Inflammation and metabolism in tissue repair and regeneration

Bacterial metabolism in the host and its association with virulence

The host restricted pathogens are competently dependent on their respective host for nutritional requirements. The bacterial metabolic pathways are surprisingly varied and remarkably flexible that in turn help them to successfully overcome competition and colonise their host. The metabolic adaptation plays pivotal role in bacterial pathogenesis. The understanding of host-pathogen metabolic crosstalk needs to be prioritized to decipher host-pathogen interactions. The review focuses on various aspects of host pathogen interactions that majorly involves adaptation of bacterial metabolism to counteract immune mechanisms by rectifying metabolic cues that provides pathogen the idea of different anatomical sites and the local physiology of the host. The key set of metabolites that are recognized as centre of competition between host and its pathogens are also briefly discussed. The factors that control the timely expression of virulence of bacterial pathogens is poorly understood. The perspective presented herein will facilitate us with a broader view of molecular mechanisms that modulates the expression of virulence factors in bacterial pathogens. The knowledge of crosslinked metabolic pathways of bacteria and their host will serve to develop novel potential therapeutics.

Fibroblast activation protein-targeted chimeric antigen-receptor-modified NK cells alleviate cardiac fibrosis

Cardiac fibrosis (CF) is a common pathophysiological process in the development of various cardiovascular diseases, during which many cardiac fibroblasts undergo myofibroblast transdifferentiation. Fibroblast activation protein (FAP) can serve as a specific target for myofibroblasts, and chimeric antigen receptor (CAR)-based therapy is a promising immunotherapy strategy. In this study, we attempted to construct CAR natural killer (NK) cells that target FAP and explored their potential therapeutic role in CF. Our results suggested FAP CAR-NK-92 cells can specifically recognize and kill FAP+ cells in vitro. In addition, compared with parental NK-92 cells, FAP CAR-NK cells cocultured with FAP HEK-293 T cells presented increased cytotoxicity, cytokine secretion, and degranulation, indicating an effect-to-target ratio dependence. Coculturing FAP CAR-NK cells with mouse cardiac fibroblast lines (MCFs) eliminated the activated fibroblasts, reduced fibrosis-related protein secretion, and significantly reversed the contractile phenotype of myofibroblasts, which is characterized by alpha-smooth muscle actin (α-SMA) and stress fiber formation. Intravenous injection of FAP CAR-NK cells in mice 7 days after Ang II/PE-induced injury significantly improved cardiac function and reduced fibrosis. In terms of the killing mechanism, the early apoptosis rate of target cells was significantly increased, the antiapoptotic protein Bcl-2 was significantly decreased, and the proapoptotic proteins Bax and Caspase 3 were markedly increased. Our findings demonstrate that FAP CAR-NK-92 cells can specifically recognize FAP+ target cells and exert potent anti-fibrotic effects both in vitro and in vivo. Therefore, FAP CAR-NK-92 cells could be considered an effective therapeutic option for CF patients.

Herbal micelles-loaded ROS-responsive hydrogel with immunomodulation and microenvironment reconstruction for diabetic wound healing

Persistent inflammation is a major cause of diabetic wounds that are difficult to heal. This is manifested in diabetic wounds with excessive reactive oxygen clusters (ROS), advanced glycation end products (AGE) and other inflammatory factors, and difficulty in polarizing macrophages toward inhibiting inflammation. Berberine is a natural plant molecule that inhibits inflammation; however, its low solubility limits its biological function through cytosis. In this study, we designed F127 micelles to encapsulate berberine with the aim of improving its solubility and bioavailability. Meanwhile, in order to achieve effective drug delivery at the wound site, we designed an injectable ferrocene-cyclodextrin self-assembled oxidation-reactive supramolecular hydrogel drug delivery system. Cellular experiments have shown that the hydrogel can reduce intracellular ROS and AGE production, attenuate cellular damage, promote macrophage polarization toward inhibition of inflammation, and reduce the secretion of inflammatory factors. In an animal model of diabetic mice, this hydrogel dressing reduces the level of inflammation in diabetic wounds, optimizes collagen deposition in diabetic wounds, and ultimately achieves high-quality diabetic wound healing. The work offers a straightforward and effective solution to the challenge of administering hydrophobic anti-inflammatory agents in the context of diabetic wound therapy.

Sodium butyrate alleviates colitis by inhibiting mitochondrial ROS mediated macrophage pyroptosis

Inflammatory bowel disease (IBD) is a chronic inflammatory bowel disease with unclear causes and limited treatment options. Sodium butyrate (NaB), a byproduct of dietary fiber in the intestine, has demonstrated efficacy in treating inflammation. However, the precise anti-inflammatory mechanisms of NaB in colon inflammation remain largely unexplored. This study aims to investigate the effects of NaB on dextran sulfate sodium (DSS)-induced colitis in rats. The findings indicate that oral administration of NaB effectively prevent colitis and reduce levels of serum or colon inflammatory factors. Additionally, NaB demonstrated in vitro inhibition of RAW264.7 inflammation cytokines induced by LPS, along with suppression of the ERK and NF-κB signaling pathway activation. Moreover, NaB mitigated LPS and Nigericin-induced RAW264.7 pyroptosis by reducing indicators of mitochondrial damage, including increased mitochondrial membrane potential (JC-1) levels and decreased Mito-ROS production. NaB increases ZO-1 and Occludin expression in CaCo2 cells by inhibiting RAW264.7 pyroptosis. These results suggest that NaB could be utilized as a therapeutic agent or dietary supplement to alleviate colitis.

Gold nanoparticles modulate macrophage polarization to promote skeletal muscle regeneration

Skeletal muscle regeneration is a complex process that depends on the interplay between immune responses and muscle stem cell (MuSC) activity. Macrophages play a crucial role in this process, exhibiting distinct polarization states-M1 (pro-inflammatory) and M2 (anti-inflammatory)-that significantly affect tissue repair outcomes. Recent advancements in nanomedicine have positioned gold nanoparticles (Au NPs) as promising tools for modulating macrophage polarization and enhancing muscle regeneration. This review examines the role of Au NPs in influencing macrophage behavior, focusing on their physicochemical properties, biocompatibility, and mechanisms of action. We discuss how Au NPs can promote M2 polarization, facilitating tissue repair through modulation of cytokine production, interaction with cell surface receptors, and activation of intracellular signaling pathways. Additionally, we highlight the benefits of Au NPs on MuSC function, angiogenesis, and extracellular matrix remodeling. Despite the potential of Au NPs in skeletal muscle regeneration, challenges remain in optimizing nanoparticle design, developing targeted delivery systems, and understanding long-term effects. Future directions should focus on personalized medicine approaches and combination therapies to enhance therapeutic efficacy. Ultimately, this review emphasizes the transformative potential of Au NPs in regenerative medicine, offering hope for improved treatments for muscle injuries and diseases.

APOBEC affects tumor evolution and age at onset of lung cancer in smokers

Most solid tumors harbor somatic mutations attributed to off-target activities of APOBEC3A (A3A) and/or APOBEC3B (A3B). However, how APOBEC3A/B enzymes affect tumor evolution in the presence of exogenous mutagenic processes is largely unknown. Here, multi-omics profiling of 309 lung cancers from smokers identifies two subtypes defined by low (LAS) and high (HAS) APOBEC mutagenesis. LAS are enriched for A3B-like mutagenesis and KRAS mutations; HAS for A3A-like mutagenesis and TP53 mutations. Compared to LAS, HAS have older age at onset and high proportions of newly generated progenitor-like cells likely due to the combined tobacco smoking- and APOBEC3A-associated DNA damage and apoptosis. Consistently, HAS exhibit high expression of pulmonary healing signaling pathway, stemness markers, distal cell-of-origin, more neoantigens, slower clonal expansion, but no smoking-associated genomic/epigenomic changes. With validation in 184 lung tumor samples, these findings show how heterogeneity in mutational burden across co-occurring mutational processes and cell types contributes to tumor development.

