Regulation of Collagen I and Collagen III in Tissue Injury and Regeneration

Roxadustat pre-conditioning and cyclic uniaxial stretching improve tenogenic differentiation potential of human adipose derived mesenchymal stromal cells

Tendon injuries represent a significant challenge to treat owing to their limited intrinsic reparative capacity. The use of mesenchymal stem cells (MSC) offers promising alternative therapeutic option to augments tendon repair. It is hypothesised that the activation of hypoxia inducible factor-1 alpha (HIF-1α), could facilitate the tendon repair process by promoting the proliferation and tenogenic differentiation of MSCs. To demonstrate this, a study was conducted incorporating the use of Roxadustat, a specific hypoxia mimetic mediator and cyclic uniaxial stretching at a frequency of 1 Hz and 8 % strain on adipose derived-mesenchymal stromal cells (ADMSCs).

METHODS

Cellular morphology, proliferation rate, tenogenic protein and gene expression levels from 8 different treatment groups were compared. These groups include untreated ADMSCs (Control), Roxadustat pre-conditioned ADMSCs (ROX), ADMSCs subjected CAY10585 treatment only (CAY), Roxadustat pre-conditioned ADMSCs with CAY10585 inhibition (ROX+CAY), ADMSCs subjected to uniaxial stretching only (S), Roxadustat pre-conditioned ADMSCs with uniaxial stretching (ROX+S), ADMSCs subjected CAY10585 with uniaxial stretching (CAY+S) and primary tenocytes (Tenocytes).

RESULTS

ROX+S group exhibited the highest expression of HIF-1α and demonstrated a significant up-regulation of collagen I and III expressions, increasing by 4.9 and 5.6-fold compared to ROX group, respectively. There is a significant increase of SCX, TNC, TNMD, COLI and COLIII expression in this combination treatment group; (SCX= 9.9, TNC= 12.6, TNMD= 7.0, COLI= 8.0 and COLIII= 10.0-fold). Conversely, the expression of the markers markedly reduced with HIF-1α inhibitor CAY10585. However, uniaxial stretching effectively counteracted the inhibitory effects of CAY10585 in the CAY+ S group, resulting in a 3.9-fold increase in SCX expression compared to CAY treatment alone.

CONCLUSION

HIF-1α accumulation promotes superior tenogenic differentiation of ADMSCs, suggesting that the combination of Roxadustat and cyclic uniaxial stretching may be a potential therapeutic mediator in tendon repair strategies.

Chitosan nanoparticles as a targeted delivery system for anti-fibrotic microRNAs for oral submucosal fibrosis treatment

Oral submucous fibrosis (OSF) is characterized by excessive extracellular matrix (ECM) deposition. Dysregulation of microRNAs (miRs) is involved in the progression of OSF, and miR manipulation could be a promising therapeutic approach. Nanoformulation can protect exogenous miRs against nuclease degradation and enhance cell retention. Accordingly, chitosan (CS), which possesses an anti-fibrotic capacity, is proposed to encapsulate miRs as nanoparticles (NPs) for treating OSF. miR-negative control (miR-NC)/CS NPs were fabricated by an ionic gelation method and characterized. Human oral submucosal fibroblasts were first subjected to arecoline stimulation to induce myofibroblast differentiation and were then transfected with a miR-145 inhibitor or miR-424 inhibitor using CS NPs. For CS NPs loaded with miR-NC, the particle size was 121.9 ± 0.1 nm with a polydispersity index of 0.162 ± 0.004 and zeta potential of + 22.4 ± 0.5 mV. Transfection of these two miRs downregulated mRNA levels of transforming growth factor beta 1, actin alpha 2 smooth muscle, collagen type I alpha 1 chain (COL1A1), COL3A1, COL4A1, matrix metalloproteinase 2, tissue inhibitor of metalloproteinase 2, and zinc finger E-box binding homeobox 1 in myofibroblasts. A Western blot analysis revealed that miR/CS NP transfection decreased alpha-smooth muscle actin and type 1 collagen protein products. Furthermore, the wound closure ability of stimulated cells was inhibited upon transfection. In conclusion. CS NPs are a good delivery vehicle for miR transfection. Transfection of a miR-145 inhibitor and miR-424 inhibitor inhibited the TGF-β signaling pathway and decreased ECM component production, and could thus be a promising treatment for OSF.

Transcriptional and post-translational mechanisms of ECM remodeling in rotator cuff tendons under hyperlipidemic conditions

Rotator cuff injuries present significant clinical challenges, often resulting in chronic pain and functional impairment. In this study, we examined the effects of hyperlipidemia (HYP), a systemic metabolic condition, on tendon health. Histological analysis of infraspinatus tendons from hyperlipidemic swine revealed well-organized extracellular matrix (ECM) structures, comparable to those in non-hyperlipidemic (NONHYP) animals, suggesting ECM reorganization. Upstream SIGNOR3.0 analysis demonstrated that tumor necrosis factor receptor-associated factor 6 (TRAF6) activates transcription factor Yin Yang 1 (YY1) via kinase signaling, underscoring its role in tendon ECM remodeling. Hence, we futher examined the role of YY1, which is a critical regulator of collagen synthesis identified through network analysis. Although TRAF6 levels remained unchanged in HYP conditions, increased YY1 expression correlated with elevated COL1 gene expression. Additionally, twist-related protein 1 (TWIST1) emerged as another key molecule, existing in both homo- and heterodimer forms in NON-HYP conditions, but only as a heterodimer in HYP. YY1 enhanced COL1 transcription in the hyperlipidemic environment, while TWIST1 heterodimer formation facilitated collagen crosslinking. Notably, increased YY1 expression inhibited MMP3, resulting in the inactivity of MMP1, MMP8, and MMP9, thereby preserving collagen levels. These findings highlight the complex molecular interactions involving transcriptional regulation by YY1 and post-translational regulation by the TWIST1 heterodimer, essential for the deposition of mature collagen fibrils and driving tendon remodeling in hyperlipidemic conditions. This study offers valuable insights for the change of tendon health condition in hyperlipidemia disease or tendon pathology.

Multiscale investigation of collagen structure in human skin and gel matrices using polarization resolved second harmonic generation microscopy

Collagen is critical to the structure and function of skin tissues, with the collagen I/III ratios influencing fibrillogenesis, fiber organization, and skin mechanics. Abnormal collagen organization, such as in fibrosis or scar tissue, compromises both skin functionality and aesthetics. In this study, we employed label-free polarization resolved second harmonic generation (PSHG) microscopy to investigate collagen structure in artificial collagen matrices with various Col I/III ratios at the fibril scale ( ∼ 1 to 3 μ m ) and in ex vivo human healthy and scarred skin at the fiber scale ( ∼ 10 to 20 μ m ). Complementary third harmonic generation (THG) microscopy provided additional structural information. Our results indicate that an increasing Col I/III ratio is associated with longer fibril length, higher PSHG intensity, and a reduced effective α -helix pitch angle of fibrils. In pure Col I, the effective α -helix pitch angle is determined to be 47 . 72 ∘ . These observations indicate alterations in fibril assembly. Furthermore, although the α -helix pitch angle of fibers in both healthy and scarred skin was approximately 46 . 7 ∘ , healthy skin exhibited 24 % greater variability in fiber orientation, suggesting a more randomized organization compared to scar tissue. THG imaging further revealed a higher cellular density in scar tissue, consistent with the inflammatory activity associated with wound healing. Immunohistochemical (IHC) staining using dermatansulphate and Col III-specific antibodies confirmed that the Col I/III ratio is higher in healthy skin (2.2) than in scarred skin (1.6). These findings underscore the potential of PSHG microscopy for label-free, quantitative assessment of collagen structure across multiple scales, with THG offering complementary cellular insights. This integrated approach represents a promising strategy for real-time, in vivo monitoring and automated quantification of collagen organization in clinical applications, including dermatology, burn treatment, and fibrosis monitoring.

Injectable hyaluronic acid hydrogels via Michael addition as dermal fillers for skin regeneration applications

This study presents the development of injectable hydrogels based on hyaluronic acid for dermal filler applications, synthesized via Michael-type addition reactions between thiolated hyaluronic acid and polyethylene glycol derivatives. By varying thiol substitution, crosslinking kinetics and hydrogel properties were optimized. Biphasic gel formulations comprising crosslinked hyaluronic acid microparticles in a non-reactive fluid phase matrix enhances injectability and versatility. Key properties, including enzymatic degradation, injectability, and rheology, were evaluated, alongside a three-dimensional culture model to simulate dermal remodelling. Selected gel formulations promoted balanced collagen synthesis and degradation, essential for skin regeneration, while showing a controlled inflammatory response, supporting tissue repair and reducing adverse effects. These findings position these hydrogels as promising candidates for safe and effective dermal filler, supporting tissue remodelling and inflammation management.

The theatrics of collagens in the myocardium: the supreme architect of the fibrotic heart

Heart failure (HF) mediated by cardiac fibrosis (CF) is characterized by an excessive accumulation of collagen-based extracellular matrix (ECM) in the myocardium. CF is a common pathophysiological condition in many heart diseases and can be distinctly categorized into two types: replacement and interstitial. In ischemic heart diseases, sudden loss of cardiomyocytes leads to the replacement of CF to prevent ventricular rupture. In contrast, excessive collagen deposition in the interstitial space between cardiomyocytes (often in response to pressure overload, chronic cardiac stress, hypertension, etc.) is termed interstitial CF. The progression of HF due to cardiac fibrosis is mainly driven by compromised diastolic function, resulting from increased stiffness of the heart wall muscle due to collagen-based scar formation. Increased myocardial stiffness is primarily catalyzed by the differential cross linking of deposited collagens forming the scar in the fibrotic heart. Although collagen deposition remained a hallmark of fibrosis, the pathophysiological progression due to biochemical alterations and mechanistic discrepancy of collagens across cardiac fibrosis subtypes remains elusive. With the advent of next-generation RNA sequencing and high-resolution mass spectrometry, mechanistic insights into collagen-mediated scar maturation have gained impetus. A deeper understanding of the spatiocellular transcriptional heterogeneity and site-specific collagen posttranslational modifications (PTMs) in maneuvering ECM remodeling is gaining attention. The unexplored mechanisms of posttranslational modifications and subsequent collagen cross linking in various cardiac fibrosis may provide the prime target for therapeutic interventions. This review comprehensively summarizes the detailed pattern, role, signaling, and mechanical contributions of different collagens and their PTMs, including cross-linking patterns as newer therapeutic regimens during cardiac fibrosis.

