Self-assembling linear and star shaped poly(ϵ-caprolactone)/poly[(meth)acrylic acid] block copolymers as carriers of indomethacin and quercetin

Abstract

A amphiphilic linear AB, BAB, and star shaped (AB)3 block copolymers of poly(ϵ-caprolactone) (PCL)/poly(meth)acrylic acid (P(M)AA) are used for the preparation of nanoparticles and drug entrapment, where indomethacin and quercetin are employed as model drugs. Drug loading experiments with the nanoparticles based on PAA block copolymers demonstrate a higher efficiency for the star structure, whereas the PMAA star copolymer presents the lowest entrapment ability. The release properties are studied at room temperature and 37 °C in phosphate buffer solutions with pH equal to 5 and 7.4. The kinetic profiles show a strong relation to the copolymer's topology, indicating the lowest release rates from the star based superstructures, while the PMAA particles are less stable than those containing PAA segment(s).

Keywords: block copolymers; drug-loading; indomethacin; micelles; poly(ϵ-caprolactone); poly[(meth)acrylic acid]; quercetin.