Strategy for Treatment of Infected Diabetic Foot Ulcers

Application of self-assembled antibacterial nanofiber loaded oriented artificial skin in infected diabetic-related wound regeneration

Diabetic patients develop wounds that exhibit delayed healing, prolonged inflammatory responses, and slower epithelialization kinetics compared to non-diabetic patients. Diabetic foot ulcers(DFUs) affect approximately 18.6 million people worldwide. The presence of a high glucose microenvironment in DFUs results in the significant accumulation of bacterial infection and advanced glycation end products (AGEs). To solve this, a self-assemble antibacterial nanofiber(ANF) loaded oriential artificial skin (ANF@OAS) was introduced in this research, which is consisted of L/D-phenylalanine derivatives coupled the natural antimicrobial peptides.The ANF@OAS can effectively reduce AGEs production and suppress multiple resistant bacteria. Additionally, the ANF@OAS can suppress infection and stimulate wound healing in infected diabetic mice.

Multifunctional combined drug-loaded nanofibrous dressings with anti-inflammatory, antioxidant stress and microenvironment improvement for diabetic wounds

The treatment of diabetic wounds remains a formidable clinical challenge worldwide. Because of persistent inflammatory reaction, excessive oxidative stress, cell dysfunction, poor blood microcirculation and other microvascular complications, diabetic wounds often fall into inflammatory circulation and are difficult to heal, making patients confront the risk of amputation. In this study, silver complex nanoparticles with Resina Draconis extract and Rhodiola rosea L. extract were loaded in situ onto thermoplastic polyurethane nanofibers to develop a multifunctional electrospun nanofiber wound dressing with excellent mechanical properties, superior water absorption and breathability, good coagulation promoting activity, strong antibacterial performance and antioxidant properties. This wound dressing could effectively enhance the migration and proliferation of fibroblasts, reduce the increased thickness of regenerated epidermis caused by diabetes, and the high expression and high lipid peroxidation levels of IL-1 β, IL-6, TNF α, iNOS and MMP-9, and raise the low expression of VEGF, which shows great potential to accelerate the wound healing of diabetic mouse models. The wound healing rate reached about 87.92%, close to the non-diabetic group. Our findings suggest a breakthrough in diabetic wound care, offering a viable solution to a long-standing medical shackle.

Bioinspired Collagen Scaffold Loaded with bFGF-Overexpressing Human Mesenchymal Stromal Cells Accelerating Diabetic Skin Wound Healing via HIF-1 Signal Pathway Regulated Neovascularization

The healing of severe chronic skin wounds in chronic diabetic patients is still a huge clinical challenge due to complex regeneration processes and control signals. Therefore, a single approach is difficult in obtaining satisfactory therapeutic efficacy for severe diabetic skin wounds. In this study, we adopted a composite strategy for diabetic skin wound healing. First, we fabricated a collagen-based biomimetic skin scaffold. The human basic fibroblast growth factor (bFGF) gene was electrically transduced into human umbilical cord mesenchymal stromal cells (UC-MSCs), and the stable bFGF-overexpressing UC-MSCs (bFGF-MSCs) clones were screened out. Then, an inspired collagen scaffold loaded with bFGF-MSCs was applied to treat full-thickness skin incision wounds in a streptozotocin-induced diabetic rat model. The mechanism of skin damage repair in diabetes mellitus was investigated using RNA-Seq and Western blot assays. The bioinspired collagen scaffold demonstrated good biocompatibility for skin-regeneration-associated cells such as human fibroblast (HFs) and endothelial cells (ECs). The bioinspired collagen scaffold loaded with bFGF-MSCs accelerated the diabetic full-thickness incision wound healing including cell proliferation enhancement, collagen deposition, and re-epithelialization, compared with other treatments. We also showed that the inspired skin scaffold could enhance the in vitro tube formation of ECs and the early angiogenesis process of the wound tissue in vivo. Further findings revealed enhanced angiogenic potential in ECs stimulated by bFGF-MSCs, evidenced by increased AKT phosphorylation and elevated HIF-1α and HIF-1β levels, indicating the activation of HIF-1 pathways in diabetic wound healing. Based on the superior biocompatibility and bioactivity, the novel bioinspired skin healing materials composed of the collagen scaffold and bFGF-MSCs will be promising for healing diabetic skin wounds and even other refractory tissue regenerations. The bioinspired collagen scaffold loaded with bFGF-MSCs could accelerate diabetic wound healing via neovascularization by activating HIF-1 pathways.

Insulin-Induced Gene 1-Enhance Secretion of BMSC Exosome Enriched in miR-132-3p Promoting Wound Healing in Diabetic Mice

Chronic diabetic wounds represent a significant clinical challenge because of impaired healing processes, which require innovative therapeutic strategies. This study explores the therapeutic efficacy of insulin-induced gene 1-induced bone marrow mesenchymal stem cell exosomes (Insig1-exos) in promoting wound healing in diabetic mice. We demonstrated that Insig1 enhanced the secretion of bone marrow mesenchymal stem cell-derived exosomes, which are enriched with miR-132-3p. Through a series of in vitro and in vivo experiments, these exosomes significantly promoted the proliferation, migration, and angiogenesis of dermal fibroblasts under high-glucose conditions. They also regulated key wound-healing factors, including matrix metalloproteinase-9, platelet-derived growth factor, vascular endothelial growth factor, transforming growth factor-β1, and platelet endothelial cell adhesion molecule-1, thereby accelerating wound closure in diabetic mice. Histological analysis showed that Insig1-exos were more effective in promoting epithelialization, enhancing collagen deposition, and reducing inflammation. Additionally, inhibition of miR-132-3p notably diminished these therapeutic effects, underscoring its pivotal role in the wound-healing mechanism facilitated by Insig1-exos. This study elucidates the molecular mechanisms through which Insig1-exos promotes diabetic wound healing, highlighting miR-132-3p as a key mediator. These findings provide new strategies and theoretical foundations for treating diabetes-related skin injuries.

Advances and applications of biomimetic biomaterials for endogenous skin regeneration

Endogenous regeneration is becoming an increasingly important strategy for wound healing as it facilitates skin's own regenerative potential for self-healing, thereby avoiding the risks of immune rejection and exogenous infection. However, currently applied biomaterials for inducing endogenous skin regeneration are simplistic in their structure and function, lacking the ability to accurately mimic the intricate tissue structure and regulate the disordered microenvironment. Novel biomimetic biomaterials with precise structure, chemical composition, and biophysical properties offer a promising avenue for achieving perfect endogenous skin regeneration. Here, we outline the recent advances in biomimetic materials induced endogenous skin regeneration from the aspects of structural and functional mimicry, physiological process regulation, and biophysical property design. Furthermore, novel techniques including in situ reprograming, flexible electronic skin, artificial intelligence, single-cell sequencing, and spatial transcriptomics, which have potential to contribute to the development of biomimetic biomaterials are highlighted. Finally, the prospects and challenges of further research and application of biomimetic biomaterials are discussed. This review provides reference to address the clinical problems of rapid and high-quality skin regeneration.

Daily crowding stress has limited, yet detectable effects on skin and head kidney gene expression in surgically tagged atlantic salmon (Salmo salar)

To ensure welfare-friendly and effective internal tagging, the tagging process should not cause a long-term burden on individuals given that tagged fish serve as representatives for the entire population in telemetry applications. To some extent, stress is inevitable within regular aquaculture practices, and thus, the consequences of long-term stress should be described in terms of their effects on internal tagging. In fish, stressors activate the Hypothalamus-Pituitary-Interrenal (HPI) and Brain-Sympathetic-Chromaffin Cell (BSC) axes, leading to neuroimmunoendocrine communication and paracrine interactions among stress hormones. The interrelation between wound healing and stress is complex, owing to their shared components, pathways, and energy demands. This study assessed 14 genes (mmp9, mmp13, il-2, il-4, il-8a, il-10, il-12, il-17d, il-1b, tnfa, ifng, leg-3, igm, and crh) in the skin (1.5 cm from the wound) and head kidney over eight weeks. These genes, associated with cell signaling in immunity, wound healing, and stress, have previously been identified as influenced and regulated by these processes. Half of a group of Atlantic salmon (n = 90) with surgically implanted dummy smart-tags were exposed to daily crowding stress. The goal was to investigate how this gene panel responds to a wound alone and then to the combined effects of wounding and daily crowding stress. Our observations indicate that chronic stress impacts inflammation and impedes wound healing, as seen through the expression of matrix metalloproteinases genes in the skin but not in the head kidney. This difference is likely due to the ongoing internal wound repair, in contrast to the externally healed wound incision. Cytokine expression, when significant in the skin, was mainly downregulated in both treatments compared to control values, particularly in the study's first half. Conversely, the head kidney showed initial cytokine downregulation followed by upregulation. Across all weeks observed and combining both tissues, the significantly expressed gene differences were 12 % between the Wound and Stress+ groups, 28 % between Wound and Control, and 25 % between Stress+ and Control. Despite significant fluctuations in cytokines, sustained variations across multiple weeks are only evident in a few select genes. Furthermore, Stress+ individuals demonstrated the most cytokine correlations within the head kidney, which may suggest that chronic stress affects cytokine expression. This investigation unveils that the presence of stress and prolonged activation of the HPI axis in an eight weeklong study has limited yet detectable effects on the selected gene expression within immunity, wound healing, and stress, with notable tissue-specific differences.

