Preparation and Evaluation of a Sulfadimethoxine‐Conjugated Hydrogel Based on N‐isopropylacrylamide as a Sustained Release Drug Delivery System

Abstract

The burst release of drugs limited the development of the thermo-responsive hydrogels based on poly N-isopropylacrylamide (NIPAAm) for application in drug delivery systems. To overcome this problem, the drug sulfadimethoxine (SDMO) was conjugated via amide bond to the PNIPAAm hydrogel instead of loaded into the system. Therefore, SDMO was modified using maleic anhydride to get N-maleyl sulfadimethoxine (NMSDMO) and then utilized that to synthesize the sulfadimethoxineconjugated PNIPAAm hydrogel (P[NIPAAm-co-NMSDMO]). The resultant monomer was then grafted into the hydrogel network at different weight percentage through radical polymerization. The NMSDMO monomer and the P[NIPAAm-co-NMSDMO] hydrogels were fully investigated. The in vitro drug released displayed sustained release in pH 5 and 7.4 for 24 h. Hydrolysis of the amide bond causes the release rate and total amount of drug to be greatest at pH 5, as compared to pH 7.4. As a result, the P[NIPAAm-co-NMSDMO] hydrogel was an effective sustained drug delivery system.

Synthesis, Self‐Assembly and Drug Controlled Releasing Performance of Triple Responsive Ternary Copolymer Micelles

“…[3] At present, according to the different drugs and releasing environment, a variety of drug-controlled releasing systems have been studied. [4] In general, there are osmotic pump oral drugs, micro drop capsules, liposomes, hydrogels, and stimulusresponsive polymer micelles. [5][6][7][8] As a kind of intelligent macromolecule, the stimulus-responsive polymer micelle can change its structure or morphology according to the external environment, which attracts more and more attention from researchers because of its wide application.…”

“…At present, according to the different drugs and releasing environment, a variety of drug‐controlled releasing systems have been studied [4] . In general, there are osmotic pump oral drugs, micro drop capsules, liposomes, hydrogels, and stimulus‐responsive polymer micelles [5–8] .…”

Synthesis and Characterization of Temperature‐/pH‐Responsive Hydrogels for Drug Delivery

“…NIPAm and its polymers can undergo a sharp bulk phase transition at the lowest phase transition temperature (32 °C). [30][31][32] Hydrophilic monomers are usually accessed to increase the lowest phase transition temperature of N-isopropyl acrylamide to approach the body temperature, such as OEGA. IA is an important effector molecule of the body's endogenous immune system.…”

“…NIPAm is the most common monomer for the preparation of intelligent hydrogels. NIPAm and its polymers can undergo a sharp bulk phase transition at the lowest phase transition temperature (32 °C) [30–32] . Hydrophilic monomers are usually accessed to increase the lowest phase transition temperature of N‐isopropyl acrylamide to approach the body temperature, such as OEGA.…”

Advanced superparamagnetic cross‐linked chitosan‐based biosorbent hydrogel for efficient removal of indigo carmine dye from water: Adsorption isotherms, kinetics, and thermodynamic studies

“…22,23 Hydrogels are cross-linked polymeric networks in three dimensions that can absorb large volumes of water or biological fluids without disintegration. 24,25 Natural polymer-based hydrogels are getting a lot of interest because biopolymer hydrogels are better due to their nontoxicity, biodegradability, and biocompatibility. 26,27 Chitosan (Cs), a carbohydrate biopolymer made by deacetylation of crustacean chitin, is an excellent biosorbent because of its low cost and biocompatibility.…”