title: Geometrically structured implants for cranial reconstruction made of biodegradable polyesters and calcium phosphate/calcium carbonate.
abstract: The aim of this study was the development of a processing pathway for manufacturing of biodegradable skull implants with individual geometry. The implants on the basis of polylactide and calcium phosphate/calcium carbonate were prepared by a combination of hot pressing and gas foaming. On the inside, the implant consists of a macroporous and faster degradable material (poly(D,L-lactide)+CaCO3) to allow the ingrowth of bone cells. The pore size is in the range of 200-400 microm. On the outside, the implant consists of a compact and slower biodegradable material (poly(L-lactide) and calcium phosphate) to ensure mechanical stability and protection. To overcome problems like inflammatory reactions caused by acidic degradation products of polylactide, the polyester was combined with basic filling materials (calcium salts). The filler neutralises the lactic acid produced during polymer degradation and increases the bioactivity of the material. The stabilised pH was demonstrated by long-term in vitro pH studies. Over a time period of 250 d in demineralised water, the pH was in the physiological range. The in vitro biocompatibility was shown by cell cultures with human osteoblasts. A good proliferation of the cells was observed over the whole test period of 4 weeks.
authors.affiliation: Solid State Chemistry, Faculty of Chemistry, University of Bochum, Universitaetsstr. 150, Bochum D-44780, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Schiller
authors.forename: Christian
authors.initials: C
authors.lastname: Rasche
authors.forename: Michael
authors.initials: M
authors.lastname: Wehmöller
authors.forename: Felix
authors.initials: F
authors.lastname: Beckmann
authors.forename: Harald
authors.initials: H
authors.lastname: Eufinger
authors.forename: Matthias
authors.initials: M
authors.lastname: Epple
authors.forename: Stephan
authors.initials: S
authors.lastname: Weihe
mesh_terms: D020341:Absorbable Implants; D018786:Bone Substitutes / Q000138:chemical synthesis / Q000737:chemistry*; D002119:Calcium Carbonate / Q000737:chemistry*; D002130:Calcium Phosphates / Q000737:chemistry*; D002455:Cell Division / Q000502:physiology; D002478:Cells, Cultured; D004548:Elasticity; D019544:Equipment Failure Analysis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000737:chemistry*; D008420:Manufactured Materials / Q000032:analysis; D008422:Materials Testing; D010006:Osteoblasts / Q000166:cytology*; D011091:Polyesters / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011474:Prosthesis Design; D019651:Plastic Surgery Procedures / Q000295:instrumentation* / Q000379:methods
chemical_list: D018786:Bone Substitutes; D002130:Calcium Phosphates; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide); C020243:calcium phosphate; D002119:Calcium Carbonate