Enhanced Mechanical Strength and Sustained Drug Release in Carrier-Free Silver-Coordinated Anthraquinone Natural Antibacterial Anti-Inflammatory Hydrogel for Infectious Wound Healing

The persistent challenge of healing infectious wounds and the rise of bacterial resistance represent significant hurdles in contemporary medicine. In this study, based on the natural small molecule drug Rhein self-assembly to form hydrogels and coordinate assembly with silver ions (Ag+), a sustained-release carrier-free hydrogel with compact structure is constructed to promote the repair of bacterial-infected wounds. As a broad-spectrum antimicrobial agent, Ag+ can avoid the problem of bacterial resistance caused by the abuse of traditional antibiotics. In addition, due to the slow-release properties of Rhein hydrogel, continuous effective concentration of Ag+ at the wound site can be ensured. The assembly of Ag+ and Rhein makes the hydrogel system with enhanced mechanical stability. More importantly, it is found that Rhein effectively promotes skin tissue regeneration and wound healing by reprogramming M1 macrophages into M2 macrophages. Further mechanism studies show that Rhein realizes its powerful anti-inflammatory activity through NRF2/HO-1 activation and NF-κB inhibition. Thus, the hydrogel system combines the excellent antibacterial properties of Ag+ with the excellent anti-inflammatory and tissue regeneration ability of Rhein, providing a new strategy for wound management with dual roles.

Smart Dressings and Their Applications in Chronic Wound Management

During chronic wound healing, the inflammatory phase can endure for extended periods, heavily impeding or halting the process. Regular inspections and dressing changes are crucial. Modern dressings like hydrogels, hydrocolloids, and foam provide protection and an optimal healing environment. However, they have limitations in offering real-time wound bed status and healing rate. Evaluation relies heavily on direct observation, and passive dressings fail to identify subtle healing differences, preventing adaptive adjustments in biological factors and drug concentrations. In recent years, the clinical field recognizes the value of integrating intelligent diagnostic tools into wound dressings. By monitoring biomarkers linked to chronic wounds' inflammatory state, real-time data can be captured, reducing medical interventions and enabling more effective treatment plans. This fosters innovation in chronic wound care. Researchers have developed smart dressings with sensing, active drug delivery, and self-adjustment capabilities. These dressings detect inflammatory markers like temperature, pH, and oxygen content, enhancing drug bioavailability on the wound surface. As wound healing technology evolves, these smart dressings hold immense potential in chronic wound care and treatment. This comprehensive review updates our understanding on the role and mechanism of action of the smart dressings in chronic refractory wounds by summarizing and discussing the latest research progresses, including the intelligent monitoring of wound oxygen content, temperature, humidity, pH, infection, and enzyme kinetics; intelligent drug delivery triggered by temperature, pH, near-infrared, and electricity; as well as the intelligent self-adjustment of pressure and shape. The review also delves into the constraints and future perspectives of smart dressings in clinical settings, thereby advancing the development of smart wound dressings for chronic wound healing and their practical application in clinical practice.

A functional hydrogel of dopamine-modified gelatin with photothermal properties for enhancing infected wound healing

Infected skin wound has gradually become a prevalent injury that affects overall health. Currently, biomaterials with good adhesion, efficient antibacterial properties, and angiogenesis are considered as a suitable way to effectively heal infected wound. Herein, a multifunctional hydrogel comprising gelatin, dopamine (DA), and ferric ions (Fe3+) was developed for infected wound healing. The modified gelatin-dopamine (Gel-DA) enhanced adhesive capability. Subsequently introducing ferric ions (Fe3+) to form Gel-DA-Fe3+ hydrogels by Fe3+ and catechol coordination bonds. The designed hydrogels demonstrated multifaceted functionality, encompassing photothermal antibacterial, angiogenesis, and so on. The introduction of DA enhanced the adhesion of Gel-DA-Fe3+ to the skin surface and might serve as a physical barrier to seal wound. Meanwhile, DA and Fe3+ jointly endowed good photothermal effects to composite hydrogels, which could eliminate over 95 % of bacteria. In vitro results revealed that Gel-DA-Fe3+ hydrogels had good biocompatibility and promoted HUVECs migration and tube formation. Furthermore, in vivo studies confirmed that Gel-DA-Fe3+ hydrogels markedly expedited the wound healing of rats through eradicating bacteria, accelerating the deposition of collagen, and promoting angiogenesis. What's more, Gel-DA-Fe3+ hydrogels under near-infrared laser had a more pronounced ability for wound healing. Therefore, Gel-DA-Fe3+ hydrogels had great potential for application in bacteria-infected wound healing.

Histone modifications and their roles in macrophage-mediated inflammation: a new target for diabetic wound healing

Impaired wound healing is one of the main clinical complications of type 2 diabetes (T2D) and a major cause of lower limb amputation. Diabetic wounds exhibit a sustained inflammatory state, and reducing inflammation is crucial to diabetic wounds management. Macrophages are key regulators in wound healing, and their dysfunction would cause exacerbated inflammation and poor healing in diabetic wounds. Gene regulation caused by histone modifications can affect macrophage phenotype and function during diabetic wound healing. Recent studies have revealed that targeting histone-modifying enzymes in a local, macrophage-specific manner can reduce inflammatory responses and improve diabetic wound healing. This article will review the significance of macrophage phenotype and function in wound healing, as well as illustrate how histone modifications affect macrophage polarization in diabetic wounds. Targeting macrophage phenotype with histone-modifying enzymes may provide novel therapeutic strategies for the treatment of diabetic wound healing.

A potential therapeutic strategy of an innovative probiotic formulation toward topical treatment of diabetic ulcer: an in vivo study

BACKGROUND

The probiotic potential of Lacticacid bacteria has been studied in various medical complications, from gastrointestinal diseases to antibiotic resistance infections recently. Moreover, diabetic ulcer (DU) is known as one of the most significant global healthcare concerns, which comprehensively impacts the quality of life for these patients. Given that the conventional treatments of DUs have failed to prevent later complications completely, developing alternative therapies seems to be crucial.

METHODS

We designed the stable oleogel-based formulation of viable probiotic cells, including Lactobacillus rhamnosus (L. rhamnosus), Lactobacillus casei (L. casei), Lactobacillus fermentum (L. fermentum), and Lactobacillus acidophilus (L. acidophilus) individually to investigate their effect on wound healing process as an in vivo study. The wound repair process was closely monitored regarding morphology, biochemical, and histopathological changes over two weeks and compared it with the effects of topical tetracycline as an antibiotic approach. Furthermore, the antibiofilm activity of probiotic bacteria was assessed against some common pathogens.

RESULTS

The findings indicated that all tested lactobacillus groups (excluded L. casei) included in the oleogel-based formulation revealed a high potential for repairing damaged skin due to the considerably more levels of hydroxyproline content of tissue samples along with the higher numerical density of mature fibroblasts cell and volume density of hair follicles, collagen fibrils, and neovascularization in comparison with antibiotic and control groups. L. acidophilus and L. rhamnosus showed the best potential of wound healing among all lactobacillus species, groups treated by tetracycline and control groups. Besides, L. rhamnosus showed a significant biofilm inhibition activity against tested pathogens.

CONCLUSIONS

This experiment demonstrated that the designed formulations containing probiotics, particularly L. acidophilus and L. rhamnosus, play a central role in manipulating diabetic wound healing. It could be suggested as an encouraging nominee for diabetic wound-healing alternative approaches, though further studies in detailed clinical trials are needed.

Injectable, reversibly thermoresponsive captopril-laden hydrogel for the local treatment of sensory loss in diabetic neuropathy

A major and irreversible complication of diabetes is diabetic peripheral neuropathy (DPN), which can lead to significant disability and decreased quality of life. Prior work demonstrates the peptide hormone Angiotensin II (Ang II) is released locally in neuropathy and drives inflammation and impaired endoneurial blood flow. Therefore, we proposed that by utilizing a local thermoresponsive hydrogel injection, we could deliver inhibitors of angiotensin-converting enzyme (ACE) to suppress Ang II production and reduce nerve dysfunction in DPN through local drug release. The ACE inhibitor captopril was encapsulated into a micelle, which was then embedded into a reversibly thermoresponsive pluronics-based hydrogel matrix. Drug-free and captopril-loaded hydrogels demonstrated excellent product stability and sterility. Rheology testing confirmed sol properties with low viscosity at ambient temperature and increased viscosity and gelation at 37 °C. Captopril-loaded hydrogels significantly inhibited Ang II production in comparison to drug-free hydrogels. DPN mice treated with captopril-loaded hydrogels displayed normalized mechanical sensitivity and reduced inflammation, without side-effects associated with systemic exposure. Our data demonstrate the feasibility of repurposing ACE inhibitors as locally delivered anti-inflammatories for the treatment of sensory deficits in DPN. To the best of our knowledge, this is the first example of a locally delivered ACE inhibitor for the treatment of DPN.

