Basic Fibroblast Growth Factor in Scarless Wound Healing

Concomitant heparin use promotes skin graft donor site healing by basic fibroblast growth factor: A pilot prospective randomized controlled study

Owing to its mitogenic and angiogenic characteristics, the use of basic fibroblast growth factor (bFGF) to promote wound healing has been investigated. However, its clinical efficacy has fallen short of expectations due to its instability. Heparin has been reported to stabilize bFGF. Therefore, we hypothesized that the combination of these agents would more effectively promote wound healing than bFGF alone; a single-center, two-arm parallel, single-blind, and a prospective randomized controlled pilot study was therefore performed involving 12 patients who underwent split-thickness skin graft harvesting. To ensure a feasible clinical treatment model, commercially available agents were used. The patients were randomly assigned to either the control group treated with bFGF (n = 6) or the intervention group treated with bFGF and heparin (n = 6) in a 1:1 ratio. The wound area and the wound area variation was assessed each week postoperatively, as was the number of days required for epithelialization. As a supplementary analysis, the least-squares means were calculated using a linear mixed-effects model. The results of this study indicate that the combination of bFGF and heparin may more effectively promote wound healing than bFGF alone, consistent with our hypothesis. A multicenter trial based on these data is ongoing.

Modulation of gene expression in skin wound healing by photobiomodulation therapy: A systematic review in vivo studies

BACKGROUND

Wound healing is a multistep process involving coordinated responses of a variety of cell types, cytokines, growth factors, and extracellular matrix (ECM) components leading to the physiological restoration of tissue integrity. Photobiomodulation therapy (PBMT) has been highlighted as an approach to improve the healing process, nonetheless at the molecular level, the effects of PBMT are not entirely understood.

AIM

To systematically review publications that investigated gene expression after PBMT during in vivo skin repair.

METHODS

An electronic search was undertaken in Medline Ovid (Wolters Kluwer), PubMed (National Library of Medicine), Web of Science (Thomson Reuters), Scopus (Elsevier), Embase, and LILACS databases. The search strategy was conducted from the terms: low-level light therapy, gene expression, and wound healing and their synonyms. The databases were consulted in December 2023 and no publication year limit was used.

RESULTS

Eleven studies were included in this review and the expression of 186 genes was evaluated. PBMT modified the expression of several targets genes studied, such as down-regulation of genes related to extracellular matrix proteases (MMP2 and MMP9) and pro-inflammatory cytokines (IL10 and IL6) and up-regulation of DNMT3A and BFGF.

CONCLUSION

This review demonstrates that PBMT is capable of regulating gene expression during wound healing. Most evidence showed a positive impact of PBMT in regulating genes linked to inflammatory cytokines improving skin wound healing. Yet, the effects of PBMT in genes involved in other mechanisms still need to be better understood.

All-in-one hydrogel patches with sprayed bFGF-loaded GelMA microspheres for infected wound healing studies

The current wound healing process faces numerous challenges such as bacterial infection, inflammation and oxidative stress. However, wound dressings used to promote wound healing, are not well suited to meet the clinical needs. Hyaluronic acid (HA) not only has excellent water absorption and good biocompatibility but facilitates cell function and tissue regeneration. Dopamine, on the other hand, increases the overall viscosity of the hydrogel and possesses antioxidant property. Furthermore, chitosan exhibits outstanding performance in antimicrobial, anti-inflammatory and antioxidant activities. Basic fibroblast growth factor (bFGF) is conducive to cell proliferation and migration, vascular regeneration and wound healing. Hence, we designed an all-in-one hydrogel patch containing dopamine and chitosan framed by hyaluronic acid (HDC) with sprayed gelatin methacryloyl (GelMA) microspheres loaded with bFGF (HDC-bFGF). The hydrogel patch exhibits excellent adhesive, anti-inflammatory, antioxidant and antibacterial properties. In vitro experiments, the HDC-bFGF hydrogel patch not only showed significant inhibitory effect on RAW cell inflammation and Staphylococcus aureus (S. aureus) growth but also effectively scavenged free radicals, in addition to promoting the migration of 3 T3 cells. In the mice acute infected wound model, the HDC-bFGF hydrogel patch adhered to the wound surface greatly accelerated the healing process via its anti-inflammatory and antioxidant activities, bacterial inhibition and pro-vascularization effects. Therefore, the multifunctional HDC-bFGF hydrogel patch holds great promise for clinical application.

Electrospray Nano-Micro Composite Sodium Alginate Microspheres with Shape-Adaptive, Antibacterial, and Angiogenic Abilities for Infected Wound Healing

Nonhealing infectious wounds, characterized by bacterial colonization, wound microenvironment destruction, and shape complexity, present an intractable problem in clinical practice. Inspired by LEGOs, building-block toys that can be assembled into desired shapes, we proposed the use of electrospray nano-micro composite sodium alginate (SA) microspheres with antibacterial and angiogenic properties to fill irregularly shaped wounds instantly. Specifically, porous poly(lactic-co-glycolic acid) (PLGA) microspheres (MSs) encapsulating basic fibroblast growth factor (bFGF) were produced by a water-in-oil-in-water double-emulsion method. Then, bFGF@MSs were blended with the SA solution containing ZIF-8 nanoparticles. The resultant solution was electrosprayed to obtain nano-micro composite microspheres (bFGF@MS/ZIF-8@SAMSs). The composite MSs' size could be regulated by PLGA MS mass proportion and electrospray voltage. Moreover, bFGF, a potent angiogenic agent, and ZIF-8, bactericidal nanoparticles, were found to release from bFGF@MS/ZIF-8@SAMSs in a controlled and sustainable manner, which promoted cell proliferation, migration, and tube formation and killed bacteria. Through experimentation on rat models, bFGF@MS/ZIF-8@SAMSs were revealed to adapt to wound shapes and accelerate infected wound healing because of the synergistic effects of antibacterial and angiogenic abilities. In summation, this study developed a feasible approach to prepare bioactive nano-micro MSs as building blocks that can fill irregularly shaped infected wounds and improve healing.

