Preparation and characterization of bioactive calcium silicate and poly(epsilon-caprolactone) nanocomposite for bone tissue regeneration.
ABSTRACT A novel biocomposite of nanosized calcium silicate (n-CS) and poly(epsilon-caprolactone) (PCL) was successfully fabricated directly using n-CS slurry, not dried n-CS powder, in a solvent-casting method. The in vitro bioactivity of the composite was evaluated by investigating the apatite-forming ability in simulated body fluid. A proliferation assay with mouse L929 fibroblasts was used to test the in vitro biocompatibility. The composition, hydrophilicity, and mechanical properties were also evaluated. Results suggest that the incorporation of n-CS could significantly improve the hydrophilicity, compressive strength, and elastic modulus of n-CS/PCL composites, with the enhancements mainly dependent on n-CS content. The n-CS/PCL composites exhibit excellent in vitro bioactivity, with surface apatite formation for 40% (w/w) n-CS (C40) exceeding that of 20% (w/w) n-CS (C20) at 7 and 14 days. The Ca/P ratios of apatite formed on C20 and C40 surfaces were 1.58 and 1.61, respectively, indicating nonstoichiometric apatite with defective structure. Composites demonstrated significantly better cell attachment and proliferation than that of PCL alone, with C40 demonstrating the best bioactivity. The apatite layers that formed on the composite surfaces facilitated cell attachment (4 h) and proliferation during the early stages (1 and 4 days). Collectively, these results suggest that the incorporation of n-CS produces biocomposites with enhanced bioactivity and biocompatibility.
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ABSTRACT: Biomedical polymer-silicate nanocomposites have potential to become critically important to the development of biomedical applications, ranging from diagnostic and therapeutic devices, tissue regeneration and drug delivery matrixes to various bio-technologies that are inspired by biology but have only indirect biomedical relation. The fundamental understanding of polymer-nanoparticle interactions is absolutely necessary to control structure-property relationships of materials that need to work within the chemical, physical and biological constraints required by an application. This review summarizes the most recent published strategies to design and develop polymer-silicate nanocomposites (including clay based silicate nanoparticles and bioactive glass nanoparticles) for a variety of biomedical applications. Emerging trends in bio-technological and biomedical nanocomposites are highlighted and potential new fields of applications are examined.Materials. 01/2010;