Physico-chemical and biocompatible properties of hydroxyapatite based composites prepared by an innovative synthesis route

The present paper aims to evaluate the physico-chemical and biocompatible properties of some new nanostructured hydroxyapatite-polyurethane (HAP-PU) composite scaffolds in direct contact with MSCs by in vitro tests. Several HAP based nanostructures were obtained by hydrothermal synthesis in various pressure conditions, i.e. pressure varying between 20-80 atm and temperature less than 1000 C. For the first time, a polyurethane with 100% hard segment content with carboxyl functional groups was used to prepare ceramic-polymer composites (80% HAP) with potential applications in bone tissue engineering. HAP crystallites with 15-35 nm in length were obtained. The results of MSCs viability indicated a slightly higher viability of HAP coatings (72% vs. control) compared to HAP-PU composites (69% vs. control) synthesized at high pressure (60 atm). This could be due to the effect of particle shape on cellular viability.

► hydroxyapatite-polymer composites were obtained by high pressure hydrothermal method
► specially designed polyurethane with a proportion of 100% of hard segments was used
► polyurethane acts as a crystal growth regulator for hydroxyapatite nanocrystallites
► viability and morphology of mesenchymal stem cells on composite surface were examined
► composites synthesized at 60 atm represent good substrates for cells proliferation