Dual-corn-derived nanofiber membrane for subconjunctival injury: Sequential release of dual-natural products for programmed anti-inflammation and anti-fibrosis

Subconjunctival injuries represent significant clinical challenges due to the complexities of post-injury inflammation and subsequent fibrosis, which lead to vision impairment; however, currently, no clinical interventions are available to resolve this problem. In this work, a novel dual drug-loaded core-shell nanofiber membrane based on two corn derivatives was fabricated via coaxial electrospinning to address this unmet clinical need. The nanofiber structure, comprising a polylactic acid shell and a zein core, sequentially released two natural products, rutin and celastrol. The rutin loaded in the polylactic acid shell was rapidly released to produce anti-inflammatory effects, whereas the celastrol loaded in the zein core was slowly released in the later stage to inhibit subconjunctival fibrosis. The in vitro results indicated that this nanofiber membrane platform significantly decreased the secretion of key proinflammatory cytokines and fibrosis biomarkers and reduced the risk of early bacterial invasion. Moreover, the in vivo results revealed that this platform not only ameliorated inflammation but also inhibited late-stage fibrosis, suggesting a promising therapeutic strategy. This study provides an effective exploration of a controlled and safe drug delivery platform, serving as a reference for effective interventions in other related diseases.

Magnesium Ions Induce Endothelial Cell Differentiation into Tip Cell and Enhance Vascularized Bone Regeneration

Vascularization has been considered an essential strategy for bone regeneration and can be promoted by magnesium ions (Mg2+). During angiogenesis, the differentiation of endothelial cells (ECs) into tip cell is a critical step since it controls the growth direction and pattern of new vascular sprouts. While several studies have noted the pro-angiogenic effects of Mg2+, however, their specific influence on tip cell formation is unclear. Therefore, this research seeks to examine the impact of Mg2+ on tip cells and elucidate the potential mechanisms involved. The results reveal that Mg2+ shows good compatibility and stimulates ECs to migrate and invade in vitro. Moreover, Mg2+ enhances EC spheroids sprouting and elevates the expression of genes linked to tip cells. The underlying mechanisms are that Mg2+ facilitates tip cell differentiation via the VEGFA-VEGFR2/Notch1 signaling pathway crosstalk and promotes migration and filopodia formation of tip cells and proliferation of stalk cells by inducing YAP nuclear translocation, culminating in the maturation of vascular networks. Furthermore, EC spheroids stimulated by Mg2+ load in hydrogel enhance vascularized bone regeneration in vivo. These findings enrich the understanding of how Mg2+ influence blood vessel formation and provide practical strategies for the development and design of magnesium-based biomaterials.

Immunomodulatory multifunctional janus collagen-based membrane for advanced bone regeneration

Guided bone regeneration (GBR) is a standard therapy for treating bone defects, with collagen-based barrier membranes widely used clinically. However, these membranes face challenges like poor mechanical properties, early bacterial invasion and immunomodulation deficiency, potentially risking GBR failure. Orchestrating macrophage activation and controlling their M1 or M2 polarization are effective strategies for bone repair. Here, we present a Janus collagen-based barrier membrane with immunomodulation. The porous layer promotes direct osteogenic differentiation and inward growth of osteoblasts. The dense layer prevents invasion of soft tissue into bone defects and protects bone defects from bacterial infection. The membrane also enhances rat bone marrow-derived mesenchymal stem cell infiltration, proliferation, and osteogenic differentiation by regulating the immune microenvironment, demonstrating superior bone regeneration compared to the commercial Bio-Gide® membrane. Overall, the Janus collagen-based membrane reduces tissue inflammation and fosters an osteoimmune environment conducive to new bone formation, offering effective material design for advanced GBR technology.

Safety assessment of multiple systemic administration of human mesenchymal stem cell-conditioned medium for various chronic diseases

Conditioned medium (CM) derived from human mesenchymal stem cells (MSCs) has shown potential as a therapeutic agent. However, the safety of its administration in human remains largely unexplored. This study evaluated the safety of multiple systemic administrations of MSC-CM, specifically adipose-derived and umbilical cord-derived MSC-CM, in 55 patients with various chronic diseases. Symptom assessments and blood tests were conducted before and after administration to monitor adverse events and measure the inflammatory marker C-reactive protein (CRP), respectively. The results demonstrated no serious adverse events attributed to MSC-CM administration. Although minor adverse events were observed, their causal relationship with MSC-CM remained unclear. Additionally, MSC-CM administration slightly reduced CRP levels, regardless of the administration route (intraarterial, intravenous, or inhalation). Additionally, a significant reduction in CRP levels was observed in patients with elevated CRP levels (CRP > 0.3) following MSC-CM administration. These findings suggest that repeated systemic administration of MSC-CM is likely safe and may have anti-inflammatory effects.

Self-Powered Algae-Integrated Wearable System for Oxygen Supplementation in Hypoxic Disease Treatment

Hypoxia serves as a critical determinant in the advancement of various intractable pathological conditions including oncological disorders and hypovascular wounds, which may profoundly attenuate the efficacy of pharmacological interventions and substantially inhibit the physiological recovery processes. Consequently, in an effort to mitigate the inherent constraints of conventional methodologies (e.g., exogenous oxygen delivery systems), a self-powered triboelectric nanogenerator (TENG)-based algae-integrated pliable and enveloped device (TAPED) operates as a wearable system to sustain oxygen generation. The TAPED system harnesses biomechanical energy generated through natural bodily movements to energize an integrated luminescent source, enabling controlled photosynthesis for sustained, on-demand oxygen production. The incorporation of TENG technology renders TAPED self-sufficient, eliminating the necessity for external recharging, reducing device mass, and improving convenience for continuous oxygen delivery. Additionally, its body-attachable design circumvents risks associated with direct algal implantation, such as immunogenic reactions and infections. Specifically, experimental application of TAPED has exhibited significant therapeutic efficacy in diverse pathological conditions, including diabetic chronic infected wounds, breast carcinoma tumors, and lactic acid accumulation consequent to strenuous exercise-induced fatigue. Collectively, the TAPED represents an advanced therapeutic approach, which holds substantial potential for translational application within clinical contexts, particularly for enhancing patient prognosis in hypoxic diseases such as oncology and wound management.

Decoding Macrophage Dynamics: A Pathway to Understanding and Treating Inflammatory Skin Diseases

Psoriasis and atopic dermatitis (AD) are both chronic inflammatory skin diseases. Their pathogenesis remains incompletely understood. The polarization states of macrophages, as a crucial part of the innate immune system, are influenced by various factors such as cytokines, inflammatory mediators, and epigenetics. Research has demonstrated that macrophages play a "double-edged sword" role in the pathological process of inflammatory skin diseases: they both drive inflammation progression and participate in tissue repair. This article summarizes the roles of macrophages in the inflammatory development and tissue homeostasis of psoriasis and atopic dermatitis. It explores the impact of different factors on macrophages and inflammatory skin diseases. In conclusion, understanding the classification and plasticity of macrophages is crucial for a deeper understanding of the pathogenesis of psoriasis and AD and the development of personalized treatments.

