Wound repair and regeneration: mechanisms, signaling, and translation

L. plantarum UBLP-40 Versus the Combined Formula of L. rhamnosus UBLP-58 and B. longum UBBL-64 in Excisional Wound Healing: A Cellular Perspective

INTRODUCTION

The utilization of probiotics in enhancing the active healing of skin wounds represents a burgeoning trend in contemporary medicine. Previous research has extensively explored wound healing mechanisms involving the strains of Lactiplantibacillus plantarum, Lacticaseibacillus rhamnosus, and Bifidobacterium longum. This study seeks to compare and interpret cellular findings derived from immunohistochemical and pathological applications.

METHODS

Three groups (the control, Lactiplantibacillus plantarum (RO1) group, and Lacticaseibacillus rhamnosus and Bifidobacterium longum (PRO2) group) underwent histological analysis, and microscopic cell counting were employed, offering insights into dynamic changes among neutrophils, lymphocytes, plasmacytes, mast cells, fibroblasts, and newly formed vessels across distinct treatment groups and temporal intervals.

RESULTS

The neutrophil count was found to be elevated in PRO2 on day 2, while the same group resulted in the highest decline on day 15. The number of fibroblasts peaked on day 4 for the PRO1 group, compared to the other two groups, which peaked on day 8. The lymphocyte count was the highest in the control group, while they peaked on day 4 in PRO2. The mast cells and plasmacytes were variable and sparse among all groups and time frames. Neovascularization was promoted by PRO1 and PRO2 groups on day 4 and remained high on day 8 for PRO2.

CONCLUSIONS

Probiotic strains can be beneficial to the human population and in assisting skin wound healing, each strain working differently and more effectively in different healing phases. Thus, a combined formula containing different probiotics to modulate various healing phases is desirable.

Microenvironment-responsive nanomedicines: a promising direction for tissue regeneration

Severe tissue defects present formidable challenges to human health, persisting as major contributors to mortality rates. The complex pathological microenvironment, particularly the disrupted immune landscape within these defects, poses substantial hurdles to existing tissue regeneration strategies. However, the emergence of nanobiotechnology has opened a new direction in immunomodulatory nanomedicine, providing encouraging prospects for tissue regeneration and restoration. This review aims to gather recent advances in immunomodulatory nanomedicine to foster tissue regeneration. We begin by elucidating the distinctive features of the local immune microenvironment within defective tissues and its crucial role in tissue regeneration. Subsequently, we explore the design and functional properties of immunomodulatory nanosystems. Finally, we address the challenges and prospects of clinical translation in nanomedicine development, aiming to propose a potent approach to enhance tissue regeneration through synergistic immune modulation and nanomedicine integration.

Variations in cell plasticity and proliferation underlie distinct modes of regeneration along the antero-posterior axis in the annelid Platynereis

The capacity to regenerate lost tissues varies significantly among animals. Some phyla, such as the annelids, display substantial regenerating abilities, although little is known about the cellular mechanisms underlying the process. To precisely determine the origin, plasticity and fate of the cells participating in blastema formation and posterior end regeneration after amputation in the annelid Platynereis dumerilii, we developed specific tools to track different cell populations. Using these tools, we find that regeneration is partly promoted by a population of proliferative gut cells whose regenerative potential varies as a function of their position along the antero-posterior axis of the worm. Gut progenitors from anterior differentiated tissues are lineage restricted, whereas gut progenitors from the less differentiated and more proliferative posterior tissues are much more plastic. However, they are unable to regenerate the stem cells responsible for the growth of the worms. Those stem cells are of local origin, deriving from the cells present in the segment abutting the amputation plane, as are most of the blastema cells. Our results favour a hybrid and flexible cellular model for posterior regeneration in Platynereis relying on different degrees of cell plasticity.

Simvastatin and adenosine-co-loaded nanostructured lipid carriers for wound healing: Development, characterization and cell-based investigation

Chronic wounds represent a significant global health burden, characterized by delayed skin healing and associated comorbidities. The present study aimed to develop nanostructured lipid carriers (NLCs) as a topical delivery system for the co-administration of simvastatin and adenosine to address chronic wound management. The rationale behind the co-delivery approach was to mitigate the cytotoxicity associated with high-dose simvastatin, while preserving its therapeutic benefits through a potential synergistic or additive effect. A significant challenge in the development of these NLCs was the encapsulation of the highly hydrophilic adenosine within the hydrophobic lipid matrix. The NLCs were prepared using a hot homogenization-sonication method with a double emulsion technique and optimized through a series of formulation trials, employing various surfactants, solid and liquid lipids, to achieve efficient drug encapsulation, particularly for the hydrophilic adenosine. Optimized formulations F5- and F10-S/A 0.6 %/2 % (containing 0.6 % simvastatin and 2 % adenosine), exhibited promising physicochemical properties. The main difference was the liquid lipid used: F5 containing Miglyol 810 N, while F10 Capmul MCM C-8. Both formulations displayed a mean particle size below 230 nm, a polydispersity index (PDI) of approximately 0.2, and a zeta potential of around -22 mV. While simvastatin association efficiency (AE) was nearly 100 %, adenosine AE was higher for F10 (24 %), compared to F5 (13.5 %). F5 demonstrated superior stability compared to F10, maintaining consistent particle size and PDI over a 60-day period. Formulation F5 also demonstrated superior cell-based in vitro performance compared to F10, with higher cell viability (MTT assay), greater cell proliferation induction (SRB assay), and enhanced cell proliferation and migration in the wound-scratch assay. While F10 displayed higher adenosine AE, F5 excelled in terms of stability and biological activity. The slightly increase in intracellular reactive oxygen species levels observed with F5 may contribute to its enhanced proliferative effects. In-depth characterization revealed that F5 comprised spherical nanoparticles, and thermal analysis indicated no significant changes in the nanocarrier structure upon drug encapsulation. Additionally, ex vivo permeability study demonstrated superior skin retention of both simvastatin and adenosine for F5 compared to an emulsion control. Overall, the F5 nanocarrier demonstrated suitable physicochemical properties, cellular biocompatibility, induction of cell proliferation and migration events, and drug retention capacity in the skin layers, indicating its potential as a promising topical treatment for difficult-to-heal wounds.

GRHL2 regulates keratinocyte EMT-MET dynamics and scar formation during cutaneous wound healing

After cutaneous wounds successfully heal, keratinocytes that underwent the epithelial-mesenchymal transition (EMT) regain their epithelial characteristics, while in scar tissue, epidermal cells persist in a mesenchymal state. However, the regulatory mechanisms governing this reversion are poorly understood, and the impact of persistent mesenchymal-like epidermal cells in scar tissue remains unclear. In the present study, we found that during wound healing, the regulatory factor GRHL2 is highly expressed in normal epidermal cells, downregulated in EMT epidermal cells, and upregulated again during the process of mesenchymal-epithelial transition (MET). We further demonstrated that interfering with GRHL2 expression in epidermal cells can effectively induce the EMT. Conversely, the overexpression of GRHL2 in EMT epidermal cells resulted in partial reversion of the EMT to an epithelial state. To investigate the effects of failed MET in epidermal cells on skin wound healing, we interfered with GRHL2 expression in epidermal cells surrounding the cutaneous wound. The results demonstrated that the persistence of epidermal cells in the mesenchymal state promoted fibrosis in scar tissue, manifested by increased thickness of scar tissue, deposition of collagen and fibronectin, as well as the activation of myofibroblasts. Furthermore, the miR-200s/Zeb1 axis was perturbed in GRHL2 knockdown keratinocytes, and transfection with miR-200s analogs promoted the reversion of EMT in epidermal cells, which indicates that they mediate the EMT process in keratinocytes. These results suggest that restoration of the epithelial state in epidermal cells following the EMT is essential to wound healing, providing potential therapeutic targets for preventing scar formation.

Exploring the Role of miR-132 in Rat Bladders and Human Urothelial Cells during Wound Healing

Urinary bladder wound healing shares many features with skin healing, involving several molecular players, including microRNAs (miRs). This study investigated the role of miR-132 in urothelial cells. We analyzed miR-132 expression in rat bladder using in situ hybridization and conducted gain and loss of miR-132 function assays in primary human urothelial cells (HUCs). These assays included cell proliferation and migration studies. To explore the regulation of miR-132 expression, cells were treated with wound-healing-related factors such as interleukin 6 (IL-6), interleukin 10 (IL-10), and transforming growth factor beta-1 (TGF-β1). Predictive bioinformatics and a literature review identified potential miR-132 targets, which were validated through real-time polymerase chain reaction (RT-PCR) and Western blot analysis. miR-132 was found to promote cellular proliferation and migration during the early stages of urothelial wound repair. Its expression was modulated by key cytokines such as IL-6, IL-10, and TGF-β1. miR-132 played a crucial role in urothelial wound healing by enhancing cell proliferation and migration, regulated by cytokines, suggesting its action within a complex regulatory network. These findings highlight the therapeutic potential of targeting miR-132 in bladder injury repair, offering new insights into bladder repair mechanisms.

