Dynamics of Transforming Growth Factor Beta Signaling in Wound Healing and Scarring

Subretinal fibrosis secondary to neovascular age-related macular degeneration: mechanisms and potential therapeutic targets

Subretinal fibrosis is the end-stage sequelae of neovascular age-related macular degeneration. It causes local damage to photoreceptors, retinal pigment epithelium, and choroidal vessels, which leads to permanent central vision loss of patients with neovascular age-related macular degeneration. The pathogenesis of subretinal fibrosis is complex, and the underlying mechanisms are largely unknown. Therefore, there are no effective treatment options. A thorough understanding of the pathogenesis of subretinal fibrosis and its related mechanisms is important to elucidate its complications and explore potential treatments. The current article reviews several aspects of subretinal fibrosis, including the current understanding on the relationship between neovascular age-related macular degeneration and subretinal fibrosis; multimodal imaging techniques for subretinal fibrosis; animal models for studying subretinal fibrosis; cellular and non-cellular constituents of subretinal fibrosis; pathophysiological mechanisms involved in subretinal fibrosis, such as aging, infiltration of macrophages, different sources of mesenchymal transition to myofibroblast, and activation of complement system and immune cells; and several key molecules and signaling pathways participating in the pathogenesis of subretinal fibrosis, such as vascular endothelial growth factor, connective tissue growth factor, fibroblast growth factor 2, platelet-derived growth factor and platelet-derived growth factor receptor-β, transforming growth factor-β signaling pathway, Wnt signaling pathway, and the axis of heat shock protein 70-Toll-like receptors 2/4-interleukin-10. This review will improve the understanding of the pathogenesis of subretinal fibrosis, allow the discovery of molecular targets, and explore potential treatments for the management of subretinal fibrosis.

Inhibition of mTOR differently modulates planar and subepithelial fibrogenesis in human conjunctival fibroblasts

PURPOSE

In the current investigation, the effects of the mTOR inhibitors, Rapa and Torin1 on the TGF-β2-induced conjunctival fibrogenesis were studied.

STUDY DESIGN

Experimental research.

METHODS

2D and 3D cultures of HconF were subjected to the following analyses; (1) planar proliferation evaluated by TEER (2D), (2) Seahorse metabolic analyses (2D), (3) subepithelial proliferation evaluated by the 3D spheroids' size and hardness, and (4) the mRNA expression of ECM proteins and their regulators (2D and 3D).

RESULT

Rapa or Torin1 both significantly increased planar proliferation in the non-TGF-β2-treated 2D HconF cells, but in the TGF-β2-treated cells, this proliferation was inhibited by Rapa and enhanced by Torin1. Although Rapa or Torin1 did not affect cellular metabolism in the non-TGF-β2-treated HconF cells, mTOR inhibitors significantly decreased and increased the mitochondrial respiration and the glycolytic capacity, respectively, under conditions of TGF-β2-induced fibrogenesis. Subepithelial proliferation, as evidenced by the hardness of the 3D spheroids, was markedly down-regulated by both Rapa and Torin1 independent of TGF-β2. The mRNA expressions of several ECM molecules and their regulators fluctuated in the cases of 2D vs 3D and TGF-β2 untreated vs treated cultures.

CONCLUSION

The present findings indicate that mTOR inhibitors have the ability to increase and to reduce planar and subepithelial proliferation in HconF cells, depending on the inhibitor being used.

Development of alginate and alginate sulfate/polycaprolactone nanoparticles for growth factor delivery in wound healing therapy

Connective tissue growth factor (CTGF) holds great promise for enhancing the wound healing process; however, its clinical application is hindered by its low stability and the challenge of maintaining its effective concentration at the wound site. Herein, we developed novel double-emulsion alginate (Alg) and heparin-mimetic alginate sulfate (AlgSulf)/polycaprolactone (PCL) nanoparticles (NPs) for controlled CTGF delivery to promote accelerated wound healing. The NPs' physicochemical properties, cytocompatibility, and wound healing activity were assessed on immortalized human keratinocytes (HaCaT), primary human dermal fibroblasts (HDF), and a murine cutaneous wound model. The synthesized NPs had a minimum hydrodynamic size of 200.25 nm. Treatment of HaCaT and HDF cells with Alg and AlgSulf2.0/PCL NPs did not show any toxicity when used at concentrations <50 µg/mL for up to 72 h. Moreover, the NPs' size was not affected by elevated temperatures, acidic pH, or the presence of a protein-rich medium. The NPs have slow lysozyme-mediated degradation implying that they have an extended tissue retention time. Furthermore, we found that treatment of HaCaT and HDF cells with CTGF-loaded Alg and AlgSulf2.0/PCL NPs, respectively, induced rapid cell migration (76.12% and 79.49%, P<0.05). Finally, in vivo studies showed that CTGF-loaded Alg and AlgSulf2.0/PCL NPs result in the fastest and highest wound closure at the early and late stages of wound healing, respectively (36.49%, P<0.001 on day 1; 90.45%, P<0.05 on day 10), outperforming free CTGF. Double-emulsion NPs based on Alg or AlgSulf represent a viable strategy for delivering heparin-binding GF and other therapeutics, potentially aiding various disease treatments.

Enhancing chronic wound healing with Thai indigenous rice variety, Kaab Dum: Exploring ER stress and senescence inhibition in HaCaT keratinocyte cell line

Kaab Dum, a prominent indigenous rice variety cultivated in the Pak Phanang Basin of Nakhon Si Thammarat, Thailand, is the focus of our study. We investigate the therapeutic potential of indigenous Kaab Dum rice extract in the context of chronic wounds. Our research encompasses an examination of the nutritional compositions and chemical profiles of Kaab Dum rice extract. Additionally, we assess how the extract affects chronic wounds in TGF-β-induced HaCaT cells. Our evaluation methods include the detection of cellular oxidative stress, the examination of endoplasmic reticulum (ER) stress, wound healing assays, analysis of cell cycle arrest and the study of cellular senescence through senescence-associated β-galactosidase (SA-β-gal) staining. Our research findings demonstrate that TGF-β induces oxidative stress in HaCaT cells, which subsequently triggers ER stress, confirmed by the expression of the PERK protein. This ER stress results in cell cycle arrest in HaCaT cells, characterized by an increase in p21 protein, a cyclin-dependent kinase inhibitor (CDKI). Ultimately, this leads to cellular senescence, as confirmed by SA-β-gal staining. Importantly, our study reveals the effectiveness of Kaab Dum rice extract in promoting wound healing in the chronic wound model. The extract reduces ER stress and senescent cells. These beneficial effects are potentially linked to the antioxidant and anti-inflammatory properties of the rice extract. The findings of our study have the potential to make significant contributions to the development of enhanced products for both the prevention and treatment of chronic wounds.

Biofabrication of Cellulose-based Hydrogels for Advanced Wound Healing: A Special Emphasis on 3D Bioprinting

Even with the current advancements in wound management, addressing most skin injuries and wounds continues to pose a significant obstacle for the healthcare industry. As a result, researchers are now focusing on creating innovative materials utilizing cellulose and its derivatives. Cellulose, the most abundant biopolymer in nature, has unique properties that make it a promising material for wound healing, such as biocompatibility, tunable physiochemical characteristics, accessibility, and low cost. 3D bioprinting technology has enabled the production of cellulose-based wound dressings with complex structures that mimic the extracellular matrix. The inclusion of bioactive molecules such as growth factors offers the ability to aid in promoting wound healing, while cellulose creates an ideal environment for controlled release of these biomolecules and moisture retention. The use of 3D bioprinted cellulose-based wound dressings has potential benefits for managing chronic wounds, burns, and painful wounds by promoting wound healing and reducing the risk of infection. This review provides an up-to-date summary of cellulose-based dressings manufactured by 3D bioprinting techniques by looking into wound healing biology, biofabrication methods, cellulose derivatives, and the existing cellulose bioinks targeted toward wound healing.

TGF-β1 inhibitor P144 protects against benign restenosis after esophageal stenting through TGF-β1/Smads signaling pathway inhibition

BACKGROUND AND STUDY AIMS

Esophageal restenosis is a serious complication after esophageal stent placement, which influences the clinical prognosis of stent implantation and the patient's quality of life. TGF-β1/Smads signaling pathway plays an important role in the development of the eosinophilic esophagitis and scar repair after skin trauma. However, the role of TGF-β1/Smads in the development of esophageal restenosis after esophageal stent placement remains unknown. Our study aimed to investigate whether TGF-β1/Smads plays an important role in the development of esophageal restenosis after esophageal stent, and whether the exogenous TGF-β1 inhibitor supplement could ameliorate the esophageal restenosis after esophageal stent.

MATERIAL AND METHODS

We established the model of esophageal restenosis after esophageal stenting in rats, and determined the expression levels of TGF-β1/Smads signaling pathway and the relevant markers of fibroblast activation by immunochemistry (IHC), Western Blot and real time qPCR. Those all the indicators were also determined in esophageal fibroblast when exposed to rhTGF-β1 with or without TGF-β1 inhibitor P144.

RESULTS

The serum level of IL-1β and TNFα were significantly increased in stent implantation group compared to blank control group, and obviously ameliorated when treated with P144. The TGF-β1/Smads signaling pathway and the relevant markers of fibroblast activation were significantly increased in stent implantation group compared to blank control group, and obviously ameliorated when treated with P144. Those all the indicators were significantly increased when exposed to rhTGF-β1, and obviously decreased when treated with P144.

