Exosomes are lipid bilayer membrane vesicles and are emerging as competent nanocarriers for drug delivery. The clinical translation of exosomes faces many challenges such as massive production, standard isolation, drug loading, stability and quality control. In recent years, artificial exosomes are emerging based on nanobiotechnology to overcome the limitations of natural exosomes. Major types of artificial exosomes include ‘nanovesicles (NVs)’, ‘exosome-mimetic (EM)’ and ‘hybrid exosomes (HEs)’, which are obtained by top-down, bottom-up and biohybrid strategies, respectively. Artificial exosomes are powerful alternatives to natural exosomes for drug delivery. Researchers from Central South University outline recent advances in artificial exosomes through nanobiotechnology and discuss their strengths, limitations and future perspectives. The development of artificial exosomes holds great values for translational nanomedicine.
Main strategies for obtaining artificial exosomes based on nanobiotechnology
A Top-down strategies for generating nanovesicles (NVs) by manipulating cells. Cells can be forced to pass through membrane pores or microfluidic devices to form NVs; cells can be disrupted by nitrogen cavitation to form NVs; sulfhydryl-blocking can lead to the release of small NVs from cells by cell membrane blebbing; cells exposed to alkaline solution will be broken into membrane sheets, which can form small NVs by sonication. B bottom-up strategies for generating fully artificial exosomes by supramolecular chemistry; synthetic materials (lipids) and key components (proteins) from cells can be combined to form exosome-mimetics (EMs) by supramolecular chemistry. C Biohybrid strategies for generating hybrid exosomes by fusing exosomes with liposomes. Isolated natural exosomes and synthetic liposome nanoparticles can be fused into hybrid exosomes (HEs) without affecting their intrinsic properties.