Multifunctional Nanosystem for Dual Anti-Inflammatory and Antibacterial Photodynamic Therapy in Infectious Diabetic Wounds

Infectious diabetic wounds present a substantial challenge, characterized by inflammation, infection, and delayed wound healing, leading to elevated morbidity and mortality rates. In this work, we developed a multifunctional lipid nanoemulsion containing quercetin, chlorine e6, and rosemary oil (QCRLNEs) for dual anti-inflammatory and antibacterial photodynamic therapy (APDT) for treating infectious diabetic wounds. The QCRLNEs exhibited spherical morphology with a size of 51 nm with enhanced encapsulation efficiency, skin permeation, and localized delivery at the infected wound site. QCRLNEs with NIR irradiation have shown excellent wound closure and antimicrobial properties in vitro, mitigating the nonselective cytotoxic behavior of PDT. Also, excellent biocompatibility and anti-inflammatory and wound healing responses were observed in zebrafish models. The infected wound healing properties in S. aureus-infected diabetic rat models indicated re-epithelization and collagen deposition with no signs of inflammation. This multifaceted approach using QCRLNEs with NIR irradiation holds great promise for effectively combating oxidative stress and bacterial infections commonly associated with infected diabetic wounds, facilitating enhanced wound healing and improved clinical outcomes.

The regulatory mechanisms of cerium oxide nanoparticles in oxidative stress and emerging applications in refractory wound care

Cerium oxide nanoparticles (CeNPs) have emerged as a potent therapeutic agent in the realm of wound healing, attributing their efficacy predominantly to their exceptional antioxidant properties. Mimicking the activity of endogenous antioxidant enzymes, CeNPs alleviate oxidative stress and curtail the generation of inflammatory mediators, thus expediting the wound healing process. Their application spans various disease models, showcasing therapeutic potential in treating inflammatory responses and infections, particularly in oxidative stress-induced chronic wounds such as diabetic ulcers, radiation-induced skin injuries, and psoriasis. Despite the promising advancements in laboratory studies, the clinical translation of CeNPs is challenged by several factors, including biocompatibility, toxicity, effective drug delivery, and the development of multifunctional compounds. Addressing these challenges necessitates advancements in CeNP synthesis and functionalization, novel nano delivery systems, and comprehensive bio effectiveness and safety evaluations. This paper reviews the progress of CeNPs in wound healing, highlighting their mechanisms, applications, challenges, and future perspectives in clinical therapeutics.

Tibial transverse transport combined with platelet-rich plasma sustained-release microspheres activates the VEGFA/VEGFR2 pathway to promote microcirculatory reconstruction in diabetic foot ulcer

This study proposes to investigate the therapeutic efficacy and mechanism of combining tibial transverse transport (TTT) with platelet-rich plasma (PRP) for diabetic foot ulcer (DFU). The diabetic rabbit model was constructed with Streptozotocin, which was intervened with TTT and PRP. PRP injection combined with TTT significantly promoted vascularisation and enhanced CD31, VEGFA, and VEGFR2 expressions compared to traditional TTT. However, the VEGFR2 inhibitor suppressed these phenomena. In the in vitro injury model, PRP reversed the diminished human umbilical vein endothelial cells (HUVECs) function and vascularisation caused by high-glucose damage. Additionally, PRP reduced inflammation and oxidative stress (approximately 47% ROS level) and enhanced VEGFA and VEGFR2 expression in HUVECs. However, the knockdown of VEGFR2 reversed the effect of PRP. In conclusion, TTT combined with intraosseous flap injection of PRP sustained-release microspheres activated the VEGFA/VEGFR2 pathway to promote microcirculatory reconstruction in DFU. These findings may provide new potential therapeutic strategies for DFU.

Nanozybiotics: Advancing Antimicrobial Strategies Through Biomimetic Mechanisms

Infectious diseases caused by bacterial, viral, and fungal pathogens present significant global health challenges. The rapid emergence of antimicrobial resistance exacerbates this issue, leading to a scenario where effective antibiotics are increasingly scarce. Traditional antibiotic development strategies are proving inadequate against the swift evolution of microbial resistance. Therefore, there is an urgent need to develop novel antimicrobial strategies with mechanisms distinct from those of existing antibiotics. Nanozybiotics, which are nanozyme-based antimicrobials, mimic the catalytic action of lysosomal enzymes in innate immune cells to kill infectious pathogens. This review reinforces the concept of nanozymes and provides a comprehensive summary of recent research advancements on potential antimicrobial candidates. Initially, nanozybiotics are categorized based on their activities, mimicking either oxidoreductase-like or hydrolase-like functions, thereby highlighting their superior mechanisms in combating antimicrobial resistance. The review then discusses the progress of nanozybiotics in treating bacterial, viral, and fungal infections, confirming their potential as novel antimicrobial candidates. The translational potential of nanozybiotic-based products, including hydrogels, nanorobots, sprays, bandages, masks, and protective clothing, is also considered. Finally, the current challenges and future prospects of nanozybiotic-related products are explored, emphasizing the design and antimicrobial capabilities of nanozybiotics for future applications.

Polydopamine-armored zeolitic imidazolate framework-8-incorporated zwitterionic hydrogel with multifunctional properties for infected wound healing

Diabetic skin wound healing is compromised by bacterial infections, oxidative stress, and vascular disruption, leading to delayed recovery and potential complications. This study developed an antibacterial, antioxidant, and adhesive hydrogel dressing that promotes rapid bacterial-infected diabetic wound healing using the biological macromolecule of polydopamine (PDA). This hydrogel comprised PDA-armored zeolitic imidazolate framework-8 nanoparticles (PDA@ZIF-8 NPs) combined with a second armor of zwitterionic polymer network (poly(acrylamide-co-sulfobetaine methacrylate); PAS), realizing low concentration Zn2+ release, good adhesion (14.7 kPa for porcine skin), and improved tensile strength (83.2 kPa). The hydrogel exhibited good antibacterial efficacy against both Staphylococcus aureus (S. aureus, 92.8 %), Escherichia coli (E. coli, 99.6 %) and methicillin-resistant S. aureus (MRSA, 99.2 %), which was attributed to the properties of the incorporated PDA@ZIF-8 NPs. Notably, in vitro, the PDA@ZIF-8 PAS hydrogel not only promoted fibroblast proliferation and migration but also facilitated endothelial cell angiogenesis. In vivo, the PDA@ZIF-8 PAS hydrogel retained its Zn2+-releasing function and effectively suppressed bacterial growth in infected wounds, thereby accelerating the regeneration of both normal and diabetic wounds. This multiarmored hydrogel is a promising sustained-release carrier for functional metal ions and drugs, making it applicable for not only skin healing, but potentially the regeneration of other complex tissues.

Exosomal miRNA-26b-5p from PRP suppresses NETs by targeting MMP-8 to promote diabetic wound healing

The utilization of platelet-rich plasma (PRP) has exhibited potential as a therapeutic approach for the management of diabetic foot ulcers (DFUs). However, it is currently not well understood how the diabetic environment may influence PRP-derived exosomes (PRP-Exos) and their potential impact on neutrophil extracellular traps (NETs). This study aims to investigate the effects of the diabetic environment on PRP-Exos, their communication with neutrophils, and the subsequent influence on NETs and wound healing. Through bulk-seq and Western blotting, we confirmed the increased expression of MMP-8 in DFUs. Additionally, we discovered that miRNA-26b-5p plays a significant role in the communication between DFUs and PRP-Exos. In our experiments, we found that PRP-Exos miR-26b-5p effectively improved diabetic wound healing by inhibiting NETs. Further tests validated the inhibitory effect of miR-26b-5p on NETs by targeting MMP-8. Both in vitro and in vivo experiments showed that miRNA-26b-5p from PRP-Exos promoted wound healing by reducing neutrophil infiltration through its targeting of MMP-8. This study establishes the importance of miR-26b-5p in the communication between DFUs and PRP-Exos, disrupting NETs formation in diabetic wounds by targeting MMP-8. These findings provide valuable insights for developing novel therapeutic strategies to enhance wound healing in individuals suffering from DFUs.