The regenerative effect of exosomes isolated from mouse embryonic fibroblasts in mice created as a sciatic nerve crush injury model

BACKGROUND

Exosomes (Exos) are candidates for functional recovery and regeneration following sciatic nerve crushed (SNC) injury due to their composition which can accelerate tissue regeneration. Therefore, mouse embryonic fibroblast-derived exosomes were evaluated for their regenerative capacity in SNC injury.

METHODS AND RESULTS

In the study, 40 Balb/c males (20 ± 5 g) and two pregnant mice (for embryonic fibroblast tissue) were used and crushed injury was induced in the left sciatic nerve with an aneurysm clamp. Sciatic nerve model mice were randomly divided into 5 groups (n = 8; control, n = 8; sham, n = 8; SNC, n = 8; Mouse embryonic fibroblast exosome (mExo), n = 8; SNC + Mouse embryonic fibroblast exosome (SNC + mExo). Rotarod tests for motor functions and hot plate and von Frey tests for sensory functions were analyzed in the groups. Expression changes of exosome genes (RARRES1, NAGS, HOXA13, and MEIS1) immunohistochemical analysis of these gene proteins, and structural exosome NF-200 and S100 proteins were evaluated by confocal microscopy. Behavioral analyses showed that the damage in SNC was significant between groups on day14 and day28 (P < 0.05). In behavioral analyses, it was determined that motor functions and mechanical sensitivity lost in SNC were regained after mExo treatment. While expression of all genes was detected in MEF-derived exosomes, the high expression was MESI1 and the low expression was HOXA13. NF200, an indicator of axon number and neurofilament density, was found to decrease in SNC (P < 0.001) and increase after treatment, but not significantly. The decreased S100 protein levels in SNC and the increase detected after treatment were not significant.

CONCLUSION

The expression of four mRNAs in mExos indicates that these genes may have an effect on regenerative processes after SNC injury. The regenerative process supported by tissue protein expressions demonstrates the therapeutic potential of mExo treatment.

Electrical stimulation: a novel therapeutic strategy to heal biological wounds

Electrical stimulation (ES) has emerged as a powerful therapeutic modality for enhancing biological wound healing. This non-invasive technique utilizes low-level electrical currents to promote tissue regeneration and expedite the wound healing process. ES has been shown to accelerate wound closure, reduce inflammation, enhance angiogenesis, and modulate cell migration and proliferation through various mechanisms. The principle goal of wound management is the rapid recovery of the anatomical continuity of the skin, to prevent infections from the external environment and maintain homeostasis conditions inside. ES at the wound site is a compelling strategy for skin wound repair. Several ES applications are described in medical literature like AC, DC, and PC to improve cutaneous perfusion and accelerate wound healing. This review aimed to evaluate the primary factors and provides an overview of the potential benefits and mechanisms of ES in wound healing, and its ability to stimulate cellular responses, promote tissue regeneration, and improve overall healing outcomes. We also shed light on the application of ES which holds excellent promise as an adjunct therapy for various types of wounds, including chronic wounds, diabetic ulcers, and surgical incisions.

Visible light accelerates skin wound healing and alleviates scar formation in mice by adjusting STAT3 signaling

During the wound healing process, the activation of signal transducer and activator of transcription 3 (STAT3) is considered crucial for the migration and proliferation of epithelial cells, as well as for establishing the inflammatory environment. However, an excessive STAT3 activation aggravates scar formation. Here we show that 450 nm blue light and 630 nm red light can differentially regulate the phosphorylation of STAT3 (p-STAT3) and its downstream cytokines in keratinocytes. Further mechanistic studies reveal that red light promotes wound healing by activating the PI3 kinase p110 beta (PI3Kβ)/STAT3 signaling axis, while blue light inhibits p-STAT3 at the wound site by modulating cytochrome c-P450 (CYT-P450) activity and reactive oxygen species (ROS) generation. In a mouse scar model, skin wound healing can be significantly accelerated with red light followed by blue light to reduce scar formation. In summary, our study presents a potential strategy for regulating epithelial cell p-STAT3 through visible light to address skin scarring issues and elucidates the underlying mechanisms.

Research on traditional Chinese medicine as an effective drug for promoting wound healing

ETHNOPHARMACOLOGICAL RELEVANCE

The incidence of skin trauma is high and the repair process is complex, often leading to poor healing and other issues, which can result in significant economic and social burdens. Traditional Chinese medicine (TCM) is a valuable resource with proven effectiveness and safety in wound repair, widely utilized in clinical practice. A systematic analysis of wound healing with a focus on TCM research progress holds both academic and clinical importance.

AIM OF THE REVIEW

This article reviews the research progress of TCM in promoting wound healing, and provides basic data for the development of innovative drugs that promote wound healing.

MATERIALS AND METHODS

This article provides a review of the literature from the past decade and conducts a thorough analysis of various databases that contain reports on the use of TCM for wound repair. The data for this systematic research was gathered from electronic databases including CNKI, SciFinder, and PubMed. The study explores and summarizes the research findings and patterns by creating relevant charts.

RESULTS

This study reviewed the mechanism of wound healing, experimental TCM methods to promote wound healing, the theory and mode of action of TCM to promote wound healing, the active ingredients of TCM that promote wound healing, the efficacy of TCM formulae to promote wound healing, and the potential toxicity of TCM and its antidotes. This study enriched the theory of TCM in promoting wound healing.

CONCLUSION

Skin wound healing is a complex process that can be influenced by various internal and external factors. This article offers a theoretical foundation for exploring and utilizing TCM resources that enhance wound repair. By analyzing a range of TCM that promote wound healing, the article highlights the clinical importance and future potential of these medicines in promoting wound healing.

Nanofat Improves Vascularization and Tissue Integration of Dermal Substitutes without Affecting Their Biocompatibility

Dermal substitutes require sufficient tissue integration and vascularization to be successfully covered with split-thickness skin grafts. To rapidly achieve this, we provide the proof of principle for a novel vascularization strategy with high translational potential. Nanofat was generated from subcutaneous adipose tissue of green fluorescence protein (GFP)+ C57BL/6J donor mice and seeded onto small samples (4 mm in diameter) of the clinically approved dermal substitute Integra®. These samples and non-seeded controls were then implanted into full-thickness skin defects in the dorsal skinfold chamber of C57BL/6J wild-type mice and analyzed by intravital fluorescence microscopy, histology and immunohistochemistry over a 14-day period. Nanofat-seeded dermal substitutes exhibited an accelerated vascularization, as indicated by a significantly higher functional microvessel density on days 10 and 14 when compared to controls. This was primarily caused by the reassembly of GFP+ microvascular fragments inside the nanofat into microvascular networks. The improved vascularization promoted integration of the implants into the surrounding host tissue, which finally exhibited an increased formation of a collagen-rich granulation tissue. There were no marked differences in the inflammatory host tissue reaction to nanofat-seeded and control implants. These findings demonstrate that nanofat significantly improves the in vivo performance of dermal substitutes without affecting their biocompatibility.

Advances in ionic liquid-based antimicrobial wound healing platforms

Wound infections, marked by the proliferation of microorganisms at surgical sites, necessitate the development of innovative wound dressings with potent bactericidal properties to curb microbial growth and prevent bacterial infiltration. This study explores the recent strides in utilizing ionic liquid-based polymers as highly promising antimicrobial agents for advanced wound healing applications. Specifically, cationic polymers containing quaternary ammonium, imidazolium, guanidinium, pyridinium, triazolium, or phosphonium groups have emerged as exceptionally effective antimicrobial compounds. Their mechanism of action involves disrupting bacterial membranes, thereby preventing the development of resistance and minimizing toxicity to mammalian cells. This comprehensive review not only elucidates the intricate dynamics of the skin's immune response and the various stages of wound healing but also delves into the synthesis methodologies of ionic liquid-based polymers. By spotlighting the practical applications of antimicrobial wound dressings, particularly those incorporating ionic liquid-based materials, this review aims to lay the groundwork for future research endeavors in this burgeoning field. Through a nuanced examination of these advancements, this article seeks to contribute to the ongoing progress in developing cutting-edge wound healing platforms that can effectively address the challenges posed by microbial infections in surgical wounds.

