Heteroarm Star-Shaped Poly (N-isopropylacryamide-co-itaconic acid) Copolymer Prepared by Glucose Core as ATRP Initiator

Abstract

Star-shaped temperature-and pH-sensitive poly (N-isopropylacryamide-co-itaconic acid) copolymer is synthesized by atom transfer radical polymerization (ATRP) using 1,2,3,4,6-penta-O-Isobutyrylbromide-a-D-glucose as 5-Arm ATRP Initiator. For ATRP of itaconic acid (IA), carboxylic groups of IA are protected via silylation by hexamethyldisilazane (HMDS) using Fe 3 O 4 as a magnetic catalyst. The polymerization is carried out in 2-propanol=toluene 50:50 (v=v) mixed solvent at 90 C. Structure of copolymers is studied with FT-IR, 1 H NMR, glass transition temperature (Tg), and scanning electron microscopy (SEM). Results of temperature, pH, and percentage variation on polymer structure and the effects on lower critical solution temperature (LCST), which is investigated with potentiometery and conductometry, show that LCST of copolymer is around body temperature and demonstrate the ability of this polymer in the design of controlled drug delivery systems. According to the obtained results from naltrexone release, the investigated star-shaped copolymer may have potential applications in the controlled release of drugs.

Preparation ofN-Isopropylacrylamide/Itaconic Acid Magnetic Nanohydrogels by Modified Starch as a Crosslinker for Anticancer Drug Carriers

“…Stimuli-responsive hydrogels response to environmental signals such as temperature, pH, ionic strength, and electric and magnetic fields [5][6][7]. Among the stimuli-responsive hydrogels, the poly(N-isopropylacrylamide) (PNIPAAm) based hydrogel sphere is the most popular temperature-responsive because it exhibits thermally reversible shrinkage or collapse above the lower critical solution temperature (LCST) in water [8][9][10][11] When the PNIPAAm based nanoparticles are used as drug carriers, the released drug amount could be autocontrolled by external temperature changes to significantly improve the curative effect and=or eliminate the side effect of the applied drug [12]. However, the PNIPAAm hydrogel is not a favored matrix for biomedical applications because of its transition temperature, lack of bioactivity and biodegradability.…”

Hydrogels for ocular drug delivery and tissue engineering

“…It should be noted that incorporation of more hydrophilic moieties (e.g., itaconic acid) with PNIPAAm hydrogel can literally bestow pH sensitivity and enhance the LCST of PNIPAAm hydrogel. 18 …”

Synthesis of Methylacryloypropyl-POSS/Poly(fluorine-acrylate) Core-Shell Nanocomposites and Effect on Thermal Properties of Materials

“…Zhang et al [18] and Saleh-Ghadimi et al [19] had reported the synthesis via RAFT polymerization of tadpoleshaped organic/inorganic hybrid POSS-containing poly(acrylic acid). Wang et al [20] had reported the synthesis of core-shell particles by batch emulsion polymerization of styrene and octavinyl-POSS.…”