Effect and mechanism of natural composite hydrogel from fish scale intercellular matrix on diabetic chronic wound repair

Diabetes mellitus is a chronic metabolic disease with prolonged low-grade inflammation and impaired cellular function, leading to poor wound healing. The treatment of diabetic wounds remains challenging due to the complex wound microenvironment. In view of the prominence of fish scales in traditional Chinese medicine and their wide application in modern medicine, we isolated the intercellular components in the scales of sea bass, obtained a natural composite hydrogel, fish scales gel (FSG), and applied it to diabetic chronic wounds. FSG was rich in collagen-like proteins, and possessed low-temperature gelation properties. In vitro, FSG was biocompatible and promoted fibroblast proliferation by approximately 40 %, endothelial cell migration by approximately 20 % and activated the M1 macrophages. In addition, FSG restored the function of fibroblasts and vascular endothelial cells damaged by high glucose. Importantly, FSG normalized the acute inflammatory response to impaired macrophages in a high-glucose microenvironment. Transcriptome analysis implies that this mechanism may involve enhanced cell signaling and cellular communication, improved sensitivity to cytokines, and activation of the TNF signaling pathway. Animal experiments confirmed that FSG significantly improved wound closure by approximately 15 % in diabetic rats, showing similar effects to acute wounds. In conclusion, the regulation of multiple cellular functions by FSG, especially the counterintuitive ability to induce acute inflammation, promoted diabetic wound healing and provides a novel therapeutic strategy for wound repair in diabetic patients.

Engineering injectable hyaluronic acid-based adhesive hydrogels with anchored PRP to pattern the micro-environment to accelerate diabetic wound healing

Diabetic wounds remain a global challenge due to disordered wound healing led by inflammation, infection, oxidative stress, and delayed proliferation. Therefore, an ideal wound dressing for diabetic wounds not only needs tissue adhesiveness, injectability, and self-healing properties but also needs a full regulation of the microenvironment. In this work, adhesive wound dressings (HA-DA/PRP) with injectability were fabricated by combining platelet rich plasma (PRP) and dopamine-modified-hyaluronic acid (HA-DA). The engineered wound dressings exhibited tissue adhesiveness, rapid self-healing, and shape adaptability, thereby enhancing stability and adaptability to irregular wounds. The in vitro experiments demonstrated that HA-DA/PRP adhesives significantly promoted fibroblast proliferation and migration, attributed to the loaded PRP. The adhesives showed antibacterial properties against both gram-positive and negative bacteria. Moreover, in vitro experiments confirmed that HA-DA/PRP adhesives effectively mitigated oxidative stress and inflammation. Finally, HA-DA/PRP accelerated the healing of diabetic wounds by inhibiting bacterial growth, promoting granulation tissue regeneration, accelerating neovascularization, facilitating collagen deposition, and modulating inflammation through inducing M1 to M2 polarization, in an in vivo model of infected diabetic wounds. Overall, HA-DA/PRP adhesives with the ability to comprehensively regulate the microenvironment in diabetic wounds may provide a novel approach to expedite the diabetic wounds healing in clinic.

A poly (lactic-co-glycolic acid) self-pumping Janus dressing with bidirectional biofluid transport for diabetic wound healing via anti-bacteria and pro-angiogenesis

Diabetic wound healing poses a substantial challenge owing to bacterial infections, insufficient angiogenesis, and excessive exudates. Currently, most of the clinical dressings used for diabetic wounds are still conventional dressings such as gauze. In this study, a three-layer Janus dressing was developed via continuous electrostatic spinning. The top-layer was composed of polylactic acid-glycolic acid and hydroxyapatite doped with silver ions and silicate. The hydrophobic top-layer prevented the adhesion of foreign bacteria. The mid-layer was composed of polyethylene glycol, polylactic acid-glycolic acid and hydroxyapatite doped with silver ions and silicate facilitated exudate absorption and bioactive ion release. The modified sub-layer containing polylactic acid-glycolic acid, hydroxyapatite doped with silver ions and silicate and sodium alginate microspheres enabled both the transport of wound exudate from the wound bed to dressing and the backflow of bioactive silver ions and silicate to the wound bed, thereby reducing infection and stimulating angiogenesis. Through in vivo and in vivo experiments, the Janus dressing showed to have antimicrobial, angiogenic, and exudate-control properties that accelerate healing in diabetic wounds. As a novel dressing, the multifunctional, self-pumping Janus wound dressing with bi-directional biofluidic transport offers a new approach to diabetic wound healing.

Copper metabolism and its role in diabetic complications: A review

Disturbances in copper (Cu) homeostasis have been observed in diabetes and associated complications. Cu is an essential micronutrient that plays important roles in various fundamental biological processes. For example, diabetic cardiomyopathy is associated with elevated levels of Cu in the serum and tissues. Therefore, targeting Cu may be a novel treatment strategy for diabetic complications. This review provides an overview of physiological Cu metabolism and homeostasis, followed by a discussion of Cu metabolism disorders observed during the occurrence and progression of diabetic complications. Finally, we discuss the recent therapeutic advances in the use of Cu coordination complexes as treatments for diabetic complications and their potential mechanisms of action. This review contributes to a complete understanding of the role of Cu in diabetic complications and demonstrates the broad application prospects of Cu-coordinated compounds as potential therapeutic agents.

Macrophage plasticity: signaling pathways, tissue repair, and regeneration

Macrophages are versatile immune cells with remarkable plasticity, enabling them to adapt to diverse tissue microenvironments and perform various functions. Traditionally categorized into classically activated (M1) and alternatively activated (M2) phenotypes, recent advances have revealed a spectrum of macrophage activation states that extend beyond this dichotomy. The complex interplay of signaling pathways, transcriptional regulators, and epigenetic modifications orchestrates macrophage polarization, allowing them to respond to various stimuli dynamically. Here, we provide a comprehensive overview of the signaling cascades governing macrophage plasticity, focusing on the roles of Toll-like receptors, signal transducer and activator of transcription proteins, nuclear receptors, and microRNAs. We also discuss the emerging concepts of macrophage metabolic reprogramming and trained immunity, contributing to their functional adaptability. Macrophage plasticity plays a pivotal role in tissue repair and regeneration, with macrophages coordinating inflammation, angiogenesis, and matrix remodeling to restore tissue homeostasis. By harnessing the potential of macrophage plasticity, novel therapeutic strategies targeting macrophage polarization could be developed for various diseases, including chronic wounds, fibrotic disorders, and inflammatory conditions. Ultimately, a deeper understanding of the molecular mechanisms underpinning macrophage plasticity will pave the way for innovative regenerative medicine and tissue engineering approaches.

Nano-enzyme functionalized hydrogels promote diabetic wound healing through immune microenvironment modulation

Non-healing diabetic wounds often culminate in amputation and mortality. The main pathophysiological features in diabetic wounds involve the accumulation of M1-type macrophages and excessive oxidative stress. In this study, we engineered a nano-enzyme functionalized hydrogel by incorporating a magnesium ion-doped molybdenum-based polymetallic oxide (Mg-POM), a novel bioactive nano-enzyme, into a GelMA hydrogel, to obtain the GelMA@Mg-POM system to enhance diabetic wound healing. GelMA@Mg-POM was crosslinked using UV light, yielding a hydrogel with a uniformly porous three-dimensional mesh structure. In vitro experiments showed that GelMA@Mg-POM extraction significantly enhanced human umbilical vein endothelial cell (HUVEC) migration, scavenged ROS, improved the inflammatory microenvironment, induced macrophage reprogramming towards M2, and promoted HUVEC regeneration of CD31 and fibroblast regeneration of type I collagen. In in vivo experiments, diabetic rat wounds treated with GelMA@Mg-POM displayed enhanced granulation tissue genesis and collagen production, as evidenced by HE and Masson staining. Immunohistochemistry demonstrated the ability of GelMA@Mg-POM to mitigate macrophage-associated inflammatory responses and promote angiogenesis. Overall, these findings suggest that GelMA@Mg-POM holds significant promise as a biomaterial for treating diabetic wounds.

Periplaneta americana extract promotes infectious diabetic ulcers wound healing by downregulation of LINC01133/SLAMF9

Wound healing in diabetic ulcers remains a significant clinical challenge, primarily due to bacterial infection and impaired angiogenesis. Periplaneta americana extract (PAE) has been widely used to treat diabetic wounds, yet its underlying mechanisms are not fully understood. This study aimed to elucidate these mechanisms by analyzing long non-coding RNA (lncRNA) expressions in the wound tissues from diabetic anal fistula patients treated with or without PAE, using high-throughput sequencing. Peripheral blood monocytes from patients were differentiated into M0 macrophages with human macrophage colony-stimulating factor (hM-CSF) and subsequently polarized into M1 macrophages with lipopolysaccharide. The results indicated that LINC01133 and SLAMF9 were downregulated in wound tissues of patients treated with PAE. Furthermore, PAE suppressed M1 macrophage polarization and enhanced human umbilical vein endothelial cell (HUVEC) proliferation, migration, and angiogenesis. These effects were diminished when LINC01133 or SLAMF9 were overexpressed. Mechanistically, LINC01133 was shown to upregulate SLAMF9 through interaction with ELAVL1. Overexpression of SLAMF9 reversed the effects of LINC01133 silencing on macrophage polarization and HUVEC functions. In conclusion, PAE facilitates the healing of infected diabetic ulcers by downregulating the LINC01133/SLAMF9 pathway.

