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In this work, we report on the fabrication of an hybrid material based on a porous silicon (PSi) layer infiltrated by an amino functionalized poly(e-caprolattone) (PCL-NH2). The organic–inorganic structure has been characterized by variable angle spectroscopic ellipsometry, optical reflectometry and water contact angle measurements. A polymer coated PSi layer, 3 μm thick, shows improved wettability and chemical stability against long lasting, up to 18 min, exposure to an alkaline environment. Even after basic treatment, the structure still retains a very good quality optical response, so that it may be proposed as a high performance platform for biochemical sensing applications.

In this work, the potential in drug nanodelivery of micelles made from poly(ϵ-caprolactone) (PCL) and poly (ethyleneoxide) (PEO) copolymers with triblock and star-diblock architectures was explored. Linear and 4-arm star-shaped PCL macromers with two or four OH end groups were prepared by ring-opening polymerization of CL and condensed with α-methoxy-ω-carboxy-PEO. The resulting amphiphilic copolymers were characterized by 1H NMR, size exclusion chromatography, and differential scanning calorimetry. Separate PCL and PEO crystalline phases were observed for both copolymers. Copolymers self-assembled in water giving critical association concentrations in the range 0.010–0.023 mg/mL. Micelles with a size of 32–45 nm were prepared by dialysis and characterized for hydrodynamic diameter and surface charge. Their potential as nanocarriers in drug delivery applications was evaluated too. Micelles were nontoxic to both Red blood cells and HeLa cells. Complement activation experiments indicated that micelles can escape the reticuloendothelial system once intravenously injected. Finally, a different uptake on HeLa cells was found for micelles obtained from triblock and star-shaped copolymers. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2008

Porous silicon based one-dimensional photonic crystals, such as Bragg mirror and optical microcavity, has been modified by infiltration of a new biocompatible polymer, an amino functionalized poly(e-caprolactone) (PCL-NH2), and characterized as optical biochemical sensors. The entrapped polymer adds strong chemical stability to the nanocrystalline matrix on exposure to alkaline solutions preserving the device sensing abilities in monitoring volatile substances and chemical compounds. On the basis of these results, these hybrid structures can be proposed as a high performance platform for biochemical applications.