Hydrogel-based nonwoven with persistent porosity for whole-stage hypertonic wound healing by regulating of water vaporization enthalpy

Moisture induced by wound exudate is crucial throughout the wound repair process. The dressing directly affects the absorption, permeation, and evaporation of the wound exudate. However, most dressings in clinical often result in excessive dryness or moisture of wound due to their monotonous structure and function, leading to ineffective thermodynamic control of evaporation enthalpy. Herein, a hydrogel-based nonwoven dressing (Gel-Fabric) with asymmetric amphiphilic surface and persistent microscopic porous structure is constructed by integrating intrinsic hydrophilic absorbent hydrogel fibers and hydrophobic ultrafine PET fibers. The novel Gel-Fabric facilitates rapid vertical drainage of wound exudate through the capillary effect and Laplace pressure synergy. Additionally, dynamic stepwise moisture management is also achieved by regulating the vaporization enthalpy of exudate. In vivo experiments confirm that Gel-Fabric significantly promotes wound healing, vascularization, and endothelialization, achieving a higher healing rate than ordinary dressings. Furthermore, compared to the clinical dressings, Gel-Fabric significantly reduces the frequency of dressing changes, offering improved outcomes for patients and more efficient wound management for healthcare providers.

Single-cell RNA sequencing highlights the role of proinflammatory fibroblasts, vascular endothelial cells, and immune cells in the keloid immune microenvironment

BACKGROUND

Keloids, characterized by an aberrant wound-healing process and a highly complex immune microenvironment, pose significant challenges for clinical management. Fibroblasts and vascular endothelial cells (VEC) were identified as the leading cells of keloid development. However, their roles in the keloid immune landscape have yet to be thoroughly elucidated.

METHODS

To explore the functional state of cells in the immune landscape of keloids, we conducted a single-cell RNA sequencing analysis on the tissue from three keloid lesions and two specimens of healthy skin. We simultaneously utilized available keloid data from the public database for external validation.

RESULTS

Specific subsets, such as proinflammatory fibroblasts (piF) and VEC, were markedly elevated in lesional skin compared to normal skin. Subsequent differential gene expression and Gene Ontology analyses indicated that these subsets may be involved in shaping the microenvironment. In keloids, there is an increased expression of immune-associated genes (P < 0.05), including TNFRSF6B, HGF, and TGFB3, alongside a decreased expression of inflammatory chemokines in the piF. Moreover, the significant upregulation of immune suppressive genes (P < 0.05), including CD39, CD73, and HIF1A, suggested the potential involvement of VEC as a conditional immune subpopulation in the keloid microenvironment. Immune cell communication analysis revealed preferential enrichment of macrophages and Tregs, highlighting intensified macrophage-centered interactions within the keloid microenvironment.

CONCLUSION

Our study highlighted the role of piF and VEC in the immune microenvironment of keloids for the first time, providing potential targets for therapeutic development.

Biomimetic Microstructured Scaffold with Release of Re-Modified Teriparatide for Osteoporotic Tendon-to-Bone Regeneration via Balancing Bone Homeostasis

Osteoporotic tendon-to-bone interface healing is challenging, with a high surgical repair failure rate of up to 68%. Conventional tissue engineering approaches have primarily focused on promoting interface healing by stimulating regeneration in either the tendon or bone. However, these methods often fall short of achieving optimal therapeutic outcomes due to their neglect of balancing bone homeostasis and remodeling the microstructure at the osteoporotic tendon-to-bone interface. Herein, a series of site-specific functional modifications are carried out on teriparatide to develop recombinant human parathyroid hormone (R-PTH). A biomimetic microstructured reconstruction scaffold (BMRP) is constructed using a decalcified mussel shell scaffold, pre-gel, and R-PTH. The BMRP mimics the microstructures of the native tendon-to-bone interface and restores the original structure of the interface tissue by repairing injured cells, balancing bone homeostasis, and remodeling the microstructure of the osteoporotic tendon-to-bone interface. In an osteoporotic rotator cuff tear model, BMRP is in situ implanted at the injured site, resulting in structural reconstruction and functional recovery. The BMRP demonstrates excellent repair effects, representing a novel therapeutical alternative for treating osteoporotic tendon-to-bone injury potential for clinical application.

Anisotropic structure of nanofiber hydrogel accelerates diabetic wound healing via triadic synergy of immune-angiogenic-neurogenic microenvironments

Wound healing in chronic diabetic patients remains challenging due to the multiple types of cellular dysfunction and the impairment of multidimensional microenvironments. The physical signals of structural anisotropy offer significant potential for orchestrating multicellular regulation through physical contact and cellular mechanosensing pathways, irrespective of cell type. In this study, we developed a highly oriented anisotropic nanofiber hydrogel designed to provide directional guidance for cellular extension and cytoskeletal organization, thereby achieving pronounced multicellular modulation, including shape-induced polarization of macrophages, morphogenetic maturation of Schwann cells, oriented extracellular matrix (ECM) deposition by fibroblasts, and enhanced vascularization by endothelial cells. Additionally, we incorporated a VEGF-mimicking peptide to further reinforce angiogenesis, a pivotal phase that interlocks with immune regulation, neurogenesis, and tissue regeneration, ultimately contributing to optimized inter-microenvironmental crosstalk. In vivo studies validated that the anisotropic bioactive nanofiber hydrogel effectively accelerated diabetic wound healing by harnessing the triadic synergy of the immune-angiogenic-neurogenic microenvironments. Our findings highlight the promising potential of combining physical and bioactive signals for the modulation of various cell types and the refinement of the multidimensional microenvironment, offering a novel strategy for diabetic wound healing.

Innovative modification strategies and emerging applications of natural hydrogel scaffolds for osteoporotic bone defect regeneration

Osteoporosis, a prevalent systemic metabolic bone disease, is characterized by diminished bone mass, microarchitectural deterioration of bone tissue, and heightened bone fragility. In osteoporotic patients, chronic and progressive bone loss often leads to fractures and, in advanced cases, critical-sized bone defects. While traditional bone repair approaches are constrained by significant limitations, the advent of bioactive scaffolds has transformed the therapeutic paradigm for osteoporotic bone regeneration. Among these innovations, natural polymer-based hydrogel scaffolds have emerged as a particularly promising solution in bone tissue engineering, owing to their superior biocompatibility, tunable biodegradation properties, and exceptional ability to replicate the native extracellular matrix environment. This review systematically explores recent breakthroughs in modification techniques and therapeutic applications of natural hydrogel scaffolds for osteoporotic bone defect repair, while critically analyzing existing clinical challenges and proposing future research trajectories in this rapidly evolving field.

Dissecting inflammation in the immunemetabolomic era

The role of immune metabolism, specific metabolites and cell-intrinsic and -extrinsic metabolic states across the time course of an inflammatory response are emerging knowledge. Targeted and untargeted metabolomic analysis is essential to understand how immune cells adapt their metabolic program throughout an immune response. In addition, metabolomic analysis can aid to identify pathophysiological patterns in inflammatory disease. Here, we discuss new metabolomic findings within the transition from inflammation to resolution, focusing on three key programs of immunity: Efferocytosis, IL-10 signaling and trained immunity. Particularly the tryptophan-derived metabolite kynurenine was identified as essential for efferocytosis and inflammation resolution as well as a potential biomarker in diverse inflammatory conditions. In summary, metabolomic analysis and integration with transcriptomic and proteomic data, high resolution imaging and spatial information is key to unravel metabolic drivers and dependencies during inflammation and progression to tissue-repair.

Mechanisms and therapeutic opportunities in metabolic aberrations of diabetic wounds: a narrative review

Metabolic aberrations are fundamental to the complex pathophysiology and challenges associated with diabetic wound healing. These alterations, induced by the diabetic environment, trigger a cascade of events that disrupt the normal wound-healing process. Key factors in this metabolic alternation include chronic hyperglycemia, insulin resistance, and dysregulated lipid and amino acid metabolism. In this review, we summarize the underlying mechanisms driving these metabolic changes in diabetic wounds, while emphasizing the broad implications of these disturbances. Additionally, we discuss therapeutic approaches that target these metabolic anomalies and how their integration with existing wound-healing treatments may yield synergistic effects, offering promising avenues for innovative therapies.

