Mesenchymal stem cell-derived extracellular vesicles as next generation drug delivery platforms

Figure 2 Engineering strategies for therapeutic cargo loading in mesenchymal stem cell-derived extracellular vesicles. A: Passive loading methods allow diffusion of small hydrophobic drugs into minimal structure disruption; B: Active loading techniques enhance cargo encapsulation through transient membrane permeabilization; C: Genetic and biogenic modification of parental mesenchymal stem cells allow selective incorporation of therapeutic molecules during extracellular vesicle formation; D: Surface engineering using targeting ligands, polyethylene glycol chains, or antibodies improve circulation duration, targeting precision, cellular uptake and tissue specific delivery. EV: Extracellular vesicle; siRNA: Small interfering RNA; MSC: Mesenchymal stem cell; PEG: Polyethylene glycol.