Key words: supercritical carbon dioxide, biomaterials, nano-scale hydroxyapatite, polylactide, selective laser sintering
Bioactive composites based on polylactide powders and nano-sized hydroxyapatite (HAP) for the production of three-dimensional scaffolds by selective laser sintering are manufactured using supercritical carbon dioxide. A mixture of powdered polymers and nano-sized HAP cannot be sintered directly by laser irradiation because continuous polymer filaments cannot be formed due to the absence of permanent contacts between polymer particles. This problem was resolved by employing for sintering composite polymer particles already containing HAP nanoparticles fabricated in the supercritical carbon dioxide medium. Mechanical tests and microscopy studies demonstrate that HAP particles are uniformly distributed in the sintered composites; the latter have no centers of destruction and withstand the same mechanical loads as pure polymer. Produced structures can be used as scaffolds in bone tissue engineering.
doi:10.1134/S1990793111080045