Despite considerable bioactivity of bioceramics such as hydroxyapatite and bioglasses, their applications were restricted duo to their poor mechanical properties. This problem could be solved via making composite with other ceramics such as forsterite. In this research, hydroxyapatite-forsterite-bioglass nanopowder and nanostructured composite coating were prepared via a sol-gel process and characterized. Also, hydroxyapatite-forsterite-bioglass nanopowder was used as a reinforcement in a composite scaffold. Then, scaffolds including PLA polymer as a matrix and composite nanopowder as a reinforcement was prepared via a particulate leaching-solvent casting. The effect of added reinforcement was investigated. To prepare composite nanopowder and coating, hydroxyapatite sol was prepared and forsterite and bioglass nanopowders with 10 percentage of weight solution were added to sol. The prepared sol was stirred at ambient temperature for 24 hours. After that, the prepared gel was dried at 80 °C and was heat treated after aging at a furnace. The similar method was used for preparing composite coatings. Stainless steel substrate (316L) was coated via dip-coating. XRD, TEM, SEM, EDS and AAS techniques were used for investigating the prepared powders, coatings and scaffolds. The evaluation of bioactivity was performed and characterized via SEM, AAS and Spectrophotometry. To investigate the effect of forsterite content, the evaluation of the mechanical properties of coatings was performed via nanoindentation tests. Results show that calcination at 600 °C was appropriate temperature to calcinate the composite powder and coating and avoid forming the secondary phases. The crystal size of hydroxyapatite in the prepared powder determined according to Scherer equation was lower than 100nm and was in agreement in results obtained with TEM. Results show the functional groups in composite nanopowder. The homogenous, free crack and adhesive coating with about 25 µm thickness was obtained. The bioactivity evaluation showed the apatite formation. Results showed that increase in forsterite content improve(increase) the mechanical properties such as hardness, elastic modulus and fracture toughness. The suitable scaffolds with reinforcement content lower than 50wt% contained porosity with 100 µm size. These porosities were appropriate to differentiation cells. The increase in reinforcement, the decrease in porosity content. These present results show that hydroxyapatite-forsterite-bioglass composite nanopowder and coating show the hopeful properties for medical applications and especially was suitable for preparing scaffolds.