Obesity and type 2 diabetes mellitus: insights from skeletal muscle extracellular matrix remodeling

Obesity and type 2 diabetes mellitus (T2DM) are metabolic diseases at epidemic proportions. The economic burden for these diseases is at an all-time high, and as such, there is an urgent need for advancements in identifying targets for treating these complex disorders. The extracellular matrix (ECM), comprising collagen, fibronectin, laminin, elastin, and proteoglycan, surrounds skeletal muscles and plays a critical role in maintaining tissue homeostasis by providing structural support and facilitating cell-to-cell communication. Disruption of the ECM signaling results in changes to its micro/macroenvironment, thereby modifying tissue homeostasis. Skeletal muscle ECM remodeling has been shown to be associated with insulin resistance, an underlying feature of obesity and T2DM. This narrative review explores the critical components of skeletal muscle ECM and its accumulation and remodeling in metabolic diseases. In addition, we discuss potential treatments to mitigate the effects of ECM remodeling in skeletal muscle. We conclude that targeting ECM remodeling in skeletal muscle represents a promising yet underexplored therapeutic avenue in the management of metabolic disorders.

ZIF-8 composite nanofibrous membranes loaded with bFGF: a new approach for tendon adhesion prevention and repair

During tendon injury repair, deficiency of basic fibroblast growth factor (bFGF) is a critical factor leading to unsatisfactory repair results. This study aims to prepare bFGF-loaded zeolite imidazole framework-8 (ZIF-8) nanocrystals using a one-pot synthesis method. Subsequently, a bilayer nanofibrous membrane incorporating these drug-loaded nanocrystals was fabricated through electrospinning technology. The potential of this composite nanofibrous membrane to facilitate the continuous release of bFGF at the site of tendon injury was evaluated, with the aim of enhancing the quality of tendon repair. The efficacy of the nanofibrous membrane in promoting tendon differentiation, preventing tendon adhesion, and facilitating tendon repair was assessed through both in vitro and in vivo experiments. At the site of tendon injury, the degradation of ZIF-8 in an acidic microenvironment resulted in the release of bFGF and Zn2+, which contributed to the enhancement of tendon repair. ZIF-8 nanocrystals achieved an encapsulation efficiency of 50.13% ± 1.42%. Following a continuous release period exceeding 40 days, the cumulative in vitro release rate was determined to be 35.02% ± 4.27%. The incorporation of ZIF-8 nanocrystals into a nanofibrous membrane demonstrated the ability to effectively preserve the bioactivity of bFGF while enabling sustained release at the site of tendon injury, thereby facilitating tendon repair. The findings offer novel insights into the treatment of tendon injuries and provide significant theoretical guidance for the tendon repair process.

Ionic Liquid-Reinforced Multifunctional Hydrogel for the Treatment of Enterocutaneous Fistula

Enterocutaneous fistulas (ECFs) profoundly impact patients' quality of life, contributing to high morbidity rates and increased mortality due to ineffective treatment options. To address this challenge, ECFGel, a multifunctional, tissue adhesive injectable hydrogel, designed to occlude, sterilize, and promote healing of ECF tracts, is developed. ECFGel is formulated using gelatin and oxidized dextran (O-Dex) as base components, which form chemical crosslinks within the hydrogel and with surrounding biological tissues, ensuring tissue adhesiveness. A choline and geranate-based ionic liquid (IL) is incorporated to provide dual functionality, potent antimicrobial activity, and mechanical enhancement. By optimizing IL concentration, ECFGel achieves rapid gelation, enhanced mechanical strength, and improved elastic recoverability. Additionally, iohexol (IOH) is added for radiopacity, enabling real-time imaging and further strengthening the hydrogel's mechanical properties. ECFGel demonstrates antiswelling properties, biodegradability, and effective tract occlusion in porcine soft tissues. It shows strong antimicrobial activity against highly resistant, patient-derived pathogens isolated from clinical ECF cases. In a porcine perianal fistula model, ECFGel enables rapid occlusion and complete healing, promoting tissue maturation, reducing bacterial load, and increasing markers of cell proliferation and vascularization compared to untreated controls. These promising results highlight ECFGel's potential as a new therapeutic option for treating infected ECFs.

An Adipose-Derived Stem Cell Exosome Sheet Promotes Oral Mucosal Wound Healing

Objective: Oral mucosal wound healing is not completely understood, and effective therapies are lacking. This study explores the potential of an adipose-derived stem cell (ADSC) exosome sheet in enhancing intraoral wound healing in rats. Approach: An ADSC exosome sheet derived from Tisseel and rat adipose tissue (ADSC-exo) was applied to 16 rats with 6 mm full-thickness mucosal hard palate wounds. Eight wounds received ADSC-exo with a superficial occlusive dressing (ADSC-exo group), and eight received only an occlusive dressing (control group). Wound closure was monitored on days 0, 2, 4, 7, and 10, with dressings changed every 2 days. On day 10, rats were sacrificed, and wounds (n = 8 per group) were collected for immunohistochemical analysis. In vitro, four ADSC-exosome concentrations (0, 4.5 × 1011, 9 × 1011, and 18 × 1011 exosomes/mL; n = 4 per group) were applied to rat oral mucosal fibroblasts to assess migration speed. Results: ADSC-exo accelerated wound closure (18% ± 5% vs. 35% ± 9% of initial wound area; p = 0.002) and fibroblast migration (for 18 × 1011 exosomes/mL at 24 h: 29.7% ± 3% vs. 62.2% ± 4% of initial gap area; p < 0.0001) compared with the control. ADSC-exo promoted reepithelialization (87% ± 14% vs. 21% ± 6%; p < 0.0001), proliferation (34 ± 12 vs. 18 ± 7 Ki67+/high-power field [HPF]; p = 0.004), and neovascularization (28 ± 9 vs. 11 ± 5 CD31+/HPF; p = 0.0002) while reducing inflammation (4 ± 1 vs. 13 ± 9 CD68+/HPF; p < 0.0001) and increasing M2 macrophages (9.2 ± 2 vs. 4.2 ± 3 CD163+/HPF; p = 0.0008). ADSC-exo increased Transforming Growth Factor beta 1 (TGF-β1) (1.3 ± 0.3 vs. 0.9 ± 0.2; p = 0.006), Smad3 (0.9 ± 0.02 vs. 0.7 ± 0.1; p = 0.006), and collagen I (1.5 ± 0.9 vs. 0.5 ± 0.3; p = 0.005) while downregulating caspase-3 (0.7 ± 0.3 vs. 1.1 ± 0.2; p = 0.003) and Bax (0.9 ± 0.2 vs. 1.4 ± 0.1; p < 0.0001). Innovation: This is the first study to demonstrate the pro-wound healing effects of an ADSC exosome sheet on intraoral wounds. This paves the way for future research and clinical applications of ADSC exosomes in mucosal wound healing. Conclusions: Application of an ADSC-exo to rat mucosal wounds significantly improved wound healing. Mechanistically, these effects may be linked to upregulated activity of the TGF-β/Smad pathway.

Exploring physiological differences in injury response by skin tone: A scoping review

AIM

To explore existing literature examining physiological differences in pressure ulcer response among individuals with differing skin tones.

METHODS

This was a scoping review. Articles meeting the inclusion criteria were retrieved from electronic databases including PubMed, CINAHL, Scopus, Cochrane, and EMBASE, using the keywords "pressure ulcer," "skin pigmentation," "melanin," and "risk factor." Data were extracted using a predesigned data extraction tool and analysed using a narrative synthesis.

RESULTS

Five papers met the inclusion criteria. Analysis of findings suggests there are potential mechanisms which may influence the skin's ability to withstand mechanical stress and its inflammatory response to damage among those with different skin tones; the structure of the stratum corneum, collagen density, fibroblast activity, mast cell density, and transepidermal water loss (TEWL). The stratum corneum can compromise skin resilience, while collagen density and fibroblast activity may impact skin strength and repair. Mast cells affect inflammation, which can exacerbate pressure ulcer damage, and increased TEWL in those with dark skin tones can result in lower water content in the stratum corneum, affecting hydration.Conversely, factors like melanosome size, hair follicle and hair fiber characteristics, sebaceous gland activity, vitamin D production, UVR protection, and desquamation rate, although relevant to overall skin health, may not directly affect the mechanical processes leading to pressure ulcer formation.

CONCLUSIONS

Physiological differences in skin structure may contribute to alterations in the response to pressure ulcer development among individuals with dark skin. Recognising these differences is important for targeted prevention strategies within diverse populations. However, further research is needed to explore the mechanisms underlying this association in greater detail.

Comparison of Biological Augmentation in Rotator Cuff Repair Using Inflamed Versus Noninflamed Bursal Tissue in Rats

PURPOSE

To examine how augmentation of a rotator cuff repair with inflamed versus noninflamed bursal tissue affects tendon-to-bone healing in a rat model of rotator cuff repair.