CONCLUSIONS

TGF-β1 Inhibitor P144 could protect against benign restenosis after esophageal stenting by down-regulating the expression levels of relevant markers of fibroblast activation through TGF-β1/Smads signaling pathway inhibition, and may be used as a novel therapy for benign restenosis after esophageal stenting.

Targeting Wnt/β-catenin signaling and its interplay with TGF-β and Notch signaling pathways for the treatment of chronic wounds

Wound healing is a tightly regulated process that ensures tissue repair and normal function following injury. It is modulated by activation of pathways such as the transforming growth factor-beta (TGF-β), Notch, and Wnt/β-catenin signaling pathways. Dysregulation of this process causes poor wound healing, which leads to tissue fibrosis and ulcerative wounds. The Wnt/β-catenin pathway is involved in all phases of wound healing, primarily in the proliferative phase for formation of granulation tissue. This review focuses on the role of the Wnt/β-catenin signaling pathway in wound healing, and its transcriptional regulation of target genes. The crosstalk between Wnt/β-catenin, Notch, and the TGF-β signaling pathways, as well as the deregulation of Wnt/β-catenin signaling in chronic wounds are also considered, with a special focus on diabetic ulcers. Lastly, we discuss current and prospective therapies for chronic wounds, with a primary focus on strategies that target the Wnt/β-catenin signaling pathway such as photobiomodulation for healing diabetic ulcers.

Exploring the impact of TGF-β family gene mutations and expression on skin wound healing and tissue repair

Transforming Growth Factor-Beta (TGF-β) signalling pathway is of paramount importance in the processes of wound healing, epidermal integrity maintenance and development of skin cancer. The objective of this research endeavour was to clarify the impact of gene mutations and variations in expression within TGF-β family on mechanisms of tissue repair, as well as to identify potential targets for therapeutic purposes in non-melanoma skin cancer (NMSC). The methods utilized in this study involved obtaining RNA-seq data from 224 NMSC patients and paired normal skin tissues from the PRJNA320473 and PRJEB27606 databases. The purpose of the differential gene expression analysis was to identify genes whose expression had changed significantly. In order to evaluate the effects and interrelationships of identified gene variants, structural analysis with AlphaFold and PDB data and network analysis with the STRING database were both utilized. Critical gene expression was externally validated through the utilization of the GEPIA database. Tumour tissues exhibited a notable upregulation of genes associated with the TGF-β pathway, specifically MMP1, MMP3, MMP9, EGF, COL3A1 and COL1A2, in comparison with normal tissues. As indicated by the central node status of these genes in the network analysis, they play a crucial role in the progression of NMSCs. The results of the structural analysis suggested that mutations might cause functional disruptions. External validation of the upregulation confirmed the expression trends and emphasized the biomarker potential of the upregulated genes. In conclusion, this research offered thorough examination of molecular modifications that occur in TGF-β family genes, which are linked to cutaneous wound healing and NMSC. The modified expression of the identified hub genes may represent innovative targets for therapeutic intervention.

A purified reconstituted bilayer matrix shows improved outcomes in treatment of non-healing diabetic foot ulcers when compared to the standard of care: Final results and analysis of a prospective, randomized, controlled, multi-centre clinical trial

As the incidence of diabetic foot ulcers (DFU) increases, better treatments that improve healing should reduce complications of these ulcers including infections and amputations. We conducted a randomized controlled trial comparing outcomes between a novel purified reconstituted bilayer membrane (PRBM) to the standard of care (SOC) in the treatment of non-healing DFUs. This study included 105 patients who were randomized to either of two treatment groups (n = 54 PRBM; n = 51 SOC) in the intent to treat (ITT) group and 80 who completed the study per protocol (PP) (n = 47 PRBM; n = 33 SOC). The primary endpoint was the percentage of wounds closed after 12 weeks. Secondary outcomes included percent area reduction, time to healing, quality of life, and cost to closure. The DFUs that had been treated with PRBM healed at a higher rate than those treated with SOC (ITT: 83% vs. 45%, p = 0.00004, PP: 92% vs. 67%, p = 0.005). Wounds treated with PRBM also healed significantly faster than those treated with SOC with a mean of 42 versus 62 days for SOC (p = 0.00074) and achieved a mean wound area reduction within 12 weeks of 94% versus 51% for SOC (p = 0.0023). There were no adverse events or serious adverse events that were related to either the PRBM or the SOC. In comparison to the SOC, DFUs healed faster when treated with PRBM. Thus, the use of this PRBM is an effective option for the treatment of chronic DFUs.

Inhibitory effects of bioactive compounds on UVB-induced photodamage in human keratinocytes: modulation of MMP1 and Wnt signaling pathways

UVB radiation significantly threatens skin health, contributing to wrinkle formation and an elevated risk of skin cancer. This study aimed to explore bioactive compounds with potential UVB-protective properties. Using in silico analysis, we chose compounds to reduce binding energy with matrix metalloproteinase-1 (MMP1). Piperitoside, procyanidin C1, and mulberrofuran E emerged as promising candidates through this computational screening process. We investigated the UVB-protective efficacy of the selected compounds and underlying mechanisms in human immortalized keratinocytes (HaCaT). We also investigated the molecular pathways implicated in their action, focusing on the transforming growth factor (TGF)-β and wingless-related integration site (Wnt)/β-catenin signaling pathways. In UVB-exposed HaCaT cells (100 mJ/cm2 for 30 min), piperitoside, procyanidin C1, and mulberrofuran E significantly reduced reactive oxygen species (ROS) and lipid peroxides, coupled with an augmentation of collagen expression. These compounds suppressed MMP1, tumor necrosis factor-alpha (TNF-α), and inducible nitric oxide synthase (iNOS) expression, while they concurrently enhanced collagen-1 (COL1A1), β-catenin (CTNNB1), and superoxide dismutase type-1 (SOD1) expression. Furthermore, Wnt/β-catenin inhibitors, when administered subsequently, partially counteracted the reduction in MMP1 expression and alleviated inflammatory and oxidative stress markers induced by the bioactive compounds. In conclusion, piperitoside, procyanidin C1, and mulberrofuran E protected against UVB-induced damage in HaCaT cells by inhibiting MMP1 expression and elevating β-catenin expression. Consequently, these bioactive compounds emerge as promising preventive agents for UVB-induced skin damage, promoting skin health.

Peripheral muscle oxygenation, pain, and disability indices in individuals with and without nonspecific neck pain, before and after myofascial reorganization®: A double-blind randomized controlled trial

To investigate whether myofascial reorganization® in the trapezius muscle (MRT) improves peripheral muscle oxygenation and pain tolerance and decreases neck disability index (NDI) scores in individuals with and without nonspecific neck pain (NP) using a double-blind randomized controlled trial. Seventy-five subjects were equally and randomly assigned to three groups: the intervention groups (experimental [EG] and sham sSG]) and the control group (CG). Several inclusion criteria were applied to the intervention groups: male or female, aged 18-32 years, self-reported NP in the last 3 months without a defined cause; at least "soft" pain in session 1 of the NDI, and at least a score of 1 on the Visual Analogue Scale (VAS). The CG was required to have NDI and VAS scores of 0 at recruitment. Intervention: The EG underwent MRT for 10 min, once a week for 6 weeks. Patients with NP in the SG underwent classical massage for the same duration and frequency. Patients in the CG had no pain and underwent no intervention. Data collection was performed using the NDI Questionnaire, a pressure algometer for pain evaluation, and near-infrared spectroscopy for muscle oxygenation measurements. It was registered as NCT03882515 at ClinicalTrials.gov. The NDI score in both the EG (p<0.001) and SG (p<0.001) decreased after 6 weeks of intervention compared to the CG. The CG demonstrated a lower basal tissue saturation (TSI) index than the EG (p<0.001) and SG (p = 0.02). The EG demonstrated higher oxyhemoglobin values than the SG (p<0.001) and CG (p = 0.03). The CG had higher pain tolerance than the EG (p = 0.01) and SG (p<0.001) post-intervention. MRT increased trapezius muscle oxygenation after 6 weeks of intervention.

Role of TGF-β3 in modulating inflammatory responses and wound healing processes in ischemic ulcers in atherosclerotic patients

Ischemic ulcers pose a multifaceted clinical dilemma for patients with atherosclerosis, frequently compounded by suboptimal wound healing mechanisms. The dual function of Transforming Growth Factor Beta 3 (TGF-β3) in ischemic ulcer healing is not fully comprehended, despite its involvement in modulating inflammatory responses and tissue regeneration. The main aim of this investigation was to clarify the functions and mechanisms by which TGF-β3 regulates inflammatory responses and promotes wound healing in patients with ischemic ulcers who have atherosclerosis. Between August 2022 and November 2023, this cross-sectional investigation was conducted on 428 patients diagnosed with atherosclerotic ischemic ulcers in Haikou, China. The expression and function of TGF-β3 were examined throughout the different stages of wound healing, including inflammation, proliferation and remodelling. In addition to documenting patient demographics and ulcer characteristics, an analysis was conducted on biopsy samples to determine the expression of TGF-β3, pro-inflammatory and anti-inflammatory markers. A subset of patients were administered topical TGF-β3 in order to evaluate its therapeutic effects. The expression pattern of TGF-β3 was found to be stage-dependent and significant, exhibiting increased levels during the phase of inflammation and reduced activity in subsequent phases. TGF-β3 levels were found to be greater in ulcers that were larger and deeper, especially in inflammatory phase. TGF-β3 applied topically induced discernible enhancement in ulcer healing parameters, such as reduction in ulcer depth and size. The therapeutic significance of TGF-β3 was emphasised due to its twofold function of regulating the inflammatory environment and facilitating the regeneration of damaged tissues. Ischemic ulcer lesion healing is significantly influenced by TGF-β3, which functions as an anti-inflammatory and pro-inflammatory mediator. Its correlation with ulcer characteristics and stages of healing suggests that it may have utility as a targeted therapeutic agent.

