A bioactive metallurgical grade porous silicon–polytetrafluoroethylene sheet for guided bone regeneration applications

Abstract

The properties of porous silicon make it a promising material for a host of applications including drug delivery, molecular and cell-based biosensing, and tissue engineering. Porous silicon has previously shown its potential for the controlled release of pharmacological agents and in assisting bone healing. Hydroxyapatite, the principle constituent of bone, allows osteointegration in vivo, due to its chemical and physical similarities to bone. Synthetic hydroxyapatite is currently applied as a surface coating to medical devices and prosthetics, encouraging bone in-growth at their surface and improving osseointegration. This paper examines the potential for the use of an economically produced porous silicon particulate-polytetrafluoroethylene sheet for use as a guided bone regeneration device in periodontal and orthopaedic applications. The particulate sheet is comprised of a series of microparticles in a polytetrafluoroethylene matrix and is shown to produce a stable hydroxyapatite on its surface under simulated physiological conditions. The microstructure of the material is examined both before and after simulated body fluid experiments for a period of 1, 7, 14 and 30 days using Scanning Electron Microscopy. The composition is examined using a combination of Energy Dispersive X-ray Spectroscopy, Thin film X-ray diffraction, Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy and the uptake/release of constituents at the fluid-solid interface is explored using Inductively Coupled Plasma-Optical Emission Spectroscopy. Microstructural and compositional analysis reveals progressive growth of crystalline, 'bone-like' apatite on the surface of the material, indicating the likelihood of close bony apposition in vivo.

Fluoride incorporation in high phosphate containing bioactive glasses and in vitro osteogenic, angiogenic and antibacterial effects

“…In addition, as little as 1 mg/L fluoride was found to promote formation of needle-like nano-crystals, which are similar to native crystals in width and thickness and therefore have the potential to possess similar mechanical properties [58,59]. mechanism is yet to be understood [69][70][71][72][73][74][75]. In this study, the released silicon concentrations into cell culture medium were ranged from 45 to 52 ppm depending on BG composition, and may contribute to the promoted proliferation, ALP activity, collagen and bone nodule formation and osteogenic gene expression in MC3T3-E1 cells by the high phosphate but fluoride free BG (P6.33F0), compared with the control (no BG).…”