Self-assembled hybrid multilamellar vesicles of phospholipids and block copolymers for efficacious delivery of insoluble drugs to cells

A surprisingly high number of drugs (>70%) emerge as insoluble compounds. Paclitaxel is aneffective chemotherapeutic drug against many forms of cancer. However, low solubility and crystallization inaqueous environments have compromised its efficacious clinical use. A promising strategy is to encapsulatepaclitaxel in drug carriers such as polymer or lipid membranes. Previous work on multilayered lipid–polymerhybrid films have shown to accommodate large paclitaxel loads and suppress crystallization. A hybrid materialcomposed of phospholipids and amphiphilic block copolymers display synergistic structural, phase-separation,and dynamical properties not seen in pure components. Using a combination of confocal laser scanningmicroscopy and X-ray scattering it is possible to, for the first time, directly monitor the formation of lipid-rich andblock copolymer-rich phase-separated domains and prove the existence of nano and microscopic domainformation in lipid-polymer hybrid multilamellar vesicles. To date, the physical and molecular factor governingthe phase separation in these hybrid polymer/lipid membranes are only partially understood. Accordingly, thiswork offers new perspectives in reaching and understanding controlled formation of novel hybrid vesicles forsmall-drug delivery systems.