Preparation and characterization of PVA/chitosan nanofibers loaded with Dragon's blood or poly helixan as wound dressings

Nanofibers have been investigated in regenerative medicine. Dragon's blood (DB)- and poly helixan PF (PHPF) are natural materials used in cosmetics. Herein, we generated DB- and PHPF-loaded polyvinyl alcohol/chitosan (PVA/CS/DB and PVA/CS/PHPF, respectively) nanofibers. PVA/CS/DB and PVA/CS/PHPF nanofibers had an average diameter of 547.5 ± 17.13 and 521 ± 24.67 nm, respectively as assessed by SEM, and a degradation rate of 43.1 and 47.6 % after 14 days, respectively. PVA/CS/DB and PVA/CS/PHPF nanofibers had a hemolysis rate of 0.10 and 0.39 %, respectively, and a water vapor transmission rate of ∼2200 g.m-2.day-1. These nanofibers exhibited favorable antimicrobial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus subtilis in vitro. PVA/CS/DB and PVA/CS/PHPF nanofibers demonstrated a sustained release of 77.91 and 76.55 % over 72 h. PVA/CS/DB and PVA/CS/PHPF nanofibers had a high rate of cytocompatibility and significantly improved the viability of NIH/3T3 cells as compared with free drugs or unloaded nanofibers. Histological inspection via H&E and Verhoeff's staining demonstrated PVA/CS/DB and PVA/CS/PHPF nanofibers enhanced the wound healing and damaged tissue recovery of unsplinted wound models by promoting epithelial layer formation, collagen deposition, and enhancing the presence of fibroblasts. Conclusively, PVA/CS/DB and PVA/CS/PHPF can be introduced as potential wound dressing candidates with favorable properties.

Bioactive nanomaterials kickstart early repair processes and potentiate temporally modulated healing of healthy and diabetic wounds

Slow-healing and chronic wounds represent a major global economic and medical burden, and there is significant unmet need for novel therapies which act to both accelerate wound closure and enhance biomechanical recovery of the skin. Here, we report a new approach in which bioactives that augment early stages of wound healing can kickstart and engender effective wound closure in healthy and diabetic, obese animals, and set the stage for subsequent tissue repair processes. We demonstrate that a nanomaterial dressing made of silk fibroin and gold nanorods (GNR) stimulates a pro-neutrophilic, innate immune, and controlled inflammatory wound transcriptomic response. Further, Silk-GNR, lasered into the wound bed, in combination with exogeneous histamine, accelerates early-stage processes in tissue repair leading to effective wound closure. Silk-GNR and histamine enhanced biomechanical recovery of skin, increased transient neoangiogenesis, myofibroblast activation, epithelial-to-mesenchymal transition (EMT) of keratinocytes and a pro-resolving neutrophilic immune response, which are hitherto unknown activities for these bioactives. Predictive and temporally coordinated delivery of growth factor nanoparticles that modulate later stages of tissue repair further accelerated wound closure in healthy and diabetic, obese animals. Our approach of kickstarting healing by delivering the "right bioactive at the right time" stimulates a multifactorial, pro-reparative response by augmenting endogenous healing and immunoregulatory mechanisms and highlights new targets to promote tissue repair.

MicroRNA-155 mediates multiple gene regulations pertinent to the role of human adipose-derived mesenchymal stem cells in skin regeneration

Introduction: The role of Adipose-derived mesenchymal stem cells (AD-MSCs) in skin wound healing remains to be fully characterized. This study aims to evaluate the regenerative potential of autologous AD-MSCs in a non-healing porcine wound model, in addition to elucidate key miRNA-mediated epigenetic regulations that underlie the regenerative potential of AD-MSCs in wounds. Methods: The regenerative potential of autologous AD-MSCs was evaluated in porcine model using histopathology and spatial frequency domain imaging. Then, the correlations between miRNAs and proteins of AD-MSCs were evaluated using an integration analysis in primary human AD-MSCs in comparison to primary human keratinocytes. Transfection study of AD-MSCs was conducted to validate the bioinformatics data. Results: Autologous porcine AD-MSCs improved wound epithelialization and skin properties in comparison to control wounds. We identified 26 proteins upregulated in human AD-MSCs, including growth and angiogenic factors, chemokines and inflammatory cytokines. Pathway enrichment analysis highlighted cell signalling-associated pathways and immunomodulatory pathways. miRNA-target modelling revealed regulations related to genes encoding for 16 upregulated proteins. miR-155-5p was predicted to regulate Fibroblast growth factor 2 and 7, C-C motif chemokine ligand 2 and Vascular cell adhesion molecule 1. Transfecting human AD-MSCs cell line with anti-miR-155 showed transient gene silencing of the four proteins at 24 h post-transfection. Discussion: This study proposes a positive miR-155-mediated gene regulation of key factors involved in wound healing. The study represents a promising approach for miRNA-based and cell-free regenerative treatment for difficult-to-heal wounds. The therapeutic potential of miR-155 and its identified targets should be further explored in-vivo.

Advances in the role and mechanism of fibroblasts in fracture healing

With the development of social population ageing, bone fracture has become a global public health problem due to its high morbidity, disability and mortality. Fracture healing is a complex phenomenon involving the coordinated participation of immigration, differentiation and proliferation of inflammatory cells, angioblasts, fibroblasts, chondroblasts and osteoblasts which synthesize and release bioactive substances of extracellular matrix components, Mortality caused by age-related bone fractures or osteoporosis is steadily increasing worldwide as the population ages. Fibroblasts play an important role in the process of fracture healing. However, it is not clear how the growth factors and extracellular matrix stiffness of the bone-regeneration microenvironment affects the function of osteoblasts and fibroblasts in healing process. Therefore, this article focuses on the role of fibroblasts in the process of fracture healing and mechanisms of research progress.

Microneedle fractional radiofrequency associated with drug delivery for facial atrophic acne scars and skin rejuvenation

Microneedle fractional radiofrequency (MFRF) has been used to improve photoaging and scars. This study aimed to evaluate the efficacy and safety of MFRF with basic fibroblast growth factor (bFGF) for facial atrophic acne scars and skin rejuvenation by blinded visual evaluation, self-report, and reflective confocal microscopy (RCM). Fifteen subjects were randomized to the MFRF with bFGF group and fifteen to the MFRF group. All subjects underwent three-session therapy and a follow-up period. Significant group differences were in ECCA, global improvement score, satisfaction, and downtime before and after treatment. Combination therapy could be more effective than monotherapy for acne scars and facial rejuvenation. In addition, RCM can be used to observe the changes in skin collagen before and after treatment in evaluating cosmetic efficacy.

