Study of dual responsive poly[(maleilated dextran)‐graft‐(N‐isopropylacrylamide)] hydrogel nanoparticles: preparation, characterization and biological evaluation

Abstract

BACKGROUND: Much interest has recently been shown in fundamental studies and technological developments of polymeric nanoparticles. Novel dual temperature‐ and pH‐sensitive stabilized nanoparticles composed of maleilated dextran (Dex‐MA) and N‐isopropylacrylamide (NIPAAm) were prepared and investigated to be used for the controlled release of 10‐hydroxycamptothecin. RESULTS: The resultant nanoparticles showed spherical geometry, with diameters ranging from 60 to 300 nm, the variation achieved by adjusting the composition ratio or the amounts of surfactant. The size of the nanoparticles increased and the zeta potential reversed with an increase of pH. Also, the lower critical solution temperature (LCST) decreased at pH = 3.0, but increased at pH = 6.0, which suggests that the LCST is dependent on pH. Drug release results obtained showed encapsulation and loading efficiencies were 62.9% and 0.82%, respectively. Cytotoxicity assay of this copolymer indicated no significant toxicity. CONCLUSION: Novel dual temperature‐ and pH‐sensitive Dex‐MA‐graft‐PNIPAAm nanoparticles may provide some advantages for anti‐cancer drug delivery due to a tunable LCST from 35 to 45 °C and controllable dimensions. These nanoscale materials could be excellent candidates for biotechnology and biomedical applications. Copyright © 2009 Society of Chemical Industry

Folate‐decorated Polysaccharide‐doxorubicin Polymer: Synthesis, Characterization, and Activity in HeLa Cells

“…Because of the protons of hydroxyl groups, the characteristic peaks of DOX at 13.1 and 14.0 ppm were present in the spectra of M.LNT‐ DOX and FA‐M.LNT‐DOX (Figure (c) and (d)) . The presence of several peaks at 6.5–9.0 ppm (Figure (d)), which could be assigned to the aromatic protons of FA according to the reported literature, confirmed the existence of the FA moiety in FA‐M.LNT‐DOX conjugate. Thus it could be concluded that the FA‐M.LNT‐DOX conjugate was successfully synthesized by this protocol.…”

Synthesis of new enzymatically degradable thermo-responsive nanogels

“…Related to the synthesis of dextran-based thermo-responsive nanogels, only two works have been published. 31,32 In both of them, nanogels were prepared by emulsion polymerization using NIPAM as a temperature-sensitive monomer and maleilated dextran or Dex-lactateHEMA as cross-linkers.…”

Dual‐pH/Magnetic‐Field‐Controlled Drug Delivery Systems Based on Fe3O4@SiO2‐Incorporated Salecan Graft Copolymer Composite Hydrogels

“…In the past few decades, much attention has been paid to the polysaccharide‐based hydrogels as drug carriers owing to their low toxicity, biocompatibility and renewability . However, some hydrogels prepared from single polysaccharide such as starch, dextran and agarose are nonresponsive to external stimuli like pH and temperature, which is considered to be a limitation in their applications as drug carriers . To address this drawback, efforts have been made to fabricate chemically modified polysaccharide‐based hydrogels by grafting.…”

“…[5] However, some hydrogels prepared from singlep olysaccharide such as starch, dextran and agarose are nonresponsive to external stimuli like pH and temperature, which is considered to be a limitation in their applications as drug carriers. [6] To address this drawback, efforts have been made to fabricatec hemically modified polysaccharide-based hydrogels by grafting. Graft copolymerization of vinyl monomers, such as N,N-diethylacrylamide, methacrylic acida nd 2-acrylamido-2-methyl-1-propanesulfonica cid, onto polysaccharide is an efficient approach to improvet he inherentp roperties of polysaccharides.…”