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Bio-degradation study of colloidal mesoporous silica nanoparticles: Effect of surface functionalization with organo-silanes and poly(ethylene glycol)
No full textTuning drug uptake and release rates through different morphologies and pore diameters of confined mesoporous silica
No full textThree ordered mesoporous silica systems (OMS) were synthesized within the channels (120-200 nm in diameter, 60 lm long) of anodic alumina membranes (AAMs), i.e., systems (i) and (ii) with pore diameters of about 4 and 6 nm having a columnar alignment of mesopores and system (iii) featuring 6 nm pores arranged in a circular structure. These model systems allow one to eliminate the effect of particle size and particle morphology of the OMS, by using systems without significant external surface. Ibuprofen, an anti-inflammatory drug, was incorporated into these OMS-AAM systems by diffusion from solution. Uptake results showed that the included OMS increases the drug adsorption capacity with respect to the AAM as such. The highest uptake values were reached in the columnar OMS-AAM system with the larger pore diameter. The circular system, having similar structural parameters as the columnar one, i.e. pore size, pore volume and nitrogen surface area, showed the lowest adsorption capacity toward ibuprofen. The low accessibility of circular mesopores through defects creates a significant diffusion resistance for the ibuprofen molecules, thus showing that pore morphology strongly influences molecular diffusion. Drug release in a time window ranging from minutes to weeks was studied in a simulated body fluid (SBF). Concerning the columnar samples, the drug release rate decreased upon reducing the pore diameter. From the circular sample the ibuprofen was released with fast kinetics; it is proposed that the drug did not deeply diffuse into the structure. Nearly 30% of the total amount adsorbed was retained in the circular sample. Furthermore, after about a day the precipitation of hydroxyapatite precursors was detected on the surface of the mesoporous host, showing that the OMS-AAM system exhibits a ‘‘bioactive" behavior. This implies that after prolonged release times the diffusion of the drug out of the system can be slowed down through partial pore blockin
Surface area enhancement by mesoporous silica deposition on microcantilever sensors for small molecule detection
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Confined polymeric nanowires into porous alumina matrix as composite piezoelectric membrane for sensing applications
No full textZnO Nanostructures for Tissue Engineering Applications
Full text linkThis review focuses on the most recent applications of zinc oxide (ZnO) nanostructures for tissue engineering. ZnO is one of the most investigated metal oxides, thanks to its multifunctional properties coupled with the ease of preparing various morphologies, such as nanowires, nanorods, and nanoparticles. Most ZnO applications are based on its semiconducting, catalytic and piezoelectric properties. However, several works have highlighted that ZnO nanostructures may successfully promote the growth, proliferation and differentiation of several cell lines, in combination with the rise of promising antibacterial activities. In particular, osteogenesis and angiogenesis have been effectively demonstrated in numerous cases. Such peculiarities have been observed both for pure nanostructured ZnO scaffolds as well as for three-dimensional ZnO-based hybrid composite scaffolds, fabricated by additive manufacturing technologies. Therefore, all these findings suggest that ZnO nanostructures represent a powerful tool in promoting the acceleration of diverse biological processes, finally leading to the formation of new living tissue useful for organ repair
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