Extracellular vesicles for delivering therapeutic agents in ischemia/reperfusion injury

Ischemia/reperfusion(I/R)injury ismarked by the restriction and subsequent restoration of blood supply to an organ.This process can exacerbate the initial tissue damage,leading to further disorders,disability,and even death.Extracellular vesicles(EVs)are crucial in cell communication by releasing cargo that regulates the physiological state of recipient cells.The development of EVs presents a novel avenue for delivering therapeutic agents in I/R therapy.The therapeutic potential of EVs derived from stem cells,endothelial cells,and plasma in I/R injury has been actively investigated.Therefore,this review aims to provide an overview of the pathological process of I/R injury and the biophysical properties of EVs.We noted that EVs serve as nontoxic,flexible,and multifunctional carriers for delivering therapeutic agents capable of intervening in I/R injury progression.The therapeutic efficacy of EVs can be enhanced through various engineering strategies.Improving the tropism of EVs via surface modification and modulating their contents via preconditioning are widely investigated in preclinical studies.Finally,we summarize the challenges in the production and delivery of EV-based therapy in I/R injury and discuss how it can advance.This review will encourage further exploration in developing efficient EV-based delivery systems for I/R treatment.

Stem cell-based ischemic stroke therapy:Novel modifications and clinical challenges

Ischemic stroke(IS)causes severe disability and high mortality worldwide.Stem cell(SC)therapy exhibits unique therapeutic potential for IS that differs from current treatments.SC’s cell homing,differentiation and paracrine abilities give hope for neuroprotection.Recent studies on SC modification have enhanced therapeutic effects for IS,including gene transfection,nanoparticle modification,biomaterial modification and pretreatment.Thesemethods improve survival rate,homing,neural differentiation,and paracrine abilities in ischemic areas.However,many problems must be resolved before SC therapy can be clinically applied.These issues include production quality and quantity,stability during transportation and storage,as well as usage regulations.Herein,we reviewed the brief pathogenesis of IS,the“multi-mechanism”advantages of SCs for treating IS,various SC modification methods,and SC therapy challenges.We aim to uncover the potential and overcome the challenges of using SCs for treating IS and convey innovative ideas for modifying SCs.

New idea to promote the clinical applications of stem cells or their extracellular vesicles in central nervous system disorders:Combining with intranasal delivery

The clinical translation of stem cells and their extracellular vesicles(EVs)-based therapy for central nervous system(CNS) diseases is booming. Nevertheless, the insufficient CNS delivery and retention together with the invasiveness of current administration routes prevent stem cells or EVs from fully exerting their clinical therapeutic potential. Intranasal(IN) delivery is a possible strategy to solve problems as IN route could circumvent the brain-blood barrier non-invasively and fit repeated dosage regimens. Herein, we gave an overview of studies and clinical trials involved with IN route and discussed the possibility of employing IN delivery to solve problems in stem cells or EVs-based therapy. We reviewed relevant researches that combining stem cells or EVs-based therapy with IN administration and analyzed benefits brought by IN route. Finally, we proposed possible suggestions to facilitate the development of IN delivery of stem cells or EVs.