Exosome membrane-coated nanosystems: Exploring biomedical applications in cancer diagnosis and therapy

Bio-mimicking principles have recently been proposed for the surface \nfunctionalization of nanoparticles (NPs). Such a strategy is \nbased on camouflaging the NP surface with functional biomembranes \nto render superior biocompatibility, interfacial features, \nimmune evasion, and active targeting properties to nanomaterials. \nIn this area of research, cell membranes derived from a \nplethora of highly optimized cells, such as red blood cells, immune \ncells, platelets, stemcells, cancer cells, and others, have been the pioneers \nas coatingmaterials. This biomimetic concept has then been \napplied to subcellular structures, namely extracellular vesicles and \nintracellular organelles. Exosomes are a nanosized extracellular \nvesicle subtype secreted by most cells. These phospholipid bilayer \nnanovesicles are surface enriched with proteins accounting for \ntheir dynamic and prominent roles in immune escape, cell-cell \ncommunication, and specific cell uptake. Their intrinsic stability, biocompatibility, \nreduced immunogenicity and toxicity, and specific \ncell-targeting features denote an optimal biological nanocarrier \nfor biomedical applications. This review highlights the current \nclinical applications of exosome membrane-coated nanosystems in \ncancer diagnosis and therapy. These biomimetic nanosystems \nhave emerged as a promising avenue to provide effective, highly \nspecific, and safer cancer-targeted applications. Finally, challenges \nhindering their clinical application will be mentioned.