Encapsulation of HaCaT Secretome for Enhanced Wound Healing Capacity on Human Dermal Fibroblasts

In the epidermal and dermal layers of the skin, diverse cell types are reconstituted during the wound healing process. Delays or failures in wound healing are a major issue in skin therapy because they prevent the normal structure and function of wounded tissue from being restored, resulting in ulceration or other skin abnormalities. Human immortalized keratinocytes (HaCAT) cells are a spontaneously immortalized human keratinocyte cell line capable of secreting many bioactive chemicals (a secretome) that stimulate skin cell proliferation, rejuvenation, and regeneration. In this study, the HaCaT secretome was encapsulated with polyesters such as poly (lactic-co-glycolic acid) (PLGA) and cassava starch in an effort to maximize its potential. According to the estimated mechanism of the HaCaT secretome, all treatments were conducted on immortalized dermal fibroblast cell lines, a model of wound healing. Encapsulation of HaCaT secretome and cassava starch enhanced the effectiveness of cell proliferation, migration, and anti-aging. On the other hand, the levels of reactive oxygen species (ROS) were lowered, activating antioxidants in immortalized dermal fibroblast cells. The HaCaT secretome induced in a dose-dependent manner the expression of antioxidant-associated genes, including SOD, CAT, and GPX. Six cytokines, including CCL2 and MCP-1, influenced immunoregulatory and inflammatory processes in cultured HaCAT cells. HaCaT secretome encapsulated in cassava starch can reduce ROS buildup by boosting antioxidant to stimulate wound healing. Hence, the HaCaT secretome may have a new chance in the cosmetics business to develop components for wound prevention and healing.

Application of polyglycolic acid sheets and basic fibroblast growth factor to prevent esophageal stricture after endoscopic submucosal dissection in pigs

BACKGROUND

Endoscopic submucosal dissection (ESD) has been the first-line treatment for early-stage esophageal cancer. However, it often causes postoperative stricture in cases requiring wide dissection. Basic fibroblast growth factor (bFGF) reportedly has anti-scarring effects during cutaneous wound healing. We hypothesized that suppressing myofibroblast activation will prevent stricture after esophageal ESD.

METHODS

We resected a complete porcine esophagus circumference section by ESD. To investigate the preventive effect of bFGF on esophageal stricture formation after ESD, we endoscopically applied bFGF-soaked poly-glycolic acid (PGA) sheets onto the wound bed after ESD and fixed them by spraying fibrin glue (PGA + bFGF group), PGA sheets alone onto the wound bed and fixed them by spraying fibrin glue (PGA group), or nothing (control group). After removing the esophagus on day 22, we evaluated the mucosal constriction rate.

RESULTS

Compared with those in the control group, esophageal stricture was significantly reduced in the PGA + bFGF group, and the areas stained with α-SMA and calponin-1 antibodies were significantly inhibited in the PGA + bFGF and PGA groups. The thickness of the fibrous layer in the PGA + bFGF group was uniform compared to that of the other groups. Thus, PGA + bFGF inhibited the development of unregulated fibroblasts in the acute phase, leading to uniform wound healing.

CONCLUSIONS

Stenosis after esophageal ESD is related to fibrosis in the acute phase. Administration of PGA and bFGF suppresses myofibroblast activation in the acute phase, thereby preventing esophageal constriction in pigs.

Concentrated Growth Factor (CGF): The Newest Platelet Concentrate and Its Application in Nasal Hyaluronic Acid Injection Complications

BACKGROUND

Several cases of wounds caused by vascular compromise after facial cosmetic injection have been reported in recent years. How to promote wound healing, restore facial appearance, and avoid secondary injury in such patients have remained a clinical challenge. Our study was designed to assess the effect of concentrated growth factor (CGF) for repairing nasal wounds after nasal hyaluronic acid injection.

METHODS

Six women with nasal wounds after hyaluronic acid injection were enrolled from June 2019 to June 2022. The average time of the first CGF treatment from admission was 2-4 days. CGF gel was prepared from each patient's blood by using a Medifuge™ system. After debridement of the wound, the prepared CGF gel was applied on the wound surface, and the wound dressing was fixed to stabilize the CGF gel. The CGF treatment interval was 3-4 days.

RESULTS

The wound began to heal after the first CGF treatment. After 2-3 CGF treatments, the wound was almost completely healed. There was no deflection of the nasal columella, and nasal ventilation function was good. There was no obvious deformity in the appearance of the nose. After follow-up ranging from 2 months to 1 year, the appearance and function of the nose showed satisfactory recovery.

CONCLUSIONS

CGF has great potential in promoting wound healing and restoring the appearance after complications from nasal hyaluronic acid injection. The preparation of CGF gel is simple, and the clinical application is convenient and safe. In future, more clinical trials are needed to further prove the efficacy and safety of CGF in the treatment of wounds secondary to cosmetic injection.

LEVEL OF EVIDENCE IV

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

Smart Dual-Sensor Wound Dressing for Monitoring Cutaneous Wounds

Managing slow-healing wounds and associated complications is challenging, time-consuming, and expensive. Systematic collection, analysis, and dissemination of correct wound status data are critical for enhancing healing outcomes and reducing complications. However, traditional data collection approaches are often neither accurate nor user-friendly and require diverse skill levels, resulting in the collection of inconsistent and unreliable data. As an advancement to the authors' previously developed hydrogel-based smart wound dressing, here is reported an enhanced integration of drug delivery and sensing (pH and glucose) modules for accelerated treatment and continuous monitoring of cutaneous wounds. In the current study, growth factor delivery modules and an array of colorimetric glucose sensors are incorporated into the dressing to promote wound healing and extend the dressing's utility for diabetic wound treatment. Furthermore, the efficacy of the wound dressing in monitoring infection and supporting wound healing via antibiotic and growth factor delivery is investigated in mice models. The updated dressing reveals excellent healing benefits on non-infected and infected wounds, as well as real-time monitoring and early detection of wound infection.

Prospective use of amniotic mesenchymal stem cell metabolite products for tissue regeneration

Chronic disease can cause tissue and organ damage constituting the largest obstacle to therapy which, in turn, reduces patients' quality-adjusted life-year. Degenerative diseases such as osteoporosis, Alzheimer's disease, Parkinson's disease, and infectious conditions such as hepatitis, cause physical injury to organs. Moreover, damage resulting from chronic conditions such as diabetes can also culminate in the loss of organ function. In these cases, organ transplantation constitutes the therapy of choice, despite the associated problems of immunological rejection, potential disease transmission, and high morbidity rates. Tissue regeneration has the potential to heal or replace tissues and organs damaged by age, disease, or trauma, as well as to treat disabilities. Stem cell use represents an unprecedented strategy for these therapies. However, product availability and mass production remain challenges. A novel therapeutic alternative involving amniotic mesenchymal stem cell metabolite products (AMSC-MP) has been developed using metabolites from stem cells which contain cytokines and growth factors. Its potential role in regenerative therapy has recently been explored, enabling broad pharmacological applications including various gastrointestinal, lung, bladder and renal conditions, as well as the treatment of bone wounds, regeneration and skin aging due to its low immunogenicity and anti-inflammatory effects. The various kinds of growth factors present in AMSC-MP, namely bFGF, VEGF, TGF-β, EGF and KGF, have their respective functions and activities. Each growth factor is formed by different proteins resulting in molecules with various physicochemical properties and levels of stability. This knowledge will assist in the manufacture and application of AMSC-MP as a therapeutic agent.

