Release Properties and Acute Biosecurity Determination of Collagen-Polyvinylpyrrolidone Loaded in Ordered Mesoporous Silica

Abstract

Mesoporous silica type SBA-15 has high specific surface area, well ordered pores and renders larges volumes, reasons for its potential use in controlled drug delivery system; in addition its non toxic nature and good biocompatibility. The aim of this work is to determine the feasibility of loading collagen-polyvinylpyrrolidone (collagen-PVP) molecules into Biocompatible Nanostructured Ordered Mesoporous Silica (BINOM-Silica). Collagen-PVP has several medical uses, such as fibrolytic activity and tissue regeneration. Therefore, this BINOM-Silica/collagen- PVP material could be used as drug delivery system for hypertrophic scarring. Different BINOMSilica materials were prepared using a triblock copolymer in an acid medium and stabilized at 557°C and later, collagen-PVP was loaded into the material. The small angle powder X-ray diffraction patterns of BINOM-Silica materials, in some cases, indicate the existence of a high degree of hexagonal mesoscopic organization. The nitrogen sorption isotherms are type IV typical of mesoporous materials with large surface area. In vitro release of collagen-PVP was carried out by mean of UV/VIS spectroscopy. The cumulative release profiles of Silica-collagen PVP in distilled water indicate a two step release, an initial fast release and a relatively slow subsequent release, indicating an appropriate delivery of collagen-PVP for therapeutic administration. BINOMSilica/ collagen-PVP intradermical administration stimulated inflammatory infiltrates only in an acute phase (day 3), demonstrating that silica materials and their combination with chemical and biological drugs could be safe for therapeutics. The absence of inflammatory infiltrates at day 7 suggested an appropriate integration of BINOM-Silica/collagen-PVP into the tissue. These results indicate that we obtained biocompatible nanostructured ordered mesoporous silica materials useful for delivery systems.