MLKL is involved in the regulation of skin wound healing and interplay between macrophages and myofibroblasts in mice

Mixed lineage kinase domain-like protein (MLKL), a critical necroptosis effector, is strongly linked to inflammation, a key component of skin wound healing. However, its precise role in the wound healing process remains inadequately characterized. This study revealed sustained MLKL overexpression throughout the wound healing process, not limited to the early inflammation phase. Wound healing was delayed in MLKL-deficient (MLKL-/-) mice compared to wild type C57BL/6J (MLKL+/+) mice, with impaired morphological and pathological recovery. MLKL deficiency reduced the synthesis of inflammatory factors (IL-6, TNF-α, PGE2), tissue repair molecules (EGF, VEGF, ERα, MMP-9), and apoptosis markers (Caspase-3, p53, Bcl-2) at wound site. Subsequently, a co-culture system was established to explore the roles of MLKL in macrophage-fibroblast interactions. M1 or M2 macrophages (M1ø or M2ø) were co-cultured with fibroblast-conditioned medium (MFbCM), and fibroblasts were co-cultured with macrophage-conditioned medium (M1ø CM or M2ø CM). The results indicated that MLKL+/+ M1ø CM and M2ø CM significantly increased ERα, VEGF and MMP-9 protein expression levels in fibroblasts, whereas this effect was impaired when MLKL-/- M1ø CM or M2ø CM were used. Similarly, MLKL+/+ MFbCM upregulated IL-6, NO, and TNF-α in M1ø and IL-10, arginase, and Ym-1 in M2ø, but these effects were diminished with MLKL-/- MFbCM treatment. These results indicate bidirectional crosstalk between macrophages and fibroblasts, in which MLKL plays a role. Additionally, PGE2 was identified as a downstream mediator of MLKL-mediated interactions between macrophages and fibroblasts. In conclusion, these findings identify MLKL as a multifunctional regulator in skin wound healing in mice.

SHP099-containing multi-targeting hydrogel promotes rapid skin reconstruction through modulating a variety of cells

Introduction

Adult wound scarring result in functional skin deficits. However, the development of effective measures to modulate the entire wound healing to encourage the skin function reconstruction is still a clinical challenge, as multiple cells are involved in wound healing hierarchically. Hydrogel scaffolds with long-lasting local release provide new insights into the clinical relevance of entire wound healing.

Methods

Herein, a multi-targeting hydrogel loaded with SHP099 (Gel-SHP) is designed to modulate multiple cells during wound repair.

Results

Our results show that Gel-SHP promotes rapid reconstruction of wound skin by modulating macrophages in the inflammatory stage, fibroblasts in the regeneration stage and smooth muscle cells in the remodelling stage. Gel-SHP could increase M2 macrophage differentiation and remodel the dermal shell of hair follicles through in situ release. Moreover, Gel-SHP may modulate myofibroblasts to promote wound contraction through SHP099-scaffold synergistic interactions.

Discussion

Our results provide new insights into the design of functional hydrogels for tissue regeneration applications. Gel-SHP as a promising tool could provide new clues and new research paradigms for future studies and understanding of the wound healing process and dermal shell formation.

Mind-body therapies and their interplay with the immune system in children and adolescents: a protocol for a systematic review and meta-analysis

BACKGROUND

Chronic inflammation is a critical public health concern that, in children and adolescents, increases the long-term risk of a variety of different health issues. While mind-body therapies like yoga, meditation, and acupuncture have shown promise in modulating immune responses in adults, their safety and effectiveness in pediatric populations remain underexplored. This protocol outlines the methodology for a systematic review and meta-analysis aimed at evaluating the effects of mind-body therapies on immune modulation in children and adolescents.

METHODS

This systematic review and meta-analysis will follow PRISMA 2020 guidelines. We will include randomized controlled trials, non-randomized controlled trials, cohort studies, and case-control studies that examine the relationship between mind-body therapies and immune markers in pediatric populations. Electronic searches will be conducted in MEDLINE, Embase, PsycINFO, CINAHL, Web of Science, and the Cochrane Library, supplemented by trial registries. Risk of bias will be assessed using the Cochrane Risk of Bias Tool (RoB 1), the Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I), and the Newcastle-Ottawa Scale (NOS). Two independent reviewers will screen studies, extract data, and assess study quality, with a third reviewer resolving any discrepancies. Results will be synthesized both narratively and through meta-analysis using R software.

DISCUSSION

The review will evaluate the effectiveness and safety of mind-body therapies on immune markers in children and adolescents. The synthesized evidence will guide clinical practice and public health policies in integrating mind-body therapies into pediatric care. The findings will also provide a foundation for future research and policymaking in this area.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42024546585.

Ferroptosis in organ fibrosis: Mechanisms and therapeutic approaches

Ferroptosis, a form of iron-dependent regulated cell death, has emerged as a critical mechanism in the pathogenesis of organ fibrosis. This review aims to provide an overview of the molecular mechanisms underlying ferroptosis and its contribution to fibrosis in various organs, including the liver, lung, heart, and kidneys. We explore how dysregulated iron metabolism, lipid peroxidation, and oxidative stress contribute to ferroptosis and subsequent tissue damage, promoting the progression of fibrosis. In addition, we highlight the complex interplay between ferroptosis and other cellular processes such as apoptosis, necrosis, and inflammation in the fibrotic microenvironment. Furthermore, this review discusses current therapeutic strategies targeting ferroptosis, including iron chelation, antioxidants, and modulators of lipid peroxidation. We also examine ongoing clinical and preclinical studies aimed at translating these findings into viable treatments for fibrotic diseases. Understanding the role of ferroptosis in organ fibrosis offers novel therapeutic opportunities, with the potential to mitigate disease progression and improve patient outcomes.

Self-Healing Hydrogel Dressing with Solubilized Flavonoids for Whole Layer Regeneration of Diabetic Wound

Hydrogels are soft, tissue-like materials that have great potential as wound dressings. However, most hydrogels are unsatisfactory in achieving whole-layer regeneration of diabetic wounds due to the complex pathological microenvironment and irregular wound shapes. Here, a glucose-responsive and self-adaptive phenylboronic acid (PBA) hydrogel solubilized strong antioxidant flavonoids (Gel-Flavonoids) is developed via dynamic borate bonds. The Gel-Flavonoids system can spontaneously confirm to the irregular wound shape and release flavonoids in a high-glucose microenvironment to effectively eliminate reactive oxygen species (ROS). The optimized Gel-Flavonoids demonstrate remarkable efficacy in inhibiting inflammation and activating fibroblasts and endothelial cells through CD36-activated lipid metabolism in macrophages and is significantly superior to commercial dressings (3M) in healing rate (> 93%, 14 days) and whole-layer regeneration effect. This study obtained a multidimensional Gel-Flavonoids system to effectively repair diabetic wounds, and reveal the underlying therapeutic mechanisms, offering a promising insight to guide the development of medical materials to treat diabetic wounds.

High-Strength Gelatin Hydrogel Scaffold with Drug Loading Remodels the Inflammatory Microenvironment to Enhance Osteoporotic Bone Repair

Osteoporosis is a widespread condition that induces an inflammatory microenvironment, limiting the effectiveness of conventional therapies and presenting significant challenges for bone defect repair. To address these issues, a high-strength gelatin hydrogel scaffold loaded with roxadustat is developed, specifically designed to remodel the inflammatory microenvironment and enhance osteoporotic bone regeneration. By incorporating minimal methacrylated hyaluronic acid (HAMA) into an o-nitrobenzyl functionalized gelatin (GelNB) matrix, a gelatin hydrogel with a fracture strength of 10 MPa is achieved, providing exceptional structural stability and enabling precise scaffold fabrication through digital light processing (DLP) 3D printing. Validated through cell experiments and animal studies, the hydrogel scaffold supports cell adhesion and migration, offers excellent tissue compatibility, and is fully degradable, meeting the requirements of a therapeutic scaffold. Including roxadustat further enhances the scaffold's functionality by regulating the inflammatory microenvironment via hypoxia-inducible factor-1α (HIF-1α) signaling, significantly improving bone defect repair in osteoporotic models. This drug-loaded scaffold effectively addresses inflammation-induced limitations and enhances the regenerative capacity of the affected area, paving the way for improved therapeutic outcomes in osteoporotic bone repair.