Targeting Signalling Pathways in Chronic Wound Healing

Chronic wounds fail to achieve complete closure and are an economic burden to healthcare systems due to the limited treatment options and constant medical attention. Chronic wounds are characterised by dysregulated signalling pathways. Research has focused on naturally derived compounds, stem-cell-based therapy, small molecule drugs, oligonucleotide delivery nanoparticles, exosomes and peptide-based platforms. The phosphoinositide-3-kinase (PI3K)/protein kinase B (AKT), Wingless-related integration (Wnt)/β-catenin, transforming growth factor-β (TGF-β), nuclear factor erythroid 2-related factor 2 (Nrf2), Notch and hypoxia-inducible factor 1 (HIF-1) signalling pathways have critical roles in wound healing by modulating the inflammatory, proliferative and remodelling phases. Moreover, several regulators of the signalling pathways were demonstrated to be potential treatment targets. In this review, the current research on targeting signalling pathways under chronic wound conditions will be discussed together with implications for future studies.

Opportunities for Bioactive Glass in Gastrointestinal Conditions: A Review of Production Methodologies, Morphology, Composition, and Performance

Bioactive glasses (BGs) are widely used in orthopedic and dental applications for their ability to stimulate endogenous bone formation and regeneration. BG applications more recently broadened to include soft tissue conditions, based on their ability to stimulate angiogenesis, soft tissue regeneration, and wound healing. Sol-gel synthesis has helped facilitate this expansion, allowing formulators to tailor the morphological characteristics of the BG matrix. The effectiveness of BGs in skin wound healing is viewed as a gateway for their use as both a therapeutic and drug delivery platform in other soft tissue applications, notably gastrointestinal (GI) applications, which form the focus of this review. Recent changes in international guidelines for GI conditions shifted clinical objectives from symptom management to mucosal wound healing. The additional scrutiny of proton pump inhibitor (PPI) safety, increasing burden of disease, and financial costs associated with gastroesophageal reflux disease (GERD), peptic ulcer disease (PUD), and inflammatory bowel disease (IBD) open new clinical possibilities for BG. This narrative literature review intersects materials engineering, formulation science, and clinical practice, setting it apart from prior literature. Broadly, current evidence for BG applications in GI conditions is sparse and under-developed, which this review directly addresses. It explores and synthesizes evidence that supports the potential use of sol-gel-derived BG for the efficacious treatment of soft tissue applications, with specific reference to GI conditions. An overview with comparative analysis of current BG synthesis techniques and associated challenges is presented, and influences of composition, biologically active ions, and morphological characteristics in soft tissue applications are explored. To contextualize this, sol-gel-derived BGs are proposed as a dual, tailorable therapeutic and drug delivery platform for upper and lower GI conditions. Future directions for this largely untapped area of translational research are also proposed, based on extant literature.

Fibrosis in burns: an overview of mechanisms and therapies

Scar development remains a common occurrence and a major healthcare challenge affecting the lives of millions of patients annually. Severe injuries to the skin, such as burns can lead to pathological wound healing patterns, often characterized by dermal fibrosis or excessive scarring, and chronic inflammation. The two most common forms of fibrotic diseases following burn trauma are hypertrophic scars (HSCs) and keloids, which severely impact the patient's quality of life. Although the cellular and molecular mechanisms are similar, HSC and keloids have several distinct differences. In this review, we discuss the different forms of fibrosis that occur postburn injury, emphasizing how the extent of burn influences scar development. Moreover, we highlight how a systemic response induced by a burn injury drives wound fibrosis, including both the role of the inflammatory response, as well as the fate of fibroblast during skin healing. Finally, we list potential therapeutics aimed at alleviating pathological scar formation. An understanding of the mechanisms of postburn fibrosis will allow us to effectively move studies from bench to bedside.

Sol-gel derived B2O3-CaO borate bioactive glasses with hemostatic, antibacterial and pro-angiogenic activities

Sol-gel borate bioactive glasses (BGs) are promising ion-releasing biomaterials for wound healing applications. Here, we report the synthesis of a series of binary B2O3-CaO borate BGs (CaO ranging from 50 to 90 mol%) using a sol-gel-based method. The influence of CaO content in B2O3-CaO borate BG on morphology, structure and ion release behavior was investigated in detail. Reduced dissolution (ion release) and crystallization could be observed in borate BGs when CaO content increased, while the morphology was not significantly altered by increasing CaO content. Our results evidenced that the ion release behavior of borate BGs could be tailored by tuning the B2O3/CaO molar ratio. We also evaluated the in vitro cytotoxicity, hemostatic, antibacterial and angiogenic activities of borate BGs. Cytocompatibility was validated for all borate BGs. However, borate BGs exhibited composition-dependent hemostatic, antibacterial and angiogenic activities. Generally, higher contents of Ca in borate BGs facilitated hemostatic activity, while higher contents of B2O3 were beneficial for pro-angiogenic activity. The synthesized sol-gel-derived borate BGs are promising materials for developing advanced wound healing dressings, given their fast ion release behavior and favorable hemostatic, antibacterial and angiogenic activities.

Carbon Dots' Potential in Wound Healing: Inducing M2 Macrophage Polarization and Demonstrating Antibacterial Properties for Accelerated Recovery

Bacterial infections and persistent inflammation can impede the intrinsic healing process of wounds. To combat this issue, researchers have delved into the potential use of carbon dots (CDs) in the regulation of inflammation and counteract infections. These CDs were synthesized using a microwave-assisted hydrothermal process and have demonstrated outstanding antibacterial and antibiofilm properties against Gram-positive and Gram-negative bacteria. Additionally, CDs displayed biocompatibility at therapeutic concentrations and the ability to specifically target mitochondria. CD treatment effectively nullified lipopolysaccharide-triggered reactive oxygen species production by macrophages, while simultaneously promoting macrophage polarization toward an anti-inflammatory phenotype (M2), leading to a reduction in inflammation and an acceleration in wound healing. In vitro scratch assays also revealed that CDs facilitated the tissue-repairing process by stimulating epithelial cell migration during reepithelialization. In vivo studies using CDs topically applied to lipopolysaccharide (LPS)-stimulated wounds in C57/BL6 mice demonstrated significant improvements in wound healing due to enhanced fibroblast proliferation, angiogenesis, and collagen deposition. Crucially, histological investigations showed no indications of systemic toxicity in vital organs. Collectively, the application of CDs has shown immense potential in speeding up the wound-healing process by regulating inflammation, preventing bacterial infections, and promoting tissue repair. These results suggest that further clinical translation of CDs should be considered.

Enhanced Proliferation and Adhesion Marker Gene Expression in Fibroblast Cells: Evaluating the Efficacy of a Non-Surgical Treatment for Urogenital Fistula

BACKGROUND Vesicovaginal fistula (VVF) due to posterior bladder wall and/or anterior vaginal wall necrosis is a condition that leads to urinary incontinence. Both microscopic and macroscopic VVFs severely impact quality of life. They are also associated with frequent recurrence after surgery. A non-surgical intervention for VVF is urgently required. A membrane bilayer could act as a mechanical tamponade and stimulate defect closure. MATERIAL AND METHODS This is an experimental study that explored the characteristics of mucoadhesive bilayer membrane complexes for non-operative treatment of VVF in vitro. We synthesized a mucoadhesive bilayer membrane, and inoculated it with cultured fibroblast cells. The mucoadhesive bilayer membrane was prepared with 3 different treatments: (1) estrogen; (2) lyophilized radiation-sterilized amnion (ALSR), a prepared amniotic membrane; and (3) arginine and glutamine (arginine+glutamine), 2 amino acids associated with wound repair. Expression levels of 3 genes, namely tumor growth factor beta (TGF-ß), lysil oxidase (LOX), and junctional adhesion molecules (JAMs), were measured using the Livak method and polymerase chain reaction (PCR). RESULTS On the fifth day after inoculation, there was no statistically significant difference in expression of the genes in the 3 conditions. However, on the tenth day, gene expression of the LOX and JAMs genes in the fibroblast cells inoculated onto the mucoadhesive bilayer membrane with arginine+glutamine was significantly higher than the expression in the fibroblast cells inoculated onto the mucoadhesive bilayer membrane with estrogen or with ALSR. CONCLUSIONS The mucoadhesive bilayer membrane complex with arginine+glutamine gave rise to the highest expression of the LOX and JAMs genes, indicating that the highest proliferation and cell adhesion were found in cells inoculated with the mucoadhesive bilayer membrane complex with arginine+glutamine.