Evaluation of the effect of a gel made with amniotic fluid formulation on the healing of diabetic foot ulcers: A triple-blind clinical trial

Aim

The aim of this study was to evaluate the effect of a gel made with amniotic fluid (AF) formulation on wound healing in diabetic foot ulcers.

Methods

This clinical trial was performed on 92 type 2 diabetic patients referring to the Diabetes Clinic of Golestan Hospital of Ahvaz, southwest of Iran in 2019-2020. Patients were randomly divided into three groups of intervention and one placebo group. The wounds of the three intervention groups were dressed with gauze impregnated with an AF formulation gel while wounds of the control group were dressed with plain gauze without any topical agent. Chi-square tests and generalized estimating equations (GEE) with a significance level of 0.05 were used to analyze the data.

Results

At the end of the eighth week of intervention, there was a statistically significant difference among the four groups in terms of wound grade, wound color, condition of the tissues surrounding the wound, the overall condition of the wound, and the duration of wound healing (P < 0.05).

Conclusions

Based on our experience with the patients in the present study, we believe that AF represents a useful and safe option for the treatment of chronic diabetic foot ulcers.

Clinical trial registration

https://en.irct.ir/trial/51551, Identifier: IRCT20201010048985N1.

Two-stage skin grafting using a basic fibroblast growth factor-impregnated artificial dermis

For traditional artificial dermises, a waiting period of approximately three weeks is required after the first implantation before they are adequately vascularized. The objective of this retrospective case series was to investigate whether full-thickness skin defects, requiring surgical reconstruction, could be successfully treated by implantation of a basic fibroblast growth factor (bFGF)-impregnated artificial dermis and secondary skin grafting with a shorter waiting period. Between January 2019 and January 2021, 19 skin defects in 14 patients (7 male and 7 female) were treated with two-stage skin grafting using bFGF-impregnated collagen-gelatin sponge (CGS). All of them were included in this case series, and the waiting period for skin grafting, success rate of skin grafting, infection during the waiting period, and scar quality 6–12 months postoperatively were retrospectively investigated. As a result, all skin grafting surgeries were successfully performed with a waiting period of 13.3 ± 4.3 days. Infection during the waiting period was observed in three lesions (15.8%); however, all infections were controllable. Postoperative scar quality was acceptable (Vancouver Scar Scale score range, 1–8). In conclusion, compared to traditional artificial dermises, bFGF-impregnated CGSs have the potential to shorten the waiting period without decreasing the success rate of skin grafting. Further studies are required to confirm this finding.

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We previously developed a novel artificial dermis which is capable of sustained release of bFGF.

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Skin defects were successfully treated by two-stage skin grafting using bFGF-impregnated CGS.

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The use of bFGF-impregnated CGS allowed for a short waiting period for secondary skin grafting.

A Novel Xenograft Model Demonstrates Human Fibroblast Behavior During Skin Wound Repair and Fibrosis

Objective: Xenografts of human skin in immunodeficient mice provide a means of assessing human skin physiology and its response to wounding. Approach: We describe a novel xenograft model using full-thickness human neonatal foreskin to examine human skin wound repair. Full-thickness 8 mm human neonatal foreskin biopsies were sutured into the dorsum of NOD scid gamma (NSG; NOD.Cg-Prkdc scidIl2rgtm1Wjl/SzJ) pups as subcutaneous grafts. At postnatal day 21 the subcutaneous grafts were exposed to cutaneous grafts. Following maturation of 2 months, xenografts were then wounded with 5 mm linear incisions and monitored until postwound day (PWD) 14 to study skin repair and fibrosis. To explore whether our model can be used to test the efficacy of topical therapies, wounded xenografts were injected with antifibrotic fibroblast growth factor 2 (FGF2) for the first four consecutive PWDs. Xenografts were harvested for analysis by histology and fluorescence-activated cell sorting (FACS). Results: Xenografts were successfully engrafted with evidence of mouse-human anastomoses and resembled native neonatal foreskin at the gross and microscopic level. Wounded xenografted skin scarred with human collagen and an expansion of CD26-positive human fibroblasts. Collagen scar was quantitated by neural network analysis, which revealed distinct clustering of collagen fiber networks from unwounded skin and wounded skin at PWD7 and PWD14. Collagen fiber networks within FGF2-treated wounds at PWD14 resembled those in untreated wounded xenografts at PWD7, suggesting that FGF2 treatment at time of wounding can reduce fibrosis. Innovation and Conclusion: This novel xenograft model can be used to investigate acute fibrosis, fibroblast heterogeneity, and the efficacy of antifibrotic agents during wound repair in human skin.

Stem Cell-Based Therapeutic Strategies in Diabetic Wound Healing

Impaired wound healing and especially the “all-too-common” occurrence of associated diabetic foot ulcers (DFU) are becoming an increasingly urgent and deteriorating healthcare issue, which drastically impact the quality of life and further heighten the risks of infection and amputation in patients with diabetes mellitus. Amongst the multifactorial wound healing determinants, glycemic dysregulation has been identified to be the primary casual factor of poor wound healing. Unfortunately, current therapeutic modalities merely serve as moderate symptomatic relieves but often fail to completely restore the wound site to its pre-injury state and prevent further recurrence. Stem cell-based therapeutics have been employed for its promising potential to address the root of the problem as they not only exhibit the capacity for self-renewal and differentiation towards multiple lineages, but also have been disclosed to participate in mediating variant growth factors and cytokines. Herein we review the current literatures on the therapeutic benefits of using various kinds of stem cells, including embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), mesenchymal stem cells (MSCs), and adipose-derived stem cells (ASCs) in diabetic wound healing by searching on the PubMed® Database for publications. This study shall serve as an overview of the current body of research with particular focus on autologous ASCs and the laboratory expandable iPSCs in hope of shedding more light on this attractive therapy so as to elevate the efficacy of wound healing that is almost always compromised in diabetic patients.

