Synthetic and viscoelastic behaviors of silicananoparticle reinforced poly(acrylamide) core–shell nanocomposite hydrogels

Organic/inorganic nanocomposite hydrogels

“…The peroxide surface of SNPs was obtained when irradiated by a 60 Co g-ray, and subsequent polymerization of AA produced silica-based hydrogels, which had no residues of initiators or crosslinkers; therefore, they can be used in biocompatible gel applications (Koo et al, 2012). g-Methacryloxypropyl trimethoxy silane was used to modify SNPs, and the resulting surface vinyl groups functionalized SNPs copolymerized with AA (Yang et al, 2013b, AM (Yang et al, 2013a), or 2-acrylamido-2-methylpropanesulfonic acid (AMPS; Wang et al, 2012), forming tough NC gels with a coreeshell structure. By mixing with copolymer containing reactive side chains (trimethoxysilyl), the hydroxyl groups present on the SNPs reacted with the trimethoxysilyl side groups, which resulted in the formation of crosslinked networks (Takafuji et al, 2011;Alam et al, 2013 Figure 21.2).…”

“…Covalent binding of SNPs with polymers was regarded as an effective method to improve the compatibility and strength of silica-based hydrogels (Yang et al, 2013a,c). It was found that covalent bonds between SNPs and PAM via silane bridges made the hydrogels exhibit excellent tensile properties, including a modulus of 9e38 kPa, a fracture strain of 700e1000%, and a fracture stress of 80e250 kPa (Yang et al, 2013a). g-Methacryloxypropyl trimethoxy silane was used to modify SNPs, and the resulting surface vinyl groups functionalized SNPs copolymerized with AA (Yang et al, 2013b, AM (Yang et al, 2013a), or 2-acrylamido-2-methylpropanesulfonic acid (AMPS; Wang et al, 2012), forming tough NC gels with a coreeshell structure.…”

Nanosilica-induced high mechanical strength of nanocomposite hydrogel for killing fluids

“…Such types of mechanically strong composite hydrogels have been developed and showed great potential applications in biological fields and industry. For example, silica/polyacrylamide core-shell nanocomposite hydrogels and poly(dimethylacrylamide)/silica hybrid hydrogels were separately synthesized in biomedical and pharmaceutical applications [25,26]. Polyacrylamide (PAM) composite hydrogel containing silica sol using free-radical polymerization was prepared for potential industrial application [27].…”

One-pot synthesis of pH-responsive hybrid nanogel particles for the intracellular delivery of small interfering RNA

“…This approach has significant potential in improving the use of small interfering RNA (siRNA) as a therapeutic agent by protecting them from intracellular nucleases found within the acidic endolysosomal vesicles [2, 7] and favor their release in the cell cytoplasm after internalization. However, the use of a hydrogel matrix as a drug delivery vehicle is limited by its low structural integrity and poor mechanical stability [8]. Furthermore, although the mechanical properties of hydrogels can be strengthened by increasing its amount of crosslinking, this also can affect its environmental responsiveness and biocompatibility [9].…”

“…These limitations can be overcome by developing a hybrid system based on the incorporation of a rigid inorganic core with a minimally crosslinked soft hydrogel matrix. The inorganic core stabilizes the hybrid system while the hydrogel matrix retains the environmental sensitivity [8, 24]. …”