Dual-Responsive pH and Temperature Sensitive Nanoparticles Based on Methacrylic Acid and Di(ethylene glycol) Methyl Ether Methacrylate for the Triggered Release of Drugs

Abstract

A series of thermo-and pH-responsive poly(methyl methacrylate)-block-poly[methacrylic acid-co-di(ethylene glycol) methyl ether methacrylate] PMMA-b-P[MAA-co-DEGMA] block copolymers were synthesized by RAFT polymerization and self-assembled into micelles. The molar ratio of MAA was altered from 0-12% in order to modulate the lower critical solution temperature (LCST) of PDEGMA. The release of the drug albendazole from the micelle was strongly dependent on the temperature and the LCST value of the polymer. Systems below the LCST released the drug slowly while increasing the temperature above the LCST or decreasing the pH value to 5 resulted in the burst-like release of the drug. ABZ delivered in this pH-responsive drug carrier had a higher toxicity than the free drug or the drug delivered in a non-responsive drug carrier.

Synthesis of inositol‐based star polymers through low ppm ATRP methods

“…). The chemical shifts, 0.55–1.38, 1.40–2.15, 3.25–3.50, 3.51–3.90, and 3.91–4.35 ppm, are mainly ascribed to the –C H 3 (α), −C H 2 – (β), −OC H 3 (e), −O–C H 2 – (d), and –O–CH 2 –C H 2 –OCO– (c) groups of PDEGMA arms, respectively, indicating the presence of PDMAEMA chains …”

“…A star block six‐arm star block copolymer with a meso ‐inositol‐based core and block copolymer arms composed of amphiphilic PDEGMA‐ b ‐PMMA have been synthesized for the first time using only 30 ppm of Cu catalytic complex, following the ARGET ATRP, SARA ATRP, and se ATRP procedures (Table ). Until now, PDEGMA‐ b ‐PMMA block copolymers were synthesized mainly by RAFT, or by ATRP, but always with very high amounts of catalyst (up to 71,200 ppm).…”

“…In the 1 H NMR spectrum (Fig. ) of Ino‐(PDEGMA 51 ‐ b ‐PMMA 30 ‐Br) 6 star block copolymer (Table , entry 7), the chemical shifts, 0.55–1.38, 1.40–2.15, and 3.51–3.90 ppm, are primarily attributable to the –CH 3 (α′), –CH 2 – (β′), and –OCH 3 (f) of PMMA units, denoting the inherence of PMMA segments …”

“…Until now, synthesis of meso ‐inositol‐centered star polymers composed of poly(di(ethylene glycol) methyl ether methacrylate) (PDEGMA) and poly(methyl methacrylate) (PMMA) has not yet been reported. Meanwhile, PDEGMA‐ b ‐PMMA block copolymers were synthesized only by RAFT and ATRP techniques, but always with significant amounts of catalyst (even up to 71,200 ppm). It is expected that these received amphiphilic star copolymers have potential in biomedical applications, including thermo‐responsive drug delivery systems, biosensors, polymer–protein conjugates, and tissue engineering solutions.…”

“…It is expected that these received amphiphilic star copolymers have potential in biomedical applications, including thermo‐responsive drug delivery systems, biosensors, polymer–protein conjugates, and tissue engineering solutions. PDEGMA is one of the most important temperature‐responsive polymer, which exhibits a reversible lower critical solution temperature‐type phase transition in aqueous solution because of the differential solvation of water‐soluble di(ethylene glycol) moieties and water‐insoluble polymethacrylate backbone segment . PDEGMA‐based polymers offer anti‐immunogenicity, non‐toxicity, and biocompatibility coupled with its facile synthesis technique by ATRP under simple, cost‐effective, and environmentally benign conditions .…”