Temperature‐responsive alginate‐g‐poly(N,N‐diethylacrylamide) copolymer: Synthesis, characterization, and swelling behavior

Abstract

Temperature‐responsive polymers have recently gained importance due to their applications in drug delivery. Herein, temperature‐responsive graft copolymer (Alg‐g‐PDEAAm) of alginate and N,N‐diethylacrylamide was synthesized by microwave‐assisted copolymerization using potassium persulfate/N,N,N′,N′‐tetramethylethylenediamine initiator system. The reaction conditions for the best grafting (331%) have been optimized by changing microwave irradiation time, temperature, N,N‐diethylacrylamide, and alginate concentrations. The spectroscopic characteristic, thermal properties, and surface morphology of the copolymers were investigated by FTIR, 1H‐NMR, DSC/TGA, XRD, gel permeation chromatography, and SEM. Furthermore, low critical solution temperatures of Alg‐g‐PDEAAm copolymers were detected by UV spectroscopy. Swelling ratio of graft microspheres was carried out at 25, 32, and 37 °C, and microspheres were found exhibiting temperature‐responsive property. Cytotoxicity test indicated the Alg‐g‐PDEAAm copolymer and its microsphere were biocompatible. Therefore, based on the results the synthesized temperature‐responsive copolymer could be considered as a promising biomaterial. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46688.

Simple Radical Polymerization of Poly(Alginate‐Graft‐N‐Isopropylacrylamide) Injectable Thermoresponsive Hydrogel with the Potential for Localized and Sustained Delivery of Stem Cells and Bioactive Molecules

“…The PNIPAAm polymer showed a two-stage degradation profile at 98 and 408 °C. [14,15] The reduction in mass until 98 °C corresponded to the evaporation of the water molecules and beyond 408 °C was indicative of decomposition. The NaAlg also exhibited multistage degradation.…”

“…Copolymerization also plays an important role in biocompatibility and biodegradability, which are essential in targeted tissue engineering and biomaterials related applications. [12][13][14][15][16] Sodium alginate (NaAlg) is a natural polysaccharide that is extracted from brown seaweeds. [10] Alginic acid is an anionic biopolymer consisting of linear chains of α-l-glucuronic acid and β-d-mannuronic acid with properties such as a high degree of aqueous solubility, a tendency for gelation when reacted with divalent cations-the resulting gels demonstrating high porosity, biocompatibility, and nontoxicity.…”

Preparation of pH‐sensitive hydrogels by graft polymerization of itaconic acid on tragacanth gum

“…3 A large number of biopolymers have been grafted with monomers to create pH-sensitive hydrogel matrices. [4][5][6][7][8][9][10][11][12] However, the choice of biopolymer as base matrix has a significant impact in terms of its physical characteristics and its impact on the grafting process. TG is one such biopolymer with a complex structure and may offer interesting features for creating graft copolymers for targeted drug delivery.…”

“…27,28 This has attracted polymer scientists to develop polymers with carboxyl functionality for bonding with various other moieties. 10,11,13,21,29 Our recent studies on the grafting of IA on TG were undertaken using microwave initiation leading to relatively high graft levels for controlled drug delivery. 26,30 However, it seems that the microwave approach may not be attractive enough for the formulation of pH-sensitive smart materials as evident from the outcome of drug release at a pH of 2.5 and 7.4.…”

“…31 There are several studies where IA has been used to graft biopolymers using chemical methods for various applications, such as super absorbency and drug delivery. 10,11 We observe that most of the published work relating to TG graft copolymers is dedicated to their broad range of applications without much focus on the kinetic parameters and their impact on the physicochemical structure of the grafted matrix. We understand that graft management within a grafted matrix may influence the properties of the material and there is a need for proper evaluation of the structure and its correlation with physical characteristics.…”