METHODS

A total of 136 Sprague-Dawley rats were randomly assigned to an inflamed or noninflamed bursal tissue application group. After detachment, the supraspinatus tendon was reattached with bursal tissue sewn onto the tendon-to-bone interface. The specimens were analyzed biomechanically 6 and at 7 weeks and immunohistologically at 1 and at 7 weeks after surgery.

RESULTS

Immunohistological results showed no significant difference in the percentage of collagen type II in the tendon-to-bone interface at 1 (P = .87) and 7 weeks (P = .42) when using autologous noninflamed bursal tissue in comparison with inflamed bursal tissue specimens. The inflamed bursa group also showed no significant difference in collagen I to III quotient (P = .14) after surgery in comparison with noninflamed bursa groups after surgery. Biomechanical assessment showed that tendon stiffness (P = .87 inflamed versus noninflammed (resp.) P = .1) and the tendon viscoelasticity (P = .12 resp. P = .07) was the same after 6 and 7 weeks when we compared the inflamed bursa with the noninflamed bursa group. There was no significant difference (P = .8 resp. P = .87) in load to failure between in both inflamed and noninflamed bursa groups after 6 and 7 weeks.

CONCLUSIONS

Autologous inflamed bursal tissue derived from the Achilles bursa and implanted to the tendon-to-bone interface after rotator cuff repair facilitates the same histologic and biomechanical healing response as using a noninflamed bursa interposition in rats.

CLINICAL RELEVANCE

During augmentation of a rotator cuff repair, it is irrelevant whether the bursa tissue is inflamed.

Circulating collagen type I fragments as specific biomarkers of cardiovascular outcome risk: Where are the opportunities?

Collagen type I (COL1) is the most abundant protein in the human body and is a main component in the extracellular matrix. The COL1 structure vastly influences normal tissue homeostasis, and changes in the matrix drive progression in multiple diseases. Cardiovascular diseases (CVD) are the leading cause of mortality and morbidity in many Western countries; alterations in the extracellular matrix turnover processes, including COL1, are known to influence the pathophysiological processes leading to CVD outcome. Peptides reflecting COL1 formation and degradation have been established and explored for over two decades in CVD. This review aims to combine and assess the evidence for using COL1-derived circulating peptides as biomarkers in CVD. Secondly, the review identifies existing pitfalls, and evaluates future opportunities for improving the technical characteristics and performance of the biomarkers for implementation in the clinical setting.

In-vivo immunocompatibility and induced regenerative potential of silk fibroin modified decellularized porcine liver scaffolds in rat subcutaneous and full-thickness abdominal wall defect models

For reconstructive surgical applications, humoral and cell-mediated immune response to scaffolds is important in determining its structural and functional integration and performance. A decellularized porcine liver matrix(DPL) mechanically augmented with impregnating silk fibroin(SF100DPL) and silk fibroin-gelatin blends(SFG5050DPL and SFG3070DPL) following citric acid crosslinking were evaluated in-vitro and in-vivo (subcutaneous and abdominal wall defect models) in comparison to unmodified DPL. Ensuring the preservation of glycosaminoglycan and the potential to induce cell migration in L929 cell line, the host immunocompatibility of the scaffolds was confirmed by implanting sub-cutaneously in rat. The modified scaffolds in the full-thickness rat abdominal wall defect model showed better integration at the defect site without any evidence of mechanical failure. The inflammatory cell response was evidently reducing with prominent neovascularization. Masson's trichrome (MT) staining and immunohistochemistry (IHC) demonstrated skeletal muscle island formation initially at the host-graft interface while extending towards the mid-graft region as time progressed. A significant decrease in the collagen III/I ratio at 90 days indicated that the neocollagen deposited at 21 days was replaced by mature collagen type I. Among the modified scaffolds evaluated, the SF100DPL and SFG5050DPL exhibited comparatively high immunocompatibility and regenerative potential that makes them suitable for various scaffold based regenerative therapies.

Platelet like cells differentiated from human adipose derived mesenchymal stem cells promote healing of tendinopathy in rats

Tendon and ligament disorders, such as tendinopathy, cause pain and limit levels of activities of daily living. Thus, devising methods to heal them is crucial. Although treatment with autologous platelet rich plasma (PRP) is reportedly useful against tendon injury, PRP requires blood sampling and its quality varies. Here we show that platelet-like cells (ASCL-PLCs) derived from a heterologous human adipose-derived mesenchymal stem cell line (ASCL) promote significant tendon repair in a collagenase-induced injury model in rat Achilles tendons. Single administration of human ASCL-PLCs to rat Achilles tendon after 2 weeks of collagenase treatment significantly increased tendon strength and improved semi-quantitative histological evaluation scores in 4 weeks relative to PBS-treated controls. Moreover, xeno-graft reactions were not evident in ASCL-PLC-administered rats. In vitro, ASCL-PLC treatment significantly upregulated Col1a1, Lox and Mkx gene expression in NIH3T3 fibroblasts and activated ERK signaling. Overall, ASCL-PLCs could serve as a useful tool to repair injured tendons and treat tendinopathy. This approach eliminates the need for blood sampling, ensures consistent quality, supports xeno-transplantation, and increases injured tendon strength.

Wound healing by enhancing cell proliferation: a thermoreversible formulation containing raloxifene

The challenge of ineffective wound healing, leading to chronic conditions necessitates the development of novel therapeutics strategies. Currently, a plethora of ailments have been researched and marketed globally to accelerate angiogenesis, re-epithelization, collagen synthesis, and proliferation. However, clinical translation remains challenging and requires rigorous pre- and post-clinical screening. Here, we have developed a formulation encapsulating Raloxifene, a repurposed drug, aimed to induce accelerated wound healing. Four different formulations (Forms 1, 2, 3, and 4) incorporating alginate, poloxamer 407 (P407), LiCl, and fetal bovine serum were prepared. Formulations were characterized by scanning electron microscopy, Fourier Transformation infrared spectroscopy, and rheology. In vitro assessments encompassing cell viability, cell migration, and drug release profile were conducted, subsequently, the in vivo wound healing potential was evaluated in Sprague Dawley (SD) rats. In results, we observed significant (p-value<0.05) wound healing by Form 3 at  14th due to up-regulation of TGFꞵ, Col-I and GSK3β genes. The histology results showed complete development of epidermis, endoderm and collagen fibers by Form 3, leading to complete healing. This formulation shows promise for clinical application in accelerated wound healing processes.

Vitamin C in Cardiovascular Disease: From Molecular Mechanisms to Clinical Evidence and Therapeutic Applications

Vitamin C, also known as ascorbic acid, is an essential nutrient that humans cannot synthesize, making its intake crucial for health. Discovered nearly a century ago, vitamin C is widely recognized for its ability to prevent scurvy and has become one of the most commonly used supplements. Beyond its antioxidant activity, vitamin C is pivotal in regulating lipid metabolism, promoting angiogenesis, enhancing collagen synthesis, modulating remodeling, and stabilizing the extracellular matrix. While preclinical studies have shown promising results, clinical trials have yielded inconsistent findings, due to suboptimal study design, results misinterpretation, and misleading conclusions. This review provides a holistic overview of existing evidence on the pleiotropic role of vitamin C in cardiovascular diseases, identifying both the strengths and limitations of current research and highlighting gaps in understandings in vitamin C's underlying mechanisms. By integrating molecular insights with clinical data and evaluating the pleiotropic role of vitamin C in cardiovascular disease management and prevention, this review aims to guide future research toward personalized, evidence-based therapeutic strategies in clinical practice.

Epigallocatechin Gallate in Camellia sinensis Ameliorates Skin Aging by Reducing Mitochondrial ROS Production

Background: Reactive oxygen species (ROS) generated by mitochondrial dysfunction damage cellular organelles and contribute to skin aging. Therefore, strategies to reduce mitochondrial ROS production are considered important for alleviating skin aging, but no effective methods have been identified. Methods: In this study, we evaluated substances utilized as cosmetic ingredients and discovered Camellia sinensis (C. sinensis) as a substance that reduces mitochondrial ROS levels. Results:C. sinensis extracts were found to act as senolytics that selectively kill senescent fibroblasts containing dysfunctional mitochondria. In addition, C. sinensis extracts facilitated efficient electron transport in the mitochondrial electron transport chain (ETC) by increasing the efficiency of oxidative phosphorylation (OXPHOS), thereby reducing mitochondrial ROS production, a byproduct of the inefficient ETC. This novel mechanism of C. sinensis extracts led to the restoration of skin aging and the skin barrier. Furthermore, epigallocatechin gallate (EGCG) was identified as an active ingredient that plays a key role in C. sinensis extract-mediated skin aging recovery. Indeed, similar to C. sinensis extracts, EGCG reduced ROS and improved skin aging in an artificial skin model. Conclusions: Our data uncovered a novel mechanism by which C. sinensis extract reverses skin aging by reducing mitochondrial ROS production via selective senescent cell death/increased OXPHOS efficiency. Our results suggest that C. sinensis extract or EGCG may be used as a therapeutic agent to reverse skin aging in clinical and cosmetic applications.