The Use of Quercetin to Improve the Antioxidant and Regenerative Properties of Frozen or Cryopreserved Human Amniotic Membrane

The biological properties of the human amniotic membrane (HAM) and its characteristic ability to be a reservoir of growth factors promoting wound healing make it an ideal biological dressing for the treatment of different clinical conditions, such as burns and non-healing wounds. However, the application of a preservation method on the HAM is required during banking to maintain biological tissue properties and to ensure the release overtime of protein content for its final clinical effectiveness after application on the wound bed. Although cryopreservation and freezing are methods widely used to maintain tissue properties, reactive oxygen species (ROS) are produced within tissue cellular components during their switching from frozen to thawed state. Consequently, these methods can lead to oxidative stress-induced cell injury, affecting tissue regenerative properties and its final clinical effectiveness. Taking advantage of the antioxidant activity of the natural compound quercetin, we used it to improve the antioxidant and regenerative properties of frozen or cryopreserved HAM tissues. In particular, we evaluated the oxidative damage (lipid peroxidation, malondialdehyde) as well as the regenerative/biological properties (bFGF growth factor release, wound healing closure, structure, and viability) of HAM tissue after its application. We identified the effectiveness of quercetin on both preservation methods to reduce oxidative damage, as well as its ability to enhance regenerative properties, while maintaining the unaltered structure and viability of HAM tissue. The use of quercetin described in this study appears able to counteract the side effects of cryopreservation and freezing methods related to oxidative stress, enhancing the regenerative properties of HAM. However, further investigations will need to be performed, starting from these promising results, to identify its beneficial effect when applied on burns or non-healing wounds.

Biomaterials-Based Regenerative Strategies for Skin Tissue Wound Healing

Skin tissue wound healing proceeds through four major stages, including hematoma formation, inflammation, and neo-tissue formation, and culminates with tissue remodeling. These four steps significantly overlap with each other and are aided by various factors such as cells, cytokines (both anti- and pro-inflammatory), and growth factors that aid in the neo-tissue formation. In all these stages, advanced biomaterials provide several functional advantages, such as removing wound exudates, providing cover, transporting oxygen to the wound site, and preventing infection from microbes. In addition, advanced biomaterials serve as vehicles to carry proteins/drug molecules/growth factors and/or antimicrobial agents to the target wound site. In this review, we report recent advancements in biomaterials-based regenerative strategies that augment the skin tissue wound healing process. In conjunction with other medical sciences, designing nanoengineered biomaterials is gaining significant attention for providing numerous functionalities to trigger wound repair. In this regard, we highlight the advent of nanomaterial-based constructs for wound healing, especially those that are being evaluated in clinical settings. Herein, we also emphasize the competence and versatility of the three-dimensional (3D) bioprinting technique for advanced wound management. Finally, we discuss the challenges and clinical perspective of various biomaterial-based wound dressings, along with prospective future directions. With regenerative strategies that utilize a cocktail of cell sources, antimicrobial agents, drugs, and/or growth factors, it is expected that significant patient-specific strategies will be developed in the near future, resulting in complete wound healing with no scar tissue formation.

Study on the action mechanism of the peptide compounds of Wuguchong on diabetic ulcers, based on UHPLC-Q-TOF-MS, network pharmacology and experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

Diabetic foot ulcers mainly refer to people who are initially diabetic and do not have peripheral neuropathy or peripheral vascular disease, but have developed foot infection, septicemia, and ulceration. Diabetic trauma disease is characterized by high sugar and very slow wound healing, which is the reason why some patients with severe diabetic trauma require amputation. Prolonged hyperglycemia can lead to changes in bodily functions and endocrine changes, which can lead to permeability damage of epidermal tissue structure, microvascular damage and, in more severe cases, nerve damage, which are also the main causes of diabetic trauma. Small molecule peptides have various biological activities, such as: lowering blood pressure, antibacterial and wound healing activities, etc. It is a drug recorded in classical Chinese medicine, it is safer to use natural active peptides to treat wounds compared to the listed drugs, and there are no side effects in its use.The wound healing effect of Wuguchong dry product has been confirmed but the mechanism is still unclear, whether it is related to the small molecule active peptides contained in it remains to be studied.

AIM OF STUDY

Objective To investigate the potential mechanism of the peptide compounds of Wuguchong (PCW) on diabetic wound healing and the relevant targets in the pathway associated with the treatment of diabetic ulcers using a systematic pharmacological and pharmacological experimental validation approach.

METHODS

1) PCW was prepared by enzymatic digestion of TCMW and analyzed by UHPLC-Q-TOF-MS. 2) Further screening of the active chemical components of PCW using PubChem, Swiss Target Prediction data. 3) Prediction of its targets using Drug Bank, CTD, and Genecards databases. 4) Construct protein/gene interactions network diagrams for PCWs acting by using Cytoscape 3.7.0 software. 5) GO and KEGG analysis of PCW targets were performed by David database. 6) Validated by AO/EB staining, scratching and in vitro tube formation methods. 7) Explored the mechanism of PCW to promote diabetic wound healing by protein blotting and immunohistochemical detection of relevant protein expression.

RESULTS

and finally: 1) After the above screening, 81 active ingredients of PCW and 94 targets acting on diabetic ulcers were obtained. 2) 30 biological processes, 30 cellular compositions and 30 molecular functions were obtained by GO analysis; 28 signaling pathways were obtained by KEGG analysis. 3) The results of AO/EB staining assay, scratch assay and in vitro tube-forming assay showed that PCW has significant pro-vascular endothelial cell proliferation and pro-angiogenic effects in vitro.

CONCLUSIONS

The results of this study confirmed the effect of the PCW in treating diabetic ulcers to a certain extent, and further revealed its mechanism of action in depth, which provides a new reference for the next step of Chinese medicine in treating diabetic ulcers.

Dual growth factor entrapped nanoparticle enriched alginate wafer-based delivery system for suppurating wounds

We have investigated the wound healing efficiency of calcium alginate wafer embedded with growth factor entrapped PLGA nanoparticle. Herein, vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) entrapped PLGA nanoparticles were synthesized and embedded in a sodium alginate gel by freeze-drying technique. The synthesized dressing exhibited a high degree of swelling and appropriate porosity. The scaffold was characterized by Scanning Electron Microscopy (SEM) showing a highly porous morphology. Also, incorporation of growth factor loaded nanoparticles in a wafer-based delivery system resulted in localized growth factor delivery at the site of the wound in a sustained manner. The biocompatibility of the scaffold was evaluated by MTT assay, which showed a higher cell proliferation in the proposed scaffold as compared to the control. In vivo wound healing efficiency of the scaffold was evaluated using a full thickness murine wound model, which showed improved re-epithelialization, collagen deposition, and angiogenesis. These results suggest the use of the scaffold as a promising wound dressing material.

