Porous scaffold of gelatin-starch with nanohydroxyapatite composite processed via novel microwave vacuum drying

Hydroxyapatite (HA) is a fundamental mineral-based biomaterial, used for preparing composites for bone repair and regeneration. Gelatin blended with starch results in scaffold composites with enhanced mechanical properties. A gelatin-starch blend reinforced with HA nanocrystals (nHA) gave biocompatible composites with enhanced mechanical properties. In this study, a porous scaffold of gelatin-starch-nHA composites was fabricated through microwave vacuum drying and crosslinking using trisodium citrate. Three different composite scaffolds were prepared at three different percentages of nHA: 20%, 30% and 40%. The microstructures and compositions of the composites were analyzed. Within the porous structure, the nHA crystals were observed to precipitate. The interaction between the gelatin-starch network film and nHA crystalline material was studied using Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction analysis (XRD). XRD reflections showed that there are two different minerals present in the scaffold composite. There were strong reflection peaks close to the 26 degrees and 32 degrees 2theta angles of HA, and close to the 8 degrees and 49 degrees 2theta angles for sodium citrate minerals. The FTIR result suggested that carboxyl groups, C=O and amino groups play crucial roles in HA formation on the surface of a gelatin network.