Synthesis and characterization of pH-responsive nanoscale hydrogels for oral delivery of hydrophobic therapeutics

Tunable poly(methacrylic acid‐co‐acrylamide) nanoparticles through inverse emulsion polymerization

“…Base‐mediated ionomer collapse is commonly used for the purification of nanoparticles, synthesized by emulsion at the lab‐scale in order to remove surfactant from the formed nanoparticles by promoting the portioning of uncharged surfactant in an organic phase . However, in this study we observed that extended incubation of polymer in basic solution, like those necessary for this purification, leads to a compositional change of the polymer.…”

“…In our initial syntheses, we selected an ionomer collapse purification schema. This schema was selected because it was previously successful in purifying alternate nanogels containg methacrylic acid . Ionomer collapse relies on the super‐collapsing of ionic gels in media with a low dielectric constant.…”

“…This schema was selected because it was previously successful in purifying alternate nanogels containg methacrylic acid. 7 Ionomer collapse relies on the super-collapsing of ionic gels in media with a low dielectric constant. Because of the polyacidic nature of our P(MAA-co-AAm) nanogel, basic conditions (0.5N NaOH) were used to charge to gel, while complexation with the sodium counterions enabled collapse and collection in low dielectric constant conditions.…”

“…Polyionic nanogels are particularly interesting, as these nanoparticles with non‐neutral surface charge are generally stable in aqueous solutions and exhibit predictable responses around their pKa. Our group and others have extensively studied the use of polyanionic and polycationic nanogels for the pH‐responsive drug delivery of small molecules and macromolecular therapeutics in the treatment of cancer, ulcerative colitis, and numerous other diseases . Each of these systems functions by entrapping the payload in a buffer condition where therapeutic‐nanomaterial interactions are favorable, followed by a predictable shift toward unfavorable interaction in the destination's physiological environment.…”

“…Our group and others have extensively studied the use of polyanionic and polycationic nanogels for the pH-responsive drug delivery of small molecules and macromolecular therapeutics in the treatment of cancer, ulcerative colitis, and numerous other diseases. [7][8][9][10] Each of these systems functions by entrapping the payload in a buffer condition where therapeuticnanomaterial interactions are favorable, followed by a predictable shift toward unfavorable interaction in the destination's physiological environment. Alternate nanogel systems include temperature-responsive monomers such as N-isopropyl acrylamide, which allow for triggerable swelling and release profiles in response to hypothermic conditions.…”