The effect of Traumeel LT ad us. vet. on the perioperative inflammatory response after castration of stallions: a prospective, randomized, double-blinded study

Introduction

Stallion castration is a standard procedure with a risk of post-surgical complications. Castration induces an acute phase response (APR). Serum Amyloid-A (SAA) is a well-studied major acute phase protein (APP), that has been shown to be a good marker for the development of post-surgical complications. The current gold standard for reducing the APR after castration is Flunixin-Meglumin, which is a non-steroidal anti-inflammatory drug (NSAID) inhibiting COX1/2. In contrast, Traumeel LT ad us. vet. can modulate the APR by induction of the inflammation resolution. The aim of this study was to compare the effect of Flunixin-Meglumin and Traumeel LT ad us. vet. on the acute phase response.

Material and methods

A total of 60 stallions were recruited and 54 stallions entered the study with 27 stallions in each treatment group. The stallions were treated pre- and postoperatively with either Flunixin-Meglumin (FL) or with Traumeel LT ad us. vet. (TR). Blood was taken before and 24 h, 48 h and 72 h after castration. The following main parameters were assessed: SAA, fibrinogen, iron, white blood cells, neutrophils, Interleukin1ß, and cortisol. Wound healing and pain were assessed at 8 time points.

Results

The main variable SAA was increased after surgery reaching a mean value of 122 µg/ml in the FL group and a mean SAA of 226 µg/ml in the TR group 48 h after surgery, reaching a significant difference only at the 24 h timepoint (p = 0.03). All stallions had the highest pain summary score 8 hours after surgery, with decreasing values thereafter. The pain scores were not statistically different at any time point. In the FL group five stallions developed a suture dehiscence compared to only one stallion in the TR group (p = 0.001).

Discussion

Within the limitations of this study, Traumeel LT ad us. vet. seems to have proresolving effects on the inflammation induced by surgery making it a valuable treatment to reduce the APR induced by castration. Due to its different mode of action, Traumeel LT ad us. vet. might be an alternative treatment option if gastrointestinal side effects or renal side effects of NSAIDs should be avoided. Further studies are needed combining Traumeel LT ad us. vet. and Flunixin.

Combination of secondary intention healing and primary closure to reconstruct large facial defects

Secondary intention healing has been a well-established method to close wounds for more than 200 years. Indeed, it represents the easiest technique in the ladder of plastic reconstruction. Primary wound closure (side-to-side closure, direct wound closure) is the second easiest method. The combination of these two techniques is already an integral aspect of specific surgical procedures, e.g. the reconstruction of the donor site of a paramedian forehead flap. This minireview will show that the combination is also a suitable alternative to classic flaps in reconstruction of different aesthetic subunits of the face. These are the scalp, the lateral cheek, the upper nasal sidewall/medial canthus and the retroauricular region. The advantages and disadvantages will be discussed and illustrated with clinical examples.

Liraglutide Promotes Diabetic Wound Healing via Myo1c/Dock5

Non-healing diabetic wounds and ulcer complications, with persistent cell dysfunction and obstructed cellular processes, are leading causes of disability and death in patients with diabetes. Currently, there is a lack of guideline-recommended hypoglycemic drugs in clinical practice, likely due to limited research and unclear mechanisms. In this study, it is demonstrated that liraglutide significantly accelerates wound closure in diabetic mouse models (db/db mice and streptozotocin-induced mice) by improving re-epithelialization, collagen deposition, and extracellular matrix remodeling, and enhancing the proliferation, migration, and adhesion functions of keratinocytes. However, these effects of improved healing by liraglutide are abrogated in dedicator of cytokinesis 5 (Dock5) keratinocyte-specific knockout mice. Mechanistically, liraglutide induces cellular function through stabilization of unconventional myosin 1c (Myo1c). Liraglutide directly binds to Myo1c at arginine 93, enhancing the Myo1c/Dock5 interaction by targeting Dock5 promoter and thus promoting the proliferation, migration, and adhesion of keratinocytes. Therefore, this study provides insights into liraglutide biology and suggests it may be an effective treatment for diabetic patients with wound-healing pathologies.

Inhibition of Ubiquitin C-Terminal Hydrolase L1 Facilitates Cutaneous Wound Healing via Activating TGF-β/Smad Signalling Pathway in Fibroblasts

Ubiquitin C-terminal hydrolase L1 (UCHL1) plays vital roles in cell proliferation, angiogenesis, inflammation and oxidative stress. Nevertheless, it is unclear whether UCHL1 could regulate the biologic behaviour of cells and ultimately influences wound healing. We aim to illustrate the roles and the underlying mechanism of UCHL1 in cutaneous wound healing. Murine full-thickness excisional wound model was utilised to study the effects of UCHL1 on wound healing through topical administration of the UCHL1 inhibitor LDN57444, followed by assessment of wound areas and histological alterations. Subsequently, ethynyldeoxyuridine, scratch and transwell assays were performed to examine fibroblast migration and proliferation. The extracellular matrix (ECM)-related genes expression and transforming growth factor-β (TGF-β)/Smad signalling pathways activation were investigated by immuno-fluorescent staining, Western blots and quantitative reverse transcription polymerase chain reaction. We identified elevated UCHL1 expression in non-healing wound tissues. The UCHL1 expression displayed a dynamic change and reached a peak on Day-7 post-wounding during the healing process in mice. Cutaneous administration of LDN57444 promoted wound healing by facilitating collagen deposition, myofibroblast activation and angiogenesis. In vitro experiments demonstrated that UCHL1 concentration dependently inhibited migration, ECM synthesis and activation of human dermal fibroblasts, which was mechanistically related to downregulation of TGF-β/Smad signalling. Furthermore, these effects could be reversed by TGF-β inhibitor SB431542. Our findings reveal that UCHL1 is a negative regulator of cutaneous wound healing and considered as a novel prospective therapeutic target for effective wound healing.

The Angiogenic Repertoire of Stem Cell Extracellular Vesicles: Demystifying the Molecular Underpinnings for Wound Healing Applications

Stem cells-derived extracellular vesicles (SC-EVs) have emerged as promising therapeutic agents for wound repair, recapitulating the biological effects of parent cells while mitigating immunogenic and tumorigenic risks. These EVs orchestrate wound healing processes, notably through modulating angiogenesis-a critical event in tissue revascularization and regeneration. This study provides a comprehensive overview of the multifaceted mechanisms underpinning the pro-angiogenic capacity of EVs from various stem cell sources within the wound microenvironment. By elucidating the molecular intricacies governing their angiogenic prowess, we aim to unravel the mechanistic repertoire underlying their remarkable potential to accelerate wound healing. Additionally, methods to enhance the angiogenic effects of SC-EVs, current limitations, and future perspectives are highlighted, emphasizing the significant potential of this rapidly advancing field in revolutionizing wound healing strategies.

Using spatial frequency domain imaging to monitor a skin biopsy wound: a pilot study

Surgical wound infection is a global postoperative issue adding a significant clinical burden and increasing healthcare costs. Early detection and subsequent diagnosis of infection is vital for accurate, early, and effective treatments. In this paper, we report a pilot study exploring spatial frequency domain imaging (SFDI) to monitor, in-vivo, a biopsy wound in human skin. The reduced scattering coefficient, μ s ' , absorption coefficient, μ a and the oxygen saturation, StO 2, were measured using a SFDI system at 617 and 850 nm. We found the μ s ' was better capable of monitoring structural changes, possible pus within the wound, re-epithelialization, and collagen fiber remodeling, than with the eye alone. The μ a map is capable of revealing the total hemoglobin distribution in the wound area but was limited in some regions due to the scab covering. This case study indicates SFDI's potential for monitoring and quantifying the process of surgical wound healing and infection.

