Healing with precision: A multi-functional hydrogel-bioactive glass dressing boosts infected wound recovery and enhances neurogenesis in the wound bed.

Chronic skin wounds, especially infected ones, pose a significant clinical challenge due to their increasing incidence and poor outcomes. The deteriorative microenvironment in such wounds, characterized by reduced extracellular matrix, impaired angiogenesis, insufficient neurogenesis, and persistent bacterial infection, has prompted the exploration of novel therapeutic strategies. In this study, we developed an injectable multifunctional hydrogel (GEL/BG@Cu + Mg) incorporating Gelatin-Tannic acid/ N-hydroxysuccinimide functionalized polyethylene glycol and Bioactive glass doped with copper and magnesium ions to accelerate the healing of infected wounds. The GEL/BG@Cu + Mg hydrogel composite demonstrates good biocompatibility, degradability, and rapid formation of a protective barrier to stop bleeding. Synergistic bactericidal effects are achieved through the photothermal properties of BG@Cu + Mg and sustained copper ions release, with the latter further promoting angiogenesis. Furthermore, the hydrogel enhances neurogenesis by stimulating axons and Schwann cells in the wound bed through the beneficial effects of magnesium ions. Our results demonstrate that the designed novel multifunctional hydrogel holds tremendous promise for treating infected wounds and allowing regenerative neurogenesis at the wound site, which provides a viable alternative for further improving clinical outcomes.

Biomimetic hybrid nanovesicles improve infected diabetic wound via enhanced targeted delivery.

Infected diabetic wounds have been raising the global medical burden because of its high occurrence and resulting risk of amputation. Impaired endothelium has been well-documented as one of the most critical reasons for unhealed wounds. Recently, endothelial cell-derived nanovesicles (NVs) were reported to facilitate angiogenesis, whereas their efficacy is limited in infected diabetic wounds because of the complex niche. In this study, extrusion-derived endothelial NVs were manufactured and then hybridized with rhamnolipid liposomes to obtain biomimetic hybrid nanovesicles (HNVs). The HNVs were biocompatible and achieved endothelium-targeted delivery through membrane CXCR4-mediated homologous homing. More importantly, the HNVs exhibited better penetration and antibacterial activity compared with NVs, which further promote the intrinsic endothelium targeting in infected diabetic wounds. Therefore, the present research has established a novel bioactive delivery system-HNV with enhanced targeting, penetration, and antibacterial activity-which might be an encouraging strategy for infected diabetic wound treatment.

Multifunctional ADM hydrogel containing endothelial cell-exosomes for diabetic wound healing.

Non-healing wound, with limited treatment options, remains a prevalent complication of diabetes mellitus. The underlying causes wherein include oxidative stress injury, bacterial infection, cellular dysfunction, and persistent inflammation. Acellular Dermal Matrix (ADM), a wound dressing composed of natural extracellular matrix and abundant bioactive factors, has been successfully developed to treat various wounds, including burns and diabetic ulcers. Protocatechualdehyde (PA) & trivalent iron ion (Fe3+) complex (Fe3+@PA) exhibits potential antioxidant and antibacterial properties. In this study, we developed a dual hydrogel network by combining Fe3+@PA complex-modified ADM with light-cured gelatin (GelMA), supplemented with exosomes derived from human umbilical vein endothelial cells (HUVEC-Exos), to create an ADM composite hydrogel system (ADM-Fe3+@PA-Exos/GelMA) with antioxidant, antibacterial, and cell-promoting functions for diabetic wound treatment. Through in vitro experiments, we investigated the biosafety, antioxidant and antibacterial properties of ADM composite hydrogel. Furthermore, we examined the protective effects of ADM composite hydrogel on diabetic wound. The above experiments collectively demonstrate that our ADM-Fe3+@PA-Exos/GelMA hydrogel promotes diabetic wound healing by eliminating bacterial infection, reduced the reactive oxygen species (ROS) levels, protecting cells against oxidative stress damage, promotingcollagen deposition and angiogenesis, which provides a promising strategy to optimize ADM for diabetic wound treatment.

Exosomal miR-125b-5p derived from adipose-derived mesenchymal stem cells enhance diabetic hindlimb ischemia repair via targeting alkaline ceramidase 2.

