Design and in vitro evaluation of delivery systems for co-delivery of siRNA and proteins by mimetic exosomes / 药学学报

To prepare the mimetic exosomes and co-delivery proteins and nucleic acids, and achieve efficient and safe co-delivery of multi-component drugs, an optimized formulation was designed by modifying a polylactic acid-glycolic acid copolymer (PLGA) matrix with a cationic lipid excipient dioleyl trimethylammonium propane (DOTAP), and a PLGA/DOTAP nanoparticles packaged protein and nucleic acid was prepared by double emulsion method, and the outermost membrane structure prepared by reverse phase evaporation method and consists of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC), cholesterol and membrane proteins. The structure of the mimetic exosomes is formed by ultrasonic dispersion and extrusion, and analyzed its characteristics and nature of the transfer effect. The size of mimetic exosomes was about 156.13 nm, with negative charge (-18.23 ± 0.57 mV), and it could efficiently co-transfer protein and siRNA, and siRNA could effectively inhibit the expression of target gene Trim28. The mimetic exosomes simulate the structure of exosomes and achieve safe and efficient co-delivery of multi-component drugs.

The role of stem cell-derived exosomes in repairing myocardial injury / 生理学报

At present, it is generally believed that the paracrine effect of stem cells in the repair of myocardial injury is one of the important ways for stem cell therapy. Exosomes are phospholipid bilayer-enclosed nanovesicles that secreted by cells under physiological and pathological conditions. Cargo loaded into exosomes including protein, lipids and nucleic acids can be delivered to recipient cells. Therefore, exosomes are recognized as important mediators for intercellular communication. It has been suggested that exosomes from stem cells (eg. embryonic stem cells, induced pluripotent stem cells, cardiac progenitor cells, mesenchymal stem cells and cardiosphere-derived cells) have protective effects against heart injury. In this review, we summarized recent research progresses on stem cell-derived exosomes in myocardial injury, including the therapeutic effects and mechanism.

Exosomes from LPS treated mesenchymal stem cells regulate proportion of Ly6C monocyte population / 中国药理学通报

Aim To determine the effect of exosomes from lipopolysaccharide-treated human bone marrow mesenchymal stem cells on proportion of Ly6Chigh and Ly6Clow monocytes/macrophages in inflammatory micro- environment. Methods BMSCs were obtained by gra-dient centrifugation, identified and then treated with li-popolysaccharide for 48 h. The exosomes were purified from conditional medium with or without LPS treatment and identified by CD63 protein using Western blot and transmission electron microscope. The diameters and concentration were detected by Nanoparticle Trafficking Analysis ( NTA ) . The monocytes/macrophages were sorted from bone marrow of the mice by magnetic beads. Cells were co-cultured with exosomes for 24 hours, and then treated with LPS for 48 hours. The proportion of Ly6C monocytes/macrophages was detec-ted by flow cytometry. Inflammatory cytokines in cell supernatant were investigated using ELISA. Results BMSCs surface markers CD44, CD90 were positively detected, but CD34, CD45 were not expressed. BM-SCs presented adipogenic differentiation ability. Exo-somes were positively expressing CD63 protein, and NTA showed that the diameters of exosomes were up to (82.4 ± 3.7 ) nm. BMSCs stimulated by LPS pro- duced more exosomes ( P < 0.01 ) . Exosomes from BMSCs with or without LPS treatment could increase the ratio of Ly6Chigh monocytes (P<0.01) and down-regulate the ratio of Ly6Chigh macrophages (P<0.05), and the effect of LPS treated-exosomes was more signif-icant than untreated-exosomes (P<0.05). Moreover, the concentration of IL-6 was also elevated under exo-somes treatment ( P <0.05 ) . Conclusions Human bone marrow mesenchymal stem cells-derived exosomes contribute to the regulation of Ly6Chigh monocytes/mac-rophages, indicating that they could be involved in the therapeutic treatment of inflammatory diseases.