Amphiphilic copolymer brush with random pH-sensitive/hydrophobic structure: synthesis and self-assembled micelles for sustained drug delivery

• DOI: 10.1039/c1sm06314f
• Publication Date: 2011-10-31T11:30:47Z
• Authors: You Qiang Yang; Xin Dong Guo; Wen Jing Lin; Li Juan Zhang; Can Yang Zhang; Yu Qian
• Keywords: Atom-transfer radical-polymerization

A random hydrophobic/pH-sensitive copolymer brush poly(polylactide methacrylate-co-methacrylic acid)-b-poly(poly(ethylene glycol) methyl ether methacrylate) [P(PLAMA-co-MAA)-b-PPEGMA] and its self-assembled micelles were developed for oral administration of hydrophobic drugs. The polymer was synthesized by the combination activators regenerated electron transfer atom radical polymerization (ARGET ATRP) ring opening (ROP). CMC P(PLAMA-co-MAA)-b-PPEGMA in aqueous solution extremely low (about 1.5 mg L−1). blank drug-loaded spherical morphology had an average size 160–220 nm, determined DLS SEM. Ibuprofen (IBU) selected as model drug encapsulated into core via a dialysis method. vitro release behavior IBU from these pH-dependent. In simulated gastric fluid (SGF, pH 1.2), cumulative less than 25% initial content over 24 h, suggesting that can be well protected harsh environment stomach. While intestinal (SIF, 7.4), ionization carboxyl groups MAA contributed to swelling micelle structure, which could accelerate micelles. 35–45% released 8 60% 100% after 56 h P(PLAMA6.3k-co-MAA3k)-b-PPEGMA4k micelles, it 50% 2 90% 10 14 P(PLAMA6.3k-co-MAA4.5k)-b-PPEGMA4k with increased MAA. All results indicate pH-sensitive may potential delivery carrier drugs sustained release.