title: A bone substitute composed of polymethylmethacrylate and alpha-tricalcium phosphate: results in terms of osteoblast function and bone tissue formation.
abstract: The biological properties of a composite polymeric matrix (PMMA + alpha-TCP) made of polymethylmethacrylate (PMMA) and alfa-tricalciumphosphate (alpha-TCP) was tested by means of in vitro and in vivo investigations. PMMA was used as a comparative material. Osteoblast cultures (MG 63) demonstrated that PMMA + alpha-TCP significantly and positively affected osteoblast viability, synthetic activity and interleukin-6 level as compared to PMMA. At 12 weeks, the PMMA + alpha-TCP implants in rabbit bone successfully osteointegrated in trabecular and cortical tissue (affinity index: 57.14+/-8.84% and 68.31+/-6.18%, respectively). The newly formed bone after tetracycline labelling was histologically observed inside PMMA + alpha-TCP porosity. The microhardness test at the bone-PMMA + alpha-TCP interface showed a significantly higher rate of newly formed bone mineralization compared with PMMA (+83.5% and +58.5%, respectively), but differences still existed between newly formed and pre-existing normal bone. It is herein hypothesized that the present positive results may be ascribed to the porous macroarchitecture of PMMA + alpha-TCP and the presence of the bioactive ceramic material that could have a synergic effect and be responsible for the improvement of (a) the material colonization by bone cells, (b) osteoblast activity, (c) osteoinduction and osteoconduction processes, (d) bone remodelling.
mesh_terms: D001843:Bone Cements / Q000737:chemistry*; D018786:Bone Substitutes / Q000737:chemistry*; D001842:Bone and Bones / Q000187:drug effects; D002130:Calcium Phosphates / Q000737:chemistry* / Q000494:pharmacology*; D002460:Cell Line; D020099:Coated Materials, Biocompatible; D006801:Humans; D010006:Osteoblasts / Q000187:drug effects* / Q000378:metabolism; D019904:Polymethyl Methacrylate / Q000737:chemistry* / Q000494:pharmacology*; D016062:Porosity; D013499:Surface Properties; D013718:Tensile Strength; D013997:Time Factors
chemical_list: D001843:Bone Cements; D018786:Bone Substitutes; D002130:Calcium Phosphates; D020099:Coated Materials, Biocompatible; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; C485838:calcium phosphate, monobasic, anhydrous; D019904:Polymethyl Methacrylate; C020243:calcium phosphate; C485829:calcium phosphate, dibasic, anhydrous