Injury From Nematode Lung Migration Induces an IL-13-Dependent Hyaluronan Matrix

A consistent feature of lung injury is a rapid and sustained accumulation of hyaluronan (HA). The rodent gut-dwelling nematode Nippostrongylus brasiliensis (Nb) induces tissue damage as it migrates through the lungs. Type 2 immune responses are essential for the repair of the lungs, hence Nb infection is a well-established model to study immune-mediated lung repair. We found that Nb infection was associated with increased HA in the lung, which peaked at d7 post-infection (p.i.). Deposition of HA in the alveolar epithelium correlated with regions of damaged tissue and the type 2 immune response, which is characterized by eosinophilia and increased type 2 cytokines such as IL-13. Consistent with the accumulation of HA, we observed increased expression of the major synthase Has2, alongside decreased expression of Hyal1, Hyal2, and Tmem2, which can degrade existing HA. Expression of Tsg6 was also increased and correlated with the presence of inter-α-inhibitor heavy chain-HA complexes (HC·HA) at d7 p.i. Using IL-13-deficient mice, we found that the accumulation of HA during Nb infection was IL-13 dependent. Our data thus provide further evidence that IL-13 is a modulator of the HA matrix during lung challenge and links IL-13-mediated HA regulation to tissue repair pathways.

Ajuga taiwanensis Extract Promotes Wound-healing via Activation of PDGFR/MAPK Pathway

Chronic and prolonged wounds are a serious public problem that may severely affect the quality of life and result in psychological pressure. Fibroblasts play a crucial role in the wound process and in skin pathology. Herbal drugs have long been used for wound care worldwide. Ajuga taiwanensis (Lamiaceae) is a folk medicine for antipyretics, anti-inflammation, and reducing swelling in Taiwan. This study aimed to investigate the effect of A. taiwanensis in wound healing and the underlying mechanisms. Under human dermal fibroblast (HDF) wound-healing activity-guided fractionation, we found that a sub-fraction (AT-M) of A. taiwanensis extract (AT) and the major ingredients significantly promoted wound healing and decreased IL-1β and - 6 expressions on HDFs. Furthermore, the fraction of AT-M enhanced wound healing on C57BL/6 mouse skins, increased PDGFR expressions, and activated the PDGFR/MAPK pathway. Taken together, A. taiwanensis extracts promote wound healing by the PDGFR pathway and lead to enhanced cell spreading and motility, thereby having a possible beneficial effect on wound healing.

Preventing bisphosphonate induced osteonecrosis of the jaw with a polyguanidine conjugate (GuaDex): A promising new approach

Osteonecrosis of the jaw (ONJ) is a relatively rare side effect after prolonged use of bisphosphonates, which are drugs used to treat bone resorption in osteoporosis and certain cancers. This study introduces a novel ONJ model in rats by combining exposure to bisphosphonates, oral surgery, and bacterial inoculation. Potential ONJ preventive effects of polyguanidine (GuaDex) or antibiotics were evaluated. The study consisted of twenty-four male Wistar rats were divided into four groups. Groups 1 to 3 were given weekly doses of i.v. Zoledronic acid (ZA), four weeks before and two weeks after an osteotomy procedure on their left mandibular first molar. Group 4 was a negative control. Streptococcus gordonii bacteria were introduced into the osteotomy pulp chamber and via the food for seven days. On day eight, the rats were given different treatments. Group 1 was given a GuaDex injection into the osteotomy socket, Group 2 was given an intramuscular (i.m.) injection of clindamycin, Group 3 (positive control) was given an i.m. injection of saline, and Group 4 was given an i.m. injection of saline. Blood samples were taken two weeks after the osteotomy procedure, after which the rats were euthanized. Bone healing, bone mineral density, histology, and blood status were analyzed. The results showed that Group 1 (GuaDex) had no ONJ, extensive ongoing bone regeneration, active healing activity, vascularization, and no presence of bacteria. Group 2 (clindamycin) showed early stages of ONJ, avascular areas, and bacteria. Group 3 showed stages of ONJ, inflammatory infiltrates, defective healing, and bacterial presence, and Group 4 had normal healing activity and no bacterial presence. Conclusion: ZA treatment and bacterial inoculation after tooth extraction inhibited bone remodeling/healing and induced ONJ characteristic lesions in the rats. Only GuaDex apparently prevented ONJ development, stimulated bone remodeling, and provided an antimicrobial effect.

Chitosan-based self-healing hydrogel dressing for wound healing

Skin has strong self-regenerative capacity, while severe skin defects do not heal without appropriate treatment. Therefore, in order to cover the wound sites and hasten the healing process, wound dressings are required. Hydrogels have emerged as one of the most promising candidates for wound dressings because of their hydrated and porous molecular structure. Chitosan (CS) with biocompatibility, oxygen permeability, hemostatic and antimicrobial properties is beneficial for wound treatment and it can generate self-healing hydrogels through reversible crosslinks, from dynamic covalent bonding, such as Schiff base bonds, boronate esters, and acylhydrazone bonds, to physical interactions like hydrogen bonding, electrostatic interaction, ionic bonding, metal-coordination, host-guest interactions, and hydrophobic interaction. Therefore, various chitosan-based self-healing hydrogel dressings have been prepared in recent years to cope with increasingly complex wound conditions. This review's objective is to provide comprehensive information on the self-healing mechanism of chitosan-based hydrogel wound dressings, discuss their advanced functions including antibacterial, conductive, anti-inflammatory, anti-oxidant, stimulus-responsive, hemostatic/adhesive and controlled release properties, further introduce their applications in the promotion of wound healing in two categories: acute and chronic (infected, burn and diabetic) wounds, and finally discuss the future perspective of chitosan-based self-healing hydrogel dressings for wound healing.

Hydrogels with Antioxidant Microparticles Systems Based on Hyaluronic Acid for Regenerative Wound Healing

This research focuses on the synthesis of hydrogels exhibiting enhanced antioxidant properties derived from hyaluronic acid (HA) and poly(ethylene brassylate-co-squaric acid) (PEBSA), a copolymacrolactone that have the ability to be used in drug delivery applications. Quercetin (Q), a bioflavonoid with strong antioxidant properties, is employed as a bioactive compound. The biomolecule is encapsulated in the polymeric network using different entrapment techniques, including the initial formation of a complex between PEBSA and Q, which is demonstrated through the dynamic light scattering technique. Fourier transform infrared spectroscopy (FT-IR) and rheological studies confirm the formation of the hydrogels, revealing the occurrence of physical interactions between the synthetic polymer and the polysaccharide. Moreover, the hydrogels demonstrate biocompatible properties after direct contact with the HDFa cell line and antioxidant properties, as revealed by DPPH tests.

Association Between BMI Reduction and Activities of Daily Living Improvement in Elderly Patients With Musculoskeletal Disorders in a Convalescent Rehabilitation Ward

Background As populations age, musculoskeletal disorders significantly affect the quality of life (QOL) and functional independence of elderly individuals. While BMI is commonly used to assess nutritional status and is linked to physical function, the relationship between BMI reduction and improvements in activities of daily living (ADL) remains unclear in elderly patients with musculoskeletal disorders. This study aimed to explore this relationship in a rehabilitation setting. Methods This retrospective cohort study included 75 elderly patients (65 years and older) with musculoskeletal disorders admitted to a convalescent rehabilitation ward. Patients were categorized into two groups based on BMI reduction: those with a decrease of ≥0.7 kg/m² and those with <0.7 kg/m². Functional Independence Measure (FIM) scores were recorded at admission and discharge. Statistical analyses, including logistic regression, were conducted to examine the relationship between BMI reduction and FIM improvement. Results There was no significant difference in FIM gain between the BMI-reduced and non-BMI-reduced groups. Logistic regression analysis also found no significant association between BMI reduction and FIM improvement, even after adjusting for age, gender, length of stay, and initial FIM scores. Discussion The absence of a significant association may be due to factors such as postoperative swelling, comorbidities, and the predominance of female participants, who may experience less muscle mass loss. Study limitations include the lack of data on dietary intake and body composition. Future research should include broader assessments, such as muscle mass and swelling, to better evaluate rehabilitation outcomes in elderly patients with musculoskeletal disorders.

Granular Biomaterials as Bioactive Sponges for the Sequestration and Release of Signaling Molecules

A major challenge for the regeneration of chronic wounds is an underlying dysregulation of signaling molecules, including inflammatory cytokines and growth factors. To address this, it is proposed to use granular biomaterials composed of jammed microgels, to enable the rapid uptake and delivery of biomolecules, and provide a strategy to locally sequester and release biomolecules. Sequestration assays on model biomolecules of different sizes demonstrate that granular hydrogels exhibit faster transport than comparable bulk hydrogels due to enhanced surface area and decreased diffusion lengths. To demonstrate the potential of modular granular hydrogels to modulate local biomolecule concentrations, microgel scaffolds are engineered that can simultaneously sequester excess pro-inflammatory factors and release pro-healing factors. To target specific biomolecules, microgels are functionalized with affinity ligands that bind either to interleukin 6 (IL-6) or to vascular endothelial growth factor A (VEGF-A). Finally, disparate microgels are combined into a single granular biomaterial for simultaneous sequestration of IL-6 and release of VEGF-A. Overall, the potential of modular granular hydrogels is demonstrated to locally tailor the relative concentrations of pro- and anti-inflammatory factors.

