title: Fabrication of poly(propylene fumarate)-based orthopaedic implants by photo-crosslinking through transparent silicone molds.
abstract: This work presents a new molding process for photo-crosslinked, degradable polymeric networks of poly(propylene fumarate) (PPF) and the crosslinking agent poly(propylene fumarate)-diacrylate (PPF-DA). Transparent room temperature vulcanizing silicone molds were fabricated for parts ranging from simple test coupons to orthopaedic implants. The PPF/PPF-DA resin blend was injected into the cavity and photo-crosslinked as light was transmitted through the mold wall. The volumetric shrinkage, mechanical properties, and the effects of gamma sterilization were reported for molded PPF/PPF-DA networks prepared with varying compositions of the two polymer components. The shrinkage decreased while the mechanical properties displayed a general increasing trend when more of the crosslinking agent was incorporated into the network. Gamma irradiation resulted in an improvement of the mechanical properties. In addition, PPF/PPF-DA replicates of a 70:30 poly(L/DL-lactide) biodegradable fixation plate and a bone allograft interbody fusion spacer were produced to evaluate the performance of PPF/PPF-DA as an orthopaedic implant and allow for a comparison to be made with materials that have been established for clinical use.
authors.affiliation: Department of Bioengineering, Rice University, PO Box 1892 MS-142, Houston, TX 77251-1892, USA.
authors.forename: Mark D
authors.initials: MD
authors.lastname: Timmer
authors.forename: Cory
authors.initials: C
authors.lastname: Carter
authors.forename: Catherine G
authors.initials: CG
authors.lastname: Ambrose
authors.forename: Antonios G
authors.initials: AG
authors.lastname: Mikos
mesh_terms: D020341:Absorbable Implants; D001672:Biocompatible Materials / Q000737:chemistry; D004343:Drug Implants / Q000737:chemistry*; D004548:Elasticity; D005650:Fumarates / Q000737:chemistry*; D005720:Gamma Rays; D008027:Light; D008422:Materials Testing; D011108:Polymers / Q000737:chemistry*; D011126:Polypropylenes / Q000737:chemistry*; D012828:Silicones / Q000737:chemistry*; D013314:Stress, Mechanical
chemical_list: D001672:Biocompatible Materials; D004343:Drug Implants; D005650:Fumarates; D011108:Polymers; D011126:Polypropylenes; D012828:Silicones; C032005:fumaric acid