Objective To delineate the mechanistic role of platelet-rich plasma (PRP)-derived extracellular vesicles (EVs) in tissue repair and regeneration, and evaluate their clinical translation potential. MethodsA systematic evidence synthesis was conducted through critical analysis of contemporary domestic and international literature, focusing on PRP-EVs’ biophysical properties, signal transduction networks, and multi-tissue regenerative efficacy. ResultsPRP-EVs coordinate hemostasis, anti-inflammatory modulation, angiogenesis, and tissue plasticity through mediation of cellular proliferation, migration, and differentiation. Their low immunogenicity and biostability constitute a novel cell-free therapeutic paradigm. ConclusionPRP-EVs exhibit substantial translational merit in regenerative medicine, yet persistent impediments in standardized isolation protocols, longitudinal biosafety verification, and clinical translation frameworks necessitate resolution.
Exosomes are nanoscale vectors with a diameter of 30~100 nm secreted by living cells, and they are important media for intercellular communication. Recent studies have demonstrated that exosomes can not only serve as biomarkers for diagnosis, but also have great potential as natural drug delivery vectors. Exosomes can be loaded with therapeutic cargos, including small molecules, proteins, and oligonucleotides. Meanwhile, the unique biological compatibility, high stability, and tumor targeting of exosomes make them attractive in future tumor therapy. Though exosomes can effectively deliver bioactive materials to receptor cells, there is a wide gap between our current understanding of exosomes and their application as ideal drug delivery systems. In this review, we will briefly introduce the function and composition of exosomes, and mainly summarize the potential advantages and challenges of exosomes as drug carriers. Finally, this review is expected to provide new ideas for the development of exosome-based drug delivery systems.
ObjectiveTo explore the potential therapeutic effects of endothelial progenitor cells derived small extracellular vesicles (EPCs-sEVs) on spinal cord injury in mice.MethodsEPCs were separated from femur and tibia bone marrow of 20 C57BL/6 male mice, and identified by double fluorescence staining and flow cytometry. Then the EPCs were passaged and the cell supernatants from P2-P4 generations EPCs were collected; the EPCs-sEVs were extracted by ultracentrifugation and identified by transmission electron microscopy, nanoflow cytometry, and Western blot. Forty C57BL/6 female mice were randomly divided into 4 groups (n=10). The mice were only removed T10 lamina in sham group, and prepared T10 spinal cord injury models in the model group and the low and high concentration intervention groups. After 30 minutes, 3 days, and 7 days of operation, the mice in low and high concentration intervention groups were injected with EPCs-sEVs at concentrations of 1×109 and 1×1010cells/mL through the tail vein, respectively. The behavioral examinations [Basso Mouse Scale (BMS) score, inclined plate test, Von Frey test] , and the gross, HE staining, and immunohistochemical staining were performed to observe the structural changes of the spinal cord at 4 weeks after operation. Another 3 C57BL/6 female mice were taken to prepare T10 spinal cord injury models, and DiR-labeled EPCs- sEVs were injected through the tail vein. After 30 minutes, in vivo imaging was used to observe whether the EPCs-sEVs reached the spinal cord injury site.ResultsAfter identification, EPCs and EPCs-sEVs derived from mouse bone marrow were successfully obtained. In vivo imaging of the spinal cord showed that EPCs-sEVs were recruited to the spinal cord injury site within 30 minutes after injection. There was no significant difference in BMS scores and the maximum angle of the inclined plate test between two intervention groups and the model group within 2 weeks after operation (P>0.05), while both were significantly better than the model group (P<0.05) after 2 weeks. The Von Frey test showed that the mechanical pain threshold of the two intervention groups were significantly higher than that of model group and lower than that of sham group (P<0.05); there was no significant difference between two intervention groups (P>0.05). Compared with the model group, the injured segment of the two intervention groups had smaller spinal cord tissue defects, less mononuclear cells infiltration, more obvious tissue structure recovery, and more angiogenesis, and these differences were significant (P<0.05); there was no significant difference between the two intervention groups.ConclusionEPCs-sEVs can promote the repair of spinal cord injury in mice and provide a new plan for the biological treatment of spinal cord injury.