INTRODUCTION: Ischemic diseases caused by diabetes continue to pose a major health challenge and effective treatments are in high demand. Mesenchymal stem cells (MSCs) derived exosomes have aroused broad attention as a cell-free treatment for ischemic diseases. However, the efficacy of exosomes from adipose-derived mesenchymal stem cells (ADSC-Exos) in treating diabetic lower limb ischemic injury remains unclear. METHODS: Exosomes were isolated from ADSCs culture supernatants by differential ultracentrifugation and their effect on C2C12 cells and HUVECs was assessed by EdU, Transwell, and in vitro tube formation assays separately. The recovery of limb function after ADSC-Exos treatment was evaluated by Laser-Doppler perfusion imaging, limb function score, and histological analysis. Subsequently, miRNA sequencing and rescue experiments were performed to figure out the responsible miRNA for the protective role of ADSC-Exos on diabetic hindlimb ischemic injury. Finally, the direct target of miRNA in C2C12 cells was confirmed by bioinformatic analysis and dual-luciferase report gene assay. RESULTS: ADSC-Exos have the potential to promote proliferation and migration of C2C12 cells and to promote HUVECs angiogenesis. In vivo experiments have shown that ADSC-Exos can protect ischemic skeletal muscle, promote the repair of muscle injury, and accelerate vascular regeneration. Combined with bioinformatics analysis, miR-125b-5p may be a key molecule in this process. Transfer of miR-125b-5p into C2C12 cells was able to promote cell proliferation and migration by suppressing ACER2 overexpression. CONCLUSION: The findings revealed that miR-125b-5p derived from ADSC-Exos may play a critical role in ischemic muscle reparation by targeting ACER2. In conclusion, our study may provide new insights into the potential of ADSC-Exos as a treatment option for diabetic lower limb ischemia.

Exosomes derived from oral squamous cell carcinoma tissue accelerate diabetic wound healing.

It is a widespread and difficult problem that refractory diabetic wounds have a poor local environment and prolonged inflammatory irritation. Tumor cell-derived exosomes play an important role in the development of tumors, as they can promote tumor cell proliferation, migration, and invasion and enhance tumor cell activity. However, tumor tissue-derived exosomes (Ti-Exos) have been less studied, and it is unclear how they affect wound healing. In this study, we extracted Ti-Exos from human oral squamous carcinoma and paracancerous tissue by ultracentrifugation, size exclusion chromatography, and ultrafiltration and performed exosome characterization. In vitro, the oral squamous cell carcinoma tissue-derived exosomes (OSCC Ti-Exos) promoted the proliferation and migration of endothelial cells, keratinocytes, and fibroblasts. In addition, in vivo experiments showed that the OSCC Ti-Exos accelerated the healing of diabetic wounds and were safe in mice. In contrast, there was no promoting effect of paracancerous tissue-derived exosomes either in vivo or in vitro. In conclusion, OSCC Ti-Exos promoted the healing of diabetic wounds, demonstrated preliminary biosafety in mice, and have promise as therapeutic applications.NEW & NOTEWORTHY Diabetic wound healing has become a public health issue that lacks effective treatment. We collected oral squamous cell carcinoma samples and paracancerous tissue and extracted Ti-Exos for verification. In vitro assays revealed that OSCC Ti-EVs could enhance the proliferation and migration of endothelial cells, keratinocytes, and fibroblasts in diabetic cell model. In vivo assays also verified that OSCC Ti-Exos could promote diabetic wound healing, demonstrated preliminary biosafety in mice, and have promise as therapeutic applications.

Tumor tissue derived extracellular vesicles promote diabetic wound healing.

The diabetic wound nowadays remains a major public health challenge, which is characterized by overproduced reactive oxygen species (ROS). However, the current therapy for diabetic wounds is limited for reliable data in the general application. The growth of tumors has been revealed to share parallels with wound healing. Extracellular vesicles (EVs) derived from breast cancer have been reported to promote cell proliferation, migration and angiogenesis. The tumor tissue-derived EVs (tTi-EVs) of breast cancer performance a feature inheritance from original tissue and might accelerate the diabetic wound healing. We wonder whether the tumor-derived EVs are able to accelerate diabetic wound healing. In this study, tTi-EVs were extracted from breast cancer tissue via ultracentrifugation and size exclusion. Subsequently, tTi-EVs reversed the H2O2-induced inhibition of fibroblast proliferation and migration. Moreover, tTi-EVs significantly accelerated wound closure, collagen deposition and neovascularization, and finally promoted wound healing in diabetic mice. The tTi-EVs also reduced the level of oxidative stress in vitro and in vivo. Besides, the biosafety of tTi-EVs were preliminarily confirmed by blood tests and morphological analysis of major organs. Collectively, the present study proves that tTi-EVs can suppress oxidative stress and facilitate diabetic wound healing, which puts forward a novel function of tTi-EVs and provides potential treatment for diabetic wounds.

