Controlled release of anticancer drugs, proteins and liposomes by polymeric microspheres

Abstract

Abstract: Polymeric microspheres were used as a versatile tool for controlled release of not only individual molecules but supramolecular structure. An anticancer drug paclitaxel (water-insoluble and small molecule) and a protein HSA (water-soluble and macromolecule) were encapsulated into polymeric microspheres by single emulsion and double emulsion techniques, respectively. The effects of materials of different hydrophobicity on the physicochemical properties of the resulted devices were investigated. PLA-PEG-PLA as the polymer, ethyl acetate/acetone as the solvent, and Vitamin E TPGS as the additive showed interesting results in adjusting/improving the microsphere properties. Liposomes, a self-assembly of lipid molecules, were incorporated into polymeric microspheres to form liposomes-in-microsphere (LIM), a novel device combining polymer-based and lipid-based delivery systems. The integrity of liposomes after being encapsulated and released from the microspheres was maintained by modifying the microencapsulation process and liposome structure. The release of liposomes from LIMs was controllable by the properties of liposomes and microspheres.