Low-temperature plasma jet suppresses bacterial colonisation and affects wound healing through reactive species

An argon-based low-temperature plasma jet (LTPJ) was used to treat chronically infected wounds in Staphylococcus aureus-laden mice. Based on physicochemical property analysis and in vitro antibacterial experiments, the effects of plasma parameters on the reactive nitrogen and oxygen species (RNOS) content and antibacterial capacity were determined, and the optimal treatment parameters were determined to be 4 standard litre per minute and 35 W. Additionally, the plasma-treated activation solution had a bactericidal effect. Although RNOS are related to the antimicrobial effect of plasma, excess RNOS may be detrimental to wound remodelling. In vivo studies demonstrated that medium-dose LTPJ promoted MMP-9 expression and inhibited bacterial growth during the early stages of healing. Moreover, LTPJ increased collagen deposition, reduced inflammation, and restored blood vessel density and TGF-β levels to normal in the later stages of wound healing. Therefore, when treating chronically infected wounds with LTPJ, selecting the medium dose of plasma is more advantageous for wound recovery. Overall, our study demonstrated that low-temperature plasma jets may be a potential tool for the treatment of chronically infected wounds.

ROS induced pyroptosis in inflammatory disease and cancer

Pyroptosis, a form of caspase-1-dependent cell death, also known as inflammation-dependent death, plays a crucial role in diseases such as stroke, heart disease, or tumors. Since its elucidation, pyroptosis has attracted widespread attention from various sectors. Reactive oxygen species (ROS) can regulate numerous cellular signaling pathways. Through further research on ROS and pyroptosis, the level of ROS has been revealed to be pivotal for the occurrence of pyroptosis, establishing a close relationship between the two. This review primarily focuses on the molecular mechanisms of ROS and pyroptosis in tumors and inflammatory diseases, exploring key proteins that may serve as drug targets linking ROS and pyroptosis and emerging fields targeting pyroptosis. Additionally, the potential future development of compounds and proteins that influence ROS-regulated cell pyroptosis is anticipated, aiming to provide insights for the development of anti-tumor and anti-inflammatory drugs.

A new mechanism in negative pressure wound therapy: interleukin-17 alters chromatin accessibility profiling

Negative pressure wound therapy (NPWT) is extensively used in clinical settings to enhance the healing of wounds. Despite its widespread use, the molecular mechanisms driving the efficacy of NPWT have not been fully elucidated. In this study, skin wound-healing models were established, with administration of NPWT. Vimentin, collagen I, and MMP9 of skin tissues were detected by immunofluorescence (IF). Gene expression analysis of skin wound tissues was performed by RNA-sequencing (RNA-seq). Protein expression was assayed by a Western blotting or IF assay, and mRNA levels were quantified by quantitative PCR. Chromatin accessibility profiles of fibroblasts following NPWT or IL-17 exposure were analyzed by ATAC-seq. In rat wound-healing models, NPWT promoted wound repair by promoting reepithelialization, extracellular matrix (ECM) synthesis, and proliferation, which mainly occurred in the early stage of wound healing. These differentially expressed genes (DEGs) in NPWT wounds versus control wounds were enriched in the IL-17 signaling pathway. IL-17 was identified as an upregulated factor following NPWT in skin wounds. Moreover, the IL-17 inhibitor secukinumab (SEC) could abolish the promoting effect of NPWT on wound healing. Importantly, chromatin accessibility profiles were altered following NPWT and IL-17 stimulation in skin fibroblasts. Our findings suggest that NPWT upregulates IL-17 to promote wound healing by altering chromatin accessibility, which is a novel mechanism for NPWT's efficacy in wound healing.NEW & NOTEWORTHY To our knowledge, this is the first report of the efficacy of negative pressure wound therapy (NPWT) in promoting wound healing via IL-17. Moreover, NPWT and IL-17 can alter chromatin accessibility. Our study identifies a novel mechanism for NPWT's efficacy in wound healing.

Gases and gas-releasing materials for the treatment of chronic diabetic wounds

Chronic non-healing wounds are a common consequence of skin ulceration in diabetic patients, with severe cases such as diabetic foot even leading to amputations. The interplay between pathological factors like hypoxia-ischemia, chronic inflammation, bacterial infection, impaired angiogenesis, and accumulation of advanced glycosylation end products (AGEs), resulting from the dysregulation of the immune microenvironment caused by hyperglycemia, establishes an unending cycle that hampers wound healing. However, there remains a dearth of sufficient and effective approaches to break this vicious cycle within the complex immune microenvironment. Consequently, numerous scholars have directed their research efforts towards addressing chronic diabetic wound repair. In recent years, gases including Oxygen (O2), Nitric oxide (NO), Hydrogen (H2), Hydrogen sulfide (H2S), Ozone (O3), Carbon monoxide (CO) and Nitrous oxide (N2O), along with gas-releasing materials associated with them have emerged as promising therapeutic solutions due to their ability to regulate angiogenesis, intracellular oxygenation levels, exhibit antibacterial and anti-inflammatory effects while effectively minimizing drug residue-induced damage and circumventing drug resistance issues. In this review, we discuss the latest advances in the mechanisms of action and treatment of these gases and related gas-releasing materials in diabetic wound repair. We hope that this review can provide different ideas for the future design and application of gas therapy for chronic diabetic wounds.

Bone transport induces the release of factors with multi-tissue regenerative potential for diabetic wound healing in rats and patients

Tibial cortex transverse distraction is a surgical method for treating severe diabetic foot ulcers (DFUs), but the underlying mechanism is unclear. We show that antioxidant proteins and small extracellular vesicles (sEVs) with multiple-tissue regenerative potential are released during bone transport (BT) in humans and rats. These vesicles accumulate in diabetic wounds and are enriched with microRNAs (miRNAs) (e.g., miR-494-3p) that have high regenerative activities that improve the circulation of ischemic lower limbs while also promoting neovascularization, fibroblast migration, and nerve fiber regeneration. Deletion of miR-494-3p in rats reduces the beneficial effects of BT on diabetic wounds, while hydrogels containing miR-494-3p and reduced glutathione (GSH) effectively repair them. Importantly, the ginsenoside Rg1 can upregulate miR-494-3p, and a randomized controlled trial verifies that the regimen of oral Rg1 and GSH accelerates wound healing in refractory DFU patients. These findings identify potential functional factors for tissue regeneration and suggest a potential therapy for DFUs.

Adipose-Derived Stem Cell Exosomes Facilitate Diabetic Wound Healing: Mechanisms and Potential Applications

Wound healing in diabetic patients is frequently hampered. Adipose-derived stem cell exosomes (ADSC-eoxs), serving as a crucial mode of intercellular communication, exhibit promising therapeutic roles in facilitating wound healing. This review aims to comprehensively outline the molecular mechanisms through which ADSC-eoxs enhance diabetic wound healing. We emphasize the biologically active molecules released by these exosomes and their involvement in signaling pathways associated with inflammation modulation, cellular proliferation, vascular neogenesis, and other pertinent processes. Additionally, the clinical application prospects of the reported ADSC-eoxs are also deliberated. A thorough understanding of these molecular mechanisms and potential applications is anticipated to furnish a theoretical groundwork for combating diabetic wound healing.

Extracellular Matrix-Mimetic Intrinsic Versatile Coating Derived from Marine Adhesive Protein Promotes Diabetic Wound Healing through Regulating the Microenvironment

The management of diabetic wound healing remains a severe clinical challenge due to the complicated wound microenvironments, including abnormal immune regulation, excessive reactive oxygen species (ROS), and repeated bacterial infections. Herein, we report an extracellular matrix (ECM)-mimetic coating derived from scallop byssal protein (Sbp9Δ), which can be assembled in situ within 30 min under the trigger of Ca2+ driven by strong coordination interaction. The biocompatible Sbp9Δ coating and genetically programmable LL37-fused coating exhibit outstanding antioxidant, antibacterial, and immune regulatory properties in vitro. Proof-of-concept applications demonstrate that the coating can reliably promote wound healing in animal models, including diabetic mice and rabbits, ex vivo human skins, and Staphylococcus aureus-infected diabetic mice. In-depth mechanism investigation indicates that improved wound microenvironments accelerated wound repair, including alleviated bacterial infection, lessened inflammation, appearance of abundant M2-type macrophages, removal of ROS, promoted angiogenesis, and re-epithelialization. Collectively, our investigation provides an in situ, convenient, and effective approach for diabetic wound repair.