Objective To compare the characteristic differences between apoptotic extracellular vesicle (ApoEV) and non-apoptotic cell-derived extracellular vesicle (NCEV) from bone marrow mesenchymal stem cells (BMSCs), and to explore their therapeutic effects on inflammatory macrophages and cisplatin-induced acute kidney injury (AKI) in mice. Methods Staurosporine (STS) was used to induce apoptosis in BMSCs, and the apoptotic model was verified by cell morphology observation, Annexin V/propidium iodide double-staining flow cytometry, and Western blot. NCEV and ApoEV were isolated via differential centrifugation combined with ultracentrifugation, and characterized using transmission electron microscopy, nanoparticle tracking analysis, and Western blot. The particle yield and protein yield of extracellular vesicles (EV) per unit donor cell were compared between the two groups. EVs were labeled with DiD, and the uptake of EV by RAW264.7 macrophages was detected using laser scanning confocal microscopy and flow cytometry. Lipopolysaccharide (LPS) was applied to stimulate RAW264.7 cells to establish an in vitro inflammatory cell model. The mRNA expression levels of interleukin 10 (IL-10), arginase 1 (Arg-1), IL-1β, IL-6, IL-18, and tumor necrosis factor α (TNF-α) were determined by real-time fluorescence quantitative PCR. The intracellular reactive oxygen species (ROS) level was measured using 2’, 7’-dichlorodihydrofluorescein diacetate fluorescent probe with laser scanning confocal microscopy and flow cytometry. EVs were labeled with cyanine 7 N-hydroxysuccinimide ester to observe their distribution in major organs and renal tissues of normal mice. A cisplatin-induced AKI mouse model was established, followed by intervention with NCEV or ApoEV. Serum creatinine (Scr), blood urea nitrogen (BUN), renal histopathological injury, kidney injury molecule 1 (Kim-1), cell apoptosis, macrophage infiltration, and DNA damage-related indicators were detected. Based on previously published proteomic data of EV derived from mouse BMSCs, differentially expressed proteins were screened and gene ontology enrichment analysis was performed. Results After STS treatment, BMSCs exhibited typical apoptotic morphology with increased early and late apoptotic rates, alongside upregulated expression of Cleaved Caspase-3 and Bcl-2-associated X protein (Bax). Both NCEV and ApoEV presented spherical or quasi-spherical structures enclosed by a lipid bilayer membrane, with similar particle sizes and Zeta potentials. Bax and tumor susceptibility gene 101 protein were detected in both vesicles, while Cleaved Caspase-3 and Bax were detectable in ApoEV. The particle yield and protein yield of ApoEV were (5.626±0.302)-fold and (2.972±0.124)-fold higher than those of NCEV, respectively (P<0.05). Compared with NCEV, RAW264.7 cells displayed significantly elevated uptake ratio and mean fluorescence intensity for ApoEV (P<0.05). Under LPS stimulation, ApoEV markedly upregulated the mRNA expressions of IL-10 and Arg-1 to levels higher than those in the NCEV treatment group (P<0.05), whereas NCEV significantly suppressed the mRNA expressions of IL-1β and IL-6. Both NCEV and ApoEV reduced intracellular ROS levels, and flow cytometry revealed that the mean 2’, 7’-dichlorofluorescein fluorescence intensity in the ApoEV group was significantly lower than that in the NCEV group (P<0.05). Ex vivo organ imaging demonstrated that the strongest fluorescent signals of both types of EVs appeared in the liver, and obvious signals were also observed in the lung, spleen, and kidney. No significant difference in relative radiation efficiency of each organ was found between the two groups (P>0.05). In cisplatin-induced AKI mice, NCEV significantly reduced serum Scr and BUN levels, while ApoEV significantly decreased serum Scr levels. Both EV preparations alleviated renal tubular histopathological damage and lowered the levels of Kim-1, Bax, TUNEL-positive cells, F4/80-positive macrophages, and serine 139-phosphorylated histone H2AX. No significant intergroup differences in the above renal injury indicators were observed between the two EV intervention groups (P>0.05). Proteomic analysis identified 50 significantly upregulated proteins and 35 significantly downregulated proteins in ApoEV relative to NCEV. The upregulated proteins in ApoEV were mainly enriched in biological processes including extracellular matrix organization, classical complement pathway activation, proteolysis, and angiogenesis. Conclusion ApoEV possess higher production yield, enhanced macrophage uptake capacity and superior anti-inflammatory regulatory activity compared with NCEV. Both ApoEV and NCEV can alleviate renal injury in cisplatin-induced AKI, providing experimental evidence supporting the translational application of ApoEV for AKI treatment.