Recent Progress on Heparin–Protamine Particles for Biomedical Application

Biomolecules are attractive building blocks with self-assembly ability, structural diversity, and excellent functionality for creating artificial materials. Heparin and protamine, a clinically relevant pair of biomolecules used in cardiac and vascular surgery, have been shown to coassemble into particulate polyelectrolyte complexes in vitro. The resulting heparin–protamine particles exhibit adhesive properties that enable advantageous interactions with proteins, cells, and various other substances and have been employed as functional materials for biomedical applications. In this review article, we summarize recent progress in research on the use of heparin–protamine particles as drug carriers, cell adhesives, and cell labels. Studies have demonstrated that heparin–protamine particles are potentially versatile in biomedical fields from drug delivery and regenerative medicine to plastic surgery.

Intravenous Infusion of Mesenchymal Stem Cells Promotes the Survival of Random Pattern Flaps in Rats

BACKGROUND

Surgical reconstruction options of soft-tissue defects often include random pattern skin flaps. Flap survival depends on flap size and rotation arc and can be challenging regarding flap perfusion, leading to wound healing complications, insufficient wound coverage, and even flap loss. Therefore, novel approaches that promote skin flap survival are required. Bone marrow-derived mesenchymal stem cells intravenous infusion is therapeutically effective in various experimental disease models by means of multimodal and orchestrated mechanisms including anti-inflammatory and immunomodulatory effects, and by means of microvasculature reestablishment.

METHODS

A modified McFarlane-type rodent skin flap model was used. After skin flap surgery, intravenous infusion of mesenchymal stem cells or vehicle was performed. In vivo optical near-infrared imaging using indocyanine green was performed, followed by histologic analysis, including hematoxylin and eosin and Masson trichrome staining, and gene expression analysis.

RESULTS

The flap survival area was greater in the mesenchymal stem cell group. In vivo optical near-infrared perfusion imaging analysis suggested that skin blood perfusion was greater in the mesenchymal stem cell group. Ex vivo histologic analysis demonstrated that the skin structure was more clearly observed in the mesenchymal stem cell group. The dermal thickness was greater in the mesenchymal stem cell group, according to the Masson trichrome staining results. The authors observed a higher expression of fibroblast growth factor 2 mRNA in the tissues of the mesenchymal stem cell group using quantitative reverse-transcription polymerase chain reaction.

CONCLUSION

These results suggest that intravenous infusion of bone marrow-derived mesenchymal stem cells promotes skin survival of random pattern flaps, which is associated with increased blood perfusion and higher expression of fibroblast growth factor 2.

Optimized Manufacture of Lyophilized Dermal Fibroblasts for Next-Generation Off-the-Shelf Progenitor Biological Bandages in Topical Post-Burn Regenerative Medicine

Cultured fibroblast progenitor cells (FPC) have been studied in Swiss translational regenerative medicine for over two decades, wherein clinical experience was gathered for safely managing burns and refractory cutaneous ulcers. Inherent FPC advantages include high robustness, optimal adaptability to industrial manufacture, and potential for effective repair stimulation of wounded tissues. Major technical bottlenecks in cell therapy development comprise sustainability, stability, and logistics of biological material sources. Herein, we report stringently optimized and up-scaled processing (i.e., cell biobanking and stabilization by lyophilization) of dermal FPCs, with the objective of addressing potential cell source sustainability and stability issues with regard to active substance manufacturing in cutaneous regenerative medicine. Firstly, multi-tiered FPC banking was optimized in terms of overall quality and efficiency by benchmarking key reagents (e.g., medium supplement source, dissociation reagent), consumables (e.g., culture vessels), and technical specifications. Therein, fetal bovine serum batch identity and culture vessel surface were confirmed, among other parameters, to largely impact harvest cell yields. Secondly, FPC stabilization by lyophilization was undertaken and shown to maintain critical functions for devitalized cells in vitro, potentially enabling high logistical gains. Overall, this study provides the technical basis for the elaboration of next-generation off-the-shelf topical regenerative medicine therapeutic products for wound healing and post-burn care.

Sustained oxygenation accelerates diabetic wound healing by promoting epithelialization and angiogenesis and decreasing inflammation

Nonhealing diabetic wounds are common complications for diabetic patients. Because chronic hypoxia prominently delays wound healing, sustained oxygenation to alleviate hypoxia is hypothesized to promote diabetic wound healing. However, sustained oxygenation cannot be achieved by current clinical approaches, including hyperbaric oxygen therapy. Here, we present a sustained oxygenation system consisting of oxygen-release microspheres and a reactive oxygen species (ROS)-scavenging hydrogel. The hydrogel captures the naturally elevated ROS in diabetic wounds, which may be further elevated by the oxygen released from the administered microspheres. The sustained release of oxygen augmented the survival and migration of keratinocytes and dermal fibroblasts, promoted angiogenic growth factor expression and angiogenesis in diabetic wounds, and decreased the proinflammatory cytokine expression. These effects significantly increased the wound closure rate. Our findings demonstrate that sustained oxygenation alone, without using drugs, can heal diabetic wounds.

RGD-Modified Alginate-GelMA Hydrogel Sheet Containing Gingival Mesenchymal Stem Cells: A Unique Platform for Wound Healing and Soft Tissue Regeneration

Soft tissue reconstruction has remained a major clinical challenge in dentistry and regenerative medicine. Although current methods have shown partial success, there are several disadvantages associated with these approaches. Gingival mesenchymal stem cells (GMSCs) can be simply obtained in the oral cavity for soft tissue augmentation. Regenerative potential of mesenchymal stem cells (MSCs) encapsulated in hydrogels is well documented. Here, an alginate-gelatin methacrylate (GelMA) hydrogel formulation is developed encapsulating GMSCs within the developed hydrogel. The results confirm that the encapsulated MSCs remain viable within the hydrogel with enhanced collagen deposition. An excisional wound model in mice is utilized to evaluate the in vivo functionality of the GMSC-hydrogel construct for wound healing and soft tissue regeneration. The histology and immunofluorescence analyses confirm the effectiveness of the GMSC-hydrogel in expediting wound healing via enhancing angiogenesis and suppressing local proinflammatory cytokines. Altogether, the findings demonstrate that GMSCs encapsulated in an engineered hydrogel sheet based on alginate and GelMA can be used to expedite wound healing and soft tissue regeneration, with potential applications in plastic and reconstructive surgery as well as dentistry.