The Effects of Perioperative Corticosteroids on Postoperative Complications After Pancreatoduodenectomy: A Debated Topic of Systematic Review and Meta-analysis

BACKGROUND

The intraoperative administration of corticosteroids has been shown to improve postoperative outcomes in patients undergoing surgery; however, the impact of corticosteroids on complications following pancreatoduodenectomy (PD) remains controversial.

OBJECTIVE

This study aimed to evaluate the efficacy of perioperative corticosteroids on postoperative complications after PD.

MATERIALS AND METHODS

A comprehensive search was conducted using the PubMed, Embase, and Web of Science databases for studies published prior to 1 July 2024. Of 7418 articles identified, a total of 5 studies were eligible for inclusion in this meta-analysis. The primary outcome was incidence of postoperative major complications (PMCs), while the additional outcomes were incidences of postoperative pancreatic fistulas (POPFs), infection, delayed gastric emptying (DGE), post-pancreatectomy hemorrhage (PPH), bile leakage, reoperation, and 30-day mortality. The study was registered in the PROSPERO database (CRD42024524936).

RESULTS

Finally, 5 studies involving 1449 patients (537 with corticosteroids and 912 without corticosteroids) were analyzed. Intraoperative corticosteroids were not associated with any improvement in PMCs (p = 0.41). The incidence of POPF (p = 0.12), infectious complications (p = 0.15), or DGE (p = 0.81) were not significantly different between the two groups. No obvious differences were found in the incidence of PPH (p = 0.42), bile leakage (p = 0.68), 30-day mortality (p = 0.99), or reoperation (p = 0.26).

CONCLUSION

Perioperative corticosteroids did not significantly demonstrate any protective advantage in terms of postoperative complications after PD. This finding may serve as a reference for the perioperative use of corticosteroids in pancreatic surgery. Well-designed clinical trials are warranted in the near future in order to provide high-level evidence.

ENKD1 modulates innate immune responses through enhanced geranylgeranyl pyrophosphate synthase activity

Inflammation is a crucial element of immune responses, with pivotal roles in host defenses against pathogens. Comprehensive understanding of the molecular mechanisms underlying inflammation is imperative for developing effective strategies to combat infectious diseases. Here, we conducted a screening analysis and identified enkurin domain-containing protein 1 (ENKD1) as a promising regulator of inflammation. We observed that ENKD1 expression was significantly reduced on activation of multiple Toll-like receptor (TLR) molecules. Deletion of ENKD1 resulted in enhanced innate immune system activation and exacerbation of septic inflammation. Mechanistically, ENKD1 interacted with geranylgeranyl diphosphate synthase 1 (GGPS1) and modulated its enzymatic activity, thereby influencing geranylgeranyl diphosphate production. This interaction ultimately led to Ras-related C3 botulinum toxin substrate 1 (RAC1) inactivation and suppression of pro-inflammatory signaling pathways. Our findings establish ENKD1 as a critical regulator of innate immune cell activation, underscoring its significant role in septic inflammation.

Selective promotion of sensory innervation-mediated immunoregulation for tissue repair

Sensory innervation triggers the regenerative response after injury. However, dysfunction and impairment of sensory nerves, accompanied by excessive inflammation impede tissue regeneration. Consequently, specific induction of sensory innervation to mediate immunoregulation becomes a promising therapeutic approach. Herein, we developed a cell/drug-free strategy to selectively boost endogenous sensory innervation to harness immune responses for promoting tissue rehabilitation. Specifically, a dual-functional phage was constructed with a sensory nerve-homing peptide and a β-subunit of nerve growth factor (β-NGF)-binding peptide. These double-displayed phages captured endogenic β-NGF and localized to sensory nerves to promote sensory innervation. Furthermore, regarding bone regeneration, phage-loaded hydrogels achieved rapid sensory nerve ingrowth in bone defect areas. Mechanistically, sensory neurotization facilitated M2 polarization of macrophages through the Sema3A/XIAP/PAX6 pathway, thus decreasing the M1/M2 ratio to induce the dissipation of local inflammation. Collectively, these findings highlight the essential role of sensory innervation in manipulating inflammation and provide a conceptual framework based on neuroimmune interactions for promoting tissue regeneration.

Exercise and tissue fibrosis: recent advances in therapeutic potential and molecular mechanisms

Tissue fibrosis represents an aberrant repair process, occurring because of prolonged injury, sustained inflammatory response, or metabolic disorders. It is characterized by an excessive accumulation of extracellular matrix (ECM), resulting in tissue hardening, structural remodeling, and loss of function. This pathological phenomenon is a common feature in the end stage of numerous chronic diseases. Despite the advent of novel therapeutic modalities, including antifibrotic agents, these have only modest efficacy in reversing established fibrosis and are associated with adverse effects. In recent years, a growing body of research has demonstrated that exercise has significant benefits and potential in the treatment of tissue fibrosis. The anti-fibrotic effects of exercise are mediated by multiple mechanisms, including direct inhibition of fibroblast activation, reduction in the expression of pro-fibrotic factors such as transforming growth factor-β (TGF-β) and slowing of collagen deposition. Furthermore, exercise has been demonstrated to assist in maintaining the dynamic equilibrium of tissue repair, thereby indirectly reducing tissue damage and fibrosis. It can also help maintain the dynamic balance of tissue repair by improving metabolic disorders, exerting anti-inflammatory and antioxidant effects, regulating cellular autophagy, restoring mitochondrial function, activating stem cell activity, and reducing cell apoptosis, thereby indirectly alleviating tissue. This paper presents a review of the therapeutic potential of exercise and its underlying mechanisms for the treatment of a range of tissue fibrosis, including cardiac, pulmonary, renal, hepatic, and skeletal muscle. It offers a valuable reference point for non-pharmacological intervention strategies for the comprehensive treatment of fibrotic diseases.

Development and Characterization of PEGylated Poly D,L-Lactic Acid Nanoparticles for Skin Rejuvenation

Recently, various biocompatible and biodegradable materials have garnered significant attention as cosmetic fillers for skin rejuvenation. Among these, poly ε-caprolactone (PCL), poly L-lactic acid (PLLA), poly D,L-lactic acid (PDLLA), and polydioxanone (PDO) microspheres have been developed and commercialized as a dermal filler. However, its irregularly hydrophobic microspheres pose hydration challenges, often causing syringe needle blockages and side effects such as delayed onset nodules and papules after the procedure. In this study, we synthesized a polyethylene glycol-poly D,L-lactic acid (mPEG-PDLLA) copolymer to address the limitations of conventional polymer fillers. Comprehensive characterization of the copolymer was performed using nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, and differential scanning calorimetry. The mPEG-PDLLA copolymers demonstrated a unimodal size distribution of approximately 121 ± 20 nm in an aqueous solution. The in vitro cytotoxicity and collagen genesis of mPEG-PDLLA copolymers were evaluated using human dermal fibroblast cells. In this study, angiogenesis was observed over time in hairless mice injected with mPEG-PDLLA copolymers, confirming its potential role in enhancing collagen synthesis. To assess the inflammatory response, the expression levels of the genes MMP1 and IL-1β were analyzed. Additionally, gene expression levels such as transforming growth factor-β and collagen types I and III were compared with Rejuran® in animal studies. The newly developed collagen-stimulating PEGylated PDLLA may be a safe and effective option for skin rejuvenation.

