TANIA GUADALUPE PENAFLOR GALINDO

The Zn−substituted HAp NPs were successfully synthesized at the initial molar ratios of (Ca+Zn)/P at 1.67 and 2.00, providing the stoichiometric Zn:HAp and carbonate Zn:CHAp NPs and the maximum Zn ion substitution in the structure is ca. 5 mol% by the XRF analysis. The 10.0−Zn:HAp and 10.0−Zn:CHAp NPs contain 0.76 and 0.68 wt% of Zn at the maxima, respectively, which is safety for cells in the animal body. The increase in the Zn ion concentration significantly induced the carbonate ion including. The crystalline size decreased with the increasing Zn ion substitution, indicating the suppression of the crystal growth by the Zn ion addition to resultantly increase the specific surface area. TEM observation clearly indicated that the needle-like shape nanoparticles were changed to the particulate shapes with increasing the Zn ion substitution to form aggregation form with the mesostructures. Thus, the morphological control by the Zn−substitution in stoichiometric and carbonate HAp NPs was successfully achieved. The Zn:HAp and Zn:CHAp NPs were deposited on the Ti-PDMS by an EPD technique obtaining an uniform and transparent Zn:HAp and Zn:CHAp NPs. The fibroblasts on the Zn−substituted HAp NP films exhibited good adhesion/spreading. In particular, the Zn:CHAp NP films are very cytocompatible. By the antibacterial test, the viable E. coli DH5α reduction was significantly observed in the films with the higher Zn amounts. Resultantly, the 5.0 and 10−Zn:CHAp NP films. Furthermore, all the nanoparticle films electrically plated on a Ti-PDMS substrate give no cytotoxicity, and the Zn:CHAp NP films significantly provided the bioactive properties for fibroblast ingrowth, suggesting the effect of Zn and carbonate ions on the cytocompatibility. Summarizing, The Zn:HAp and Zn:CHAp NP films with the optimized cytocompatible and antibacterial properties were successfully prepared as the Ti-PDMS surface modification technique.[Doctoral thesis] Doctoral supervisor: Dr. Motohiro Tagaya