ECM-mimicking nanofibrous scaffold enriched with dual growth factor carrying nanoparticles for diabetic wound healing

Polymeric nanofibrous scaffolds provide fine-tuned structures with inter-connecting pores resembling the natural extracellular matrix (ECM) in tissues, and show good potential in assisting the creation of artificial functional tissue. Additional application of growth factors helps to regulate the cellular behaviors and tissue assembly in the scaffolds, which eases the healing process. In this study, we synthesized an electrospun polymer scaffold system enriched with nanoparticles containing growth factors for accelerated healing of diabetic wounds. BSA nanoparticles were synthesized by cross-linking with PEG aldehyde. To free the amino group of BSA, heparin was conjugated by EDC/NHS chemistry. The angiogenic growth factors bFGF and VEGF were bound to heparin by electrostatic interaction. These nanoparticles were adsorbed on to electrospun collagen/PLGA/chitosan nanofibers. The synthesized nanofiber system was evaluated in vitro for its cell viability and proliferation. In vivo experiments conducted in a streptozotocin-induced diabetic mice model showed accelerated wound healing. The excellent healing efficiency of this ECM-mimicking nanofiber scaffold makes it a great candidate for therapeutic application in diabetic wounds.

Healing and Angiogenic Properties of Collagen/Chitosan Scaffolds Enriched with Hyperstable FGF2-STAB® Protein: In Vitro, Ex Ovo and In Vivo Comprehensive Evaluation

Wound healing is a process regulated by a complex interaction of multiple growth factors including fibroblast growth factor 2 (FGF2). Although FGF2 appears in several tissue engineered studies, its applications are limited due to its low stability both in vitro and in vivo. Here, this shortcoming is overcome by a unique nine-point mutant of the low molecular weight isoform FGF2 retaining full biological activity even after twenty days at 37 °C. Crosslinked freeze-dried 3D porous collagen/chitosan scaffolds enriched with this hyper stable recombinant human protein named FGF2-STAB® were tested for in vitro biocompatibility and cytotoxicity using murine 3T3-A31 fibroblasts, for angiogenic potential using an ex ovo chick chorioallantoic membrane assay and for wound healing in vivo with 3-month old white New Zealand rabbits. Metabolic activity assays indicated the positive effect of FGF2-STAB® already at very low concentrations (0.01 µg/mL). The angiogenic properties examined ex ovo showed enhanced vascularization of the tested scaffolds. Histological evaluation and gene expression analysis by RT-qPCR proved newly formed granulation tissue at the place of a previous skin defect without significant inflammation infiltration in vivo. This work highlights the safety and biocompatibility of newly developed crosslinked collagen/chitosan scaffolds involving FGF2-STAB® protein. Moreover, these sponges could be used as scaffolds for growing cells for dermis replacement, where neovascularization is a crucial parameter for successful skin regeneration.

Platelet-Rich Plasma: Evolving Role in Plastic Surgery

BACKGROUND

The use of platelet-rich plasma has emerged as one of the most desired nonsurgical treatments for facial rejuvenation and hair restoration. It has grown to encompass a wide variety of applications within the field of plastic surgery, including its use in combination with microneedling, laser, and fat-grafting procedures.

METHODS

In this article, the authors aim to (1) describe the preparation process of platelet-rich plasma; (2) discuss the proposed science behind platelet-rich plasma with regard to its evolving role in hair restoration and facial rejuvenation; and (3) highlight the recent literature examining its widespread use.

RESULTS

Based on the available literature, there is a therapeutic advantage to the use of platelet-rich plasma as a single treatment modality for alopecia and skin rejuvenation and in combination with laser skin treatment and fat grafting. There is, however, a considerable amount of variability in the processing, preparation, and treatment modalities.

CONCLUSIONS

Despite a lack of standardized protocols for platelet-rich plasma preparation and a scarcity of large-scale studies with long-term follow-up, there is convincing evidence with objective measurement modalities that display positive outcomes after treatment for skin rejuvenation, hair regrowth, wound healing, and fat graft take.

Achillea Species as Sources of Active Phytochemicals for Dermatological and Cosmetic Applications

Achillea spp. is well known for its broad range of applications and long history of use in traditional medicine around the world. Health benefits of Achillea extracts result from the multitude of secondary metabolites identified in the plants from this genus that include flavonoids, phenolic acids, terpenes, guaianolides, phytosterols, fatty acids, and organic acids. The properties of several Achillea extracts meet also the expectations of a vividly developing cosmetic market. An increasing number of studies on the dermatological properties of Achillea spp. are observed in the recent years, with Achillea millefolium L. being the most studied and used representative of the genus. There is strong scientific evidence showing that also other yarrow species might be rich sources of effective cosmetic ingredients, with skin calming and rejuvenating properties, wound healing activity, and anti-inflammatory potential. Several Achillea extracts and isolated compounds were also shown to display significant tyrosinase inhibitory, antioxidant, and antimicrobial properties and thus are interesting candidates for active ingredients of medications and cosmetic products protecting the skin from the harmful impact of environmental stressors. The aim of this review is to collect the current information on the composition and cosmeceutical significance of different Achillea species.

In vitro vascularization of tissue engineered constructs by non-viral delivery of pro-angiogenic genes

Vascularization is still one of the major challenges in tissue engineering. In the context of tissue regeneration, the formation of capillary-like structures is often triggered by the addition of growth factors which are associated with high cost, bolus release and short half-life. As an alternative to growth factors, we hypothesized that delivering genes-encoding angiogenic growth factors to cells in a scaffold microenvironment would lead to a controlled release of angiogenic proteins promoting vascularization, simultaneously offering structural support for new matrix deposition. Two non-viral vectors, chitosan (Ch) and polyethyleneimine (PEI), were tested to deliver plasmids encoding for vascular endothelial growth factor (pVEGF) and fibroblast growth factor-2 (pFGF2) to human dermal fibroblasts (hDFbs). hDFbs were successfully transfected with both Ch and PEI, without compromising the metabolic activity. Despite low transfection efficiency, superior VEGF and FGF-2 transgene expression was attained when pVEGF was delivered with PEI and when pFGF2 was delivered with Ch, impacting the formation of capillary-like structures by primary human dermal microvascular endothelial cells (hDMECs). Moreover, in a 3D microenvironment, when PEI-pVEGF and Ch-FGF2 were delivered to hDFbs, cells produced functional pro-angiogenic proteins which induced faster formation of capillary-like structures that were retained in vitro for longer time in a Matrigel assay. The dual combination of the plasmids resulted in a downregulation of the production of VEGF and an upregulation of FGF-2. The number of capillary-like segments obtained with this system was inferior to the delivery of plasmids individually but superior to what was observed with the non-transfected cells. This work confirmed that cell-laden scaffolds containing transfected cells offer a novel, selective and alternative approach to impact the vascularization during tissue regeneration. Moreover, this work provides a new platform for pathophysiology studies, models of disease, culture systems and drug screening.

