Effect of Pluronic F127 on the 3D pore morphology of poly(N‐isopropylacrylamide‐co‐acrylic acid) hydrogels and their nitric oxide release from S‐nitrosoglutathione

Abstract

AbstractChanging the pore morphology of hydrogels can be an effective strategy to modulate their drug release profiles. Herein, Pluronic F127 was used to change the three‐dimensional pore morphology of crosslinked poly(N‐isopropylacrylamide‐co‐acrylic acid) (P[NIPAm‐co‐AAc]) hydrogels. F127 reduced the pore diameters from 20 ± 4 to 2.9 ± 0.4 μm and from 11 ± 1 to 1.4 ± 0.4 μm in hydrogels synthesized at 8 and 30°C, respectively. Small‐angle X‐ray scattering indicates that the segregation of the F127 during the polymerization process induces F127 phase transitions from unimers (at 8°C) or cubic‐packed micelles (at 30°C) to a lamellar structure. P(NIPAm‐co‐AAc) hydrogels charged with S‐nitrosoglutathione (GSNO), released nitric oxide (NO) spontaneously during hydration. The decrease in the pore diameter led to a twofold to threefold increase in the rate of water absorption and a fourfold to sixfold increase in the rate of NO release of the hydrogels. F127 can be used to change the pore morphology of P(NIPAm‐co‐AAc) hydrogels, with concomitant changes in their rate of hydration and NO release from GSNO, opening a new perspective for their use in topical NO delivery.