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Artemisinin (ART) is a natural anti-malarial sesquiterpene lactone with anticancer properties, but its application is limited because of its low water solubility. To increase the bioavailability and water solubility of ART, we synthesized three series of poly (ɛ-caprolactone)-poly (ethylene glycol)-poly (ɛ-caprolactone) (PCL-PEG-PCL) tri-block copolymers. The structure of the copolymers was characterized by HNMR, FTIR, DSC and GPC techniques. ART was encapsulated inside micelles by a nanoprecipitation method which leading to the formation of ART/PCL-PEG-PCL micelles. The obtained micelles were characterized by DLS and AFM technique. The results showed that the average size of micelles was about 83.22 nm. ART was encapsulated into PCL-PEG-PCL micelles with encapsulation efficacy of 89.23 ± 1.41%. In vivo results demonstrated that this formulation significantly increased drug accumulation in tumours. Pharmacokinetic study in rats revealed that in vivo drug exposure of ART was significantly increased and prolonged by intravenously administering ART-loaded micelles when compared with the same dose of free ART. The MTT assay showed that bare PCL-PEG-PCL micelles is non-toxic to MCF7 and 4T1 cancer cell lines whereas the ART/PCL-PEG-PCL micelles showed a specific toxicity to both cancer cell lines. Therefore, the polymeric micellar formulation of ART based copolymer could provide a desirable process for ART delivery.

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Background: Artemisinin is a sesquiterpene lactone chemical extract from Artemisia annua, is poorly resolvable in water and a fast-acting blood active in treating the acute attack of malaria. Methods: Artemisinin was encapsulated within mPEG-PCL micelles with a single-step nano-precipitation method, leading to formation of ART/ mPEG-PCL micelles. mPEG-PCL copolymers was characterized in vitro by HNMR, FTIR and DSC techniques. Copolymers with artemisinin were self-assembled into micelles in aqueous solution. The consequential micelles were further characterized by various techniques such as DLS and AFM. Results: The results exhibited the successful formation of spherical artemisinin-loaded micelles. The artemisinin-loaded micelles showed high loading efficiency. The encapsulation efficiency of artemisinin was 63±2.31%. In vitro release of artemisinin from artemisinin-entrapped micelles followed remarkably sustained release profile. Conclusion: The results indicated that the successful formulation of artemisinin loaded mPEG-PCL micelles can improve the drug delivery of artemisinin. The results showed that nanomicelles can be promising drug delivery systems for sustaining release of artemisinin.