Bleomycin loaded exosomes enhanced antitumor therapeutic efficacy and reduced toxicity

Bleomycin (BLM) is a chemotherapeutic agent with potent antitumor activity against the tumor. However, lung fibrosis is the main drawback that limits BLM use. Tumor targeted, safe, efficient and natural delivery of BLM is important to increase the effectiveness and reduce the toxic side effects. Although tumor derived Exosomes (Exo), provide a potential vehicle for in vivo drug delivery due to their cell tropism. This study primarily focuses on generating a natural delivery platform for Exo loaded with BLM and testing its therapeutic efficacy against cancer.Exosomes were isolated from cancer cells and incubated with BLM. Exo were characterized by transmission electron microscopy, western blot analysis and nanoparticle tracking analysis. We performed in vitro and in vivo analyses to evaluate the effect of Exo-BLM.Exosomes loaded with BLM are highly cancer targeting and cause the cytotoxicity of tumor cells by ROS. The fluorescence images showed that Exo-BLM accumulated in cancer cells. The results revealed that Exo-BLM induces tumor cell apoptosis by the caspase pathway. In vivo, the treatment of Exo-BLM showed targeted ability and enhanced the antitumor activity.This study provides an avenue for specific BLM therapeutics with minimal side effects.