Eobania vermiculata whole-body muscle extract-loaded chitosan nanoparticles enhanced skin regeneration and decreased pro-inflammatory cytokines in vivo

BACKGROUND

Usually, wounds recover in four to six weeks. Wounds that take longer time than this to heal are referred to as chronic wounds. Impaired healing can be caused by several circumstances like hypoxia, microbial colonization, deficiency of blood flow, reperfusion damage, abnormal cellular reaction and deficiencies in collagen production. Treatment of wounds can be enhanced through systemic injection of the antibacterial drugs and/or other topical applications of medications. However, there are a number of disadvantages to these techniques, including the limited or insufficient medication penetration into the underlying skin tissue and the development of bacterial resistance with repeated antibiotic treatment. One of the more recent treatment options may involve using nanotherapeutics in combination with naturally occurring biological components, such as snail extracts (SE). In this investigation, chitosan nanoparticles (CS NPs) were loaded with an Eobania vermiculata whole-body muscle extract. The safety of the synthesized NPs was investigated in vitro to determine if these NPs might be utilized to treat full-skin induced wounds in vivo.

RESULTS

SEM and TEM images showed uniformly distributed, spherical, smooth prepared CS NPs and snail extract-loaded chitosan nanoparticles (SE-CS NPs) with size ranges of 76-81 and 91-95 nm, respectively. The zeta potential of the synthesized SE-CS NPs was - 24.5 mV, while that of the CS NPs was 25 mV. SE-CS NPs showed a remarkable, in vitro, antioxidant, anti-inflammatory and antimicrobial activities. Successfully, SE-CS NPs (50 mg/kg) reduced the oxidative stress marker (malondialdehyde), reduced inflammation, increased the levels of the antioxidant enzymes (superoxide dismutase and glutathione), and assisted the healing of induced wounds. SE-CS NPs (50 mg/kg) can be recommended to treat induced wounds safely. SE was composed of a collection of several wound healing bioactive components [fatty acids, amino acids, minerals and vitamins) that were loaded on CS NPs.

CONCLUSIONS

The nanostructure enabled bioactive SE components to pass through cell membranes and exhibit their antioxidant and anti-inflammatory actions, accelerating the healing process of wounds. Finally, it is advised to treat rats' wounds with SE-CS NPs.

Human fetal dermal fibroblast-myeloid cell diversity is characterized by dominance of pro-healing Annexin1-FPR1 signaling

Fetal skin achieves scarless wound repair. Dermal fibroblasts play a central role in extracellular matrix deposition and scarring outcomes. Both fetal and gingival wound repair share minimal scarring outcomes. We tested the hypothesis that compared to adult skin fibroblasts, human fetal skin fibroblast diversity is unique and partly overlaps with gingival skin fibroblasts. Human fetal skin (FS, n = 3), gingiva (HGG, n = 13), and mature skin (MS, n = 13) were compared at single-cell resolution. Dermal fibroblasts, the most abundant cluster, were examined to establish a connectome with other skin cells. Annexin1-FPR1 signaling pathway was dominant in both FS as well as HGG fibroblasts and related myeloid cells while scanty in MS fibroblasts. Myeloid-specific FPR1-ORF delivered in murine wound edge using tissue nanotransfection (TNT) technology significantly enhanced the quality of healing. Pseudotime analyses identified the co-existence of an HGG fibroblast subset with FPR1high myeloid cells of fetal origin indicating common underlying biological processes.

Anastomotic stenosis of bioengineered trachea grafts is driven by transforming growth factor β1-induced signaling, proinflammatory macrophages, and delayed epithelialization

Objective

Anastomotic stenosis caused by hypertrophic granulation tissue often develops in response to orthotopically implanted bioengineered tracheal grafts. To determine mechanisms responsible for the development and persistence of this granulation tissue, we looked for changes in gene expression from tissue specimens from the graft-native interface.

Methods

RNA was isolated from paraffin-embedded tissue samples of the anastomotic sites of orthotopically implanted bioengineered tracheal grafts of 9 animals. Tissue samples were binned into 3 groups based on degree of stenosis: no stenosis (<5%), mild stenosis (25%-50%), and moderate and severe stenosis (≥75%). Sections of healthy trachea tissue were used as control. The expression levels of ∼200 genes related to wound healing, plus several endogenous controls, were measured with a pathway-focused predesigned primer array.

Results

Expression of ARG2, IL4, RPL13 A, TGFBR3, and EGFR decreased, whereas expression of RUNX2 was increased in stenotic wounds compared with nonstenotic tissue. Based on the cell types present in the trachea and wound healing, this expression profile indicates a lack of M2 anti-inflammatory macrophages, absent epithelial cells, and transforming growth factor β1-induced signaling.

Conclusions

These findings represent a significant step for tracheal tissue engineering by identifying several key mechanisms present in stenotic granulation tissue. Further research must be conducted to determine what modifications of the graft substrate and which coadministered therapeutics can be used to prevent the development of hypertrophic granulation tissue.

Skin wound healing effects of (+)-syringaresinol from ginseng berry

Background

Ginseng has been used as a traditional medicine and functional cosmetic ingredients for many years. Recent studies have focused on the potential biological effects of the ginseng berry and its ingredients. (+)-Syringaresinol (SYR) is enriched in ginseng berry and its beneficial effects on the skin have been recently reported. However, little is known about the its effects on the wound healing process of skin.

Methods

Here, we evaluated the skin wound healing effect of (+)-SYR using the human fibroblast Hs68 cell and ex vivo pig and human skin tissue model. Scratch wound test and hydrogen peroxide (HPO) induce chemical wound model were employed.

Results

(+)-SYR promoted the migration and proliferation of Hs68 cells without significant cytotoxicity at the tested concentrations. Especially, in ex vivo pig and human skin tissue, HPO-induced chemical wound was recovered almost completely by (+)-SYR. In line with the finding in Hs68, the protein expression levels of TGF-β and PCNA, a proliferation marker were increased, demonstrating the beneficial effects of (+)-SYR on skin wound repair.

Conclusion

Collectively, we demonstrated that (+)-SYR from ginseng berry, can enhance the wound healing effect by accelerating cell proliferation and skin regeneration, suggesting the potential utility of (+)-SYR for skin wound repair.

Nanofibrous Polycaprolactone Membrane with Bioactive Glass and Atorvastatin for Wound Healing: Preparation and Characterization

Skin wound healing is one of the most challenging processes for skin reconstruction, especially after severe injuries. In our study, nanofiber membranes were prepared for wound healing using an electrospinning process, where the prepared nanofibers were made of different weight ratios of polycaprolactone and bioactive glass that can induce the growth of new tissue. The membranes showed smooth and uniform nanofibers with an average diameter of 118 nm. FTIR and XRD results indicated no chemical interactions of polycaprolactone and bioactive glass and an increase in polycaprolactone crystallinity by the incorporation of bioactive glass nanoparticles. Nanofibers containing 5% w/w of bioactive glass were selected to be loaded with atorvastatin, considering their best mechanical properties compared to the other prepared nanofibers (3, 10, and 20% w/w bioactive glass). Atorvastatin can speed up the tissue healing process, and it was loaded into the selected nanofibers using a dip-coating technique with ethyl cellulose as a coating polymer. The study of the in vitro drug release found that atorvastatin-loaded nanofibers with a 10% coating polymer revealed gradual drug release compared to the non-coated nanofibers and nanofibers coated with 5% ethyl cellulose. Integration of atorvastatin and bioactive glass with polycaprolactone nanofibers showed superior wound closure results in the human skin fibroblast cell line. The results from this study highlight the ability of polycaprolactone-bioactive glass-based fibers loaded with atorvastatin to stimulate skin wound healing.

TGF-β Isoforms Affect the Planar and Subepithelial Fibrogenesis of Human Conjunctival Fibroblasts in Different Manners

Three highly homologous isoforms of TGF-β, TGF-β-1~3, are involved in the regulation of various pathophysiological conditions such as wound healing processes in different manners, despite the fact that they bind to the same receptors during their activation. The purpose of the current investigation was to elucidate the contributions of TGF-β-1 ~3 to the pathology associated with conjunctiva. For this purpose, the biological effects of these TGF-β isoforms on the structural and functional properties of two-dimensional (2D) and three-dimensional (3D) cultured human conjunctival fibroblasts (HconF) were subjected to the following analyses: 1) transendothelial electrical resistance (TEER), a Seahorse cellular metabolic measurement (2D), size and stiffness measurements of the 3D HTM spheroids, and the qPCR gene expression analyses of extracellular matrix (ECM) components (2D and 3D). The TGF-β isoforms caused different effects on the proliferation of the HconF cell monolayer evaluated by TEER measurements. The differences included a significant increase in the presence of 5 ng/mL TGF-β-1 and -2 and a substantial decrease in the presence of 5 ng/mL TGF-β-3, although there were no significant differences in the response to the TGF-β isoforms for cellular metabolism among the three groups. Similar to planar proliferation, the TGF-β isoforms also induced diverse effects toward the mechanical aspects of 3D HconF spheroids, where TGF-β-1 increased stiffness, TGF-β-2 caused no significant effects, and TGF-β-3 caused the downsizing of the spheroids and stiffness enhancement. The mRNA expression of the ECMs were also modulated in diverse manners by the TGF-β isoforms as well as the culture conditions for the 2D vs. 3D isoforms. Many of these TGF-β-3 inducible effects were markedly different from those caused by TGF-β1 and TGF-β-2. The findings presented herein suggest that the three TGF-β isoforms induce diverse and distinctly different effects on cellular properties and the expressions of ECM molecules in HconF and that these changes are independent of cellular metabolism, thereby inducing different effects on the epithelial and subepithelial proliferation of human conjunctiva.

