Preconditioning and Engineering Strategies for Improving the Efficacy of Mesenchymal Stem Cell-Derived Exosomes in Cell-Free Therapy

Figure 4

Three common strategies for membrane surface modification of MSC-exosomes include genetic engineering, chemical modification, and membrane fusion. Genetic engineering fuses gene sequences of guidance proteins or peptides with those of selected exosomal membrane proteins and can effectively display specific guidance peptides and proteins on the exosomal surface. In contrast, chemical modifications display a variety of natural and synthetic ligands or receptors on the membrane surface through covalent or noncovalent modifications. Membrane fusion uses extrusion to fuse exosomes with other membrane structures, an approach that confers new functional and therapeutic benefits to them.