Milk-exosome based pH/light sensitive drug system to enhance anticancer activity against oral squamous cell carcinoma.

A multimodal drug delivery system targeting the tumor microenvironment is an inspiring method for treating cancer tissues, including oral squamous cell carcinomas (OSCC). Such approaches require an efficient and safe drug carrier. Bovine milk derived exosomes are ideal because the source is adequate and have advantages of both synthetic and cell-mediated nano carriers. In the present study, we developed a pH/light sensitive drug system based on milk-exosomes for OSCC therapy. It was called exosome-doxorubicin-anthracene endoperoxide derivative (Exo@Dox-EPT1, NPs). Milk-exosomes were conjugated to doxorubicin (Dox) by a pH-cleavable bond, which can rapture under an acidic microenvironment. Besides, endoperoxides and chlorin e6 (Ce6) were also loaded and the endoperoxides undergo thermal cycloreversion and release singlet oxygen to kill cancer cells. We have also investigated the body distribution, antitumor effects, and biocompatibility of the nanoparticles. The new milk-exosome-based drug delivery system showed controlled drug-release, biocompatibility and, proved to be effective in treating OSCC.