Thermosensitive and antioxidant wound dressings capable of adaptively regulating TGFβ pathways promote diabetic wound healing

Various therapies have been utilized for treating diabetic wounds, yet current regiments do not simultaneously address the key intrinsic causes of slow wound healing, i.e., abnormal skin cell functions (particularly migration), delayed angiogenesis, and chronic inflammation. To address this clinical gap, we develop a wound dressing that contains a peptide-based TGFβ receptor II inhibitor (PTβR2I), and a thermosensitive and reactive oxygen species (ROS)-scavenging hydrogel. The wound dressing can quickly solidify on the diabetic wounds following administration. The released PTβR2I inhibits the TGFβ1/p38 pathway, leading to improved cell migration and angiogenesis, and decreased inflammation. Meanwhile, the PTβR2I does not interfere with the TGFβ1/Smad2/3 pathway that is required to regulate myofibroblasts, a critical cell type for wound healing. The hydrogel's ability to scavenge ROS in diabetic wounds further decreases inflammation. Single-dose application of the wound dressing significantly accelerates wound healing with complete wound closure after 14 days. Overall, using wound dressings capable of adaptively modulating TGFβ pathways provides a new strategy for diabetic wound treatment.

Prostanoid FP and EP2 Receptor Agonists Induce Epithelial and Subepithelial Fibrogenetic Changes in Human Conjunctival Fibroblasts in Different Manners

Purpose: To examine the effects of prostanoid FP and EP2 receptor agonists, PGF2α and Omidenepag (OMD), respectively, on the transforming growth factor beta (TGF-β2) induced conjunctival fibrogenesis. Methods: Two-dimension (2D) and three-dimension (3D) cultures of these fibroblasts were subjected to following analyses: (1) planar proliferation evaluated by transendothelial electron resistance (TEER) measurements, (2) real-time metabolic analyses, (3) subepithelial proliferation evaluated by 3D spheroid' size and stiffness measurements, and (4) the mRNA expression of extracellular matrix (ECM) molecules and their modulators. Results: TGF-β2 induced increase in the planar proliferation was significantly decreased or enhanced by PGF2α or OMD, respectively. The proportion of oxygen consumption required to drive ATP synthesis compared with that driving proton leakage was increased by PGF2α and OMD independently with TGF-β2. In contrast, maximal mitochondrial respiration was decreased by PGF2α and OMD, and the OMD-induced effect was further enhanced by the presence of TGF-β2. In addition, the TGF-β2 dependent increase in the glycolytic capacity was cancelled by PGF2α and/or OMD. Alternatively, subepithelial proliferation, as evidenced by the stiffness of the 3D spheroids, was substantially increased by both PGF2α and OMD, and these were differently modulated by TGF-β2. The expression of several related factors as above fluctuated among the conditions for both 2D and 3D and TGF-β2 untreated or treated cultures. Conclusion: The present findings indicate that the prostanoid FP or the EP2 receptor agonist may solely and differently induce the planar and subepithelial proliferation of HconF cells and these were also modulated by TGF-β2.

Spring-Powered Needle-Free Injection of Triamcinolone Acetonide and 5-Fluorouracil for Keloid Treatment

Introduction

Keloid is an abnormal fibroproliferative healing response characterized by excessive and invasive tissue growth beyond the wound boundaries. The conventional treatment involves injecting drugs such as triamcinolone acetonide (TA), 5-fluorouracil (5-FU), or their combination intralesionally. However, the pain associated with injections often leads to low patient compliance and treatment failure. The spring-powered needle-free injector (NFI) provides an affordable alternative option for drug delivery with reduced pain.

Case

This case report presents a 69-year-old female patient with a keloid treated using a spring-powered needle-free injector (NFI) for drug delivery. The keloid was assessed using the Vancouver Scar Scale (VSS) and the Patient and Observer Scar Assessment Scale (POSAS). The patient's pain level was measured using the Numeric Pain Rating Scale (NPRS). TA and 5-FU mixed with lidocaine were loaded into the NFI and injected at a dose of 0.1 mL/cm². The treatment was repeated twice a week. After four sessions, the keloid flattened by 0.5 cm, VSS score decreased from 11 to 10, and POSAS scores decreased from 49 to 43 (observer) and from 50 to 37 (patient). The NPRS during each procedure was 1, indicating minimal pain.

Discussion

The spring-powered NFI is a simple and cost-effective device that operates based on Hooke's law, producing a high-pressure fluid jet for effective skin penetration. The NFI demonstrated effectiveness in treating keloid lesions, resulting in visible improvement after four treatments.

Conclusion

The spring-powered NFI offers an affordable and painless alternative to keloid treatment.

Bilateral post-LASIK exacerbation of granular corneal dystrophy with epithelial ingrowth

A male patient in his 30s, with a history of bilateral microkeratome-assisted myopic laser-assisted in situ keratomileusis (LASIK) 8 years ago at another centre, presented to us with gradually progressive diminution of vision and glare in both eyes for the last 4 years. On presentation, uncorrected distance visual acuity (UDVA) was 6/24 and 6/15 in the right eye and left eye, respectively, with normal intraocular pressures. Slit-lamp examination and anterior segment optical coherence tomography revealed well-defined white deposits, limited to an area within the LASIK flap. The deposits were confluent, at the level of the LASIK flap interface, and few discrete opacities were present in the posterior stroma. His father also had a similar clinical picture in both eyes. A diagnosis of both eyes post-LASIK exacerbation of granular corneal dystrophy with epithelial ingrowth was made. He underwent right eye femtosecond laser-assisted sutureless superficial anterior lamellar keratoplasty. At 6-month follow-up, UDVA improved to 6/12 with graft clarity of 4+ and coexistent grade 1 epithelial ingrowth.

Injection of stem cells derived from allogeneic adipose tissue, a new strategy for the treatment of diabetic wounds

A diabetic wound is one of the major complications of Diabetes mellitus. Considering the impact of these wounds on the health and quality of life of diabetic patients, the need for a suitable treatment is essential. Adipose-derived stem cells (ASCs) play a role in healing diabetic wounds. The purpose of this study is to examine the effect of ASCs on skin wound healing in diabetic rats. Rats were divided into three groups, diabetics treated with ASCs, non-diabetic, and diabetic (treated with phosphate-buffered saline). Skin wounds and its margin were examined to measure the level of vascular endothelial growth factor (VEGF) and transforming growth factor-beta (TGF-β) and histopathological examinations on three, six, and nine days after wound formation and treatment. As a result, the administration of ASCs can reduce the healing time of skin wounds in diabetic rats by controlling inflammation and increasing angiogenesis.

Arnica montana L. associated with microcurrent accelerates the dermis reorganisation of skin lesions

The aim of this study was to test the effect of electrical stimulation in association with topical Arnica montana gel on organisational changes in the dermis during tissue repair. An experimental rat incisional skin lesion was used for the study. This involved making an incisional lesion on the dorsum of the animals using a scalpel. Ninety-six animals were used divided into the following groups: control (C), microcurrent (MC); topical treatment with Arnica montana gel (ARN); the ARN + microcurrent (ARN + MC). Treatments were administered daily, and injured tissue samples were collected and processed on Days 2, 6 and 10 for dermis analyses. Myeloperoxidase levels were greater in control than in treatment groups on Days 2 and 6. F4/80 expression was similar among all treatment groups and greater than that in control on Day 2. On Day 6, the expression of vascular endothelial growth factor was higher in the MC group than that in other groups, whereas transforming growth factor-β expression increased in the MC and ARN + MC groups on Day 10. The expression of matrix metalloproteinase-2 was higher in the ARN + MC group when compared with other groups on Day 10. Expression levels of collagen I were increased in the ARN and ARN + MC groups when compared with control and MC groups on Day 6, while expression of collagen III was enhanced in MC, ARN, and ARN + MC groups when compared with the control. The protocol combining microcurrent with topical application of ARN reduces the inflammatory process, increases myofibroblasts proliferation and decreases the presence of macrophages in the dermis during skin repair in rats.

Human In Vitro Skin Models for Wound Healing and Wound Healing Disorders

Skin wound healing is essential to health and survival. Consequently, high amounts of research effort have been put into investigating the cellular and molecular components involved in the wound healing process. The use of animal experiments has contributed greatly to the knowledge of wound healing, skin diseases, and the exploration of treatment options. However, in addition to ethical concerns, anatomical and physiological inter-species differences often influence the translatability of animal-based studies. Human in vitro skin models, which include essential cellular and structural components for wound healing analyses, would improve the translatability of results and reduce animal experiments during the preclinical evaluation of novel therapy approaches. In this review, we summarize in vitro approaches, which are used to study wound healing as well as wound healing-pathologies such as chronic wounds, keloids, and hypertrophic scars in a human setting.

Model to Inhibit Contraction in Third-Degree Burns Employing Split-Thickness Skin Graft and Administered Bone Marrow-Derived Stem Cells

Third-degree burns typically result in pronounced scarring and contraction in superficial and deep tissues. Established techniques such as debridement and grafting provide benefit in the acute phase of burn therapy, nevertheless, scar and contraction remain a challenge in deep burns management. Our ambition is to evaluate the effectiveness of novel cell-based therapies, which can be implemented into the standard of care debridement and grafting procedures. Twenty-seven third-degree burn wounds were created on the dorsal area of Red Duroc pig. After 72 h, burns are surgically debrided using a Weck knife. Split-thickness skin grafts (STSGs) were then taken after debridement and placed on burn scars combined with bone marrow stem cells (BM-MSCs). Biopsy samples were taken on days 17, 21, and 45 posttreatment for evaluation. Histological analysis revealed that untreated control scars at 17 days are more raised than burns treated with STSGs alone and/or STSGs with BM-MSCs. Wounds treated with skin grafts plus BM-MSCs appeared thinner and longer, indicative of reduced contraction. qPCR revealed some elevation of α-SMA expression at day 21 and Collagen Iα2 in cells derived from wounds treated with skin grafts alone compared to wounds treated with STSGs + BM-MSCs. We observed a reduction level of TGFβ-1 expression at days 17, 21, and 45 in cells derived from wounds treated compared to controls. These results, where the combined use of stem cells and skin grafts stimulate healing and reduce contraction following third-degree burn injury, have a potential as a novel therapy in the clinic.

