title: Liquid-phase laser process for simple and area-specific calcium phosphate coating.
abstract: Simple, mild, and area-specific calcium phosphate (CaP) coating techniques are useful for the production and surface modification of biomaterials. In this study, an area-specific CaP coating technique for polymer substrates was successfully developed using a liquid-phase laser process. In the proposed method, Nd-YAG laser light (355 nm, 30 Hz, and 1-3 W) irradiated an ethylene-vinyl alcohol copolymer (EVOH) substrate immersed in a supersaturated CaP solution for various periods of time (up to 30 min). The CaP-forming ability increased with an increase in the laser power and irradiation period. At the optimal laser power (3 W), a continuous CaP layer formed within 30 min on the laser-irradiated surface of the EVOH substrate. The formation of CaP was attributed to laser absorption by the EVOH substrate, which promoted the surface modification of EVOH and an increase in the temperature of the solution near the surface of the substrate. The resulting CaP coating showed better cell adhesion property than the naked EVOH substrate. The proposed CaP coating technique is simple (quick and single step) and area specific. Furthermore, the present process is carried out under mild conditions, that is, at normal pressures and temperatures in a safe aqueous medium. These are significant advantages of the proposed CaP coating technique.
authors.affiliation: Nanosystem Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan. a-oyane@aist.go.jp
authors.forename: Ayako
authors.initials: A
authors.lastname: Oyane
authors.forename: Ikuko
authors.initials: I
authors.lastname: Sakamaki
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Shimizu
authors.forename: Kenji
authors.initials: K
authors.lastname: Kawaguchi
authors.forename: Naoto
authors.initials: N
authors.lastname: Koshizaki
mesh_terms: D000818:Animals; D016466:CHO Cells; D002130:Calcium Phosphates / Q000494:pharmacology*; D002452:Cell Count; D045744:Cell Line, Tumor; D020099:Coated Materials, Biocompatible / Q000494:pharmacology*; D006224:Cricetinae; D006801:Humans; D007834:Lasers; D008422:Materials Testing / Q000379:methods*; D008855:Microscopy, Electron, Scanning; D044367:Phase Transition / Q000187:drug effects; D056951:Photoelectron Spectroscopy; D011145:Polyvinyls / Q000737:chemistry; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties / Q000187:drug effects; D013696:Temperature; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D002130:Calcium Phosphates; D020099:Coated Materials, Biocompatible; D011145:Polyvinyls; D012996:Solutions; D014867:Water; C020320:ethylene-vinyl alcohol copolymer; C020243:calcium phosphate