A Pro-Healing and Antibacterial Bio-Based Hydrogel Barrier for the Prevention of Intestinal Anastomotic Leakage

Postoperative leakage at the colorectal anastomosis is recognized as a significant and serious complication. Its pathogenic factors are complex, the onset process is hidden, and it is often complicated with severe abdominal infection, which leads to sepsis and even multiple organ failure. In order to develop a new type of multifunctional biomaterial which can prevent intestinal bacterial translocation, intestinal fluid spillage and promote the healing of intestinal anastomosis, we prepared a multifunctional temperature-sensitive extracellular matrix hydrogel with the extracellular matrix (ECM) of porcine small intestinal submucosa (SIS) physically modified by boric acid and 4-ARM-PEG-SC as raw materials, in order to avoid abdominal infection and prevent anastomotic leakage. A series of experiments showed that the prepared hydrogel had stable structure, could resist the erosion of digestive juice in physiological range and had good tissue adhesion and mechanical properties, excellent antiexplosion ability and self-healing. Combined with its injectability, it could effectively seal the anastomosis. In vitro experiments showed that the hydrogel had effective antidigestion ability, good antibacterial properties, excellent cell and blood compatibility, as well as antioxidant and anti-inflammatory capabilities. Experiments revealed that the hydrogel could effectively optimize the local microenvironment of the anastomosis, promote the tissue repair of the anastomosis and effectively reduce the incidence of colonic anastomotic leakage in rats by promoting the key factors of cell proliferation, facilitating vascular formation and curtailing the expression of pro-inflammatory factors. The findings of this study pave the way for novel strategies in creating multifunctional materials designed to prevent and manage anastomotic leakage.

Review of Preclinical and Clinical Studies Supporting the Role of Polydeoxyribonucleotide in the Treatment of Tendon Disorders

Tendon disorders are among the most common musculoskeletal conditions, accounting for 30% to 50% of all sports-related injuries. Injured tendons heal slowly and often fail to regain their original structural integrity and mechanical strength, creating significant challenges for physicians. Recently, investigations have reported that polydeoxyribonucleotide (PDRN) plays a key role in promoting tendon healing. For example, preclinical studies indicate that PDRN can enhance tendon repair by inhibiting inflammation and cell apoptosis while promoting collagen production. In clinical studies, the effectiveness and safety of PDRN were also confirmed for managing several conditions, including plantar fasciitis, epicondylitis, Achilles tendinopathy, pes anserine tendinopathy, and chronic rotator cuff disease. In light of these findings, this article aims to review the preclinical and clinical studies that support the role of PDRN in the treatment of tendon disorders. A search was conducted in Medline and PubMed from January 1994 to October 2024 to find relevant research. Ultimately, the review included 3 preclinical studies and 8 clinical studies, involving a total of 318 patients. In conclusion, PDRN is a promising therapeutic option for treating tendon disorders. However, further preclinical and clinical studies are needed to better understand its effects on tendon disorders and to support future clinical applications.

Collagen-Based Wound Dressings: Innovations, Mechanisms, and Clinical Applications

Collagen-based wound dressings have developed as an essential component of contemporary wound care, utilizing collagen's inherent properties to promote healing. This review thoroughly analyzes collagen dressing advances, examining different formulations such as hydrogels, films, and foams that enhance wound care. The important processes by which collagen promotes healing (e.g., promoting angiogenesis, encouraging cell proliferation, and offering structural support) are discussed to clarify its function in tissue regeneration. The effectiveness and adaptability of collagen dressings are demonstrated via clinical applications investigated in acute and chronic wounds. Additionally, commercially accessible collagen-based skin healing treatments are discussed, demonstrating their practical use in healthcare settings. Despite the progress, the study discusses the obstacles and restrictions encountered in producing and adopting collagen-based dressings, such as the difficulties of manufacturing and financial concerns. Finally, the current landscape's insights indicate future research possibilities for collagen dressing optimization, bioactive agent integration, and overcoming existing constraints. This analysis highlights the potential of collagen-based innovations to improve wound treatment methods and patient care.

Exploration of biomaterial-tissue integration in heterogeneous microporous annealed particle scaffolds in subcutaneous implants over 12 months

Microporous annealed particle (MAP) scaffolds are comprised of hydrogel microparticles with inter- and intra-particle cross-links that provide structure and cell-scale porosity, making them an increasingly attractive option for injectable tissue augmentation. Many current injectable biomaterials create a substantial foreign body response (FBR), while MAP scaffolds mitigate this response and have the potential to facilitate the formation of new tissue, though this de novo tissue formation is poorly understood. Here, we leverage a subcutaneous implant model to explore the maturation of MAP implants with and without heparin microislands (µislands) over one year to identify the effect of bioactive particles on scaffold maturation. Implants were measured and explanted after 1, 3, 6, and 12 months and analyzed using immunofluorescence staining and RNA-sequencing. No fibrous capsule or significant FBR was observed, and though a significant amount of MAP remains at 12 months, we still see a volume decrease over time. Heparin µislands facilitate increased cell infiltration and recruit a wider variety of cells at 1 month than blank MAP scaffolds, although this effect diminishes after 3 months. Transcriptomics reveal a potential activation of the complement-mediated immune response at 12 months in both groups, possibly associated with pore collapse in the implants. A single 12-month sample avoided this outcome, yielding complete cell infiltration, vascularization, and substantial matrix deposition throughout. Future work will characterize the effect of implantation site and facilitate increased matrix deposition to support the scaffold and prevent pore collapse. STATEMENT OF SIGNIFICANCE: Injectable biomaterials are increasingly used clinically for soft tissue augmentation and regeneration but still face significant issues from the foreign body reaction. While some materials intentionally promote this response to stimulate collagen deposition, porous materials like MAP scaffolds can mitigate the immune response and allow for true tissue integration. However, this integration is poorly understood, particularly on long timescales, as traditional materials are dominated by inflammatory signals. In this work, we leverage a minimally inflammatory subcutaneous implant to investigate the maturation of MAP scaffolds with and without bioactive heparin-containing particles. The results presented here contribute a better understanding of the long-term material-tissue dynamics of MAP scaffolds that can inform future material design for tissue augmentation.

Recombinant Humanized Collagen: A Promising Treatment for Pelvic Organ Prolapse via Enhanced Fibroblast Function and Angiogenesis

INTRODUCTION AND HYPOTHESIS

The treatment of pelvic organ prolapse (POP) presents significant challenges. It is important to explore safer and more effective treatment modalities. Recombinant humanized collagen (rhCol) is a promising biomaterial with excellent biocompatibility and pro-regenerative properties. Therefore, this study aims to evaluate the potential applications of rhCol in POP treatment.

METHODS

Vaginal wall tissues were collected from three non-POP and five POP patients to analyze extracellular matrix (ECM) changes via histological staining. Primary fibroblasts isolated from POP vaginal tissues were treated with rhCol III. Cell proliferation, migration, senescence, and ECM synthesis were assessed. A simulated birth injury (SBI) rat model was used to evaluate ECM remodeling following rhCol injection into the vaginal wall. Additionally, the angiogenic potential of rhCol III was examined in vivo and in vitro.

RESULTS

POP patient tissues and fibroblasts exhibited lower expression levels of type I and III collagen compared to non-POP samples. At a 1 mg/ml concentration, rhCol III promoted fibroblast proliferation and migration, reduced cellular senescence, and enhanced ECM synthesis. In the vaginal wall, the expression of COL1A1 and COL3A1 in the rhCol group was significantly higher than that in the SBI group, with a marked increase in the levels of CD31, CD34, and VEGFA. Furthermore, rhCol III improved the proliferation, migration, and tubule formation capacities of HUVECs.

CONCLUSIONS

rhCol III may promote ECM remodeling in an injured vaginal wall by restoring fibroblast function and stimulating angiogenesis, offering a novel biomaterial-based strategy for POP treatment.

Peptide-Based Functional Amyloid Hydrogel Enhances Wound Healing in Normal and Diabetic Rat Models

The inability to heal on time is a key component of chronic wounds, which can result in economic, psychological, and physiological burdens. Hydrogels based on amyloid can imitate the extracellular matrix and function as scaffolds for healing wounds. In this direction, a wound dressing inspired by peptide-based amyloid hydrogel is fabricated here. The results demonstrate that the amyloid hydrogel improves the three essential components of skin tissue regeneration: cell migration, proliferation, and collagen remodeling, both in vitro and in vivo. Furthermore, the amyloid hydrogel accelerates wound healing and promotes wound closure within 9 and 15 d in normal and diabetic rats, respectively. Microscopic evaluation of the wound region demonstrates the ultimate stages of regeneration and skin reformation toward normal skin compared to the untreated wound. Hematoxylin and eosin-stained hydrogel-treated wound sites reveal faster dermal bridging, angiogenesis, and epidermal repair in both acute and chronic conditions. The hydrogel creates an environment that encourages the growth of dermal fibroblasts and the release of cytokines, decreasing inflammation with concomitant enhancement of collagen production at the site of injury. Thus, these findings suggest that amyloid-based hydrogel can be a promising candidate for application in acute and chronic wound healing.

Hypoxia-induced HIF-1α accumulation promotes superior tenogenic differentiation potential of human adipose-derived mesenchymal stromal cells

Tendon injuries remains a challenge to treat owing to its poor intrinsic reparative ability. It is hypothesised that hypoxic conditioning of mesenchymal stem cells (MSC) through the activation of hypoxia-inducible factor-1 alpha (HIF-1α), may enhance tendon repair process by promoting cellular proliferation and tenogenic differentiation. To demonstrate this, a study using roxadustat, a specific hypoxia mimetic mediator and HIF-1α inducer was conducted on adipose-derived mesenchymal stromal cells (AD-MSCs). Cellular morphology, proliferation rates, tenogenic protein and gene expression levels in untreated AD-MSCs (Group 1), roxadustat pre-conditioned AD-MSCs (Group 2), AD-MSCs subjected to CAY10585 (Group 3), roxadustat pre-conditioned AD-MSCs with CAY10585 (Group 4) and untreated primary tenocytes (Group 5) were evaluated. MSCs pre-conditioned with 12.5µM roxadustat for 24 hours showed the highest expression of HIF-1α without affecting the proliferation rates of AD-MSCs. However, significant reduction of HIF-1α levels was observed when the cells were treated with 3.5µM CAY10585. Roxadustat significantly up-regulated collagen I and III expressions by 6.6 and 6.3-fold respectively. HIF-1α promoted Scleraxis, Tenascin-C and Collagen III expressions, resulting in an increase of 6, 7, and 3 folds respectively. Conversely, using CAY10585 reduced these expressions to 3, 2 and 1 folds respectively. These trends were observed in the gene expression levels across Groups 1 to 4. However, the expression of these genes in Group 2 was significantly lower as compared to Group 5. Conclusion: HIF-1α accumulation promotes superior cell proliferation and tenogenic differentiation of AD-MSCs, indicating that roxadustat may be a potential therapeutic mediator in tendon repair strategies.