Establishment and characterization of immortalized human vocal fold fibroblast cell lines

PURPOSE

Vocal fold scarring is abnormal scar tissue in the lamina propria layer of the vocal fold. To facilitate investigation of vocal fold scarring, we established and characterized immortalized human vocal fold fibroblast (iHVFF) cell lines.

METHODS

Human vocal fold fibroblasts were immortalized by introducing Simian virus 40 large T antigen (SV40TAg) by transfection. Successfully transfected fibroblasts were sorted using flow cytometry. Immunofluorescence cytochemistry and western blot were applied to analyze the expression of fibronectin, vimentin, alpha-smooth muscle actin (α-SMA) and fibroblast activation protein (FAP). Cell proliferation rate was measured by CCK-8 assay. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to analyze the mRNA expression level.

RESULTS

The iHVFFs continued to proliferate for more than 30 generations and appeared spindle-shaped. The expression of Vimentin and α-SMA were detected in both iHVFFs and primary fibroblasts, and enhanced expression of FAP was observed in iHVFFs. Furthermore, iHVFFs exhibited an increased proliferative capability compared with the primary fibroblasts. RT-qPCR results suggested that collagen type III alpha 1 chain (COL3A1), interleukin-6, cyclooxygenase 2 (COX2), hyaluronan synthase 2 (HAS2), hepatocyte growth factor (HGF) in the iHVFFs significantly increased, whereas transforming growth factor-β1 (TGF-β1), elastin and matrix metallopeptidase-1 (MMP-1) expression significantly downregulated. No differences in mRNA expression of α-SMA, fibronectin and collagen type I alpha 2 chain (COL1A2) were noted between iHVFFs and primary fibroblasts.

CONCLUSION

iHVFFs can be used as a novel tool cell for future researches on the mechanisms of pathogenesis and treatment of vocal fold scarring.

Flavonoids as Potential Wound-Healing Molecules: Emphasis on Pathways Perspective

Wounds are considered to be a serious problem that affects the healthcare sector in many countries, primarily due to diabetes and obesity. Wounds become worse because of unhealthy lifestyles and habits. Wound healing is a complicated physiological process that is essential for restoring the epithelial barrier after an injury. Numerous studies have reported that flavonoids possess wound-healing properties due to their well-acclaimed anti-inflammatory, angiogenesis, re-epithelialization, and antioxidant effects. They have been shown to be able to act on the wound-healing process via expression of biomarkers respective to the pathways that mainly include Wnt/β-catenin, Hippo, Transforming Growth Factor-beta (TGF-β), Hedgehog, c-Jun N-Terminal Kinase (JNK), NF-E2-related factor 2/antioxidant responsive element (Nrf2/ARE), Nuclear Factor Kappa B (NF-κB), MAPK/ERK, Ras/Raf/MEK/ERK, phosphatidylinositol 3-kinase (PI3K)/Akt, Nitric oxide (NO) pathways, etc. Hence, we have compiled existing evidence on the manipulation of flavonoids towards achieving skin wound healing, together with current limitations and future perspectives in support of these polyphenolic compounds as safe wound-healing agents, in this review.

Small extracellular vesicles from mesenchymal stem cells: A potential Weapon for chronic non-healing wound treatment

Chronic non-healing wounds have posed a severe threat to patients mentally and physically. Behavior dysregulation of remaining cells at wound sites is recognized as the chief culprit to destroy healing process and hinders wound healing. Therefore, regulating and restoring normal cellular behavior is the core of chronic non-healing wound treatment. In recent years, the therapy with mesenchymal stem cells (MSCs) has become a promising option for chronic wound healing and the efficacy has increasingly been attributed to their exocrine functions. Small extracellular vesicles derived from MSCs (MSC-sEVs) are reported to benefit almost all stages of wound healing by regulating the cellular behavior to participate in the process of inflammatory response, angiogenesis, re-epithelization, and scarless healing. Here, we describe the characteristics of MSC-sEVs and discuss their therapeutic potential in chronic wound treatment. Additionally, we also provide an overview of the application avenues of MSC-sEVs in wound treatment. Finally, we summarize strategies for large-scale production and engineering of MSC-sEVs. This review may possibly provide meaningful guidance for chronic wound treatment with MSC-sEVs.

Local anti-inflammatory effect and immunomodulatory activity of chitosan-based dressing in skin wound healing: A systematic review

BACKGROUND AND AIM

Wound healing is a complex process comprised of several distinct phases. An imbalance in any of the stages creates a chronic wound with the potential to cause life-threatening complications for patients. Chitosan (CS) is a biopolymer that has shown to positively impact the different healing phases. This systematic review aimed to evaluate the anti-inflammatory and immunomodulatory properties of CS-based wound therapy for the skin healing process after an injury.

METHODS

A systematic review was conducted in November 2021 following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. The PubMed, Embase, Google Scholar, and Cochrane online databases were queried to capture all publications in the past 10 years that investigated the CS effects on inflammation and immune reaction.

RESULTS

A total of 234 studies were screened after removing duplicates and 14 articles fulfilled our inclusion and exclusion criteria. In the studies, CS was combined with a wide range of products. One clinical trial was found that treated patients with diabetic foot ulcers. All animal models in the studies used a full-thickness skin wound to test the effectiveness of CS in the healing process. Decreased pro-inflammatory cytokine levels, a shortened inflammatory phase and accelerated wound closure was observed in all of the studies.

CONCLUSIONS

CS proved to be a feasible, versatile, and multifaceted biomaterial that enhances the biological response to a skin injury. When combined with other products, its potential to boost the healing process through regulation of the inflammatory and cellular activity is increased.

RELEVANCE FOR PATIENTS

Although few clinical trials have been completed, CS has become an excellent alternative to modulate the local inflammatory response promoting wound healing. Especially in patients with associated comorbidities that affect the typical resolution of skin healing, such as diabetes and vascular insufficiency. Therefore, using bioactive wound dressings based on CS combined with nanoparticles, growth factors, lived cells, or medications released in a controlled manner positively impacts patient life by shorting the wound healing process.

The Role of Local Inflammation and Hypoxia in the Formation of Hypertrophic Scars-A New Model in the Duroc Pig

Hypertrophic scars continue to be a major burden, especially after burns. Persistent inflammation during wound healing appears to be the precipitating aspect in pathologic scarring. The lack of a standardized model hinders research from fully elucidating pathophysiology and therapy, as most therapeutic approaches have sparse evidence. The goal of this project was to investigate the mechanisms of scar formation after prolonged wound inflammation and to introduce a method for generating standardized hypertrophic scars by inducing prolonged inflammation. Four wound types were created in Duroc pigs: full-thickness wounds, burn wounds, and both of them with induced hyperinflammation by resiquimod. Clinical assessment (Vancouver Scar Scale), tissue oxygenation by hyperspectral imaging, histologic assessment, and gene expression analysis were performed at various time points during the following five months. Native burn wounds as well as resiquimod-induced full-thickness and burn wounds resulted in more hypertrophic scars than full-thickness wounds. The scar scale showed significantly higher scores in burn- and resiquimod-induced wounds compared with full-thickness wounds as of day 77. These three wound types also showed relative hypoxia compared with uninduced full-thickness wounds in hyperspectral imaging and increased expression of HIF1a levels. The highest number of inflammatory cells was detected in resiquimod-induced full-thickness wounds with histologic features of hypertrophic scars in burn and resiquimod-induced wounds. Gene expression analysis revealed increased inflammation with only moderately altered fibrosis markers. We successfully created hypertrophic scars in the Duroc pig by using different wound etiologies. Inflammation caused by burns or resiquimod induction led to scars similar to human hypertrophic scars. This model may allow for the further investigation of the exact mechanisms of pathological scars, the role of hypoxia and inflammation, and the testing of therapeutic approaches.

Smurf2 Regulates Inflammation and Collagen Processing in Cutaneous Wound Healing through Transforming Growth Factor-β/Smad3 Signaling

Wound healing is a highly conserved process that restores the integrity and functionality of injured tissues. Transforming growth factor (TGF)-β is a master regulator of wound healing, whose signaling is attenuated by the E3 ubiquitin ligase Smurf2. Herein, the roles of Smurf2 in cutaneous wound healing were examined using a murine incisional cutaneous model. Loss of Smurf2 increased early inflammation in the wounds and led to narrower wounds with greater breaking strength. Loss of Smurf2 also led to more linearized collagen bundles in normal and wounded skin. Gene expression analyses by real-time quantitative PCR indicated that Smurf2-deficient fibroblasts had increased levels of TGF-β/Smad3 signaling and changes in expression profile of genes related to matrix turnover. The effect of Smurf2 loss on wound healing and collagen bundling was attenuated by the heterozygous loss of Smad3. Together, these results show that Smurf2 affects inflammation and collagen processing in cutaneous wounds by down-regulating TGF-β/Smad3 signaling.