Laser Therapy in Hypertrophic and Keloid Scars: A Systematic Review and Network Meta-analysis

BACKGROUND

Laser therapy has emerged as a promising treatment modality for improving the appearance and symptoms associated with hypertrophic and keloid scars. In this network meta-analysis, we aimed to evaluate the efficacy of different laser types in treating hypertrophic and keloid scars.

METHODS

A comprehensive search of four databases was conducted to identify relevant studies published up until July 2023. Data were extracted from eligible studies and pooled as mean difference (MD) for continuous outcomes and risk ratio (RR) for dichotomous data in a network meta-analysis (NMA) model, using R software.

RESULTS

A total of 18 studies, comprising 550 patients, were included in the analysis. Pooling our data showed that fractional carbon dioxide (FCO2) plus 5-fluorouracil (5-FU) was superior to control in terms of Vancouver Scar Scale (VSS), pliability score, and thickness; [MD = - 5.97; 95% CI (- 7.30; - 4.65)], [MD = - 2.68; 95% CI (- 4.03; - 1.33)], [MD = - 2.22; 95% CI (- 3.13; - 1.31)], respectively. However, insignificant difference was observed among FCO2 plus 5-FU compared to control group in terms of erythema, vascularity, redness and perfusion, and pigmentation [MD = - 0.71; 95% CI (- 2.72; 1.30)], [MD = - 0.44; 95% CI (- 1.26; 0.38)], respectively.

CONCLUSION

Our NMA found that the FCO2 plus 5-FU was the most effective intervention in decreasing the VSS and thickness, while FCO2 plus CO2 was the most effective intervention in decreasing the pliability score. Further research is needed to determine the optimal laser parameters and long-term efficacy of laser therapy in hypertrophic and keloid scars.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

A site-specific phosphorylation in FSTL1 determines its promigratory role in wound healing

Follistatin like-1 (FSTL-1) is a secreted glycoprotein of mesenchymal in origin. In human skin, FSTL1 is upregulated in the epidermal keratinocytes upon acute injury and is required for the migration of keratinocytes. Failure to upregulate FSTL1 leads to the lack of keratinocyte migration and the non-healing nature of diabetic foot ulcer (DFU). FSTL1 undergoes extensive post-translational modification (PTM) at specific residues. Glycosylation at N144, N175 and N180, are the only experimentally demonstrated PTM in FSTL1, wherein, N180 and N144 glycosylations have been found to be critical for its function in cardiac tissue regeneration and pre-adipocyte differentiation, respectively. However, it is not known if PTMs other than glycosylation occurs in FSTL1 and how it impacts its pro-migratory function. Using in-silico analysis of mass spectrometric datasets, we found a novel PTM, namely, Serine 165 (S165) phosphorylation in FSTL1. To address the role of S165 phosphorylation in its pro-migratory function, a phosphorylation defective mutant of FSTL1 (S165A) was constructed by converting serine 165 to alanine and over expressed in 293T cells. S165A mutation did not affect the secretion of FSTL1 in vitro. However, S165A abolished the pro-migratory effect of FSTL1 in cultured keratinocytes likely via its inability to facilitate ERK signaling pathway. Interestingly, bacterially expressed recombinant FSTL1, trans-dominantly inhibited wound closure in keratinocytes highlighting the prime role of FSTL1 phosphorylation for its pro-migratory function. Further, under high glucose conditions, which inhibited scratchwound migration of keratinocytes, we noticed a significant decrease in S165 phosphorylation. Taken together, our results reveal a hitherto unreported role of FSTL1 phosphorylation PTM with profound implications in wound healing.

Self-crosslinking hyaluronic acid-based hydrogel with promoting vascularization and ROS scavenging for wound healing

Skin wound dressings are commonly utilized for the treatment of skin injuries, as they effectively facilitate wound healing and possess anti-inflammatory and antibacterial properties. However, conventional dressings fail to inhibit ROS production and promote vascularization, leading to delayed wound healing. Here, we developed injectable self-crosslinking hydrogels through thiolated hyaluronic acid (HASH/rhCOLIII) with enhancing the ROS inhibitory capacity while preserving the cell adhesion ability of hyaluronic acid. Additionally, recombinant humanized collagen type III (rhCOLIII) is incorporated via electrostatic adsorption to further enhance mechanical strength and angiogenesis properties of the hydrogel. The HASH/rhCOLIII demonstrated excellent biocompatibility, remarkable ROS scavenging ability, as well as hemostatic and angiogenic properties. Cell experiment results show that HASH/rhCOLIII has excellent biocompatibility and can significantly promote angiogenesis. Animal experiments results showed that HASH/rhCOLIII exhibits anti-inflammatory effects, significantly accelerating wound healing in a full-thickness skin defect model. These findings highlight that HASH/rhCOLIII hydrogel holds great promise as an advanced dressing for effective wound healing.

Molecular mechanisms of mechanosensing and plasticity of tendons and ligaments

Tendons and ligaments, crucial components of the musculoskeletal system, connect muscles to bones. In the realm of sports, tendons and ligaments are vulnerable tissues, with injuries such as Achilles tendon rupture and anterior cruciate ligament tears directly impacting an athlete's career. Furthermore, repetitive trauma and tissue degeneration can lead to conditions like secondary osteoarthritis, ultimately affecting the overall quality of life. Recent research highlights the pivotal role of mechanical stress in maintaining homeostasis within tendons and ligaments. This review delves into the latest insights on the structure of tendons and ligaments and the plasticity of tendon tissue in response to mechanical loads.

Scar matrix drives Piezo1 mediated stromal inflammation leading to placenta accreta spectrum

Scar tissue formation is a hallmark of wound repair in adults and can chronically affect tissue architecture and function. To understand the general phenomena, we sought to explore scar-driven imbalance in tissue homeostasis caused by a common, and standardized surgical procedure, the uterine scar due to cesarean surgery. Deep uterine scar is associated with a rapidly increasing condition in pregnant women, placenta accreta spectrum (PAS), characterized by aggressive trophoblast invasion into the uterus, frequently necessitating hysterectomy at parturition. We created a model of uterine scar, recapitulating PAS-like invasive phenotype, showing that scar matrix activates mechanosensitive ion channel, Piezo1, through glycolysis-fueled cellular contraction. Piezo1 activation increases intracellular calcium activity and Protein kinase C activation, leading to NF-κB nuclear translocation, and MafG stabilization. This inflammatory transformation of decidua leads to production of IL-8 and G-CSF, chemotactically recruiting invading trophoblasts towards scar, initiating PAS. Our study demonstrates aberrant mechanics of scar disturbs stroma-epithelia homeostasis in placentation, with implications in cancer dissemination.

Clinical, mechanistic, and therapeutic landscape of cutaneous fibrosis

When dysregulated, skin fibrosis can lead to a multitude of pathologies. We provide a framework for understanding the wide clinical spectrum, mechanisms, and management of cutaneous fibrosis encompassing a variety of matrix disorders, fibrohistiocytic neoplasms, injury-induced scarring, and autoimmune scleroses. Underlying such entities are common mechanistic pathways that leverage morphogenic signaling, immune activation, and mechanotransduction to modulate fibroblast function. In light of the limited array of available treatments for cutaneous fibrosis, scientific insights have opened new therapeutic and investigative avenues for conditions that still lack effective interventions.