Fibrosis: cross-organ biology and pathways to development of innovative drugs

Fibrosis is a pathophysiological mechanism involved in chronic and progressive diseases that results in excessive tissue scarring. Diseases associated with fibrosis include metabolic dysfunction-associated steatohepatitis (MASH), inflammatory bowel diseases (IBDs), chronic kidney disease (CKD), idiopathic pulmonary fibrosis (IPF) and systemic sclerosis (SSc), which are collectively responsible for substantial morbidity and mortality. Although a few drugs with direct antifibrotic activity are approved for pulmonary fibrosis and considerable progress has been made in the understanding of mechanisms of fibrosis, translation of this knowledge into effective therapies continues to be limited and challenging. With the aim of assisting developers of novel antifibrotic drugs, this Review integrates viewpoints of biologists and physician-scientists on core pathways involved in fibrosis across organs, as well as on specific characteristics and approaches to assess therapeutic interventions for fibrotic diseases of the lung, gut, kidney, skin and liver. This discussion is used as a basis to propose strategies to improve the translation of potential antifibrotic therapies.

The fibroinflammatory response in cancer

Fibroinflammation refers to the highly integrated fibrogenic and inflammatory responses mediated by the concerted function of fibroblasts and innate immune cells in response to tissue perturbation. This process underlies the desmoplastic remodelling of the tumour microenvironment and thus plays an important role in tumour initiation, growth and metastasis. More specifically, fibroinflammation alters the biochemical and biomechanical signalling in malignant cells to promote their proliferation and survival and further supports an immunosuppressive microenvironment by polarizing the immune status of tumours. Additionally, the presence of fibroinflammation is often associated with therapeutic resistance. As such, there is increasing interest in targeting this process to normalize the tumour microenvironment and thus enhance the treatment of solid tumours. Herein, we review advances made in unravelling the complexity of cancer-associated fibroinflammation that can inform the rational design of therapies targeting this.

Advancements in 3D gel culture systems for enhanced angiogenesis in bone tissue engineering

Angiogenesis-osteogenesis coupling is a crucial process in bone tissue engineering, requiring a suitable material structure for vessel growth. Recently, the 3D culture system has gained significant attention due to its benefits in cell growth, proliferation and tissue regeneration. Its most notable advantage is its ECM-like function, which supports endothelial cell adhesion and facilitates the formation of vascular-like networks-crucial for angiogenesis-osteogenesis coupling. Hydrogels, with their highly hydrophilic polymer network resembling the extracellular matrix, make the 3D gel culture system an ideal approach for angiogenesis due to its cellular integrity and adjustable properties. This article reviews the current use of 3D gel culture systems in bone tissue engineering, covering substrates, characteristics and processing technologies, thereby offering readers profound insights into these systems.

Wound healing and anti-inflammatory effects of LAA, the N-acetyl-D-galactosamine-binding lectin from seeds of Luetzelburgia auriculata (Allemão) ducke

Cutaneous wounds represent a significant health concern, and effective treatment strategies are crucial for optimal healing. This study investigates the therapeutic potential of Luetzelburgia auriculata lectin (LAA), a plant-derived protein, in accelerating wound closure. Excisional wounds were created on the backs of mice, which were subsequently treated topically with LAA solutions at two concentrations (100 µg/mL and 200 µg/mL) or saline control. Wound healing was assessed through clinical observations, including wound area measurement and inflammatory score, as well as histopathological analysis and measurement of inflammatory cytokines. LAA significantly accelerated wound closure, reduced inflammation, and promoted tissue regeneration. Histological analysis revealed enhanced re-epithelialization, increased fibroblast proliferation, and improved collagen deposition in LAA-treated wounds compared with the control group. Furthermore, LAA treatment significantly reduced the levels of proinflammatory cytokines in wound tissues (interleukin-6, tumor necrosis factor-alpha, and monocyte chemoattractant protein-1). These findings suggest that LAA exerts its beneficial effects through a multifaceted mechanism, likely involving anti-inflammatory properties and stimulation of cellular processes crucial for tissue repair. This study provides preliminary evidence for the therapeutic potential of LAA in wound healing and warrants further investigation into its underlying mechanisms and clinical applications.

Long-lasting comfort ocular surface drug delivery by in situ formation of an adhesive lubricative Janus nanocoating

Topical drug delivery on ocular surface always suffers from frequent administration and low bioavailability due to short drug residence. Despite advances of different adhesive ophthalmic drugs in extending release, cornea and eyelid nonselective adhesion inevitably causes ocular discomfort and even damage. Here, we describe in situ formation of an adhesive lubricative Janus nanocoating (ALJN) to enable long-lasting comfort drug delivery. By iron complexation, an asymmetric ALJN is formed on ocular surface via facile sequential instillation. The adhesive polyphenol inner layer binding with ocular surface enables drug loading and sustained release, while the lubricative zwitterionic polymer outer layer prevents eyelid adhesion to ensure comfort. Following instillation, ALJN retains on ocular surface over 24 hours and reduces blinking frequency to normal level. Moreover, ALJN demonstrates remarkable therapeutic potential in mouse and rabbit models of corneal contusion and alkali burn. This work proposes a comfortable long-lasting topical delivery platform for treating various ocular diseases.

Electrospinning in promoting chronic wound healing: materials, process, and applications

In the field of wound treatment, chronic wounds pose a significant burden on the medical system, affecting millions of patients annually. Current treatment methods often fall short in promoting effective wound healing, highlighting the need for innovative approaches. Electrospinning, a technique that has garnered increasing attention in recent years, shows promise in wound care due to its unique characteristics and advantages. Recent studies have explored the use of electrospun nanofibers in wound healing, demonstrating their efficacy in promoting cell growth and tissue regeneration. Researchers have investigated various materials for electrospinning, including polymers, ceramics, carbon nanotubes (CNTs), and metals. Hydrogel, as a biomaterial that has been widely studied in recent years, has the characteristics of a cell matrix. When combined with electrospinning, it can be used to develop wound dressings with multiple functions. This article is a review of the application of electrospinning technology in the field of wound treatment. It introduces the current research status in the areas of wound pathophysiology, electrospinning preparation technology, and dressing development, hoping to provide references and directions for future research.

An active shrinkage and antioxidative hydrogel with biomimetic mechanics functions modulates inflammation and fibrosis to promote skin regeneration

Achieving scar-free skin regeneration in clinical settings presents significant challenges. Key issues such as the imbalance in macrophage phenotype transition, delayed re-epithelialization, and excessive proliferation and differentiation of fibroblasts hinder wound healing and lead to fibrotic repair. To these, we developed an active shrinkage and antioxidative hydrogel with biomimetic mechanical functions (P&G@LMs) to reshape the healing microenvironment and effectively promote skin regeneration. The hydrogel's immediate hemostatic effect initiated sequential remodeling, the active shrinkage property sealed and contracted the wound at body temperature, and the antioxidative function eliminated ROS, promoting re-epithelialization. The spatiotemporal release of LMs (ACEI) during the inflammation phase regulated macrophage polarization towards the anti-inflammatory M2 phenotype, promoting progression to the proliferation phase. However, the profibrotic niche of macrophages induced a highly contractile α-SMA positive state in myofibroblasts, whereas the sustained LMs release could regulate this niche to control fibrosis and promote the correct biomechanical orientation of collagen. Notably, the biomimetic mechanics of the hydrogel mimicked the contraction characteristics of myofibroblasts, and the skin-like elastic modulus could accommodate the skin dynamic changes and restore the mechanical integrity of wound defect, partially substituting myofibroblasts' mechanical role in tissue repair. This study presents an innovative strategy for skin regeneration.

Efficacy of Formulation With Potential as Herbal Medicine on Second Degree Burn Wound: Biochemical and Molecular Evaluation

BACKGROUND

Burn injury is a condition caused by heat, cold, electricity, synthetic substances, and radiation, and it causes psychological and physical problems in the affected individuals.

