title: In-situ sol-gel synthesis and characterization of bioactive pHEMA/SiO2 blend hybrids.
abstract: A novel procedure to synthesize poly(2-hydroxyethylmethacrylate)-silica blend hybrids is presented. Methacrylate monomers bearing an alkoxysilyl unit, prepared by Michael addition of 2-hydroxyethylmethacrylate (HEMA) to 3-Aminopropyltriethoxysilane (APTS) were employed. By (13)C NMR and mass analysis it was possible to establish the formation of coupling hybrid species. Hybrid materials, with final concentration ranging from 10% to 30% w/w of silica gel to the mass of polymer, were obtained through basic catalyzed sol-gel process of tetraethoxysilane (TEOS) and the alkoxysilyl unit of the hybrid monomer, followed by in-situ free-radical polymerization. The hybrids were characterized as far as concerns their thermal properties (glass transition temperature, decomposition temperature), their sorption behavior in water, and in-vitro bioactivity. Optical transparency, higher glass transition temperature, and higher decomposition temperature than pHEMA suggest an increase in either density or intensity of cross-links between the organic and the inorganic phases. The swelling ratio of the 30% hybrids is comparable to pHEMA, whereas it is lower for the other compositions. In-vitro bioactivity of the hybrids, due to the inorganic phase, was ascertained. Soaking time required for apatite deposition on the samples surface decreases as the content of silica gel increases. Therefore, the obtained bioactive hybrids can be used to make bioactive scaffolds for bone engineering.
authors.affiliation: Interdisciplinary Centre of Biomedical Materials (CRIB), Università di Napoli Federico II, Naples 80-80125, Italy.
authors.forename: B
authors.initials: B
authors.lastname: Silvestri
authors.affiliation: Dipartimento di Ingegneria dei Materiali e della Produzione, Università di Napoli Federico II, Naples 80-80125, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Luciani
authors.affiliation: Dipartimento di Ingegneria dei Materiali e della Produzione, Università di Napoli Federico II, Naples 80-80125, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Costantini
authors.affiliation: Dipartimento di Ingegneria dei Materiali e della Produzione, Università di Napoli Federico II, Naples 80-80125, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Tescione
authors.affiliation: Dipartimento di Ingegneria dei Materiali e della Produzione, Università di Napoli Federico II, Naples 80-80125, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Branda
authors.affiliation: Dipartimento di Chimica Organica e Biochimica, Università di Napoli Federico II, Naples 4-80126, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Pezzella
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D001826:Body Fluids / Q000737:chemistry; D020100:Hydrogels / Q000737:chemistry*; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry*; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D044367:Phase Transition; D012822:Silicon Dioxide / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D001672:Biocompatible Materials; D020100:Hydrogels; D008689:Methacrylates; D012822:Silicon Dioxide