Bioactive vapor deposited calcium-phosphate silica sol-gel particles for directing osteoblast behavior.

Silica-based materials are being developed and used for a variety of applications in orthopedic tissue engineering. In this work, we characterize the ability of a novel silica sol vapor deposition system to quickly modify biomaterial substrates and modulate surface hydrophobicity, surface topography, and composition. We were able to show that surface hydrophobicity, surface roughness, and composition could be rapidly modified. The compositional modification was directed towards generating apatitic-like surface mineral compositions (Ca/P ratios ∼1.30). Modified substrates were also capable of altering cell proliferation and differentiation behavior of preosteoblasts (MC3T3) and showed potential once optimized to provide a simple means to generate osteo-conductive substrates for tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2135-2148, 2016.

Development of vapor deposited silica sol-gel particles for use as a bioactive materials system.

Silica-based sol-gel and bioglass materials are used in a variety of biomedical applications including the surface modification of orthopedic implants and tissue engineering scaffolds. In this work, a simple system for vapor depositing silica sol-gel nano- and micro-particles onto substrates using nebulizer technology has been developed and characterized. Particle morphology, size distribution, and degradation can easily be controlled through key formulation and manufacturing parameters including water:alkoxide molar ratio, pH, deposition time, and substrate character. These particles can be used as a means to rapidly modify substrate surface properties, including surface hydrophobicity (contact angle changes >15°) and roughness (RMS roughness changes of up to 300 nm), creating unique surface topography. Ions (calcium and phosphate) were successfully incorporated into particles, and induced apatitie-like mineral formation upon exposure to simulated body fluid Preosteoblasts (MC3T3) cultured with these particles showed up to twice the adhesivity within 48 h when compared to controls, potentially indicating an increase in cell proliferation, with the effect likely due to both the modified substrate properties as well as the release of silica ions. This novel method has the potential to be used with implants and tissue engineering materials to influence cell behavior including attachment, proliferation, and differentiation via cell-material interactions to promote osteogenesis.