Time-course of changes in fibrous components in a thioacetamide-induced liver fibrosis model in cynomolgus monkeys

In liver fibrosis, the possible causes of irreversibility include the accumulation of collagen I during extracellular matrix remodeling, together with the deposition of elastic fibers in later stages. Drug development targeting liver fibrosis should preferably employ models that closely mimic human diseases. To better understand the progress of fibrosis in a cynomolgus monkey liver fibrosis model, we evaluated the time-course of changes in the fibrosis score, collagens, and elastic fibers. The animals were subcutaneously administered thioacetamide twice a week (experiment 1) or once every 2 weeks (experiment 2). Liver tissues were collected at 8 and 16 (experiment 1) or 10 and 20 (experiment 2) weeks of administration, and 12 weeks after withdrawal (experiments 1 and 2). The fibrosis score was evaluated by Masson's trichrome staining. Immunohistochemistry for collagen Ia1, III, and IV, and Elastica van Gieson staining were also performed. Fibrosis was observed from week 8 (experiment 1) or 10 (experiment 2), and in most animals, it progressed during the administration period. After withdrawal, the fibrosis scores tended to decrease. Collagen IV was predominant in the early stage but was replaced by collagen I after 20 weeks in both experiments. Collagen III distributed mostly along with collagen I throughout the study period. The elastic fibers deposition was markedly limited throughout the experiment. Fibrous component examination showed that the main collagen type contributing to fibrosis shifted from collagen IV to I after 20 weeks or later and revealed that the fibrosis status is not fully reflected in the fibrosis score.

Risk Factors, Incidence, and Management of Re-Injury following Repair of Shoulder Rotator Cuff

Rotator cuff tears are among the most common musculoskeletal injuries worldwide, often requiring surgical intervention to restore shoulder function. Despite improvements in surgical techniques, rotator cuff re-injury remains a significant challenge, influenced by a combination of patient-related and procedural factors. The incidence of re-injury after surgery ranges from 15% to 21%, varying based on the severity of the initial injury and adherence to rehabilitation. In this article, we critically examine the risk factors, incidence, and management strategies associated with rotator cuff re-injury. Key risk factors include advanced age, larger tear size, poor tissue quality, high activity levels, and comorbid conditions like diabetes and hyperlipidemia. Age-related degenerative changes, muscle atrophy, and fatty infiltration impair tendon healing, increasing the risk of re-injury. Emerging geometric classifications of rotator cuff tears (Types 1-4) provide valuable insights into prognosis and guide surgical approaches. Management strategies for re-injury include both conservative approaches, such as physical therapy and activity modification, and surgical revisions, including tendon transfers and superior capsular reconstruction. Novel interventions like biological scaffolds, mesenchymal stem cell therapy, and machine learning-driven rehabilitation protocols are being explored to enhance tendon healing and reduce re-injury rates. However, gaps remain in understanding the biological mechanisms of tendon repair and optimizing personalized treatment strategies. Future research should focus on integrating biomolecular insights with clinical practice to improve outcomes and reduce the burden of rotator cuff re-injury.

Bacterial cell wall-specific nanomedicine for the elimination of Staphylococcus aureus and Pseudomonas aeruginosa through electron-mechanical intervention

Personalized synergistic antibacterial agents against diverse bacterial strains are receiving increasing attention in combating antimicrobial resistance. However, the current research has been struggling to strike a balance between strain specificity and broad-spectrum bactericidal activity. Here, we propose a bacterial cell wall-specific antibacterial strategy based on an in situ engineered nanocomposite consisting of carbon substrate and decorated TiOx dots, termed TiOx@C. The fiber-like carbon substrate of TiOx@C is able to penetrate the bacterial membrane of Pseudomonas aeruginosa (P. aeruginosa), but not that of Staphylococcus aureus (S. aureus) due to its thicker bacterial wall, thus achieving bacterial wall specificity. Furthermore, a series of experiments demonstrate the specific electro-mechanical co-sterilization effect of TiOx@C. On the one hand, TiOx@C can disrupt the electron transport chain and block the energy supply of S. aureus. On the other hand, TiOx@C capable of destroying the membrane structure of P. aeruginosa could cause severe mechanical damage to P. aeruginosa as well as inducing oxidative stress and protein leakage. In vivo experiments demonstrate the efficacy of TiOx@C in eliminating 97% of bacteria in wounds and promoting wound healing in wound-infected female mice. Overall, such a bacterial cell wall-specific nanomedicine presents a promising strategy for non-antibiotic treatments for bacterial diseases.

Cutaneous wound healing functions of novel milk-derived antimicrobial peptides, hLFT-68 and hLFT-309 from human lactotransferrin, and bLGB-111 from bovine β-lactoglobulin

The absence of multi-functional antimicrobial agents in clinical settings hinders cutaneous wound healing. Milk-derived antimicrobial peptides (MAPs) may be the imperative solution to wound repair, combining the dermatic curative properties of antimicrobial peptides with the biological activity of milk. Three novel MAPs, which were hLFT-68 (IAENRADAV) and hLFT-309 (GSPSGQKDLLF) identified in human milk and bLGB-111 (LDTDYKKY) identified in bovine milk in our previous work, were initially investigated for their function in wound healing. In vitro, the antibacterial activity and cellular mechanism of the MAPs were examined. It was found that they presented inhibition for Staphylococcus aureus and Escherichia coli, decreased the secretion of inflammatory factors (IL-1β, IL-6, and TNF-α), and promoted fibroblast and keratinocyte proliferation. An infected wound model was established to evaluate the in vivo anti-inflammatory and regeneration properties of the MAPs. The wound area shrank more rapidly, and the wound inflammation was reduced by MAP treatment. Especially on days 3-5 after mouse modeling, the wound repair rate increased by up to 35%. Furthermore, it was suggested that they encouraged collagen synthesis and deposition, and tissue regeneration. The presented results indicated that MAPs accelerated the recovery of infected wounds, possessing the potential for developing wound-healing therapy.

Development and functional evaluation of recombinant type III collagen intrauterine implant gel

Intrauterine adhesion (IUA) is a prevalent complication arising from uterine surgery, significantly impacting women's fertility and overall quality of life. The conventional clinical approach involves hysteroscopic separation of uterine adhesions, though this method poses operational challenges and carries risks of postoperative re-adhesion. Alternatively, the intraoperative placement of intrauterine devices or support balloons can act as a physical barrier to prevent adhesion formation. However, its effectiveness is limited and it may result in secondary damage to the endothelial tissue. To tackle these challenges, we have engineered a temperature-responsive hydrogel incorporating Pluronic HP407/HP188 pharmaceutical excipients and recombinant type III collagen (rCol III) as a bioactive element. Upon in situ injection into the uterine cavity, this hydrogel transitions from a sol-gel phase to a gel in response to body temperature changes, thereby minimizing nonspecific distribution and prolonging the duration of treatment. In vitro studies demonstrate that rCol III temperature-responsive hydrogels exhibit favorable biocompatibility, exhibit a recruitment effect on human endometrial stromal cells, suppress the expression of the fibrotic factor transforming growth factor beta 1 and promote angiogenesis. To evaluate its efficacy in preventing IUA via in vivo experiments, we employed sexually mature female rats for IUA modeling and compared its performance with a commercially available product, cross-linked sodium hyaluronate gel. The results indicate that rCol III temperature-responsive hydrogels significantly enhance retention at the injury site, substantially promote endometrial regeneration, augment endometrial blood supply and reduce abnormal fibrin deposition. This study suggests that rCol III temperature-responsive hydrogels can effectively prevent post-surgical uterine adhesions, highlighting their potential as a promising adhesion prevention strategy.

Network Pharmacology, Molecular Docking and Experimental Validation on Potential Application of Diabetic Wound Healing of Cinnamomum zeylanicum Through Matrix Metalloproteinases-8 And 9 (MMP-8 And MMP-9)

Background

Diabetic wounds are a significant clinical challenge due to impaired healing processes often exacerbated by elevated matrix metalloproteinases (MMPs). Cinnamomum zeylanicum, known for its anti-inflammatory and antioxidant properties, has shown potential in promoting wound healing. This study investigates the molecular docking and experimental validation of Cinnamomum zeylanicum's effects on diabetic wound healing, focusing on its interaction with matrix metalloproteinases-8 (MMP-8) and 9 (MMP-9).

Methods

Molecular docking studies were performed to predict the binding affinity of Cinnamomum zeylanicum compounds to MMP-8 and MMP-9. Diabetic wound healing was evaluated using in vivo models where wounds were induced and treated with Cinnamomum zeylanicum extract. Various parameters were measured, including wound contraction, hydroxyproline content, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and malondialdehyde (MDA) levels. Biochemical analyses included glucose levels, fasting blood glucose (FBG), oral glucose tolerance test (OGTT), and histomorphological examination of skin tissues.

Results

Molecular docking results indicated a high binding affinity of Cinnamomum zeylanicum's bioactive compounds with MMP-8 and MMP-9, suggesting potential inhibition. Experimental validation showed significant improvement in wound contraction and increased hydroxyproline content, indicating enhanced collagen synthesis. Antioxidant enzyme activities (SOD, GPx, CAT) were significantly elevated, while MDA levels were reduced, reflecting decreased oxidative stress. Biochemical analysis demonstrated improved glucose homeostasis with reduced FBG and enhanced OGTT responses. Histomorphological studies revealed improved tissue architecture and re-epithelialization in treated wounds.