Fabrication of fiber-particle structures by electrospinning/electrospray combination as an intrinsic antioxidant and oxygen-releasing wound dressing

In this study, we employed a combination of electrospinning and electrospray techniques to fabricate wound dressings with a particle-fiber structure, providing dual characteristics of oxygen-releasing and intrinsic antioxidant properties, simultaneously. The electrospun part of the dressing was prepared from a blend of polycaprolactone/gallic acid-grafted-gelatin (GA-g-GE), enabling intrinsic ROS scavenging. To the best of our knowledge, this is the first time that PCL/GA-g-GE was fabricated by electrospinning. Furthermore, polyvinyl pyrrolidone (PVP) microparticles, containing calcium peroxide nanoparticles (CNPs), were considered as the oxygen production agent through the electrospray part. The CNP content was 1% and 3% w/w of PVP while biopolymer:PCL was 10% w/w. The fabricated structures were characterized in terms of fiber/particle morphology, elemental analysis, oxygen release behavior, ROS inhibition capacity, and water contact angle assessments. The covalent bonding of gallic acid to gelatin was confirmed by 1H-NMR, UV spectroscopy, and FTIR. According to the SEM results, the morphology of the prepared PCL/biopolymer fibers was bead-free and with a uniform average diameter. The analysis of released oxygen showed that by increasing the weight percentage of CNPs from 1 to 3 wt%, the amount of released oxygen increased from 120 mmHg to 195 mmHg in 24 h, which remained almost constant until 72 h. The obtained DPPH assay results revealed that the introduction of GA-g-GE into the fibrous structure could significantly improve the antioxidant properties of wound dressing compared to the control group without CNPs and modified gelatine. In vitro, the fabricated wound dressings were evaluated in terms of biocompatibility and the potential of the dressing to protect human dermal fibroblasts under oxidative stress and hypoxia conditions by an MTT assay. The presence of GA-g-GE led to remarkable protection of the cells against oxidative stress and hypoxia conditions. In vivo studies revealed that the incorporation of intrinsic ROS inhibition and oxygen-releasing properties could significantly accelerate the wound closure rate during the experimental period (7, 14, and 21 days). Additionally, histopathological investigations in terms of H&E and Masson's trichrome staining showed that the incorporation of the two mentioned capabilities remarkably facilitated the wound-healing process.

Colloidal Hydrogel with Staged Sequestration and Release of Molecules Undergoing Competitive Binding

Competitive binding of distinct molecules in the hydrogel interior can facilitate dynamic exchange between the hydrogel and the surrounding environment. The ability to control the rates of sequestration and release of these molecules would enhance the hydrogel's functionality and enable targeting of a specific task. Here, we report the design of a colloidal hydrogel with two distinct pore dimensions to achieve staged, diffusion-controlled scavenging and release dynamics of molecules undergoing competitive binding. The staged scavenging and release strategy was shown for CpG oligodeoxynucleotide (ODN) and human epidermal growth factor (hEGF), two molecules exhibiting different affinities to the quaternary ammonium groups of the hydrogel. Fast ODN scavenging from the ambient environment occurred via diffusion through submicrometer-size hydrogel pores, while delayed hEGF release from the hydrogel was governed by its diffusion through nanometer-size pores. The results of the experiments were in agreement with simulation results. The significance of staged ODN-hEGF exchange was highlighted by the dual anti-inflammation and tissue proliferation hydrogel performance.

SPRR1B+ keratinocytes prime oral mucosa for rapid wound healing via STAT3 activation

Oral mucosal wounds exhibit accelerated healing with reduced scarring compared to cutaneous wounds, representing an optimal wound healing paradigm. However, the specific cellular subtypes orchestrating the efficient healing of mucosal tissues remain elusive. Through a comprehensive analysis integrating bulk-mRNA and single-cell sequencing data during the wound healing process in oral mucosa and skin, we have delineated a distinct set of genes markedly upregulated during tissue repair. This collection of wound healing-associated genesets was highly enriched in a specific keratinocyte subpopulation identified as STAT3-activated SPRR1B+ keratinocytes. Notably, despite the inherent rapidity of oral mucosal healing, the induction of SPRR1B+ keratinocytes is evident in both skin and mucosal wound healing processes in murine model. Intriguingly, these wound healing-promoting SPRR1B+ keratinocytes, which are induced via STAT3 activation, inherently abundant in unwounded normal mucosa but absent in normal skin. SPRR1B knockdown significantly inhibits mucosal keratinocyte migration, a critical attribute for effective wound healing. In summary, through analysis of human oral and skin wound healing processes at single-cell resolution, coupled with validation in murine model, suggests STAT3-activated SPRR1B+ keratinocytes are associated with the rapid mucosal repair process. This discovery underscores the potential application of SPRR1B+ keratinocytes in the therapeutic management of chronic or non-healing wounds.

Advancements in diabetic foot ulcer research: Focus on mesenchymal stem cells and their exosomes

Diabetes represents a widely acknowledged global public health concern. Diabetic foot ulcer (DFU) stands as one of the most severe complications of diabetes, its occurrence imposing a substantial economic burden on patients, profoundly impacting their quality of life. Despite the deepening comprehension regarding the pathophysiology and cellular as well as molecular responses of DFU, the current therapeutic arsenal falls short of efficacy, failing to offer a comprehensive remedy for deep-seated chronic wounds and microvascular occlusions. Conventional treatments merely afford symptomatic alleviation or retard the disease's advancement, devoid of the capacity to effectuate further restitution of compromised vasculature and nerves. An escalating body of research underscores the prominence of mesenchymal stem cells (MSCs) owing to their paracrine attributes and anti-inflammatory prowess, rendering them a focal point in the realm of chronic wound healing. Presently, MSCs have been validated as a highly promising cellular therapeutic approach for DFU, capable of effectuating cellular repair, epithelialization, granulation tissue formation, and neovascularization by means of targeted differentiation, angiogenesis promotion, immunomodulation, and paracrine activities, thereby fostering wound healing. The secretome of MSCs comprises cytokines, growth factors, chemokines, alongside exosomes harboring mRNA, proteins, and microRNAs, possessing immunomodulatory and regenerative properties. The present study provides a systematic exposition on the etiology of DFU and elucidates the intricate molecular mechanisms and diverse functionalities of MSCs in the context of DFU treatment, thereby furnishing pioneering perspectives aimed at harnessing the therapeutic potential of MSCs for DFU management and advancing wound healing processes.

Deep learning reveals a damage signalling hierarchy that coordinates different cell behaviours driving wound re-epithelialisation

One of the key tissue movements driving closure of a wound is re-epithelialisation. Earlier wound healing studies describe the dynamic cell behaviours that contribute to wound re-epithelialisation, including cell division, cell shape changes and cell migration, as well as the signals that might regulate these cell behaviours. Here, we have used a series of deep learning tools to quantify the contributions of each of these cell behaviours from movies of repairing wounds in the Drosophila pupal wing epithelium. We test how each is altered after knockdown of the conserved wound repair signals Ca2+ and JNK, as well as after ablation of macrophages that supply growth factor signals believed to orchestrate aspects of the repair process. Our genetic perturbation experiments provide quantifiable insights regarding how these wound signals impact cell behaviours. We find that Ca2+ signalling is a master regulator required for all contributing cell behaviours; JNK signalling primarily drives cell shape changes and divisions, whereas signals from macrophages largely regulate cell migration and proliferation. Our studies show deep learning to be a valuable tool for unravelling complex signalling hierarchies underlying tissue repair.

Analysis of Biogenic Amines and Small Molecule Metabolites in Human Diabetic Wound Ulcer Exudate

Diabetic foot ulcers (DFUs) pose a significant challenge in wound care due to their chronic nature and impaired healing processes. This study examines the biogenic amines and small molecule metabolites present in DFU wound exudates to identify their potential roles in wound healing. Under an IRB-approved protocol, wound fluid samples were collected from 25 diabetic patients and analyzed using ultrahigh-pressure liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry. The analysis identified 721 metabolites, with 402 confirmed through stringent criteria. Key metabolites significantly contributing to the wound exudates include betaine, lactic acid, carnitine, choline, creatine, and metformin (a widely used first-line treatment for type 2 diabetes). These molecules are known to influence wound healing processes, such as collagen synthesis, angiogenesis, inflammation modulation, and energy metabolism. Notably, the presence of drugs such as metformin and beclomethasone in the exudates suggests significant pharmacodynamic interactions that could influence wound healing. Specifically, we discovered that the combined use of insulin and metformin administered systemically significantly increased the concentration of metformin in the wound exudates (from 0.3% ± 0.0 to 3.1% ± 3.4; p = 0.00 49). This study highlights the complexity of DFU exudate composition and underscores the potential for targeted metabolic profiling to develop personalized wound care strategies.

