GROWTH OF HYDROXYAPATITE INSIDE A BIOCOMPATIBLE MESOPOROUS ORDERED SILICA

A. DÍAZ; T. LÓPEZ; J. MANJARREZ; E. BASALDELLA; J. M. MARTÍNEZ-BLANES; J. A. ODRIOZOLA

Acta Biomaterialia

Elsevier

Año: 2006 vol. 2 p. 173 - 179

ABSTRACT   A novel biomaterial (HA-SBA-15) has been developed based on the growth of calcium phosphate hydroxyapatite (HA) nanoparticles inside an ordered sol-gel silica network (SBA-15). The hydroxyl groups present on the silica nanostructure surface brought about cationic defects in silicium sites, mainly in those of tetrahedral symmetry, and promoted the formation of siloxanes. This particular network leads to the fixation of calcium cations to the silica matrix as a result of coordination chemistry interactions. XRD, BET, XPS, TEM, SEM tests and tissue brain biocompatibility tests were made. SEM and TEM analysis revealed the crystallization of hydroxyapatite inside the silica network. It was observed that the Ca incorporation at the beginning of the silica synthesis generates nucleation sites for the growth of hydroxyapatite crystals in the SBA-15 mesoporous cavities. Specific surface areas between 760 and 260 m2/g and narrow pore size distributions about 50 Å for pure silica and 140 Å for silica with hydroxyapatite were obtained. After the histopatologycal study no changes were observed in the near tissue. The results confirm the synthesis of a silica-based composite containing HA nanoparticles with potential application as leading biomaterial that could be additionally used as a porous matrix for the controlled in-situ delivery of chemotherapic drugs to malignant solid tumors.