A one-two punch strategy for diabetic wound management based on an antibiotic-hybrid biomineralized iron sulfide nanoparticle

Bacterial infection and immune imbalance are the primary culprits behind chronic wounds in individuals with diabetes, impeding the progression of damaged tissues towards normal healing. To achieve a harmonious balance between pro- and anti-inflammation within these infected areas, herein, we propose a one-two punch strategy for on-demand therapy of diabetes-infected wounds, utilizing an azithromycin (AZM)-hybrid nanocomposite termed GOx@FexSy/AZM. During the infective stage, the nanocomposite facilitates the production of ROS, coupled with the burst release of AZM and H2S gas, effectively dismantling biofilms and achieving rapid sterilization. Subsequently, the hyperinflammatory response induced by antibiosis is significantly mitigated through the synergistic action of tissue H2S and the prolonged half-life of AZM. These components inhibit the activity of pro-inflammatory transcription factors (AP-1 and NF-κB) within macrophages, thereby promoting the polarization of macrophages towards a reparative M2 phenotype and facilitating tissue remodeling. By catering to the diverse requirements of wound healing at different stages, this nanocomposite accelerates a sensible transition from inflammation to the reparative phase. In summary, this one-two punch strategy gives an instructive instance for procedural treatment of diabetes wound infection. STATEMENT OF SIGNIFICANCE: The treatment of diabetic wound infection presents two major challenges: the diminished antibacterial efficacy arising from biofilm formation and bacterial resistance, as well as the inadequate transition of the wound microenvironment from pro-inflammatory to anti-inflammatory states after bacterial clearance. In this work, a biomineralized iron sulfide nanocomposite was prepared to mediate cascade catalytic (ROS storm) / antibiotic (AZM) / gas (H2S) triple-synergetic antibacterial therapy during the initial stage of bacterial infection, achieving the goal of rapid bactericidal effect; Subsequently, the residual H2S and long half-life AZM would inhibit the key pro-inflammatory transcription factors and promote the macrophages polarization to reparative M2, which effectively mediated tissue repair after hyperinflammatory reactions, leading to orderly treatment of hyperglycemic infected wounds.

All-in-one polysaccharide hydrogel with resistant vascular burst pressure and cooperative wound microenvironment regulation for fatal arterial hemorrhage and diabetic wound healing

Fatal massive hemorrhage and diabetic wound healing are world widely challenging in surgical managements, and uncontrolled bleeding, chronic inflammation and damaged remodeling heavily hinder the whole healing processes. Considering hemostasis, inflammation and wound microenvironment cooperatively affect the healing progression, we design all-in-one beta-glucan (BG) hybrid hydrogels reinforced with laponite nanoclay that demonstrate tunable tissue adhesion, resistant vascular burst pressure and cooperative wound microenvironment regulation for arterial hemostasis and diabetic wound prohealing. Those hydrogels had honeycomb-like porous microstructure with average pore size of 7-19 μm, tissue adhesion strength of 18-46 kPa, and vascular burst pressure of 58-174 mmHg to achieve superior hemostasis in rat liver and femoral artery models. They could effectively scavenge reactive oxygen species, transform macrophages from proinflammatory M1 into prohealing M2, and shorten the inflammation duration via synergistic actions of BG and nitric oxide (NO). Single treatment of NO-releasing BG hybrid hydrogels attained complete closure of diabetic wounds within 14 days, orchestrated to accelerate the epithelization and dermis growth, and restored normal vascularization, achieving high performance healing with optimal collagen deposition and hair follicle regeneration. Consequently, this work opens up a new avenue to design all-in-one polysaccharide hydrogels for applications in massive bleeding hemostats and diabetic wound dressings.

Proanthocyanidins-based tandem dynamic covalent cross-linking hydrogel for diabetic wound healing

Wound healing in diabetic patients presents significant challenges in clinical wound care due to high oxidative stress, excessive inflammation, and a microenvironment prone to infection. In this study, we successfully developed a multifunctional tandem dynamic covalently cross-linked hydrogel dressing aimed at diabetic wound healing. This hydrogel was constructed using cyanoacetic acid functionalized dextran (Dex-CA), 2-formylbenzoylboric acid (2-FPBA) and natural oligomeric proanthocyanidins (OPC), catalyzed by histidine. The resulting Dex-CA/OPC/2-FPBA (DPOPC) hydrogel can be dissolved triggered by cysteine, thereby achieving "controllable and non-irritating" dressing change. Furthermore, the incorporation of OPC as a hydrogel building block endowed the hydrogel with antioxidant and anti-inflammatory properties. The cross-linked network of the DPOPC hydrogel circumvents the burst release of OPC, enhancing its biosafety. In vivo studies demonstrated that the DPOPC hydrogel significantly accelerated the wound healing process in diabetic mice compared to a commercial hydrogel, achieving an impressive wound closure rate of 98 % by day 14. The DPOPC hydrogel effectively balanced the disrupted inflammatory state during the healing process. This dynamic hydrogel based on natural polyphenols is expected to be an ideal candidate for dressings intended for chronic wounds.

Promoting Diabetic Wound Healing through a Hydrogel-Based Cascade Regulation Strategy of Fibroblast-Macrophage

The management of diabetic wounds (DWs) continues to pose a significant challenge in the field of medicine. DWs are primarily prevented from healing due to damage to macrophage efferocytosis and fibroblast dysfunction. Consequently, a treatment strategy that involves both immunoregulation and the promotion of extracellular matrix (ECM) formation holds promise for healing DWs. Nevertheless, existing treatment methods necessitate complex interventions and are associated with increased costs, for example, the use of cytokines and cell therapy, both of which have limited effectiveness. In this study, a new type of ruthenium (IV) oxide nanoparticles (RNPs)-laden hybrid hydrogel dressing with a double network of Pluronic F127 and F68 has been developed. Notably, the hybrid hydrogel demonstrates remarkable thermosensitivity, injectability, immunoregulatory characteristics, and healing capability. RNPs in hydrogel effectively regulate both fibroblasts and macrophages in a cascade manner, stimulating fibroblast differentiation while synergistically enhancing the efferocytosis of macrophage. The immunoregulatory character of the hydrogel aids in restoring the intrinsic stability of the immune microenvironment in the wound and facilitates essential remodeling of the ECM. This hydrogel therefore offers a novel approach for treating DWs through intercellular communication.

Antidiabetic Potential of Tea and Its Active Compounds: From Molecular Mechanism to Clinical Evidence

Diabetes mellitus (DM) is a chronic endocrine disorder that poses a long-term risk to human health accompanied by serious complications. Common antidiabetic drugs are usually accompanied by side effects such as hepatotoxicity and nephrotoxicity. There is an urgent need for natural dietary alternatives for diabetic treatment. Tea (Camellia sinensis) consumption has been widely investigated to lower the risk of diabetes and its complications through restoring glucose metabolism homeostasis, safeguarding pancreatic β-cells, ameliorating insulin resistance, ameliorating oxidative stresses, inhibiting inflammatory response, and regulating intestinal microbiota. It is indispensable to develop effective strategies to improve the absorption of tea active compounds and exert combinational effects with other natural compounds to broaden its hypoglycemic potential. The advances in clinical trials and population-based investigations are also discussed. This review primarily delves into the antidiabetic potential and underlying mechanisms of tea active compounds, providing a theoretical basis for the practical application of tea and its active compounds against diabetes.

Shengjihuayu formula ameliorates the oxidative injury in human keratinocytes via blocking JNK/c-Jun/MMPs signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The reactive oxygen species (ROS) surge in the chronic wound tissue of diabetic ulcers (DUs) aggravates the inflammatory response. The oxidative stress state during inflammation will exacerbate inflammation and cause tissue damage, resulting in prolonged wound healing. Shengjihuayu Formula (SJHYF) is a renowned Chinese medicine prescription for treating chronic wounds in diabetic ulcers. Growing clinical evidence has demonstrated that SJHYF exhibits superior therapeutic efficacy and has a favorable safety profile. However, the underlying mechanisms by which SJHYF ameliorates oxidative damage under pathological conditions of DUs remain unclear.

OBJECTIVE

To investigate the cytoprotective properties of SJHYF on hydrogen peroxide (H2O2)-induced cell damage in human HaCaT keratinocytes and to explore its potential targets and molecular pathways in treating DUs using RNA-seq.

METHODS

HaCaT cells were incubated with H2O2 for 24 h to construct an oxidative stress cell model. Cell viability and proliferation were measured using the MTT and EdU assays, respectively. Cell migration was assessed using the scratch assay, and the fluorescence intensity of ROS was measured using the DCFH-DA probe. The chemical components of SJHYF were analyzed by UPLC-Q-TOF/MS, while the therapeutic effects of SJHYF on H2O2-induced HaCaT cells were analyzed using RNA-Seq. The potential target genes were validated using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). At the same time, the pathway phenotype expression of SJHYF on the protection of H2O2-induced HaCaT cells was explored using Western Blot.

RESULTS

The application of SJHY at a concentration of 0.25 mg/mL promoted cell proliferation, cell migration, and reduced ROS production. In addition, SJHYF was detected to have a total of 93 active compounds, including key components such as Galloyl-beta-D-glucose, Danshensu, Procyanidin B2, Catechin, and Alkannin. The RNA-seq analysis identified several core targets namely KRT17, TGM1, JUNB, PRDX5, TXNIP, PRDX1, HSP90AA1, HSP90AB1, HSPA8, and TNF-α. Western blot revealed the presence of the JNK/c-Jun/MMPs pathway and its related transcription factors.