Activin A Modulates Betaglycan Shedding via the ALK4-SMAD3-Dependent Pathway in Endometriotic Cells

The TGF-β superfamily members, activins and inhibins, are mainly involved in cell proliferation, cell survival, invasion, immune surveillance, and lesion growth in endometriosis. Herein, we investigated the modulation of the TGF-β type III receptor (betaglycan or BG) by activin A and inhibin A in endometriosis in vitro. Often, BG undergoes ectodomain shedding releasing soluble BG (sBG) which frequently antagonizes TGF-β signaling. The effects of activin A on BG shedding and signaling pathways involved were evaluated with the inhibitors LY364947 and SIS3, siRNA knockdown in human endometrial cells (12Z, THESC, Ishikawa, and primary stromal cells) and were quantified with BG ELISAs. The effects of activin A and inhibin A on the secretion of MMP2 and MMP3 were analyzed using ELISAs. The effects of activin A on the BG expression were analyzed using RT-qPCR and western blot. The CCK-8 and BrdU assays were used to evaluate the effects of the recombinant BG on cell viability and proliferation. Activin A stimulation resulted in a significant time- and dose-dependent reduction in BG shedding, which was found to be activin A/ALK-4/SMAD3- but not SMAD2-dependent. Activin A increased the BG mRNA expression but had no effect on the protein expression. Likewise, inhibin A was found to block BG shedding. Activin A, but not inhibin A, significantly enhanced the secretion of MMP2 and MMP3. The recombinant BG had no effect on the viability and proliferation of endometriotic cells. Together, these observations support a novel role for activin A with BG in modulating the TGF-β superfamily ligands in endometrial cells in vitro.

Influence of Transforming Growth Factors beta 1 and beta 3 in the Scar Formation Process

BACKGROUND

Transforming growth factor-beta (TGF-β) plays an instrumental role in forming scars and keloids. TGF-β isoforms exhibit differential expression, indicating distinct wound healing and scar formation functions. However, the role of TGF-β1 and TGF-β3 in wound healing and scar formation remains unclear. This study aimed to compare the specific roles of TGF-β1 and TGF-β3 in wound healing and scar formation by biomolecular analysis.

MATERIALS AND METHODS

The study was conducted by cell isolation and culture cells from a total of 20 human samples. Normal human fibroblasts (NHF) were isolated from normal human samples and myofibroblasts from the different scar types, namely hypertrophic (HT) and keloid (K) scars. NHF and cells from the HT, and K scar, each of which were divided into 3 sample groups: the untreated control, TGF-β1 (10 µg/mL)-treated group, and TGF-β3 (10 µg/mL)-treated group. The results of confocal microscopy and fluorescence-activated cell sorting experiments were compared.

RESULTS

Both the HT and K groups had higher α-smooth muscle actin (α-SMA) expression than the NHF group in the untreated control group. In comparison with the untreated group, NHFs showed a significant increase in α-SMA expression in the TGF-β1-treated group. HT showed a high α-SMA level, which was statistically significant compared with the normal fibroblasts. In the TGF-β3-treated group, α-SMA expression was slightly increased in NHF as compared with the untreated group. TGF-β3 treated HT exhibited a greater reduction in α-SMA expression than in the TGF-β1 treated HT. K, on the other hand, had only a minimal effect on the treatment of TGF-β1 and TGF-β3.

CONCLUSIONS

The findings suggest that TGF-β3 may play a regulatory role in the wound repair process, which could be useful in the development of scar-reducing therapies for patients with scar-related cosmetic concerns.

Immunohistochemical expression of Axin-2, as an implication of the role of stem cell in scar pathogenesis and prognosis

BACKGROUND

Wound healing is a multi-phased process. A disruption in these phases could result in a persistent wound or an atypical scar. Wounding activates wingless proteins (Wnt) signaling, which aids in the healing process. Axis inhibition protein-2 regulates a variety of cellular activities through the Wnt and other pathways.

AIM

To assess the role of Axin-2 in patients with abnormal scars, using immunohistochemical study.

METHODS

This case-control study enrolled a total of 60 participants: 30 patients with abnormal scars (12 hypertrophic scars, 13 atrophic scars, and 5 keloid scars) and 30 age, sex, and site matched, apparently healthy controls. For immunohistochemistry examination of Axin-2 expression, skin samples were obtained from (i) lesional and (ii) perilesional skin of patients with aberrant scars, as well as (iii) normal control's skin.

RESULTS

Epidermal Axin-2 expression positivity, cellular topography, intensity, and H score showed significant differences between the groups (p < 0.05). In the dermis (fibroblast/myofibroblast), there were significant differences in Axin-2 expression positivity, location, intensity, and H score (p < 0.001 for all). The epidermal Axin-2 H score and the Manchester scale had a significant positive correlation (r = 0.832, p = 0.001). The epidermal Axin-2 H score and age (r = -0.576, p = 0.001), and the Stony Brook scale (r = -0.419, p = 0.021), had significant negative correlations.

CONCLUSION

Axin-2 overexpression might be accused in pathogenesis of abnormal scar and clinical worse scar outcome. In order to deprive scars of their regenerative cell pools, future scar therapies may target Axin-2 as a stem cell marker.

Transforming growth factor-β in tumour development

Transforming growth factor-β (TGFβ) is a ubiquitous cytokine essential for embryonic development and postnatal tissue homeostasis. TGFβ signalling regulates several biological processes including cell growth, proliferation, apoptosis, immune function, and tissue repair following injury. Aberrant TGFβ signalling has been implicated in tumour progression and metastasis. Tumour cells, in conjunction with their microenvironment, may augment tumourigenesis using TGFβ to induce epithelial-mesenchymal transition, angiogenesis, lymphangiogenesis, immune suppression, and autophagy. Therapies that target TGFβ synthesis, TGFβ-TGFβ receptor complexes or TGFβ receptor kinase activity have proven successful in tissue culture and in animal models, yet, due to limited understanding of TGFβ biology, the outcomes of clinical trials are poor. Here, we review TGFβ signalling pathways, the biology of TGFβ during tumourigenesis, and how protein quality control pathways contribute to the tumour-promoting outcomes of TGFβ signalling.

Characterization of Polyphenolic Compounds from Bacopa procumbens and Their Effects on Wound-Healing Process

Wounds represent a medical problem that contributes importantly to patient morbidity and to healthcare costs in several pathologies. In Hidalgo, Mexico, the Bacopa procumbens plant has been traditionally used for wound-healing care for several generations; in vitro and in vivo experiments were designed to evaluate the effects of bioactive compounds obtained from a B. procumbens aqueous fraction and to determine the key pathways involved in wound regeneration. Bioactive compounds were characterized by HPLC/QTOF-MS, and proliferation, migration, adhesion, and differentiation studies were conducted on NIH/3T3 fibroblasts. Polyphenolic compounds from Bacopa procumbens (PB) regulated proliferation and cell adhesion; enhanced migration, reducing the artificial scratch area; and modulated cell differentiation. PB compounds were included in a hydrogel for topical administration in a rat excision wound model. Histological, histochemical, and mechanical analyses showed that PB treatment accelerates wound closure in at least 48 h and reduces inflammation, increasing cell proliferation and deposition and organization of collagen at earlier times. These changes resulted in the formation of a scar with better tensile properties. Immunohistochemistry and RT-PCR molecular analyses demonstrated that treatment induces (i) overexpression of transforming growth factor beta (TGF-β) and (ii) the phosphorylation of Smad2/3 and ERK1/2, suggesting the central role of some PB compounds to enhance wound healing, modulating TGF-β activation.

TGF-β at the crossroads of multiple prognosis in breast cancer, and beyond

Transforming growth factor β (TGF-β), a pluripotent cytokine and a multifunctional growth factor has a crucial role in varied biological mechanisms like invasion, migration, epithelial-mesenchymal transition, apoptosis, wound healing, and immunosuppression. Moreover, it also has an imperative role both in normal mammary gland development as well as breast carcinogenesis. TGF-β has shown to have a paradoxical role in breast carcinogenesis, by transitioning from a growth inhibitor to a growth promoter with the disease advancement. The inter-communication and crosstalk of TGF-β with different signaling pathways has strengthened the likelihood to explore it as a comprehensive biomarker. In the last two decades, TGF-β has been studied extensively and has been found to be a promising biomarker for early detection, disease monitoring, treatment selection, and tumor progression making it beneficial for disease management. In this review, we focus on the signaling pathways and biological activities of the TGF-β family in breast cancer pathogenesis and its role as a circulatory and independent biomarker for breast cancer progression and metastasis. Moreover, this review highlights TGF-β as a drug target, and the underlying mechanisms through which it is involved in tumorigenesis that will aid in the development of varied therapies targeting the different stages of breast cancer.

FGF-2 enhances fibrogenetic changes in TGF-β2 treated human conjunctival fibroblasts

The objective of the current study was to examine the effects of fibroblast growth factor-2 (FGF-2) on conjunctival fibrogenesis that was induced by the presence of transforming growth factor-β2 (TGF-β2). Two-dimension (2D) and three-dimension (3D) cultured human conjunctival fibroblasts (HconF) were used for this purpose. The 2D and 3D cultured HconF were characterized by transendothelial electrical resistance (TEER) and FITC dextran permeability measurements (2D), real-time metabolic analyses (2D), size and stiffness measurements (3D), and the mRNA expression of extracellular matrix molecules, their modulators, Tissue inhibitor of metalloproteinases and matrix metalloproteinases and ER-stress related genes (2D and 3D). FGF-2 significantly increased planar proliferation, as evidenced by TEER values and FITC dextran permeability, and shifted glucose metabolism to the energetic phenotype of 2D HconF cells, and the stiffness of the 3D spheroids, and these effects were further enhanced in the presence of TGF-β2. Analyses of the expression of possible candidate molecules involved in cell architecture and stress indicated that some additive effects caused by both factors were also recognized in some of these molecules. The findings reported herein indicate that the FGF-2, either along or additively with TGF- β2 increased the fibrogenetic changes on the plane as well as in the spatial space of HconF cells.

