Preparation and characterization of nanostructured and high transparent hydrogel films with pH sensitivity and application

Abstract

Novel nanostructured, high transparent, and pH sensitive poly(2-hydroxyethyl methacrylate-comethacryliac acid)/poly(vinyl alcohol) (P(HEMA-co-MA)/ PVA) interpenetrating polymer network (IPN) hydrogel films were prepared by precipitation copolymerization of aqueous phase and sequential IPN technology. The first P(HEMA-co-MA) network was synthesized in aqueous solution of PVA, then followed by aldol condensation reaction, it formed multiple IPN nanostructured hydrogel film. The film samples were characterized by IR, SEM, DSC, and UV-vis spectrum. The transmittance arrived at 93%. Swelling and deswelling behaviors showed the multiple IPN nanostuctured film had rapid response. The mechanical properties of all the IPN films improved than that of PVA film. Using crystal violet as a model drug, the release behaviors of the films were studied. The results showed that compared with PVA, which had low drug loading and exhibited high and burst release, the three IPN films had high drug loading and exhibited sustained release. Besides, the release followed different release mechanism at pH ¼ 4.0 and pH ¼ 7.4, respectively.

Viscoelastic Behavior of Rubbery Materials

“…These are dilute aqueous IPNs, which react to changes in pH, temperature, or the presence of specific chemicals. Their biocompatibility, high water content, and ability to respond to stimuli have led to use of IPN hydrogels as biomaterials for tissue engineering [104,105,106] and for controlled drug delivery [107,108,109,110]. These materials, sometime confusingly referred to as double-network hydrogels, can exhibit enhanced performance [111,112,113,114].…”

Poly(2‐hydroxyethyl methacrylate) nanocomposites: From a nonionic gel to pH sensitivity

“…Such chemical and thermal stability make P(HEMA) hydrogels also suitable materials for development of controlled drug delivery systems [27, 28]. However, many of their potential applications are hindered by their limited water uptake [29], low mechanical strength, and slow response rate [30, 31]. Furthermore, the release of a drug through a network gel based on P(HEMA) is strongly affected by the water swelling capacity [27], and responsivity to the external conditions is of special importance for controlled release systems.…”

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“…In this process, at least one of the monomer must be hydrophilic to make them swellable, for example, triblock poly(ethylene glycol)-poly(ε-caprolactone)-poly(ethylene glycol), copolymer of glycerol, and polyethylene oxide of different molecular weights. [6] The interpenetrating polymeric hydrogels are produced by the penetration of one cross-linked network into another linear polymer without any other chemical bonds between them. Due to the absence of restricting interpenetrating elastic network, interpenetrating networks (IPNs) can further adequately secure rapid kinetic response rates to temperature or pH, for example, entrapment of linear cationic polyallyl ammonium chloride in acrylamide/ acrylic acid copolymer hydrogel.…”

“…The most important characteristic properties of the hydrogels that are needed to be evaluated before their applications are swelling behavior: One of the most important properties of hydrogels is its ability to absorb liquids (swelling thermodynamics) and the rate at which the hydrogels absorb the liquid (swelling kinetics). [6] Types of hydrogels Stimuli responsive hydrogels, pH responsive hydrogels, temperature responsive hydrogels, thermoreversible hydrogels, glucose responsive hydrogels, antigen-responsive hydrogels, light-sensitive system ion sensitive system, and magnetically responsive system. [2,6,7]…”