Fig. 4

Approaches to constructing biomimetic exosome-like nanoparticles. Approaches to constructing biomimetic exosome-like NPs, which can be used as an alternative to natural exosomes, include: a generation of exosome-mimetic nanovesicles through direct extrusion of progenitor cells through porous membranes or by forcing them to move through microfluidic devices (a, a top-down approach). Preparation of synthetic exosome-like NPs using a synthetic strategy inspired by natural exosomes that involves self-assembly of synthetic phospholipid bilayers with specific antibodies, peptides, or surface proteins from biomembranes (b, a bottom-up approach). Fabrication of hybrid exosome-like nanovesicles by fusion of nanovesicles (natural exosomes or cell membrane nanovesicles) with synthetic liposomes through a top-down approach (c), or by fusion of two or more different biomembranes to generate hybrid membranes that incorporate multiple functionalities of different membrane types, and generation of exosomal-membrane- or cell membrane-coated NPs by coating NP cores with biomembranes (exosomal membranes or cell membrane nanovesicles, respectively) via top-down approaches (d). NP nanoparticle