Synthesis and characterization of amphiphilic star-shaped copolymers based on β-cyclodextrin for micelles drug delivery.

PURPOSE: A series of β-CD amphiphilic star-shaped copolymers with exceptional characteristics were synthesized and their potential as carriers for micelles drug delivery was investigated.

METHODS: A series of amphiphilic copolymers based on β-CD were synthesized by introducing poly (acrylic acid)-co-poly(methyl methacrylate)-poly (vinyl pyrrolidone) or poly (acrylic acid)-co-poly(methyl methacrylate)-co-poly(monoacylated-β-CD)-poly (vinyl pyrrolidone) blocks to the primary hydroxyl group positions of β-CD. The micellization behavior of the copolymers, the synthesis conditions, characteristics, drug release in vitro and tissue distribution of vinpocetine (VP) micelles in vivo were investigated.

RESULTS: Around 60 types of β-CD amphiphilic star-shaped copolymers were successfully synthesized and the critical micelle concentration ranged from 9.80 × 10-4 to 5.24 × 10-2 g/L. The particle size, drug loading and entrapment efficiency of VP-loaded β-CD-P4 micelles prepared with optimal formulation were about 65 nm, 21.44 ± 0.14%, and 49.05 ± 0.36%, respectively. The particles had good sphericity. The cumulative release rates at 72 h of VP-loaded β-CD-P4 micelles in pH 1.0, pH 4.5, pH 6.5, or pH 7.4 media were 93%, 69%, 49%, and 43%, respectively. And, the lung targeting efficiency of VP-loaded β-CD-P4 micelles was 8.98 times higher than that of VP injection.

CONCLUSION: The VP-loaded β-CD-P4 micelles exhibited controlled-release property, pH-induced feature and lung targeting capacity compared with VP injection, suggesting that the β-CD-P4 copolymers are an excellent candidate for micelles drug delivery.