CONCLUSION

SJHYF displays significant protective effects on H2O2-induced oxidative cell damage in HaCaT cells via blocking the JNK/c-Jun/MMPs pathway.

Analyzing Immune Cell Infiltration and Copper Metabolism in Diabetic Foot Ulcers

Background

Diabetes impairs wound healing, notably in diabetic foot ulcers (DFU). Stress, marked by the accumulation of lipoylated mitochondrial enzymes and the depletion of Fe-S cluster proteins, triggers cuproptosis-a distinct form of cell death. The involvement of copper in the pathophysiology of DFU has been recognized, and currently, a copper-based therapeutic strategy is emerging as a viable option for enhancing ulcer healing. This study investigates genes linked to copper metabolism in DFU, aiming to uncover potential targets for therapeutic intervention.

Methods

Two diabetic wound Gene Expression Omnibus (GEO) datasets were analyzed to study immune cell dysregulation in diabetic wounds. Differentially expressed genes related to copper metabolism were identified and analyzed using machine learning methods. Gene ontology, pathway enrichment, and immune infiltration analyses were performed using DFU samples. The expression of identified genes was validated using qRT-PCR and single-cell RNA sequencing.

Results

Ten genes associated with copper metabolism were identified. Among these, SLC31A1 and ADNP were found to be significantly differentially expressed in DFU. Notably, SLC31A1 exhibited higher expression in macrophages, whereas ADNP was found to be highly expressed in fibroblasts and chondrocytes.

Conclusion

The study indicates a close link between copper metabolism, the infiltration of immune cells, and DFU. It proposes that copper metabolism could influence the progression of DFU through the activation of immune responses. These observations offer fresh perspectives on the underlying mechanisms of DFU and identify potential targets for therapeutic intervention.

Stem Cell-Derived Extracellular Vesicles: Promising Therapeutic Opportunities for Diabetic Wound Healing

Wound healing is a sophisticated and orderly process of cellular interactions in which the body restores tissue architecture and functionality following injury. Healing of chronic diabetic wounds is difficult due to impaired blood circulation, a reduced immune response, and disrupted cellular repair mechanisms, which are often associated with diabetes. Stem cell-derived extracellular vesicles (SC-EVs) hold the regenerative potential, encapsulating a diverse cargo of proteins, RNAs, and cytokines, presenting a safe, bioactivity, and less ethical issues than other treatments. SC-EVs orchestrate multiple regenerative processes by modulating cellular communication, increasing angiogenesis, and promoting the recruitment and differentiation of progenitor cells, thereby potentiating the reparative milieu for diabetic wound healing. Therefore, this review investigated the effects and mechanisms of EVs from various stem cells in diabetic wound healing, as well as their limitations and challenges. Continued exploration of SC-EVs has the potential to revolutionize diabetic wound care.

The role of FGF-21 in promoting diabetic wound healing by modulating high glucose-induced inflammation

Background

Wound healing is a complex biological process that can be impaired in individuals with diabetes. Diabetic wounds are a serious complication of diabetes that require promoting diagnosis and effective treatment. FGF-21, a member of the endocrine FGF factors family, has caught the spotlight in the treatment of diabetes for its beneficial effects on accelerating human glucose uptake and fat catabolism. However, the therapeutic efficacy of FGF-21 in promoting diabetic wounds remains unknown. This study aims to evaluate the therapeutic potential of FGF-21 in promoting diabetic wound healing.

Methods

we investigated the effects of FGF-21 on wound healing related-cells under high-glucose conditions using various assays such as CCK8, scratch assay, flow cytometry analysis, endothelial tube-formation assay, and transmission electron microscopy. Furthermore, we used db/db mice to verify the healing-promoting therapeutic effects of FGF-21 on diabetic wounds. We also conducted qRT-PCR, Western blot, and immunofluorescence staining analyses to elucidate the underlying mechanism.

Result

Our results indicate that FGF-21 treatment restored hyperglycemic damage on endothelial cell proliferation, migration, and tube-forming ability. It also reduced endothelial cell death rates under high-glucose conditions. TEM analysis showed that FGF-21 treatment effectively restored mitochondrial damage and morphological changes in endothelial cells caused by glucose. Additionally, qRT-PCR and Western blot analysis indicated that FGF-21 treatment restored inflammatory responses caused by hyperglycemic damage. Animal experiments confirmed these findings, suggesting that FGF-21 may be a promising candidate for the treatment of non-healing diabetic wounds due to its effectiveness in stimulating angiogenesis and anti-inflammatory function.

Conclusion

Our study provides evidence that FGF-21 is an essential regulator of wound-related cells under high-glucose conditions and has the potential to be a novel therapeutic target for accelerating diabetic wound healing.

Multifunctional antibacterial hydrogels for chronic wound management

Chronic wounds have gradually evolved into a global health challenge, comprising long-term non-healing wounds, local tissue necrosis, and even amputation in severe cases. Accordingly, chronic wounds place a considerable psychological and economic burden on patients and society. Chronic wounds have multifaceted pathogenesis involving excessive inflammation, insufficient angiogenesis, and elevated reactive oxygen species levels, with bacterial infection playing a crucial role. Hydrogels, renowned for their excellent biocompatibility, moisture retention, swelling properties, and oxygen permeability, have emerged as promising wound repair dressings. However, hydrogels with singular functions fall short of addressing the complex requirements associated with chronic wound healing. Hence, current research emphasises the development of multifunctional antibacterial hydrogels. This article reviews chronic wound characteristics and the properties and classification of antibacterial hydrogels, as well as their potential application in chronic wound management.

Mesoporous MOFs with ROS scavenging capacity for the alleviation of inflammation through inhibiting stimulator of interferon genes to promote diabetic wound healing

Excessive production of reactive oxygen species (ROS) and inflammation are the key problems that impede diabetic wound healing. In particular, dressings with ROS scavenging capacity play a crucial role in the process of chronic wound healing. Herein, Zr-based large-pore mesoporous metal-organic frameworks (mesoMOFs) were successfully developed for the construction of spatially organized cascade bioreactors. Natural superoxide dismutase (SOD) and an artificial enzyme were spatially organized in these hierarchical mesoMOFs, forming a cascade antioxidant defense system, and presenting efficient intracellular and extracellular ROS scavenging performance. In vivo experiments demonstrated that the SOD@HMUiO-MnTCPP nanoparticles (S@M@H NPs) significantly accelerated diabetic wound healing. Transcriptomic and western blot results further indicated that the nanocomposite could inhibit fibroblast senescence and ferroptosis as well as the stimulator of interferon genes (STING) signaling pathway activation in macrophages mediated by mitochondrial oxidative stress through ROS elimination. Thus, the biomimetic multi-enzyme cascade catalytic system with spatial ordering demonstrated a high potential for diabetic wound healing, where senescence, ferroptosis, and STING signaling pathways may be potential targets.

Tannic acid and silicate-functionalized polyvinyl alcohol-hyaluronic acid hydrogel for infected diabetic wound healing

Healing of chronic diabetic wounds is challenging due to complications of severe inflammatory microenvironment, bacterial infection and poor vascular formation. Herein, a novel injectable polyvinyl alcohol-hyaluronic acid-based composite hydrogel was developed, with tannic acid (TA) and silicate functionalization to fabricate an 'all-in-one' hydrogel PTKH. On one hand, after being locally injected into the wound site, the hydrogel underwent a gradual sol-gel transition in situ, forming an adhesive and protective dressing for the wound. Manipulations of rheological characteristics, mechanical properties and swelling ability of PTKH could be performed via regulating TA and silicate content in hydrogel. On the other hand, PTKH was capable of eliminating reactive oxygen species overexpression, combating infection and generating a cell-favored microenvironment for wound healing acceleration in vitro. Subsequent animal studies demonstrated that PTKH could greatly stimulate angiogenesis and epithelization, accompanied with inflammation and infection risk reduction. Therefore, in consideration of its impressive in vitro and in vivo outcomes, this 'all-in-one' multifunctional hydrogel may hold promise for chronic diabetic wound treatment.

Bioactive triterpenoid compounds of Poria cocos (Schw.) Wolf in the treatment of diabetic ulcers via regulating the PI3K-AKT signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Diabetic ulcers represent a chronic condition characterized by prolonged hyperglycemia and delayed wound healing, accompanied by endocrine disorders, inflammatory responses, and microvascular damage in the epidermal tissue, demanding effective clinical treatment approaches. For thousands of years, ancient Chinese ethnopharmacological studies have documented the use of Poria cocos (Schw.) Wolf in treating diabetic ulcers. Recent research has substantiated the diverse pharmacological effects of Poria cocos (Schw.) Wolf, including its potential to alleviate hyperglycemia and exhibit anti-inflammatory, antioxidant, and immune regulatory properties, which could effectively mitigate diabetic ulcer symptoms. Furthermore, being a natural medicine, Poria cocos (Schw.) Wolf has demonstrated promising therapeutic effects and safety in the management of diabetic ulcers, holding significant clinical value. Despite its potential clinical efficacy and applications in diabetic ulcer treatment, the primary active components and underlying pharmacological mechanisms of Poria cocos (Schw.) Wolf remains unclear. Further investigations are imperative to establish a solid foundation for drug development in this domain.