AIMS

In this study, it was aimed to investigate the healing effect of the spray formulation prepared using ethanol extracts of Olea europaea and Aloe vera leaves, Cocus nucifera fruit, and Chamomilla recutita flower plants (OACC) in a second-degree burn model created in rats, using biochemical and molecular parameters.

METHODS

Experimental groups were assigned to Healthy control (HC), Burn control (BC), Silver-Sulfadiazine (SS) and OACC. A deep second-degree burn was induced on the lower back and upper back of each rat under standard burning procedures, respectively. Experiments were performed using serum and skin tissue samples obtained on the 3rd-21st days after the burns were created. Malondialdehyde (MDA) and superoxide dismutase (SOD) levels were calculated. Transforming Growth Factor Beta-1 (Tgf-β1), Vascular Endothelial Growth Factor-alfa (Vegf-α), interleukin-6 (Il-6) and Tumor Necrosis Factor Alpha (Tnf-α) mRNA expression levels were determined using real-time polymerase chain reaction (RT-PCR).

RESULTS

AOCC reduced the increased MDA levels in serum related to the burning event, while increasing the decreased SOD enzyme activity levels. In addition, AOCC decreased the gene expression levels of Tgf-β1 and Vegf-α, which are growth factors that were increased in the burn group, and Il-6 and Tnf-α, which are oxidative stress markers.

CONCLUSIONS

We believe that our study will shed light on the detailed examination of biochemical and molecular pathways affecting the wound healing process in future studies and will contribute to opening new doors for treatment.

A thermosensitive chitin hydrogel with mild photothermal-chemotherapy for facilitating multidrug-resistant bacteria infected wound healing

Bacterial infection of skin wounds leads to serious health problems, including skin defects, inflammatory pain, and even death. To meet the requirements for successful treatment of complicated wounds, a multifunctional dressing is thus highly desirable. In this work, a thermosensitive hydrogel dressing (HBCA) exhibiting injectability, adaptiveness and mild photothermal antibacterial activity was developed for effective infected wound treatment. The HBCA hydrogel was constructed by integrating Ag NPs-incorporated quaternized chitin (DQCA) into the matrix of hydroxybutyl chitin. Laser irradiation could activate the photothermal DQCA to generate heat and rapidly induce the destruction of the bacterial integrity. Meanwhile, the release of DQCA can be accelerated by laser-mediated heating in a controllable manner, quickly reaching the effective concentration and leading to bacterial inactivation in a combined way. The HBCA hydrogel possessed broad-spectrum antibacterial and antibiofilm effect under mild temperature (~48 °C), through combining photothermal therapy (PTT) with chemotherapeutic DQCA. Furthermore, the mouse full-thickness MRSA-infected wound healing test demonstrated that the HBCA hydrogel could accelerate wound regeneration by reducing the inflammatory response, promoting re-epithelialization as well as collagen maturation. This work presents an efficacious and straightforward antibacterial hydrogel dressing that incorporates mild-temperature PTT, particularly in the realm of multidrug-resistant bacterial infection therapies.

Rescue of non-healing, degenerative salivary glands by cholinergic-calcium signaling

Chronic degenerative wounds are often deemed irreparable, directing research efforts to focus predominantly on acute tissue injury regeneration while leaving endogenous repair mechanisms for chronically damaged tissues largely unexplored. In this study, we demonstrate that non-healing, severely degenerated salivary gland tissues can be fundamentally restored through first-line treatment with muscarinic agonists. This approach rescues tissue structure and function, returning it to a homeostatic-like state, and reactivates endogenous regeneration processes to drive new cell expansion that persists for months post-treatment. Furthermore, neuromimetic activation profoundly depletes radiation-induced DNA damage and re-establishes the nerve-acinar relationship, ultimately restoring the tissues physiological capacity to maintain homeostasis, even in the absence of treatment. We show that full recovery of organ function, comparable to uninjured controls, is primarily mediated by the re-differentiation of aberrantly de-differentiated epithelial acinar cells and the restoration of mitochondrial function via a muscarinic-calcium signaling pathway. These findings challenge the prevailing notion that chronic organ degeneration is irreversible and propose a readily testable therapeutic strategy for epithelial restoration with potential applications across a spectrum of chronic injuries.

Regenerative effect of lyophilized dental follicle mesenchymal stem cells and platelet-rich fibrin in skin wounds in geriatric and young rats

The aim of this study was to investigate the regenerative effect of lyophilized dental follicle mesenchymal stem cells (DF-MSCs) combined with rat platelet-rich fibrin (PRF) on geriatric skin wounds. Human DF-MSCs which were isolated from the wisdom teeth of healthy donors and PRF were mixed and incubated in a 37 °C incubator for 1-2 h containing 1 million cells in 150 mg PRF. The mixture was suspended in a freeze-drying solution and then lyophilized. Wounds were created on the back skin of Wistar albino rats using a 6 mm punch. Lyophilized DF-MSCs, PRF, or PRF + DF-MSCs were applied to the wounds of rats. On the 15th day, the wound area was histopathologically evaluated in rats. Blood samples from rats were analyzed for total antioxidant status (TAOS), and inflammatory cytokine levels using ELISA. In both young and geriatric rats treated with lyophilized PRF + DF-MSCs, wound area began to significantly decrease from the 10th day compared to the untreated group (p < 0.05). Histopathological examination revealed that in the lyophilized PRF + DF-MSCs treated groups, epithelial integrity and scarless healing significantly increased compared to the untreated groups (p < 0.05). There were no significant differences in TAOS, total oxidant status (TOS), tumor necrosis factor (TNF), interleukin-6 (IL6), and hydroxyproline levels in serum samples from young rats on the 15th day. In geriatric rats, hydroxyproline (HYPS) levels were increased in the DF-MSC and PRF + DF-MSC groups (p < 0.01), TNF was significantly elevated in PRF geriatric group and IL6 was increased in the PRF group compared to the control group (p = 0.01). Lyophilized PRF + DF-MSCs, which is a shelf-stable and ready-to-use product, hold promise, especially for traumatic wounds in geriatric individuals with longer healing times.

Autophagy in Tissue Repair and Regeneration

Autophagy is a cellular recycling system that, through the sequestration and degradation of intracellular components regulates multiple cellular functions to maintain cellular homeostasis and survival. Dysregulation of autophagy is closely associated with the development of physiological alterations and human diseases, including the loss of regenerative capacity. Tissue regeneration is a highly complex process that relies on the coordinated interplay of several cellular processes, such as injury sensing, defense responses, cell proliferation, differentiation, migration, and cellular senescence. These processes act synergistically to repair or replace damaged tissues and restore their morphology and function. In this review, we examine the evidence supporting the involvement of the autophagy pathway in the different cellular mechanisms comprising the processes of regeneration and repair across different regenerative contexts. Additionally, we explore how modulating autophagy can enhance or accelerate regeneration and repair, highlighting autophagy as a promising therapeutic target in regenerative medicine for the development of autophagy-based treatments for human diseases.

Pulsed electromagnetic fields modulate energy metabolism during wound healing process: an in vitro model study

BACKGROUND

Pulsed electromagnetic fields (PEMFs) therapy was extensively investigated to treat wound healing, which is a highly metabolically demanding process. However, the effect of PEMFs on energy metabolism in wound healing remains largely unexplored. Therefore, our study aims to demonstrate the role of PEMFs on energy metabolism in wound healing.

METHODS

Scratch-wound healing assay and cell viability assay were performed for the in vitro study of the effect of PEMFs on cell migration and viability. Seahorse assay was conducted for energy metabolism analysis while holo-tomographic microscopy for fine changes of L929 cells. Mitochondrial membrane potential assay and intracellular reactive oxygen species (ROS) and pH assay were performed for analyzing the changes of mitochondrial function.

