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.

Surface-dependent effect of functional silica fillers on photocuring kinetics of hydrogel materials

“…Poly(2‐hydroxyethyl methacrylate) (poly‐HEMA) belongs to the class of polymers known as hydrogels . The unique properties of hydrogels stem from a combination of the properties of the polymer phase and aqueous phases, because they adsorb large amounts of water or biological fluids without dissolutions.…”

“…It has been shown for instance, that silica particles improve swelling properties with respect to poly‐HEMA, although an adverse effect of silica addition was also reported . The water uptake at equilibrium decreases with the increase in filler content, or achieve lower swelling behavior for lower silica content . Despite the large number of works on the poly‐HEMA/silica, only few articles focused on the kinetics of the thermal or photocuring process.…”

“…[25][26][27][28] The unique properties of hydrogels stem from a combination of the properties of the polymer phase and aqueous phases, because they adsorb large amounts of water or biological fluids without dissolutions. Due to the high capability of water uptake, nontoxicity, and favorable compatibility to tissues and blood, poly-HEMA is an attractive biomaterial for V C 2014 Wiley Periodicals, Inc. many biomedical applications, such as drug delivery systems, [25][26][27][28][29] antithrombotic devices and implants contact or intraocular lenses, [25][26][27][28][29][30][31] vascular prostheses, 25,27,29 soft-tissue replacement, 25,27,29 and coating on the surface of implantable biosensors. 26 One problem often encountered on optimizing hydrogel formulations for specific end-uses is poor mechanical strength, which can restrict the utility of the materials.…”

Bionanocomposites Assembled by “From Bottom to Top” Method

“…As it was noted, bioactive nanocomposites can be used for frames structuring in engineering of bone tissue [170,172,174,175,[178][179][180].…”

Synergistic effect of graphene and silicon dioxide hybrids through hydrogen bonding self-assembly in elastomer composites

“…SiO 2 applied in composites have attracted much research attention [18][19][20][21][22] in the last few decades owing to the superior properties of SiO 2 nanoparticles such as toughness, tensile strength, thermal stability, gas separation performance, high scattered performance, and thermal resistance 23 and they have various applications in high-performance coatings, 24,25 bers, 26,27 bioactive polymers, 28,29 rubber composites etc. [30][31][32] The nanometer-sized SiO 2 particles are used not only as a kind of ller, but also as reinforcing 33,34 and toughening 35 agents that can impart good mechanical properties, thermal stability, and toughness, as well as magnetic and optical properties to the polymers.…”