Exosome-drug conjugates delivery: a promising strategy for ameliorating the pharmacokinetic profile of artesunate

Artesunate (ATS) is considered the most widely employed artemisnin derivative in the treatment of <i>Plasmodium falciparum</i> malaria. However, poor solubility and low bioavailability of ATS limit its further clinical application. Herein, we developed a new strategy based on the exosome (exo) - drug conjugation (EDC) using the milk-derived exosomes for ATS delivery. The Exo-ATS conjugates (EACs) which formed via a facile bio-conjugation of ATS to the exosomal surface, have been demonstrated to be able to not only boost the solubility and bioavailability of ATS but also enable a sustained-release of ATS from exosomes. Maximal improvement of 71.4-fold in the solubility of ATS was attained by EACs. The corresponding entrapment efficiency and drug loading capacities were found to be 90.3% and 73.9% for EACs, respectively. Further, <i>in vivo</i> pharmacokinetics study manifested that maximum 2.6-fold improved bioavailability of ATS was achieved by oral delivery of EACs. Moreover, EACs displayed a distinct sustained-release profile of maximum 36.2-fold prolonged half-life of ATS via intravenous delivery. We reported that for the first time the administration of EACs could be a potential drug delivery strategy aimed at ameliorating the pharmacokinetic profile of ATS based on our encouraging results and hoped that our work opened up a new avenue for the development of EDC delivery system.