Synthesis and swelling properties of pH‐ and temperature‐sensitive interpenetrating polymer networks composed of polyacrylamide and poly(γ‐glutamic acid)

Abstract

Novel hydrogels of interpenetrating polymer networks (IPNs) composed of polyacrylamide and poly(c-glutamic acid) were synthesized. In these systems, both polymers were crosslinked independently; this reduced the potential loss of a polymer during the washing process, as often occurs in semi-IPN systems. Interpolymer interactions were investigated with Fourier transform infrared spectroscopy and differential scanning calorimetry. These studies suggested possible interactions between both polymers by the formation of hydrogen bonds. The swelling behavior of these hydrogels was analyzed by immersion of the hydrogel samples in deionized water at 25 and 37 C and in buffer solutions with pHs of 3, 7, and 10. The kinetics of swelling showed increases in the values of the swelling ratio with increasing immersion time in the swelling medium, molar proportion of the biopolymer in the hydrogel, temperature, and pH of the swelling medium. All of the hydrogels swelled rapidly and reached equilibrium in an average time of 40 min.

Preparation and Characterization of Coaxial Electrospun Fibers Containing Triclosan for Comparative Study of Release Properties with Amoxicillin and Epicatechin

“…These results are consistent with the results reported by several authors [36][37][38][39]. As it is known, for the formation of a hydrogen bond, a hydrogen donor molecule and an acceptor are needed.…”

Kinetics of drug release from drug carrier of polymer/TiO2 nanotubes composite—pH dependent study

“…This resulted in a fast carprofen burst release (Figure ) similar to that of pure TiO 2 nanotubes (Figure ) at these two pH values. The slightly increased drug release rate at pH = 10.5 compared to that of pH = 7.4 for both drugs is due to the full ionization of PLGA at pH of 10.5, leading to a stronger electrostatic repulsion between the carboxylic groups as well as a higher degree of PLGA network swelling and water uptake . Consequently, the drug release was accelerated at pH = 10.5 compared to pH = 7.4.…”

“…The slightly increased drug release rate at pH 5 10.5 compared to that of pH 5 7.4 for both drugs is due to the full ionization of PLGA at pH of 10.5, leading to a stronger electrostatic repulsion between the carboxylic groups as well as a higher degree of PLGA network swelling and water uptake. 3,23,24 Consequently, the drug release was accelerated at pH 5 10.5 compared to pH 5 7.4. In contrast, at pH 5 7.4 and 10.5, lidocaine has much improved and slower burst release ( Figure 5) compared to that of without polymer Figure 3).…”

Multi-responsive hydrogels for drug delivery and tissue engineering applications

“…An IPN exhibits the individual stimuli responses of its constituents with the additional possibility of increased mechanical integrity, tunable network properties and cell compatibility [ 67 , 68 ]. Multi-responsive properties incorporated into IPNs include temperature response with biodegradability [ 60 , 69 , 70 ], pH-response and hydrophobicity [ 70 ], or the combination of temperature and pH response [ 71–75 ].…”

“…An IPN can be used to combine interesting properties of synthetic polymers, such as the swelling response of polyacrylamide (PAAm), with the biodegradability and biocompatibility of a biopolymer such as poly(γ-glutamic acid) (γ-PGA) [ 60 ]. The molar proportions of PAAm and γ-PGA were varied, resulting in temperature-dependent swelling that could be increased by incorporating more γ-PGA.…”