Uso del polipéptido antimicrobiano KR-12, para la biofuncionalización de prótesis óseas compuestas por la aleación metálica TI6AL7NB

Abstract

Currently, there are many efforts to find bone implants and prostheses that adapt well to each person and do not cause problems, especially in terms of infections of the same. The main objective of this work is to find a material with bioactivity, which, besides inhibiting the growth of bacterial strains that cause infections, is biocompatible with the cells that cover the implant and, therefore, does not affect its rate of proliferation, adhesion or cause cytotoxicity to them. For this, in this study the surface of what would be the material that makes up an implant, in this case the Ti6Al7Nb metallic alloy, has been biofunctionalized. The process of biofunctionalization consisted of anchoring the antimicrobial peptide KR-12 to the surface, thanks to a simple method such as the use of a silane as coupling agent, which in this study were APTES and CPTES. Synthesis of the KR-12 peptide was performed by the standard solid phase synthesis technique (SPPS) based on Fmoc / tBu, and a purity of the peptide higher than 98% was obtained. The characterization of the surfaces obtained before and after the anchoring of the peptide was carried out to verify the binding of KR-12. This characterization was obtained by X-ray photoelectron spectroscopy (XPS) analysis, fluorescent staining of KR-12 and water contact angle measurement, which demonstrated the success of KR-12 anchoring on the surface. Tests were performed to evaluate the cytocompatibility of the material with human osteoblastic cells (hOB), obtaining good results of cell viability and proliferation. In addition, the antimicrobial activity of KR-12 at a concentration of 0.5 mg / ml was demonstrated against Staphylococcus aureus, the bacterial strain most frequently present in infections of implants and bone prostheses. Therefore, the cytocompatibility with human osteoblastic cells and the antimicrobial activity of Ti6Al7Nb coated with KR-12, make it a candidate to improve the clinical efficacy of bone implants