β-lactam Functionalized Poly(isoprene-b-ethylene oxide) Amphiphilic Block Copolymer Micelles as a New Nanocarrier System for Curcumin

Curcumin is a natural compound with biological activities and potent anticancer effects that has the drawback of poor water solubility which leads to low bioavailability. In this work curcumin was formulated in new physicochemically characterized micellar carriers composed of new synthetic block copolymers. The study of the in vitro release rate of curcumin from the formulas, as well as the in vitro activity of free curcumin and of curcumin-loaded into micelles, against a panel of colorectal cancer cell lines was also part of this study. New β—lactam functionalized poly(isoprene-b-ethylene oxide) amphiphilic block copolymers, were synthesized by the combination of anionic polymerization and selective postpolymerization functionalization of the polyisoprene block with chlorosulfonylisocyanate. Micelles composed of the synthetic copolymers were formulated in order to incorporate curcumin. As the results revealed, increase in the percentage of the lipophilic block of micelles, led to higher encapsulation efficiency and loading capacity while the size was found to be smaller and the in vitro release rate slower. In vitro cytotoxicity results showed similar or slightly higher activity for curcuminloaded into micelles than free curcumin, a fact that could be attributed to the similar in vitro cellular uptake profiles of curcumin and of curcumin-loaded into micelles.