Milk-derived exosomes carrying siRNA-KEAP1 promote diabetic wound healing by improving oxidative stress.

Diabetic wounds are a serious complication of diabetes mellitus (DM) that can lead to persistent infection, amputation, and even death. Prolonged oxidative stress has been widely recognized as a major instigator in the development of diabetic wounds; therefore, oxidative stress is considered a promising therapeutic target. In the present study, Keap1/Nrf2 signaling was confirmed to be activated in streptozotocin (STZ)-induced diabetic mice and methylglyoxal (MGO)-treated human umbilical vein endothelial cells (HUVECs). Knockdown of Keap1 by siRNA reversed the increase in Keap1 levels, promoted the nuclear translocation of Nrf2, and increased the expression of HO-1, an antioxidant protein. To explore therapeutic delivery strategies, milk-derived exosomes (mEXOs) were developed as a novel, efficient, and non-toxic siRNA carrier. SiRNA-Keap1 (siKeap1) was loaded into mEXOs by sonication, and the obtained mEXOs-siKeap1 were found to promote HUVEC proliferation and migration while relieving oxidative stress in MGO-treated HUVECs. Meanwhile, in a mouse model of diabetic wounds, injection of mEXOs-siKeap1 significantly accelerated diabetic wound healing with enhanced collagen formation and neovascularization. Taken together, these data support the development of Keap1 knockdown as a potential therapeutic strategy for diabetic wounds and demonstrated the feasibility of mEXOs as a scalable, biocompatible, and cost-effective siRNA delivery system. The therapeutic effect of siKeap1-loaded mEXOs on diabetic wound healing was assessed. First, we found that the expression of Keap1 was upregulated in the wounds of diabetic mice and in human umbilical vein endothelial cells (HUVECs) pretreated with methylglyoxal (MGO). Next, we extracted exosomes from raw milk by differential centrifugation and loaded siKeap1 into milk-derived exosomes by sonication. The in vitro application of the synthetic complex (mEXOs-siKeap1) was found to increase the nuclear localization of Nrf2 and the expression of the antioxidant protein HO-1, thus reversing oxidative stress. Furthermore, in vivo mEXOs-siKeap1 administration significantly accelerated the healing rate of diabetic wounds (Scheme 1). Scheme 1 Schematic diagram. A Synthesis of mEXOs-siKeap1 complex. B Mechanism of mEXOs-siKeap1 in vitro. C The treatment effect of mEXOs-siKeap1 on an in vivo mouse model of diabetic wounds.

Exosomes from Adipose Stem Cells Promote Diabetic Wound Healing through the eHSP90/LRP1/AKT Axis.

Oxidative damage is a critical cause of diabetic wounds. Exosomes from various stem cells could promote wound repair. Here, we investigated the potential mechanism by which exosomes from adipose-derived stem cells (ADSC-EXOs) promote diabetic wound healing through the modulation of oxidative stress. We found that ADSC-EXOs could promote proliferation, migration, and angiogenesis in keratinocytes, fibroblasts, and endothelial cells. Furthermore, ADSC-EXOs reduced the reactive oxygen species (ROS) levels in these cells and protected them against hypoxic and oxidative stress damage. Finally, the local injection of ADSC-EXOs at wound sites significantly increased collagen deposition and neovascularization while reducing ROS levels and cell death; thus, it led to accelerated diabetic wound closure. The mechanism underlying ADSC-EXO functions involved heat-shock protein 90 (HSP90) expressed on the cell surface; these functions could be inhibited by an anti-HSP90 antibody. Exosomal HSP90 could bind to the low-density lipoprotein receptor-related protein 1 (LRP1) receptor on the recipient cell membrane, leading to activation of the downstream AKT signaling pathway. Knockdown of LRP1 and inhibition of the AKT signaling pathway by LY294002 in fibroblasts was sufficient to impair the beneficial effect of ADSC-EXOs. In summary, ADSC-EXOs significantly accelerated diabetic wound closure through an exosomal HSP90/LRP1/AKT signaling pathway.