Delivery of miR-130a-3p Through Adipose-Derived Stem Cell-Secreted EVs Protects Against Diabetic Peripheral Neuropathy via DNMT1/NRF2/HIF1α/ACTA1 Axis

Adipose-derived stem cells in diabetic foot care: Bridging clinical trials and practical application

Diabetic foot ulcers (DFUs) pose a critical medical challenge, significantly im-pairing the quality of life of patients. Adipose-derived stem cells (ADSCs) have been identified as a promising therapeutic approach for improving wound healing in DFUs. Despite extensive exploration of the mechanical aspects of ADSC therapy against DFU, its clinical applications remain elusive. In this review, we aimed to bridge this gap by evaluating the use and advancements of ADSCs in the clinical management of DFUs. The review begins with a discussion of the classification and clinical management of diabetic foot conditions. It then discusses the current landscape of clinical trials, focusing on their geographic distribution, reported efficacy, safety profiles, treatment timing, administration techniques, and dosing considerations. Finally, the review discusses the preclinical strategies to enhance ADSC efficacy. This review shows that many trials exhibit biases in study design, unclear inclusion criteria, and intervention protocols. In conclusion, this review underscores the potential of ADSCs in DFU treatment and emphasizes the critical need for further research and refinement of therapeutic approaches, with a focus on improving the quality of future clinical trials to enhance treatment outcomes and advance the field of diabetic wound care.

Non-coding RNAs in diabetic peripheral neuropathy: their role and mechanisms underlying their effects

Diabetic peripheral neuropathy (DPN) is a complication of diabetes with a high rate of disability. However, current clinical treatments for DPN are suboptimal. Non-coding RNAs (ncRNAs) are a type of RNAs that are not translated into proteins. NcRNAs perform functions that regulate epigenetic modifications, transcriptional or post-transcriptional regulators of proteins, and thus participate in the physiological and pathological processes of the body. NcRNAs play a role in the progress of DPN by affecting the processes of inflammation, oxidative stress, cellular autophagy or apoptosis. Therefore, ncRNAs treatment is regarded as a promising therapeutic approach for DPN. In addition, since some ncRNAs present stably in the blood of DPN patients, they are considered as potential biomarkers that contribute to early clinical diagnosis. In this paper, we review the studies on the role of ncRNAs in DPN in the last decade, and discuss the mechanisms of ncRNAs, aiming to provide a reference for the future research on the treatment and early diagnosis of DPN.

Genetically engineered loaded extracellular vesicles for drug delivery

The use of extracellular vesicles (EVs) for drug delivery is being widely explored by scientists from several research fields. To fully exploit their therapeutic potential, multiple methods for loading EVs have been developed. Although exogenous methods have been extensively utilized, in recent years the endogenous method has gained significant attention. This approach, based on parental cell genetic engineering, is suitable for loading large therapeutic biomolecules such as proteins and nucleic acids. We review the most commonly used EV loading methods and emphasize the inherent advantages of the endogenous method over the others. We also examine the most recent advances and applications of this innovative approach to inform on the diverse therapeutic opportunities that lie ahead in the field of EV-based therapies.

Nrf2 activation: a key mechanism in stem cell exosomes-mediated therapies

Exosomes are nano-sized membrane extracellular vesicles which can be released from various types of cells. Exosomes originating from inflammatory or injured cells can have detrimental effects on recipient cells, while exosomes derived from stem cells not only facilitate the repair and regeneration of damaged tissues but also inhibit inflammation and provide protective effects against various diseases, suggesting they may serve as an alternative strategy of stem cells transplantation. Exosomes have a fundamental role in communication between cells, through the transfer of proteins, bioactive lipids and nucleic acids (like miRNAs and mRNAs) between cells. This transfer significantly impacts both the physiological and pathological functions of recipient cells. Nuclear factor erythroid 2-related factor 2 (Nrf2), a transcription factor, is able to mitigate damage caused by oxidative stress and inflammation through various signaling pathways. The positive effects resulting from the activation of the Nrf2 signaling pathway in different disorders have been documented in various types of literature. Studies have confirmed that exosomes derived from stem cells could act as Nrf2 effective agonists. However, limited studies have explored the Nrf2 role in the therapeutic effects of stem cell-derived exosomes. This review provides a comprehensive overview of the existing knowledge concerning the role of Nrf2 signaling pathways in the impact exerted by stem cell exosomes in some common diseases.

New concepts drive the development of delivery tools for sustainable treatment of diabetic complications

Diabetic complications, especially diabetic retinopathy, diabetic nephropathy and painful diabetic neuropathy, account for a large portion of patients with diabetes and display rising global prevalence. They are the leading causes of blindness, kidney failure and hypersensitivity to pain caused by diabetes. Current approved therapeutics against the diabetic complications are few and exhibit limited efficacy. The enhanced cell-specificity, stability, biocompatibility, and loading capacity of drugs are essential for the mitigation of diabetic complications. In the article, we have critically discussed the recent studies over the past two years in material sciences and biochemistry. The insightful concepts in these studies drive the development of novel nanoparticles and mesenchymal stem cells-derived extracellular vesicles to meet the need for treatment of diabetic complications. Their underlying biochemical principles, advantages and limitations have been in-depth analyzed. The nanoparticles discussed in the article include double-headed nanodelivery system, nanozyme, ESC-HCM-B system, soft polymer nanostars, tetrahedral DNA nanostructures and hydrogels. They ameliorate the diabetic complication through attenuation of inflammation, apoptosis and restoration of metabolic homeostasis. Moreover, mesenchymal stem cell-derived extracellular vesicles efficiently deliver therapeutic proteins to the retinal cells to suppress the angiogenesis, inflammation, apoptosis and oxidative stress to reverse diabetic retinopathy. Collectively, we provide a critical discussion on the concept, mechanism and therapeutic applicability of new delivery tools to treat these three devastating diabetic complications.