Novel poly(N‐isopropylacrylamide)/clay/poly(acrylamide) IPN hydrogels with the response rate and drug release controlled by clay content

Abstract

Novel interpenetrating network (IPN) hydrogels (PNIPAAm/clay/PAAm hydrogels) based on poly(N-isopropylacrylamide) (PNIPAAm) crosslinked by inorganic clay and poly(acrylamide) (PAAm) crosslinked by organic crosslinker were prepared in situ by ultraviolet (UV) irradiation polymerization. The effects of clay content on temperature dependence of equilibrium swelling ratio, deswelling behavior, thermal behavior, and the interior morphology of resultant IPN hydrogels were investigated with the help of Fourier transform infrared spectroscopy, differential scanning calorimeter (DSC), scanning electron microscope (SEM). Study on temperature dependence of equilibrium swelling ratio showed that all IPN hydrogels exhibited temperature-sensitivity. DSC further revealed that the temperature-sensitivity was weakened with increasing amount of clay. Study on deswelling behavior revealed that IPN hydrogels had much faster response rate when comparing with PNIPAAm/ clay hydrogels, and the response rate of IPN hydrogels could be controlled by clay content. SEM revealed that there existed difference in the interior morphology of IPN hydrogels between 20 [below lower critical solution temperature (LCST)] and 50 C (above LCST), and this difference would become obvious with a decrease in clay content. For the standpoint of applications, oscillating swelling/deswelling behavior was investigated to determine whether properties of IPN hydrogels would be stable for potential applications. Bovine serum albumin (BSA) was used as model drug for in vitro experiment, the release data suggested that the controlled drug release could be achieved by modulating clay content. V V C 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: [96][97][98][99][100][101][102][103][104][105][106] 2009

Synthesis and properties of thermo- and pH-sensitive poly(diallyldimethylammonium chloride)/poly(N,N-diethylacrylamide) semi-IPN hydrogel

“…The slower and smaller magnitude of the oscillatory action of PDEA would limit its potential applications in such areas like the on-off switches for controlled drug release [16]. This faster and larger magnitude of oscillating responses from semi-IPN hydrogels may be advantageous for practical applications in many fields such as bioengineering and biotechnology because faster response kinetics of the oscillating deswelling-swelling property of hydrogels to small temperature cycles (e.g.…”

“…cycled around the physiologic temperature) of the hydrogel are important, which would be stable for potential applicants. So it is necessary to investigate the oscillating deswelling-swelling kinetics in response to the temperature changes around the body temperature [16,35]. Fig.…”

“…Moreover, the method has been reported to present some possible advantages. For example, the process of preparation is simple and feasible, and the combination of temperature response with other properties can retain its individual response behavior [15][16][17].…”

Synthesis and characterization of polyhedral oligomeric silsesquioxane hybrid co‐crosslinked poly(N‐isopropylacrylamide‐co‐dimethylaminoethyl methacrylate) hydrogels

“…So far, owing to the perfect reactivity, acute responsibility, available, and tunable lower critical solution temperature ( LCST) of NIPA monomer, the frequently used method for preparing temperature and pH double‐responsive hydrogels was to add the ionic segments into PNIPA gels. Many pioneers have focused on this subject, typically, the ionic monomer acrylic acid (AAc) and PAAc was added into PNIPA gels by copolymerization, graft and linear polymer penetrating networks (semi‐IPNs) techniques, which could achieve the introduction of pH sensitiveness into the thermo‐sensitive gels . However, the incorporation of pH sensitivity might ruin the thermosensitivity of the copolymerized hydrogel and a high content of comonomer might lead to the complete suppression of thermosensitivity .…”

Desenvolvimento de uma membrana nanoestruturada à base de poliacrilamida para veiculação de proteínas

“…A poliacrilamida (poli-2-propenamida) é formada por unidades de acrilamida (Figura 6), as quais a constituem em um polímero termosensível amplamente utilizado para síntese de hidrogéis (BURILLO & OGAWA, 1986;GUILHERME et al, 2003;SANCHEZ-DÍAZ et al, 2006;BARDAJEE et al, 2008;LI et al, 2008;ZHAO et al, 2010, CLOUTIER et al, 2013. Sua massa molar é de 2,5.…”