AIM OF THE STUDY AND MATERIALS AND METHODS

In this study, we aimed to identify the active compounds and potential targets of Poria cocos (Schw.) Wolf using UHPLC-Q-TOF-MS and TCMSP databases. Additionally, we attempt to identify targets related to diabetic ulcers. Following enrichment analysis, a network of protein-protein interactions was constructed to identify hub genes based on the common elements between the two datasets. To gain insights into the binding activities of the hub genes and active ingredients, molecular docking analysis was employed. Furthermore, to further validate the therapeutic effect of Poria cocos (Schw.) Wolf, we exerted in vitro experiments using human umbilical vein vascular endothelial cells and human myeloid leukemia monocytes (THP-1). The active ingredient of Poria cocos (Schw.) Wolf was applied in these experiments. Our investigations included various assays, such as CCK-8, scratch test, immunofluorescence, western blotting, RT-PCR, and flow cytometry, to explore the potential of Poria cocos (Schw.) Wolf triterpenoid extract (PTE) in treating diabetic ulcers.

RESULTS

The findings here highlighted PTE as the primary active ingredient in Poria cocos (Schw.) Wolf. Utilizing network pharmacology, we identified 74 potential targets associated with diabetic ulcer treatment for Poria cocos (Schw.) Wolf, with five hub genes (JUN, MAPK1, STAT3, AKT1, and CTNNB1). Enrichment analysis revealed the involvement of multiple pathways in the therapeutic process, with the PI3K-AKT signaling pathway showing significant enrichment. Through molecular docking, we discovered that relevant targets within this pathway exhibited strong binding with the active components of Poria cocos (Schw.) Wolf. In vitro experiments unveiled that PTE (10 mg/L) facilitated the migration of human umbilical vein vascular endothelial cells (P < 0.05). PTE also increased the expression of CD31 and VEGF mRNA (P < 0.05) while activating the expressions of p-PI3K and p-AKT (P < 0.05). Moreover, PTE demonstrated its potential by reducing the expression of IL-1β, IL-6, TNF-α, and NF-κB mRNA in THP-1 (P < 0.05) and fostering M2 macrophage polarization. These results signify the potential therapeutic effects of PTE in treating diabetic ulcers, with its beneficial actions mediated through the PI3K-AKT signaling pathway.

CONCLUSIONS

PTE is the main active ingredient in Poria cocos (Schw.) Wolf that exerts therapeutic effects. Through PI3K-AKT signaling pathway activation and inflammatory response reduction, PTE promotes angiogenesis, thereby healing diabetic ulcers.

NIR-activated electrospun nanodetonator dressing enhances infected diabetic wound healing with combined photothermal and nitric oxide-based gas therapy

Diabetic wounds pose a challenge to healing due to increased bacterial susceptibility and poor vascularization. Effective healing requires simultaneous bacterial and biofilm elimination and angiogenesis stimulation. In this study, we incorporated polyaniline (PANI) and S-Nitrosoglutathione (GSNO) into a polyvinyl alcohol, chitosan, and hydroxypropyltrimethyl ammonium chloride chitosan (PVA/CS/HTCC) matrix, creating a versatile wound dressing membrane through electrospinning. The dressing combines the advantages of photothermal antibacterial therapy and nitric oxide gas therapy, exhibiting enduring and effective bactericidal activity and biofilm disruption against methicillin-sensitive Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, and Escherichia coli. Furthermore, the membrane's PTT effect and NO release exhibit significant synergistic activation, enabling a nanodetonator-like burst release of NO through NIR irradiation to disintegrate biofilms. Importantly, the nanofiber sustained a uniform release of nitric oxide, thereby catalyzing angiogenesis and advancing cellular migration. Ultimately, the employment of this membrane dressing culminated in the efficacious amelioration of diabetic-infected wounds in Sprague-Dawley rats, achieving wound closure within a concise duration of 14 days. Upon applying NIR irradiation to the PVA-CS-HTCC-PANI-GSNO nanofiber membrane, it swiftly eradicates bacteria and biofilm within 5 min, enhancing its inherent antibacterial and anti-biofilm properties through the powerful synergistic action of PTT and NO therapy. It also promotes angiogenesis, exhibits excellent biocompatibility, and is easy to use, highlighting its potential in treating diabetic wounds.

Effects of Nanoparticle-Mediated Dihydromyricetin to Diabetic Wounds: An In Vivo Study

Diabetic wound is one of the serious complications of diabetes, and the wound is persistent and easily recurring, which seriously endangers the health and life of patients. How to effectively promote the healing of diabetic wounds has been a hot spot and difficult area of clinical research. Some previous studies have shown that dihydromyricetin has the effects of regulating blood glucose, controlling the severity, and inhibiting scarring. In the present study, we used polylactic-co-glycolic acid nanoparticles as a carrier to load dihydromyricetin to make drug-loaded nanoparticles and applied them dropwise (200 µL) to diabetic mice wounds by topical application to observe the healing and scar formation of diabetic wounds. We found that the healing rate of the diabetic mice was faster and the scar formation was less obvious. In addition, the elevated blood glucose level and weight loss of the mice in the treatment group were also reduced. Therefore, nanoparticle-mediated dihydromyricetin may be an effective treatment for diabetic wounds.

IGF2BP2 regulates the inflammation of fibroblast-like synoviocytes via GSTM5 in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease with an unknown etiology. RA cannot be fully cured and requires lengthy treatment, imposing a significant burden on both individuals and society. Due to the lack of specific drugs available for treating RA, exploring a key new therapeutic target for RA is currently an important task. Activated fibroblast-like synoviocytes (FLSs) play a crucial role in the progression of RA, which release interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α resulting in abnormal inflammatory reaction in the synovium. A previous study has highlighted the correlation of m6A reader insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) with inflammation-related diseases in human. However, the role of IGF2BP2 in the inflammatory reaction of FLSs during RA progression has not been assessed. In this study, IGF2BP2 expression was decreased in the synovial tissues of RA patients and collagen-induced arthritis (CIA) rats. Intra-articular injection of an adeno-associated virus (AAV) vector overexpressing IGF2BP2 relieved paw swelling, synovial hyperplasia and cartilage destruction in CIA rats. IGF2BP2 overexpression also inhibited lipopolysaccharide (LPS)-mediated RA fibroblast-like synoviocytes (RA-FLSs) migration and invasion accompanied by a decreased level of inflammatory factors in vitro. Conversely, IGF2BP2 suppression promoted RA-FLSs migration and invasion with an elevated level of inflammatory factors in vitro. The sequencing result showed that glutathione S-transferase Mu 5 (GSTM5), a key antioxidant gene, was the target mRNA of IGF2BP2. Further experiments demonstrated that IGF2BP2 strengthened the stability of GSTM5 mRNA, leading to weakened inflammatory reaction and reduced expression of matrix metalloproteinase 9 and 13 (MMP9, MMP13). Therefore, IGF2BP2-GSTM5 axis may represent a potential therapeutic target for RA treatment.

Glucose-Responsive Self-Healing Bilayer Drug Microneedles Promote Diabetic Wound Healing Via a Trojan-Horse Strategy

Chronic nonhealing wounds are serious complications of diabetes with a high morbidity, and they can lead to disability or death. Conventional drug therapy is ineffective for diabetic wound healing because of the complex environment of diabetic wounds and the depth of drug penetration. Here, we developed a self-healing, dual-layer, drug-carrying microneedle (SDDMN) for diabetic wound healing. This SDDMN can realize transdermal drug delivery and broad-spectrum sterilization without drug resistance and meets the multiple needs of the diabetic wound healing process. Quaternary ammonium chitosan cografted with dihydrocaffeic acid (Da) and l-arginine and oxidized hyaluronic acid-dopamine are the main parts of the self-healing hydrogel patch. Methacrylated poly(vinyl alcohol) (methacrylated PVA) and phenylboronic acid (PBA) were used as the main part of the MN, and gallium porphyrin modified with 3-amino-1,2 propanediol (POGa) and insulin were encapsulated at its tip. Under hyperglycaemic conditions, the PBA moiety in the MN reversibly formed a glucose-boronic acid complex that promoted the rapid release of POGa and insulin. POGa is disguised as hemoglobin through a Trojan-horse strategy, which is then taken up by bacteria, allowing it to target bacteria and infected lesions. Based on the synergistic properties of these components, SDDMN-POGa patches exhibited an excellent biocompatibility, slow drug release, and antimicrobial properties. Thus, these patches provide a potential therapeutic approach for the treatment of diabetic wounds.