Small angle neutron scattering study of doxorubicina€“surfactant complexes encapsulated in block copolymer micelles

摘要

Self-assembling behaviour of block copolymers and their ability to evade the immune system through polyethylene oxide stealth makes it an attractive candidate for drug encapsulation. Micelles formed by polyethylene oxidea€“polypropylene oxidea€“polyethylene oxide triblock copolymers (PEOa€“PPOa€“PEO), pluronic P123, have been employed for encapsulating the anti-cancer drug doxorubicin hydrochloride. The binding affinity of doxorubicin within the micelle carrier is enhanced through complex formation of drug and anionic surfactant, aerosol OT (AOT). Electrostatic binding of doxorubicin with negatively charged surfactants leads to the formation of hydrophobic druga€“surfactant complexes. Surfactant-induced partitioning of the anti-cancer drug into nonpolar solvents such as chloroform is investigated. SANS measurements were performed on pluronic P123 mi-celles in the presence of druga€“surfactant complex. No significant changes in the structure of the micelles are observed upon drug encapsulation. This demonstrates that surfactanta€“drug complexes can be encapsulated in block copolymer micelles without disrupting the structure of aggregates.