title: Relationship between bioceramics sintering and micro-particles-induced cellular damages.
abstract: We performed experimental studies to confirm the hypothesis that cellular damages occurring around implanted biphasic bioceramics could be related to a micro-particles release because of an insufficient sintering. First, an in vitro cytotoxicity study was performed on four biphasic ceramic (BCP) samples. Without treatment of the extraction medium, a cytotoxicity was observed, although after centrifugation this cytotoxicity disappeared in all samples. Second, micro-particles of hydroxyapatite (HA), beta-tricalcium phosphate (beta-TCP) and 40% beta-TCP/60%HA mixture were used for a cell inhibition study. A decrease of cell viability was observed with the increase in particles concentration. At 10000 particles per cell, the viability and proliferation were completely inhibited. Third, HA, beta-TCP and BCP ceramic granules were implanted in rabbit femoral cavities for 12 weeks. No degradation of HA granules was observed. The degradation was higher for beta-TCP (40%) than for BCP (5%). On the other hand, new bone formation was significantly higher for beta-TCP (21%) and HA (18%) than for BCP (12%). More micro-particles were formed around BCP granules than around beta-TCP, and phagocytised by macrophages. The release of ceramic micro-particles could be related to the sintering process. BCP ceramic have to be sintered at only 1160 degrees C. Consequently, HA micro-particles of BCP ceramic are incompletely sintered and easily released after immersion or implantation. The microparticles could be at the origin of local inflammation and cell damage and could perhaps modify osteogenesis. Attention must be paid to this problem especially with BCP ceramics because of the sintering difficulties of this bioceramic.
authors.affiliation: Laboratoire de Recherche sur les Biomatériaux et les Biotechnologies (LR2B), Université du Littoral Côte d'Opale, 52 Rue Du Docteur Calot, 62608 Berck sur Mer Cedex, France. irms@hopale.com
authors.forename: Jianxi
authors.initials: J
authors.lastname: Lu
authors.forename: Marie-Claude
authors.initials: MC
authors.lastname: Blary
authors.forename: Sébastien
authors.initials: S
authors.lastname: Vavasseur
authors.forename: Michel
authors.initials: M
authors.lastname: Descamps
authors.forename: Karine
authors.initials: K
authors.lastname: Anselme
authors.forename: Pierre
authors.initials: P
authors.lastname: Hardouin
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D002130:Calcium Phosphates / Q000737:chemistry; D002460:Cell Line; D002470:Cell Survival; D002516:Ceramics / Q000737:chemistry*; D005269:Femur / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D005347:Fibroblasts / Q000473:pathology*; D005547:Foreign Bodies / Q000209:etiology* / Q000473:pathology* / Q000503:physiopathology; D006358:Hot Temperature; D006882:Hydroxyapatites / Q000737:chemistry; D008422:Materials Testing; D051379:Mice; D008863:Microspheres; D019736:Prostheses and Implants / Q000009:adverse effects*; D011817:Rabbits; D013223:Statistics as Topic; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D002130:Calcium Phosphates; D006882:Hydroxyapatites; C485817:beta-tricalcium phosphate; C018392:tricalcium phosphate