title: Controlled release of platelet-derived growth factor using ethylene vinyl acetate copolymer (EVAc) coated on stainless-steel wires.
abstract: Controlled delivery of bioactive molecules to modulate or control biological processes has a number of clinical applications. The present study reports a delivery system which was designed to deliver growth factors locally to a fracture site. Ethylene vinyl acetate copolymer (EVAc), bovine serum albumin (BSA) and platelet-derived growth factor (PDGF-BB) were combined and coated onto a stainless-steel Kirschner wire (K-wire). A K-wire can be used as an intramedullary nail in small animal fractures, such as the rat. PDGF-BB stimulates thymidine uptake in human bone cell cultures when released from the K-wire delivery system. BSA release was modified by providing a final coating on the K-wire of 10% pure EVAc at the end of the fabrication. Electron microscopic examination of the surface of the rods revealed different surface pores on the K-wires coated with pure EVAc. Differences in porosity and tortuosity may account, in part, for the different release kinetics observed.
authors.affiliation: Graduate School for Biomedical Engineering, University of New South Wales, Sydney, Australia.
authors.forename: W R
authors.initials: WR
authors.lastname: Walsh
authors.forename: H D
authors.initials: HD
authors.lastname: Kim
authors.forename: Y S
authors.initials: YS
authors.lastname: Jong
authors.forename: R F
authors.initials: RF
authors.lastname: Valentini
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000592:standards*; D001858:Bone Nails / Q000592:standards; D002478:Cells, Cultured; D003692:Delayed-Action Preparations; D017102:Fracture Healing; D006801:Humans; D008855:Microscopy, Electron, Scanning; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism; D010982:Platelet-Derived Growth Factor / Q000008:administration & dosage*; D011145:Polyvinyls / Q000008:administration & dosage / Q000737:chemistry*; D011994:Recombinant Proteins / Q000008:administration & dosage; D012710:Serum Albumin, Bovine / Q000008:administration & dosage; D013232:Steel; D013499:Surface Properties; D013936:Thymidine / Q000008:administration & dosage
chemical_list: D001672:Biocompatible Materials; D003692:Delayed-Action Preparations; D010982:Platelet-Derived Growth Factor; D011145:Polyvinyls; D011994:Recombinant Proteins; D013232:Steel; C016438:ethylenevinylacetate copolymer; D012710:Serum Albumin, Bovine; D013936:Thymidine