Evaluation of Biotechnological Active Peptides Secreted by Saccharomyces cerevisiae with Potential Skin Benefits

Biotechnological active peptides are gaining interest in the cosmetics industry due to their antimicrobial, anti-inflammatory, antioxidant, and anti-collagenase (ACE) effects, as well as wound healing properties, making them suitable for cosmetic formulations. The antimicrobial activity of peptides (2-10 kDa) secreted by Saccharomyces cerevisiae Ethanol-Red was evaluated against dermal pathogens using broth microdilution and challenge tests. ACE was assessed using a collagenase activity colorimetric assay, antioxidant activity via spectrophotometric monitoring of nitrotetrazolium blue chloride (NBT) reduction, and anti-inflammatory effects by quantifying TNF-α mRNA in lipopolysaccharides (LPS)-exposed dermal fibroblasts. Wound healing assays involved human fibroblasts, endothelial cells, and dermal keratinocytes. The peptides (2-10 kDa) exhibited antimicrobial activity against 10 dermal pathogens, with the Minimum Inhibitory Concentrations (MICs) ranging from 125 µg/mL for Staphylococcus aureus to 1000 µg/mL for Candida albicans and Streptococcus pyogenes. In the challenge test, peptides at their MICs reduced microbial counts significantly, fulfilling ISO 11930:2019 standards, except against Aspergillus brasiliensis. The peptides combined with MicrocareⓇ SB showed synergy, particularly against C. albicans and A. brasilensis. In vitro, the peptides inhibited collagenase activity by 41.8% and 94.5% at 250 and 1000 µg/mL, respectively, and demonstrated antioxidant capacity. Pre-incubation with peptides decreased TNF-α expression in fibroblasts, indicating anti-inflammatory effects. The peptides do not show to promote or inhibit the angiogenesis of endothelial cells, but are able to attenuate fibrosis, scar formation, and chronic inflammation during the final phases of the wound healing process. The peptides showed antimicrobial, antioxidant, ACE, and anti-inflammatory properties, highlighting their potential as multifunctional bioactive ingredients in skincare, warranting further optimization and exploration in cosmetic applications.

Advances in Electrospun Nanofiber Membranes for Dermatological Applications: A Review

In recent years, a wide variety of high-performance and versatile nanofiber membranes have been successfully created using different electrospinning methods. As vehicles for medication, they have been receiving more attention because of their exceptional antibacterial characteristics and ability to heal wounds, resulting in improved drug delivery and release. This quality makes them an appealing choice for treating various skin conditions like wounds, fungal infections, skin discoloration disorders, dermatitis, and skin cancer. This article offers comprehensive information on the electrospinning procedure, the categorization of nanofiber membranes, and their use in dermatology. Additionally, it delves into successful case studies, showcasing the utilization of nanofiber membranes in the field of skin diseases to promote their substantial advancement.

Expanding Our Horizons: AIE Materials in Bacterial Research

Bacteria share a longstanding and complex relationship with humans, playing a role in protecting gut health and sustaining the ecosystem to cause infectious diseases and antibiotic resistance. Luminogenic materials that share aggregation-induced emission (AIE) characteristics have emerged as a versatile toolbox for bacterial studies through fluorescence visualization. Numerous research efforts highlight the superiority of AIE materials in this field. Recent advances in AIE materials in bacterial studies are categorized into four areas: understanding bacterial interactions, antibacterial strategies, diverse applications, and synergistic applications with bacteria. Initial research focuses on visualizing the unseen bacteria and progresses into developing strategies involving electrostatic interactions, amphiphilic AIE luminogens (AIEgens), and various AIE materials to enhance bacterial affinity. Recent progress in antibacterial strategies includes using photodynamic and photothermal therapies, bacterial toxicity studies, and combined therapies. Diverse applications from environmental disinfection to disease treatment, utilizing AIE materials in antibacterial coatings, bacterial sensors, wound healing materials, etc., are also provided. Finally, synergistic applications combining AIE materials with bacteria to achieve enhanced outcomes are explored. This review summarizes the developmental trend of AIE materials in bacterial studies and is expected to provide future research directions in advancing bacterial methodologies.

The role of SLC7A11 in diabetic wound healing: novel insights and new therapeutic strategies

Diabetic wounds are a severe complication of diabetes, characterized by persistent, non-healing ulcers due to disrupted wound-healing mechanisms in a hyperglycemic environment. Key factors in the pathogenesis of these chronic wounds include unresolved inflammation and antioxidant defense imbalances. The cystine/glutamate antiporter SLC7A11 (xCT) is crucial for cystine import, glutathione production, and antioxidant protection, positioning it as a vital regulator of diabetic wound healing. Recent studies underscore the role of SLC7A11 in modulating immune responses and oxidative stress in diabetic wounds. Moreover, SLC7A11 influences critical processes such as insulin secretion and the mTOR signaling pathway, both of which are implicated in delayed wound healing. This review explores the mechanisms regulating SLC7A11 and its impact on immune response, antioxidant defenses, insulin secretion, and mTOR pathways in diabetic wounds. Additionally, we highlight the current advancements in targeting SLC7A11 for treating related diseases and conceptualize its potential applications and value in diabetic wound treatment strategies, along with the challenges encountered in this context.

Recombinant collagen for the repair of skin wounds and photo-aging damage

The skin, being the body's primary defense mechanism, is susceptible to various injuries such as epidermal wounds, natural aging, and ultraviolet-induced damage. As a result, there is growing interest in researching skin repair methods. Traditional animal-derived collagen, widely available on the market, poses risks due to its immunogenicity and potential for viral contamination. In contrast, recombinant collagen sourced from human genes offers a safer alternative. To investigate the potential of human recombinant collagen in skin repair, our research team applied two types, type I human collagen (Col I) and CF-1552(I), to two different skin injury models: a wound-healing model and a photo-aging model. Our findings indicate that both Col I and CF-1552(I) effectively enhance wound healing and repair skin damaged by ultraviolet exposure. Notably, CF-1552(I) showed effects comparable to Col I in promoting cell proliferation in the wound-healing model and increasing malondialdehyde content in the photo-aging model, suggesting that CF-1552(I) may offer greater potential for skin repair compared to the larger Col I molecule.

Novel Therapeutic Mechanisms and Strategies for Intracerebral Hemorrhage: Focusing on Exosomes

Intracerebral hemorrhage (ICH) is a primary, non-traumatic cerebral event associated with substantial mortality and disability. Despite advancements in understanding its etiology and refining diagnostic techniques, a validated treatment to significantly improve ICH prognosis remains elusive. Exosomes, a subtype of extracellular vesicles, encapsulate bioactive components, predominantly microRNAs (miRNAs), facilitating and regulating intercellular communication. Currently, exosomes have garnered considerable interests in clinical transformation for their nanostructure, minimal immunogenicity, low toxicity, inherent stability, and the ability to traverse the blood-brain barrier. A wealth of studies has demonstrated that exosomes can improve the prognosis of ICH through anti-apoptosis, neurogenesis, angiogenesis, anti-inflammation, immunomodulation, and autophagy, primarily via the transportation or overexpression of selected miRNAs. More importantly, exosomes can be easily customized with specific miRNAs or bioactive compounds to establish delivery systems, broadening their potential applications. This review focuses on the therapeutic potential of exosomes in ICH, reviewing the mechanisms of molecular biology mediated by certain miRNAs, discussing the benefits, challenges, and future prospects in ICH treatment. We hope comprehensive understanding of exosomes based on miRNAs will provide new insights into the treatment of ICH and guide the translation of exosome's research from laboratory to clinical practice.

Reshaped commensal wound microbiome via topical application of Calvatia gigantea extract contributes to faster diabetic wound healing

Background

Calvatia gigantea (CG) is widely used as a traditional Chinese medicine for wound treatment. In this study, we aimed to determine the effects of CG extract (CGE) on diabetic wound healing and the commensal wound microbiome.

Method

A wound model was established using leptin receptor-deficient db/db mice, with untreated mice as the control group and CGE-treated mice as the treatment group. The wound healing rate, inflammation and histology were analyzed. Additionally, wound microbiome was evaluated via 16S ribosomal RNA (rRNA) gene sequencing.

Results

CGE significantly accelerated the healing of diabetic ulcer wounds, facilitated re-epithelialization, and downregulated the transcription levels of the inflammatory cytokines, interleukin-1β and tumor necrosis factor-α. Furthermore, CGE treatment positively affected the wound microbiome, promoting diversity of the microbial community and enrichment of Escherichia-Shigella bacteria in the CGE-treated group.

Conclusions

Overall, CGE enhanced diabetic wound healing by modulating the wound microbiome and facilitating macrophage polarization during inflammation. These findings suggest modulation of the commensal wound microbiome using medicinal plants as a potential therapeutic strategy for diabetic wounds.