Conclusion

Cinnamomum zeylanicum exhibits promising potential in diabetic wound healing by modulating MMP-8 and MMP-9 activities, enhancing antioxidant defenses, and improving glucose regulation. These findings support its therapeutic application for diabetic wounds, providing a foundation for further clinical investigations.

Piezoelectric poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) microspheres for collagen regeneration and skin rejuvenation

Introduction

Skin aging is an inevitable physiological process driven by factors like cellular senescence, ultraviolet radiation (UV) radiation, and environmental pollutants. A key feature is the accelerated collagen degradation in the dermal extracellular matrix, leading to visible signs such as sagging, wrinkles, and hyperpigmentation. Traditional fillers, such as hyaluronic acid and collagen-based fillers, offer only temporary volume enhancement without stimulating collagen regeneration. Studies have shown that electrical signals generated by piezoelectric materials can promote tissue regeneration.

Methods

This study explored the potential of piezoelectric PHBHHx microspheres as an innovative skin filler for enhancing collagen regeneration and improving maxillofacial aesthetics, with the aid of low-intensity pulsed ultrasound (LIPUS) stimulation. A comprehensive characterizations of the piezoelectric PHBHHx microspheres were conducted, and their potential to stimulate collagen regeneration was assessed using a subcutaneous injection model in New Zealand white rabbits.

Results

The results indicated that PHBHHx microspheres exhibited stable degradation properties, great piezoelectric properties and excellent biocompatibility. Moreover, when stimulated by LIPUS, the collagen-regenerating effect of PHBHHx microspheres was further enhanced, histological analysis revealed a denser and more organized collagen structures in LIPUS-stimulated PHBHHx group.

Discussion

These findings highlight the potential of PHBHHx microspheres as an advanced biomaterial for applications in aesthetic medicine, particularly in promoting collagen regeneration and enhancing skin rejuvenation.

Neural Markers Predict Tendon Healing Outcomes in an Ovine Achilles Tendon Injury Model: Spontaneous Repair Versus Amniotic Epithelial Cell-Induced Regeneration

Tendon injuries pose a clinical challenge due to tendons' limited recovery. Emerging evidence points to the nervous system's critical role in tendon healing, with neural markers NGF, NF-200, NPY, CGRP, and GAL modulating inflammation, cell proliferation, and extracellular matrix (ECM) remodeling. This study investigates the predictive role of selected neural markers in a validated ovine Achilles tendon injury model, comparing spatio-temporal expression patterns in regenerating tendons transplanted with amniotic epithelial stem cells (AECs) versus spontaneous healing (CTR) 14 and 28 days post-injury (p.i.). AEC-treated tissues showed a spatio-temporal modulation of NF-200, NGF, NPY, CGRP, GAL, and enhanced ECM remodeling, with greater cell alignment, lower angle deviation, and accelerated collagen maturation, with a favorable Collagen type 1 (COL1) to Collagen type 3 (COL3) ratio. Pearson's matrix analysis revealed significant positive correlations between NGF, CGRP, and GAL expression, along a positive correlation between the three neural markers and cell alignment and angle deviation. As opposed to CTR, in AEC-treated tendons, lower levels of NGF, CGRP, and GAL correlated positively with improved tissue organization, suggesting these markers may predict successful tendon regeneration. The findings highlight the neuro-mediated activity of AECs in tendon regeneration, with NGF, CGRP, and GAL emerging as key predictive biomarkers for tendon healing.

Bovine Dermal Collagen Matrix Promotes Vascularized Tissue Generation Supporting Early Definitive Closure in Full-Thickness Wounds: A Pre-clinical Study

Objective Dermal matrices are commonly used to manage full-thickness wounds, impacting both functional and aesthetic outcomes. However, standard materials typically require 14-28 days to develop sufficient tissue for autografting. This study aimed to assess the potential of a novel bovine dermal collagen matrix (BDCM) to decrease the time required to develop tissue for autografting for accelerating the timeline for definitive wound closure. Methods Full-thickness excisional wounds were surgically created on Yorkshire pigs and treated with crosslinked collagen-based dermal matrices, including a bovine dermal collagen matrix (BDCM; Cohealyx, Collagen Matrix Inc., Oakland, NJ), a collagen-glycosaminoglycan matrix (ColGAG; Integra Bilayer Wound Matrix, Integra Life Sciences, Plainsboro, NJ), or a fish skin graft matrix (FSG; Kerecis Graft Guide, Isafjorour, Iceland). Seven days after application, matrix attachment and infection status were assessed, along with histological analyses of cellular infiltration, collagen deposition, and angiogenesis. The wound beds were then autografted and monitored for an additional 35 days to evaluate wound healing parameters, including skin graft take, re-epithelialization, and wound contraction. Results Seven days post-autografting, autograft take was 96.88 ± 7.04% for BDCM-treated wounds compared to 85.00 ± 34.10% and 68.00 ± 27.97% for ColGAG and FSG-treated wounds, respectively. The coefficient of variation was 7% for BDCM-treated wounds compared to approximately 40% for ColGAG and FSG-treated wounds. Histological analysis revealed that BDCM-treated wounds contained a persisting collagen scaffold that allowed cellular infiltration and angiogenesis with no infection. At 42 days, BDCM showed significantly less wound contraction (p<0.05) compared to the other dermal matrix-treated wounds. Conclusion Bovine dermal collagen matrix enables rapid cellular infiltration and vascularized tissue deposition, supporting highly consistent autograft take at seven days. The possibility of reducing time to definitive closure has the potential to significantly improve clinical outcomes of acute full-thickness wounds and lower the overall cost of treatment.

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.

Unfolded protein responses: Dynamic machinery in wound healing

Skin wound healing is a dynamic process consisting of multiple cellular and molecular events that must be tightly coordinated to repair the injured tissue efficiently. The healing pace is decided by the type of injuries, the depth and size of the wounds, and whether wound infections occur. However, aging, comorbidities, genetic factors, hormones, and nutrition also impact healing outcomes. During wound healing, cells undergo robust processes of synthesizing new proteins and degrading multifunctional proteins. This imposes an increasing burden on the endoplasmic reticulum (ER), causing ER stress. Unfolded protein response (UPR) represents a collection of highly conserved stress signaling pathways originated from the ER to maintain protein homeostasis and modulate cell physiology. UPR is known to be beneficial for tissue healing. However, when excessive ER stress exceeds ER's folding potential, UPR pathways trigger cell apoptosis, interrupting tissue regeneration. Understanding how UPR pathways modulate the skin's response to injuries is critical for new interventions toward the control of acute and chronic wounds. Herein, in this review, we focus on the participation of the canonical and noncanonical UPR pathways during different stages of wound healing, summarize the available evidence demonstrating UPR's unique position in balancing homeostasis and pathophysiology of healing tissues, and highlight the understudied areas where therapeutic opportunities may arise.

Effects of Thai Kaempferia Parviflora Extract on Human Gingival Fibroblasts: An in vitro Study of Wound Healing

Aim

Gingival fibroblasts are key players in oral wound healing as they migrate to the wound and produce extracellular matrix. Although contemporary methods can enhance healing, there is ongoing interest in alternative medicine due to its accessibility. Kaempferia parviflora, a traditional Thai herb, has been comprehensively studied for its pharmacological properties; however, its specific roles in wound healing remain to be explored. Thus, our study aimed to investigate the effects of K. parviflora extract (KPE) on the proliferation, migration, and collagen production of human gingival fibroblasts (HGFs).

Methods

HGFs were treated with 0.46-7.5 mg/mL KPE, followed by determination of cell viability using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on days 1, 3, 5, and 7, and cell migration was assessed using scratch assay at 12, 24, and 48 h. Collagen production was analyzed by picrosirius red staining and real-time polymerase chain reaction (qRT-PCR) on days 7, 14, and 21.

Results

At 0.46 mg/mL, KPE induced cell proliferation in HGFs on days 3, 5, and 7, whereas higher concentrations were cytotoxic to HGFs. This concentration also enhanced cell migration at all time points, whereas higher doses hampered this process. KPE at 0.46 mg/mL stimulated collagen production and upregulated the expressions of COL3A1 and COL1A1 genes on day 14, although these levels were decreased by day 21.

Conclusions

KPE could promote proliferation, migration, and collagen production in HGFs, demonstrating its potential use as an adjunctive treatment for oral wounds. Nevertheless, establishing a safety margin is crucial before clinical application due to the possibility of cytotoxicity at higher concentrations.

Preparation of thermoresponsive & enzymatically crosslinkable gelatin-gellan gum bioink: A protein-polysaccharide hydrogel for 3D bioprinting of complex soft tissues

Developing superior bioinks present several challenges in achieving ideal properties such as biocompatibility, viscosity, degradation rates & mechanical properties which are required to make functional tissue constructs. Various attempts have been made to prepare excellent bioink compositions that are suitable to address the above challenges. Herein, a versatile combination of gelatin (GL) - gellan gum (GG) bioink was successfully formulated & the bioink 7.5GL/2GG was found to be ideal for printing complex and highly intricate structures with excellent shape fidelity. Two different crosslinkers namely transglutaminase (TG) and calcium chloride (CaCl2) were utilized for crosslinking. The rheological properties of GL/GG bioink indicated that TG and dual (TG + CaCl2) crosslinked constructs had storage modulus equivalent to the that of native skin. Direct and indirect cytotoxicity assays revealed that the developed constructs were cytocompatible as well as hemocompatible. The 3D bioprinted GL/GG constructs crosslinked with only TG showed better cell viability, proliferation, cell spreading and wound healing efficiency in vitro compared to dual crosslinked constructs. In conclusion, TG crosslinking of 7.5GL/2GG bioink was ideal for bioprinting of skin tissue constructs for regenerative medicine applications. By altering the concentrations & printing conditions, this bioink may be tuned for other soft tissue engineering applications.

