Nanoscale control of silks for regular hydroxyapatite formation

The control of nanoparticle shape is still a challenge for different hydroxyapatite (HA) preparation ways. In the present study, silk fibroin with regular nanostructures was firstly prepared and then employed to regulate the mineralization of HA nanocrystals. The morphology and crystal structure of the deposition were investigated by SEM, X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Compared to previous studies in which silk fibroin with different nanostructures was used as template, the present study revealed that the HA nanoparticle shape could be controlled through regulating the nanostructure of silk fibroin. Using silk nanospheres as template, the shape of HA gradually changed from pin-like structure to rice-like structure following the increase of silk fibroin content. Then some HA nanofibers were prepared with short silk nanofibers as template. The results indicated that it is feasible to achieve the shape control of HA nanoparticles through further regulating the nanostructure of silk fibroin template, which would greatly facilitate the application of HA in different fields.