatin matrix.
abstract: Novel techniques for creating a strong bond between polymeric matrices and biometals are required. We immobilized polymeric matrices on the surface of biometal for drug-eluting stents through covalent bond. We performed to improve the bonding strength between a cobalt-chromium alloy and a citric acid-crosslinked gelatin matrix by ultraviolet irradiation on the surface of cobalt-chromium alloy. The ultraviolet irradiation effectively generated hydroxyl groups on the surface of the alloy. The bonding strength between the gelatin matrix and the alloy before ultraviolet irradiation was 0.38 ± 0.02 MPa, whereas it increased to 0.48 ± 0.02 MPa after ultraviolet irradiation. Surface analysis showed that the citric acid derivatives occurred on the surface of the cobalt-chromium alloy through ester bond. Therefore, ester bond formation between the citric acid derivatives active esters and the hydroxyl groups on the cobalt-chromium alloy contributed to the enhanced bonding strength. Ultraviolet irradiation and subsequent immobilization of a gelatin matrix using citric acid derivatives is thus an effective way to functionalize biometal surfaces.
authors.affiliation: 1Biomaterials Unit, Nano-life field, International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki, Japan.
authors.forename: Motoki
authors.initials: M
authors.lastname: Inoue
authors.forename: Makoto
authors.initials: M
authors.lastname: Sasaki
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Katada
authors.forename: Tetsushi
authors.initials: T
authors.lastname: Taguchi
mesh_terms: D000497:Alloys; D002857:Chromium / Q000737:chemistry*; D019343:Citric Acid / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry*; D005780:Gelatin / Q000737:chemistry*; D013499:Surface Properties; D014466:Ultraviolet Rays
chemical_list: D000497:Alloys; D002857:Chromium; D019343:Citric Acid; D003035:Cobalt; D005780:Gelatin
keywords: Cobalt–chromium alloy; bonding strength; citric acid; covalent bond; gelatin; ultraviolet irradiation