Electrospun Chitosan-Polyvinyl Alcohol Nanofiber Dressings Loaded with Bioactive Ursolic Acid Promoting Diabetic Wound Healing

The design and development of novel dressing materials are urgently required for the treatment of chronic wounds caused by diabetic ulcers in clinics. In this study, ursolic acid (UA) extracted from Chinese herbal plants was encapsulated into electrospun nanofibers made from a blend of chitosan (CS) and polyvinyl alcohol (PVA) to generate innovative CS-PVA-UA dressings for diabetic wound treatment. The as-prepared CS-PVA-UA nanofiber mats exhibited randomly aligned fiber morphology with the mean fiber diameters in the range of 100-200 nm, possessing great morphological resemblance to the collagen fibrils which exist in the native skin extracellular matrix (ECM). In addition, the CS-PVA-UA nanofiber mats were found to possess good surface hydrophilicity and wettability, and sustained UA release behavior. The in vitro biological tests showed that the high concentration of UA could lead to slight cytotoxicity. It was also found that the CS-PVA-UA nanofiber dressings could significantly reduce the M1 phenotypic transition of macrophages that was even stimulated by lipopolysaccharide (LPS) and could effectively restore the M2 polarization of macrophages to shorten the inflammatory period. Moreover, the appropriate introduction of UA into CS-PVA nanofibers decreased the release levels of TNF-α and IL-6 inflammatory factors, and suppressed oxidative stress responses by reducing the generation of reactive oxygen species (ROS) as well. The results from mouse hepatic hemorrhage displayed that CS-PVA-UA nanofiber dressing possessed excellent hemostatic performance. The in vivo animal experiments displayed that the CS-PVA-UA nanofiber dressing could improve the closure rate, and also promote the revascularization and re-epithelization, as well as the deposition and remodeling of collagen matrix and the regeneration of hair follicles for diabetic wounds. Specifically, the mean contraction rate of diabetic wounds using CS-PVA-UA nanofiber dressing could reach 99.8% after 18 days of treatment. In summary, our present study offers a promising nanofibrous dressing candidate with multiple biological functions, including anti-inflammation, antioxidation, pro-angiogenesis, and hemostasis functions, for the treatment of hard-to-heal diabetic wounds.

Exosomes released by melanocytes modulate fibroblasts to promote keloid formation: a pilot study

Keloids are a common type of pathological scar as a result of skin healing, which are extremely difficult to prevent and treat without recurrence. The pathological mechanism of keloids is the excessive proliferation of fibroblasts, which synthesize more extracellular matrices (ECMs), including type I/III collagen (COL-1/3), mucopolysaccharides, connective tissue growth factor (CTGF, also known as cellular communication network factor 2 (CCN2)), and fibronectin (FN) in scar tissue, mostly through the abnormal activation of transforming growth factor-‍β (TGF-‍β)/Smads pathway (Finnson et al., 2013; Song et al., 2018). Genetic factors, including race and skin tone, are considered to contribute to keloid formation. The reported incidence of keloids in black people is as high as 16%, whereas white people are less affected. The prevalence ratio of colored people to white people is 5:1‍‍-‍‍15:1 (Rockwell et al., 1989; LaRanger et al., 2019). In addition, keloids have not been reported in albinism patients of any race, and those with darker skin in the same race are more likely to develop this disease (LaRanger et al., 2019). Skin melanocyte activity is significantly different among people with different skin tones. The more active the melanocyte function, the more melanin is produced and the darker the skin. Similarly, in the same individual, the incidence of keloids increases during periods when melanocytes are active, such as adolescence and pregnancy. Keloids rarely appear in areas where melanocytes synthesize less melanin, such as in the palms and soles. Thus, the formation of keloids seems to be closely related to melanocyte activity.

A Randomized Controlled Trial on the Effect of Local Insulin Glargine on Venous Ulcer Healing

INTRODUCTION

To determine whether the local administration of insulin glargine compared with placebo in nondiabetic patients with venous ulcers (VUs) leads to increased wound healing.

METHODS

A randomized controlled trial using a split-plot design was performed in 36 adults with leg VUs >25 cm² and more than 3 mo of evolution. Each hemi-wound received either 10 UI insulin glargine or saline solution once a day for 7 d. Size of the wounds, thermal asymmetry, the number of blood vessels, and the percentage area of collagen content in wound biopsies were assessed at baseline and after 7 d of treatment. Blood capillary glucose was monitored once a day after the insulin injection.

RESULTS

After 7 d of treatment, the hemi-wounds treated with insulin glargine were significantly smaller, had less thermal asymmetry, more blood vessels, and more collagen content than the saline-treated side. Correlation between thermal asymmetry and the number of blood vessels was also found (r² = 66.2, P < 0.001). No patient presented capillary glucose levels ≤3.3 mmol/L nor any adverse effects.

CONCLUSIONS

In nondiabetic patients with chronic VUs, the topical administration of insulin glargine seems to be safe and promotes wound healing and tissue repair after 7 d of treatment.

Modified hyaluronic acid-collagen matrices trigger efficient gene transfer and prohealing behavior in fibroblasts for improved wound repair

Growth factor therapy has demonstrated great promise for chronic wound repair, but controlling growth factor activity and cell phenotype over desired time frames remains a critical challenge. In this study, we developed a gene-activated hyaluronic acid-collagen matrix (GAHCM) comprising DNA/polyethylenimine (PEI) polyplexes retained on hyaluronic acid (HA)-collagen hydrogels using collagen mimetic peptides (CMPs). We hypothesized that manipulating both the number of CMP-collagen tethers and the ECM composition would provide a powerful strategy to control growth factor gene transfer kinetics while regulating cell behavior, resulting in enhanced growth factor activity for wound repair. We observed that polyplexes with 50% CMP-modified PEI (50 CP) showed enhanced retention of polyplexes in HCM hydrogels by 2.7-fold as compared to non-CMP modified polyplexes. Moreover, the incorporation of HA in the hydrogel promoted a significant increase in gene transfection efficiency based upon analysis of Gaussia luciferase (GLuc) reporter gene expression, and gene expression could be attenuated by blocking HA-CD44 signaling. Furthermore, when fibroblasts were exposed to vascular endothelial growth factor-A (VEGF-A)-GAHCM, the 50 CP matrix facilitated sustained VEGF-A production for up to 7 days, with maximal expression at day 5. Application of these VEGF-A-50 CP samples stimulated prolonged pro-healing responses, including the TGF-β1-induced myofibroblast-like phenotypes and enhanced closure of murine splinted wounds. Overall, these findings demonstrate the use of ECM-based materials to stimulate efficient gene transfer and regulate cellular phenotype, resulting in improved control of growth factor activity for wound repair. GAHCM have significant potential to overcome key challenges in growth factor therapy for regenerative medicine. STATEMENT OF SIGNIFICANCE: Despite great promise for growth factor therapies in wound treatment, controlling growth factor activity and providing a microenvironment for cells that maximizes growth factor signaling have continued to limit the success of existing formulations. Our GAHCM strategy, combining CMP gene delivery and hyaluronic acid-collagen matrix, enabled enhanced wound healing efficacy via the combination of controlled and localized growth factor expression and matrix-mediated regulation of cell behavior. Incorporation of CMPs and HA in the same matrix synergistically enhanced VEGF activity as compared with simpler matrices. Accordingly, GAHCM will advance our ability to leverage growth factor signaling for wound healing, resulting in new long-term treatments for recalcitrant wounds.

Comparative studies on the effect of pig adipose-derived stem cells (pASCs) preconditioned with hypoxia or normoxia on skin wound healing in mice

Adipose-derived stem cells (ASCs) from human and animal fat have emerged as therapeutic alternatives for damaged tissues. Pre-conditioning of ASCs with hypoxia results in their functional enhancement, which might facilitate the process of healing. However, there is still a critical need for large-scale preclinical studies to reinforce the translation of these findings into clinical practice for humans and in veterinary medicine. Here, we adapted a full-thickness excisional skin wound mouse model to evaluate and compare the effect of pig adipose-derived stem cells (pASCs) cultured under normoxia (pASCs-Nor) or hypoxia (pASCs-Hyp) on the healing process. We show that pASCs-Hyp accelerated re-epithelialization, increased hyaluronic acid (HA) content, and decreased scar elevation index (SEI) during the late stage of healing (day 21). Transplantation of pASCs-Hyp also promoted expression of angiogenic marker VegfA and decreased levels of pro-scarring Tgfβ1. Mice tolerated xenotransplantation of the pASCs with no impact on macrophage (CD68 -positive cell) content. However, wounds treated with pASCs-Hyp exhibited decreased elasticity at the early stage of healing and increased expression of Wnt signaling members including Wnt10a, Wnt11, and β-catenin, which are associated with scar-forming wound repair. In conclusion, pASCs treatment may provide a critical step toward the evaluation of pASCs as therapeutically relevant cells in the context of wound healing.