Probiotic-Derived P8 Protein: Promoting Proliferation and Migration in Stem Cells and Keratinocytes

Probiotics exert various effects on the body and provide different health benefits. Previous reports have demonstrated that the P8 protein (P8), isolated from Lactobacillus rhamnosus, has anticancer properties. However, its efficacy in stem cells and normal cells has not been reported. In this study, the effect of P8 on cell proliferation and wound healing was evaluated, investigating its underlying mechanism. Based on scratch assay results, we demonstrated that P8 treatment significantly increases wound healing by activating the cell cycle and promoting stem cell stemness. Cellular mechanisms were further investigated by culturing stem cells in a medium containing Lactobacillus-derived P8 protein, revealing its promotion of cell proliferation and migration. Also, it is found that P8 enhances the expression of stemness markers, such as OCT4 and SOX2, along with activation of the mitogen-activated protein kinase (MAPK) signaling and Hippo pathways. These results indicate that P8 can promote cell growth by increasing stem cell proliferation, migration, and stemness in a manner associated with MAPK and Hippo signaling, which could contribute to the increased wound healing after P8 treatment. Furthermore, P8 could promote wound healing in keratinocytes by activating the MAPK signaling pathways. These results suggest that P8 might be a promising candidate to enhance stem cell culture efficiency by activating cell proliferation, and enhance therapeutic effects in skin diseases.

Bioactivity, Efficacy, and Safety of a Wound Healing Ointment With Medicinal Plant Bioactives: In Vitro and In Vivo Preclinical Evaluations

Chronic wounds have a significant impact on patients' quality of life, necessitating the management of pain, infection, bleeding, and emotional challenges. Debridement, which involves the removal of nonviable tissue, is crucial for promoting wound healing. In addition to surgical methods, cost-effective alternatives such as local solutions and ointments with biological properties have been explored. The use of natural compounds with anti-inflammatory, antibacterial, and collagen-synthesizing abilities holds promise for wound healing. This in vitro and in vivo preclinical study aimed to assess the safety and effectiveness of a wound healing ointment containing bioactive ingredients derived from medicinal plants (extracts, essential oils, and vegetable oils). The chemical composition of the ointment was characterized using Fourier transform infrared (FTIR) spectroscopy to gain insights into its synergistic action. Preclinical tests were conducted following standardized protocols. FTIR analysis revealed similarities between the product's spectrum and that of bioactive compounds. The in vitro tests demonstrated that all formulations of the ointment induced no cell death, DNA damage, or acute toxicity in cell cultures (p < 0.05). No lethal dose was observed, indicating the safety of the ointment at all concentrations. The ointment also stimulated a notably more organized, significantly higher collagen production compared to control groups (p < 0.05). In vivo preclinical analyses also demonstrated no adverse responses being effective in the healing process compared to the control group (silver sulfadiazine) in terms of wound contraction and ulcer re-epithelization (p < 0.05). Significantly higher means of wound contraction were observed in the groups treated with the bioactive-containing ointment when compared to both the positive control group (sulfadiazine) and the control untreated groups (p < 0.05). The regenerative ointment exhibited excellent biocompatibility and bioactivity in in vitro and in vivo studies, contributing to the development of innovative and sustainable wound management therapies.

miRNAs and their multifaceted role in cutaneous wound healing

The dynamic, complex process of cutaneous wound healing is required to restore skin integrity following an injury. This intricate process consists of four sequential and overlapping phases: hemostasis, inflammation, proliferation, and remodeling. Hemostasis immediately begins to function in response to vascular injury, forming a clot that stops the bleeding. To fight infection and remove debris, immune cells are enlisted during the inflammatory phase. Angiogenesis, re-epithelialization, and the creation of new tissue are all components of proliferation, whereas tissue maturation and scarring are the outcomes of remodeling. Chronic wounds, like those found in diabetic ulcers, frequently stay in a state of chronic inflammation because they are unable to go through these stages in a coordinated manner. The important regulatory roles that microRNAs (miRNAs) play in both normal and pathological wound healing have been highlighted by recent investigations. The miRNAs, small non-coding RNAs, modulate gene expression post-transcriptionally, profoundly impacting cellular functions. During the inflammatory phase, miRNAs control pro- and anti-inflammatory cytokines, as well as the activity of immune cells such as neutrophils and macrophages. Additionally, miRNAs are essential components of signaling networks related to inflammation, such as the toll-like receptor (TLR), nuclear factor kappa B (NF-kB), and Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathways. Some miRNAs have been discovered to either increase or alleviate inflammatory reactions, indicating their potential as therapeutic targets. Other miRNAs aid in angiogenesis by promoting the development of new blood vessels, which are essential for providing oxygen and nutrients to the healing tissue. They also affect keratinocyte migration and proliferation during the re-epithelialization phase, which involves growing new epithelial cells over the lesion. Another function of miRNAs is that they control the deposition of extracellular matrix (ECM) and the creation of scars during the remodeling phase. The abnormal expression of miRNAs in chronic wounds has led to the exploration of miRNA-based treatments. With a focus on resistant instances such as diabetic wounds, these therapeutic techniques seek to improve wound healing results by correcting the dysregulated miRNA expression.

Dermal Fibroblast-Derived Exosomes Promotes Bone-to-Tendon Interface Healing of Chronic Rotator Cuff Tear in Rabbit Model

PURPOSE

To investigate the efficacy of exosomes derived from dermal fibroblasts (DF-Ex) on bone-to-tendon interface (BTI) healing in a chronic rotator cuff tear (RCT) model of rabbit.

METHODS

After extraction of DF-Ex, the characterization of DF-Ex was identified in the in vitro study. In the in vivo experiment, 48 rabbits were randomly allocated into 3 groups. To create chronic RCT models, transected tendons were left untreated for 6 weeks and then were repaired in a transosseous manner. Different materials were injected into repair site according to the allocated group (group A: saline, group B: fibrin glue only, group C: DF-Ex with fibrin glue; n = 16 for each). Genetic and immunofluorescence analyses were conducted at 4 weeks post-surgery. Furthermore, genetic, histologic, and biomechanical analyses were conducted at 12 weeks post-surgery.

RESULTS

In vitro analyses revealed the exosomal marker proteins CD9, CD63, and ALIX were positively expressed in DF-Ex, whereas negative control Calnexin was nearly absent. In vivo analyses showed that group C had the highest mRNA expression levels of COL1A1, COL3A1, and ACAN among all groups (P < .001, P = .007, and P = .002, respectively) at 4 weeks postsurgery. Meanwhile, there were more preliminary fibrocartilaginous matrix (aggrecan+/collagen II+) formation in group C. At 12 weeks postsurgery, group C had better collagen fiber continuity and orientation, denser collagen fibers, more mature bone-to-tendon junction, and greater fibrocartilage layer formation compared with the other groups (all P < .05). Moreover, group C also had greater load-to-failure value (53.3 ± 6.1 N/kg, P < .001).

CONCLUSIONS

Topical DF-Ex administration effectively promoted BTI healing by upregulating the COL1A1, COL3A1, and ACAN mRNA expression levels at an early stage and enhancing the structural and biomechanical properties at 12 weeks after surgical repair of a chronic RCT model of rabbit.

CLINICAL RELEVANCE

The study could be a transitional study to investigate the efficacy of DF-Ex on BTI healing for surgical repair of chronic RCTs as a powerful biological agent in humans.

Enhanced Fluorescence Imaging of Implants Based on Polyester Copolymers in Combination With MRI

Nowadays, many biodegradable materials are offered for biomedical applications, but there are only a few in vivo methods for their detection and monitoring. In this work, implants based on biodegradable polyester copolymers were labeled with indocyanine green (ICG) for fluorescence imaging in combination with tissue optical clearing (TOC) and magnetic resonance imaging (MRI). The results include in vitro degradation modeling followed by in vivo imaging of copolymer samples that were subcutaneously implanted in BALB/c mice. TOC with 70% glycerol has been demonstrated to significantly improve sample visualization. The TOC efficiency parameter Q demonstrated the variability of effects correlating with the timing of follow-up in the postimplantation period. It has been shown that nonhealing wounds, peri-implantation inflammation, or fibrosis, confirmed by MRI, affect the effectiveness of TOC in the range from Q = -30% to 70%.

Collagen metabolism and incisional hernia recurrence: a comparative study between oncologic and non-oncologic patients

A significant challenge in incisional hernia repair is the recurrence risk, which may be influenced by the structural integrity of collagen within the tissue. This study investigated the role of collagen metabolism in hernia recurrence by comparing oncologic and non-oncologic patients, focusing on collagen I/III ratios and their impact on tissue strength and surgical outcomes. A comparative clinical study was conducted on 50 patients (30 oncologic, 20 non-oncologic) undergoing incisional hernia repair. Collagen composition was analyzed using stereomicroscopy, and statistical comparisons were performed using independent t-tests and chi-square tests to assess differences in recurrence rates and tissue properties between groups. Results indicated that oncologic patients had significantly lower collagen I/III ratios (P < 0.001), suggesting structurally weaker tissue, which correlated with higher recurrence rates (18% in oncologic vs. 10% in non-oncologic patients). Furthermore, the sublay mesh repair technique demonstrated superior outcomes with lower recurrence rates compared to onlay repair, reinforcing its role in mitigating complications associated with poor collagen integrity. The study results indicated that oncologic patients had impaired collagen remodeling, contributing to an increased risk of recurrence. Individualized surgical strategies, including targeted preoperative interventions, may help mitigate these risks and enhance patient outcomes. Given the observed disparities, further research is warranted to explore targeted therapeutic approaches that enhance tissue quality and improve long-term surgical success in high-risk patient populations.