Molecular evolution of wound healing-related genes during cetacean secondary aquatic adaptation

The marine environment presents challenges for wound healing in cetaceans, despite their remarkable recovery abilities with minimal infections or complications. However, the molecular mechanism underlying this efficient wound healing remains underexplored. To better understand the molecular mechanisms behind wound healing in cetaceans, we investigated the evolutionary patterns of 37 wound healing-related genes in representative mammals. We found wound healing-related genes experience adaptive evolution in cetaceans: (1) Three extrinsic coagulation pathway-related genes-tissue factor (F3), coagulation factor VII (F7), and coagulation factor X (F10)-are subject to positive selection in cetaceans, which might promote efficient hemostasis after injury; positive selection in transforming growth factor-beta 2 (TGF-β2), transforming growth factor-beta 3 (TGF-β3), and platelet-derived growth factor D (PDGFD), which play immunological roles in wound healing, may help cetaceans enhance inflammatory response and tissue debridement. (2) Coagulation factor XII (F12) is the initiation factor in the intrinsic coagulation pathway. It had a premature stop codon mutation and was subjected to selective stress relaxation in cetaceans, suggesting that the early termination of F12 may help cetaceans avoid the risk of vascular blockage during diving. (3) Fibrinogen alpha chain (FGA) and FIII, which were detected to contain the specific amino acid substitutions in marine mammals, indicating similar evolutionary mechanisms might exist among marine mammals to maintain strong wound-healing ability. Thus, our research provides further impetus to study the evolution of the wound healing system in cetaceans and other marine mammals, extending knowledge of preventing coagulation disorder and atherosclerosis in humans.

A comparison of several separation processes for eggshell membrane powder as a natural biomaterial for skin regeneration

BACKGROUND

Numerous studies have focused on skin damage, the most prevalent physical injury, aiming to improve wound healing. The exploration of biomaterials, specifically eggshell membranes (ESMs), is undertaken to accelerate the recovery of skin injuries. The membrane must be separated from the shell to make this biomaterial usable. Hence, this investigation aimed to identify more about the methods for membrane isolation and determine the most efficient one for usage as a biomaterial.

METHODS AND MATERIALS

For this purpose, ESM was removed from eggs using different protocols (with sodium carbonate, acetic acid, HCl, calcium carbonate, and using forceps for separation). Consequently, we have examined the membranes' mechanical and morphological qualities.

RESULTS

According to the analysis of microscopic surface morphology, the membranes have appropriate porosity. MTT assay also revealed that the membranes have no cytotoxic effect on 3T3 cells. The results indicated that the ESM had acquired acceptable coagulation and was compatible with blood. Based on the obtained results, Provacol 4 (0.5-mol HCl and neutralized with 0.1-mol NaOH) was better than other methods of extraction and eggshell separation because it was more cell-compatible and more compatible with blood.

CONCLUSION

This study demonstrates that ESMs can be used as a suitable biomaterial in medical applications.

Application of Bletilla striata polysaccharide hydrogel for wound healing among in diabetes

Diabetes has become an increasingly serious global health crisis. Long-term hyperglycemia can lead to vascular and neurological disorders, thus deterring wound healing. Therefore, exploring treatment modalities for wounds in individuals with diabetes is clinically significant. Bletilla striata polysaccharide and bioactive natural polymers carbomer 940 and carboxymethyl chitosan (CMC) are cross-linked to form the Bletilla striata polysaccharide hydrogel (named CCHG/BSP). Upon characterization, we found that the hydrogel has a porous structure and good mechanical and moisture retention properties. A hemolysis test revealed that the hydrogel had high safety. Furthermore, the hydrogel effectively promoted proliferation and migration in mouse L929 fibroblasts. In back wounds inflicted in a streptozotocin-induced mouse model of diabetes, the CCHG/BSP hydrogel significantly promoted wound healing. Hematoxylin-eosin, Masson's trichrome, and immunohistochemical staining of tissues around the wound suggest that the mechanism underlying wound healing in diabetes may involve the promotion of angiogenesis, regulation of inflammation, and promotion of collagen regeneration. This provides a foundation for studies on and the development of new BSP pharmacotherapeutic products and the clinical application of its hydrogel dressing, and provide novel avenues for treating wounds in individuals with diabetes.

Clinicopathological and cellular senescence biomarkers in chronic stalled wounds

BACKGROUND

Chronic wounds have been associated with an elevated burden of cellular senescence, a state of essentially irreversible cell cycle arrest, resistance to apoptosis, and a secretory phenotype. However, whether senescent cells contribute to wound chronicity in humans remains unclear. The objective of this article is to assess the role of clinicopathological characteristics and cellular senescence in the time-to-healing of chronic wounds.

METHODS

A cohort of 79 patients with chronic wounds was evaluated in a single-center academic practice from February 1, 2005, to February 28, 2015, and followed for up to 36 months. Clinical characteristics and wound biopsies were obtained at baseline, and time-to-healing was assessed. Wound biopsies were analyzed histologically for pathological characteristics and molecularly for markers of cellular senescence. In addition, biopsy slides were stained for p16INK4a expression.

RESULTS

No clinical or pathological characteristics were found to have significant associations with time-to-healing. A Cox proportional hazard ratio model revealed increased CDKN1A (p21CIP1/WAF1) expression to predict longer time-to-healing, and a model adjusted for gender and epidermal hyperplasia revealed increased CDKN1A expression and decreased PAPPA expression to predict longer time-to-healing. Increased p16INK4a staining was observed in diabetic wounds compared to non-diabetic wounds, and the same association was observed in the context of high dermal fibrosis.

CONCLUSIONS

The findings of this pilot study suggest that senescent cells contribute to wound chronicity in humans, especially in diabetic wounds.

In Situ Triggered Self-Contraction Bioactive Microgel Assembly Accelerates Diabetic Skin Wound Healing by Activating Mechanotransduction and Biochemical Pathway

Chronic nonhealing skin wounds, characterized by reduced tissue contractility and inhibited wound cell survival under hyperglycemia and hypoxia, present a significant challenge in diabetic care. Here, an advanced self-contraction bioactive core-shell microgel assembly with robust tissue-adhesion (SMART-EXO) is introduced to expedite diabetic wound healing. The SMART-EXO dressing exhibits strong, reversible adhesion to damaged tissue due to abundant hydrogen and dynamic coordination bonds. Additionally, the core-shell microgel components and dynamic coordination bonds provide moderate rigidity, customizable self-contraction, and an interlinked porous architecture. The triggered in situ self-contraction of the SMART-EXO dressing enables active, tunable wound contraction, activating mechanotransduction in the skin and promoting the optimal fibroblast-to-myofibroblast conversion, collagen synthesis, and angiogenesis. Concurrently, the triggered contraction of SMART-EXO facilitates efficient loading and on-demand release of bioactive exosomes, contributing to re-epithelialization and wound microenvironment regulation in diabetic mice. RNA-seq results reveal the activation of critical signaling pathways associated with mechanosensing and exosome regulation, highlighting the combined biomechanical and biochemical mechanisms. These findings underscore SMART-EXO as a versatile, adaptable solution to the complex challenges of diabetic wound care.

An overview of conventional and investigational phosphodiesterase 5 inhibitors for treating erectile dysfunction and other conditions

INTRODUCTION

There is a rising concern about developing innovative, efficacious PDE5I molecules that provide better safety, efficacy, and tolerability with less adverse effects. Innovative PDE5I with dual targets have also been defined in the literature. Additionally, some of PDE5I are able to selectively inhibit other enzymes such as histone deacetylase, acetylcholine esterase, and cyclooxygenase or act as nitric oxide donors. This review presents knowledge concerning the advanced trends and perspectives in using PDE5I in treatment of ED and other conditions.

AREAS COVERED

Pre-clinical and early clinical trials that investigated the safety, efficacy, and tolerability of novel PDE5I such as Udenafil, Mirodenafil, Lodenafil, Youkenafil, Celecoxib, and TPN729 in treatment of ED and other conditions.

EXPERT OPINION

Preclinical and limited early clinical studies of the new molecules of PDE5I have demonstrated encouraging results; however, safety, efficacy, and tolerability are still issues that necessitate further long-term multicenter clinical studies to ensure justification of their uses in treatment of ED and other conditions. Progress in molecular delivery techniques and tailored patient-specific management and additional therapeutic technology will dramatically improve care for ED and other conditions. The dream of ED and many other conditions becoming more effectively managed may be feasible in the near future.