RESULTS

PEMFs with specific parameter (4mT, 80 Hz) promoted cell migration and viability. Glycolysis stress and mitochondria stress test revealed that PEMFs-exposed L929 cells was highly glycolytic for energy generation. Besides, PEMFs enhanced intracellular acidification and maintained low level of intracellular ROS in L929 cells. Compared to control group, much more vesicles were generated and then transported to regions close to the nuclear in L929 cells treated with PEMFs.

CONCLUSIONS

Our major findings revealed for the first time that PEMFs induce metabolic reprogramming of fibroblast shifting from mitochondrial respiration to glycolysis, accompanied with an increase of vesicular transport, which is closely related to wound healing in vitro.

Compliant immune response of silk-based biomaterials broadens application in wound treatment

The unique properties of sericin and silk fibroin (SF) favor their widespread application in biopharmaceuticals, particularly in wound treatment and bone repair. The immune response directly influences wound healing cycle, and the extensive immunomodulatory functions of silk-based nanoparticles and hydrogels have attracted wide attention. However, different silk-processing methods may trigger intense immune system resistance after implantation into the body. In this review, we elaborate on the inflammation and immune responses caused by the implantation of sericin and SF and also explore their anti-inflammatory properties and immune regulatory functions. More importantly, we describe the latest research progress in enhancing the immunotherapeutic and anti-inflammatory effects of composite materials prepared from silk from a mechanistic perspective. This review will provide a useful reference for using the correct processes to exploit silk-based biomaterials in different wound treatments.

Regulation of 5-fluorouracil-induced intestinal damage by the interleukin-23/interleukin-22 axis in chemotherapy

5-Fluorouracil (5-FU) is a primary chemotherapeutic agent for gastrointestinal cancers, known to improve survival but also cause significant intestinal damage, affecting patient quality of life. This study investigated the IL-23-IL-22 axis's role in moderating 5-FU-induced intestinal damage. We analyzed paracancerous tissue damage in colon cancer patients with different Tumor Regression Grade (TRG) and found a direct correlation between TRG and tissue damage severity, indicating that higher chemotherapy effectiveness is linked to increased tissue damage. In a 5-FU-treated mouse model, we observed severe intestinal damage and a reduction in proliferative cells. Transcriptome sequencing and immunofluorescence revealed that myeloid cells in damaged tissues produced IL-23, which activated ILC3s to secrete IL-22, promoting tissue repair and homeostasis. IL-22 supplementation in deficient mice significantly mitigated damage, underscoring the IL-22/IL-23 axis's potential as a therapeutic target to reduce chemotherapy-induced damage and enhance recovery. This research advances understanding of the biochemical responses to chemotherapy and suggests new avenues for developing therapies to maintain intestinal integrity during cancer treatment.

Research Advances and Application Progress on miRNAs in Exosomes Derived From M2 Macrophage for Tissue Injury Repairing

Tissue injury repair is a multifaceted and dynamic process characterized by complex interactions among various immune cells, with M2 macrophages assuming a crucial role. Exosomes derived from M2-type macrophages (M2-Exos) significantly influence the injury repair process through intercellular communication mediated by enriched microRNAs (miRNAs). This review aims to elucidate the biological processes underlying exosome formation, the synthesis and function of miRNAs, and the diverse methodologies employed for exosome extraction. Furthermore, we provide a comprehensive summary of the established multifarious functions and mechanisms of M2-Exos miRNAs in tissue injury repair across different systems, while also exploring their potential applications in disease prevention, diagnosis, and clinical practice. Despite the challenges encountered, the therapeutic use of M2-Exos in clinical contexts appears promising, prompting research efforts to focus on improving the efficiency of exosome extraction and application, as well as ensuring the safety of their clinical utilization.

The Implications of Brain-Derived Neurotrophic Factor in the Biological Activities of Platelet-Rich Plasma

Platelet-rich plasma (PRP) is a biological blood-derived therapeutic obtained from whole blood that contains higher levels of platelets. PRP has been primarily used to mitigate joint degeneration and chronic pain in osteoarthritis (OA). This clinical applicability is based mechanistically on the release of several proteins by platelets that can restore joint homeostasis. Platelets are the primary source of brain-derived neurotrophic factor (BDNF) outside the central nervous system. Interestingly, BDNF and PRP share key biological activities with clinical applicability for OA management, such as anti-inflammatory, anti-apoptotic, and antioxidant. However, the role of BDNF in PRP therapeutic activities is still unknown. Thus, this work aimed to investigate the implications of BDNF in therapeutic outcomes provided by PRP therapy in vitro and in-vivo, using the MIA-OA animal model in male Wistar rats. Initially, the PRP was characterized, obtaining a leukocyte-poor-platelet-rich plasma (LP-PRP). Our assays indicated that platelets activated by Calcium release BDNF, and suppression of M1 macrophage polarization induced by LP-PRP depends on BDNF full-length receptor, Tropomyosin Kinase-B (TrkB). OA animals were given LP-PRP intra-articular and showed functional recovery in gait, joint pain, inflammation, and tissue damage caused by MIA. Immunohistochemistry for activating transcriptional factor-3 (ATF-3) on L4/L5 dorsal root ganglia showed the LP-PRP decreased the nerve injury induced by MIA. All these LP-PRP therapeutic activities were reversed in the presence of TrkB receptor antagonist. Our results suggest that the therapeutic effects of LP-PRP in alleviating OA symptoms in rats depend on BDNF/TrkB activity.

The dual role of PGAM5 in inflammation

In recent years, the focus on human inflammation in research has increased, with aging-related inflammation widely recognized as a defining characteristic of aging. Inflammation is strongly correlated with mitochondrial dysfunction. Phosphoglycerate mutase family member 5 (PGAM5) is a novel modulator of mitochondrial homeostasis in response to mechanical stimulation. Here we review the structure and sublocalization of PGAM5, introduce its importance in programmed cell death and summarize its crucial roles in the development and progression of inflammatory diseases such as pneumonia, hepatitis, neuroinflammation and aging. Notably, PGAM5 has dual effects on controlling inflammation: distinct PGAM5-mediated mitochondrial functions exhibit cellular heterogeneity, leading to its dual functions in inflammation control. We therefore highlight the double-edged sword nature of PGAM5 as a potential critical regulator and innovative therapeutic target in inflammation. Finally, the challenges and future directions of the use of PGAM5, which has dual properties, as a target molecule in the clinic are discussed. This review provides crucial insights to guide the development of intelligent therapeutic strategies targeting PGAM5-specific regulation to treat intractable inflammatory conditions, as well as the potential extension of its broader application to other diseases to achieve more precise and effective treatment outcomes.

A tactfully designed photothermal agent collaborating with ascorbic acid for boosting maxillofacial wound healing

Maxillofacial injuries that may cause severe functional and aesthetic damage require effective and immediate management due to continuous exposure to diverse microbial populations. Moreover, drug resistance, biofilm formation, and oxidative stress significantly impede timely bacterial removal and immune function, making the exploration of advanced materials for maxillofacial wound healing an appealing yet highly challenging task. Herein, a near-infrared photothermal sterilization agent was designed, encapsulated with liposomes and coated with ascorbic acid known for its antioxidant and immune-regulatory functions. The resulting nanoparticles, 4TPE-C6T-TD@AA, effectively neutralize reactive oxygen species generated by lipopolysaccharides, facilitate the conversion of pro-inflammatory M1 macrophages to anti-inflammatory M2 macrophages, and eliminate >90% of Staphylococcus aureus and Escherichia coli by disrupting bacterial physiological functions upon exposure to 808 nm laser irradiation. In vivo experiments demonstrate that 4TPE-C6T-TD@AA rapidly eliminates bacteria from infected wounds in the maxillofacial region of rats, and significantly promotes healing in S. aureus-infected wounds by enhancing collagen formation and modulating the inflammatory microenvironment. In conclusion, this study presents a promising therapeutic strategy for effectively combating bacterial infections and excessive inflammation in treating maxillofacial injuries.