A human skin-on-a-chip platform for microneedling-driven skin cancer treatment

Skin-on-a-chip models provide physiologically relevant platforms for studying diseases and drug evaluation, replicating the native skin structures and functions more accurately than traditional 2D or simple 3D cultures. However, challenges remain in creating models suitable for microneedling applications and monitoring, as well as developing skin cancer models for analysis and targeted therapy. Here, we developed a human skin/skin cancer-on-a-chip platform within a microfluidic device using bioprinting/bioengineering techniques. The fabricated skin models include vascular, dermal, and epidermal layers, demonstrating increased functionalities and maturation of dermal (Collagen I & Fibronectin for 7 days) as well as epidermal (Filaggrin & Keratin 10, 14, and 19 at the air-liquid interface (ALI) for 21 days) layers. Histological analysis confirmed the formation of a differentiated epidermis and ridges at the dermal-epidermal junction in our model, closely resembling native skin tissue. Melanoma cells were embedded approximately 400 μm beneath the epidermis to simulate tumor invasion into the dermis. The platform was further used to test doxorubicin (DOX)-loaded gelatin methacryloyl (GelMA) microneedles (MNs) for localized transdermal drug delivery targeting melanoma. The DOX-loaded MNs penetrated uniformly to a depth of approximately 600 μm, effectively reaching the melanoma cells. Drug delivery via MNs demonstrated significantly higher efficiency than diffusion through media flow, confirming the practicality and robustness of the proposed model for future therapeutic applications.

The Role of Umbilical Cord Mesenchymal Stem Cell-Derived Extracellular Vesicles in Modulating Dermal Fibroblast Activity: A Pathway to Enhanced Tissue Regeneration

Extracellular vesicles (EVs) secreted by umbilical cord-derived mesenchymal stem cells (UC-MSCs) hold significant promise as therapeutic agents in regenerative medicine. This study investigates the effects of UC-MSC-derived EVs on dermal fibroblast function, and their potential in wound healing applications. EVs were characterized by nanoparticle tracking analysis and transmission electron microscopy, revealing a mean size of 118.6 nm, consistent with exosomal properties. Dermal fibroblasts were treated with varying concentrations of EVs (25-100 µg/mL), and their impacts on cellular metabolism, mitochondrial activity, reactive oxygen species (ROS) production, wound closure, inflammatory cytokine secretion, growth factor production, and extracellular matrix (ECM) gene expression were evaluated. At lower concentrations (25-50 µg/mL), EVs significantly enhanced fibroblast metabolic and mitochondrial activity. However, higher concentrations (≥75 µg/mL) increased ROS levels, suggesting potential hormetic effects. EVs also modulated inflammation by reducing pro-inflammatory cytokines (IL-6, TNF-α) while promoting pro-regenerative cytokines (IL-33, TGF-β). Treatment with 50 µg/mL of EVs optimally stimulated wound closure and growth factor secretion (VEGF, BDNF, KGF, IGF), and upregulated ECM-related gene expression (type I and III collagen, fibronectin). These findings demonstrate that UC-MSC-derived EVs exert multifaceted effects on dermal fibroblast function, including enhanced cellular energetics, stimulation of cell migration, regulation of inflammation, promotion of growth factor production, and increased ECM synthesis. This study highlights the potential of EVs as a novel therapeutic strategy for wound healing and tissue regeneration, emphasizing the importance of optimizing EV concentration for maximal therapeutic efficacy.

The addition of mesenchymal stem cells in a bioabsorbable scaffold does not enhance tendon healing after a repair of rotator cuff tear

PURPOSE

The purpose of the study is to evaluate the healing potential of a full-thickness tendon defect in the rotator cuff of rabbits using a bioabsorbable scaffold impregnated with bone marrow-mesenchymal stem cells (BM-MSCs) or rotator cuff-derived mesenchymal stem cells (RC-MSCs).

METHODS

Sixteen adult rabbits were subjected to a full-thickness rotator cuff deficit. Rabbits were randomly assigned to four groups of four animals. In Group 0 (control), the deficit was left untreated. In Group 1, the deficit was treated with a single synthetic scaffold alone. In Group 2, the deficit was treated with the previous scaffold loaded with allogeneic BM-MSCs. In Group 3, the deficit was treated with the previous scaffold loaded with allogenic RC-MSCs. After animal sacrifice, tissue samples were subjected to histological and immunohistochemical analysis.

RESULTS

Group 1 showed the highest mean tendon maturing score (15.3 ± 0.9) postoperatively, being significantly higher, in comparison to groups 0, 2 and 3 (p = 0.01, 0.02 and 0.01, respectively). Group 1 showed the highest mean collagen I/collagen III ratio (1.4 ± 0.8) postoperatively but without any statistical significance.

CONCLUSIONS

The utilization of MSCs in rotator cuff repair in a rabbit model has not been associated with an enhancement in tendon healing in 16 weeks postoperatively, in comparison to controls and bioabsorbable scaffolds. The addition of MSCs does not result in better rotator cuff healing.

LEVEL OF EVIDENCE

Not applicable. This is an animal study.

Exosome laden sprayable thermo-sensitive polysaccharide-based hydrogel for enhanced burn wound healing

Severe burns pose significant threats to patient well-being, characterized by pain, inflammation, bacterial infection, and extended recovery periods. While exosome-loaded hydrogels have demonstrated considerable promise in wound healing, current formulations often fall short of achieving optimal therapeutic efficacy for burn wounds due to challenges related to their adaptability to wound shape and limited anti-bacterial capabilities. In this study a novel exosome laden sprayable thermosensitive polysaccharide-based hydrogel (ADA-aPF127@LL18/Exo) comprising alginate dialdehyde (ADA) and aminated Pluronic F127 (aPF127) was fabricated via Schiff base reaction. ADA-aPF127@LL18/Exo exhibited sustained release of exosome and enhanced antibacterial efficacy. Furthermore, the biological assessments displayed excellent biocompatibility and enhanced in vitro cell proliferation and migration. In a deep partial thickness burn model, ADA-aPF127@LL18/Exo significantly augmented wound healing processes by accelerating epithelialization, promoting granulation tissue formation and collagen deposition, inducing hair follicle regeneration, effectively mitigating inflammatory responses, and facilitating enhanced neovascularization. In conclusion, ADA-aPF127@LL18/Exo represents a highly promising therapeutic dressing for the treatment of deep burns, exhibiting multifaceted properties conducive to efficient wound management.

Fetal Skin Wound Healing: Key Extracellular Matrix Components and Regulators in Scarless Healing

Fetal skin at early gestational stage is able to regenerate and heal rapidly after wounding. The exact mechanisms and molecular pathways involved in this process are however still largely unknown. The numerous differences in the skin of the early fetus versus skin in later developmental stages might provide clues for the mechanisms of scarless healing. This review summarizes the differences between mammalian fetal skin and the skin at later developmental phases in healthy and wounded conditions, focusing on extracellular matrix components, which are crucial factors in the microenvironment that direct cells and tissue functions and hence the wound healing process.

Efficacy and mechanism of Schisandra chinensis active component Gomisin A on diabetic skin wound healing: network pharmacology and in vivo experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

Schisandra chinensis (Turcz.) Baill., a common traditional Chinese herbal medicine, has been used for the treatment of diabetes mellitus and its complications. However, the major active component for treating diabetic foot ulcers, a serious complication of diabetes mellitus, was unclear. This study aimed to predict the treatment effect of the active components in Schisandra chinensis against diabetic skin wound using network pharmacology and to confirm the underlying mechanism using a diabetic skin wound model in vivo.

AIM OF THE STUDY

To study the effects and underlying mechanisms of Schisandra chinensis and its main component Gomisin A on diabetic skin wound healing by network pharmacology and high-fat diet (HFD)-induced obese mice model in vivo.

MATERIALS AND METHODS

To determine the effectiveness of Schisandra chinensis on diabetic skin wound, network pharmacology was first used. Components of Schisandra chinensis were obtained from the Traditional Chinese Medicine Systems Pharmacology database. The active components were further verified through absorption, distribution, metabolism and excretion. The potential targets of the active components were identified from the Traditional Chinese Medicine Systems Pharmacology, SwissTargetPrediction, TargetNet, and the Comparative Toxicogenomics Database. Targets related to diabetic skin wound were collected from the GeneCards, OMIM, DisGeNET, and PharmGKB databases. The interaction network formed by the intersection of the two datasets was analyzed using Gephi. Network-based proximity was used to predict the network distance between the active components of Schisandra chinensis and diabetic skin wound. Gomisin A was found to have the lowest Z-score and was administered either orally or via topical injection to HFD-induced obese mice daily until the wounds healed, and its effects on skin wound healing were evaluated.

RESULTS

Only five active ingredients of Schisandra chinensis were screened in our system: Gomisin A, Longikaurin A, Deoxyharringtonine, Wuweizisu C, and Interiotherin B, which can regulate biological processes related to diabetic skin wound, including positive regulation of phosphorous metabolic process, positive regulation of cell migration, and response to wounding. Network proximity analysis found that Gomisin A has the closest distance-based Z-score among the diabetic skin wound modules and drug targets in the human protein-protein interaction network. The HFD-induced obese mice model further revealed that Gomisin A accelerated skin wound healing by increasing insulin sensitivity and decreasing the advanced glycation end-products mediated toll-like receptor 4 (TLR4)-p38 MAPK-IL6 inflammation signaling pathway.

CONCLUSIONS

The network pharmacology and in vivo studies indicated that Gomisin A from Schisandra chinensis played a crucial role in improving diabetic skin wound healing.