bFGF and collagen matrix hydrogel attenuates burn wound inflammation through activation of ERK and TRK pathway

Burn injuries are most challenging to manage since it causes loss of the integrity of large portions of the skin leading to major disability or even death. Over the years, hydrogels are considered as a significant delivery system for wound treatment because of several advantages over other conventional formulations. We hypothesized that the bFGF-collagen-AgSD incorporated hydrogel formulation can accelerate the rate of burn healing in animal model and would promote fibroblast cell proliferation. Neovascularization and re-epithelialization is a hall mark of burn wound healing. In the present study, histopathological investigation and scanning electron microscopy of skin tissue of Wistar rats showed almost complete epithelialisation after 16 days in the treatment group. The developed hydrogel showed significantly accelerated wound closure compared with a standard and control group. The faster wound closure resulted from increased re-epithelialization and granulation tissue formation because of the presence of collagen and growth factor. Expressions of proteins such as TrkA, p- TrkA, ERK1/2, p-ERK1/2, NF-kβ, and p-NF-kβ involved in nerve growth factor (NGF) signalling pathway were analysed by western blot. All the findings obtained from this study indicated that the hydrogel can be considered as a promising delivery system against second degree burn by faster healing.

Healing features of experimental injuries of soft tissues that contain foreign bodies in the form of fragments of military personnel uniforms

INTRODUCTION

The healing of combat wounds can be complicated by the presence of foreign bodies. The present research aimed to study the regeneration of soft tissue injuries complicated by foreign bodies in the form of fragments of military uniforms.

METHODS

60 rats were divided into four groups: intact (Int), control (Con) and two experimental (EG1, EG2). In Con, wounds were sutured without implantation of foreign bodies. A uniform consisting of 100% cotton was used as foreign bodies for EG1 and a uniform consisting of 65% cotton and 35% polyester for EG2. Histological studies were performed according to generally accepted methods. The growth factors wеre determined by ELISA.

RESULTS

In EG1, the inflammatory reaction proceeded protractedly, which complicated the development of granulation tissue. In EG2, considering the moderate inflammatory reactions, healing of the wounds became possible. The increase of the growth factors content in Con was maximal at the 15th day: basic fibroblast growth factor (bFGF)-2.2 times and vascular endothelial growth factor (VEGF)-1.6 times (p<0.001). In experimental groups, the bFGF content was maximal at the 60th day and exceeded the normal values by 1.7 times in EG1 and by 2.6 times in EG2 (p<0.001); the level of VEGF was slightly higher than that in healthy animals.

CONCLUSIONS

The study showed wound healing in all groups. The repair of injuries in rats of EG1 and EG2 was complicated by the textile implant and took longer. The dynamics of the content of growth factors reflected the impairment of wound healing processes. These violations were more pronounced in the EG1 group.

Fibroblast Growth Factor in Diabetic Foot Ulcer: Progress and Therapeutic Prospects

Diabetic foot ulcer (DFU) is a combination of neuropathy and various degrees of peripheral vasculopathy in diabetic patients resulting in lower extremity infection, ulcer formation, and deep-tissue necrosis. The difficulty of wound healing in diabetic patients is caused by a high glucose environment and various biological factors in the patient. The patients' skin local microenvironment changes and immune chemotactic response dysfunction. Wounds are easy to be damaged and ulcerated repeatedly, but difficult to heal, and eventually develop into chronic ulcers. DFU is a complex biological process in which many cells interact with each other. A variety of growth factors released from wounds are necessary for coordination and promotion of healing. Fibroblast growth factor (FGF) is a family of cell signaling proteins, which can mediate various processes such as angiogenesis, wound healing, metabolic regulation and embryonic development through its specific receptors. FGF can stimulate angiogenesis and proliferation of fibroblasts, and it is a powerful angiogenesis factor. Twenty-three subtypes have been identified and divided into seven subfamilies. Traditional treatments for DFU can only remove necrotic tissue, delay disease progression, and have a limited ability to repair wounds. In recent years, with the increasing understanding of the function of FGF, more and more researchers have been applying FGF-1, FGF-2, FGF-4, FGF-7, FGF-21 and FGF-23 topically to DFU with good therapeutic effects. This review elaborates on the recently developed FGF family members, outlining their mechanisms of action, and describing their potential therapeutics in DFU.

Enhancement of Wound Healing Efficacy by Increasing the Stability and Skin-Penetrating Property of bFGF Using 30Kc19α-Based Fusion Protein

The instability of recombinant basic fibroblast growth factor (bFGF) is a major disadvantage for its therapeutic use and means frequent applications to cells or tissues are required for sustained effects. Originating from silkworm hemolymph, 30Kc19α is a cell-penetrating protein that also has protein stabilization properties. Herein, it is investigated whether fusing 30Kc19α to bFGF can enhance the stability and skin penetration properties of bFGF, which may consequently increase its therapeutic efficacy. The fusion of 30Kc19α to bFGF protein increases protein stability, as confirmed by ELISA. 30Kc19α-bFGF also retains the biological activity of bFGF as it facilitates the migration and proliferation of fibroblasts and angiogenesis of endothelial cells. It is discovered that 30Kc19α can improve the transdermal delivery of a small molecular fluorophore through the skin of hairless mice. Importantly, it increases the accumulation of bFGF and further facilitates its translocation into the skin through follicular routes. Finally, when applied to a skin wound model in vivo, 30Kc19α-bFGF penetrates the dermis layer effectively, which promotes cell proliferation, tissue granulation, angiogenesis, and tissue remodeling. Consequently, the findings suggest that 30Kc19α improves the therapeutic functionalities of bFGF, and would be useful as a protein stabilizer and/or a delivery vehicle in therapeutic applications.

Third-degree burn mouse treatment using recombinant human fibroblast growth factor 2

Fibroblast growth factor 2 (FGF-2) is a multifunctional protein that has major roles in wound healing, tissue repair, and regeneration. This therapeutic protein is widely used for burn treatment because it can stimulate cell proliferation and differentiation, angiogenesis, and extracellular matrix remodeling. In this study, we developed a simple method using a controlled heated brass rod to create a homogenous third-degree burn murine model and evaluated the treatment using recombinant human FGF-2 (rhFGF-2). The results indicated that the wound area was 0.83 ± 0.05 cm² and wound depth was 573.42 ± 147.82 μm. Mice treated with rhFGF-2 showed higher rates of wound closure, granulation tissue formation, angiogenesis, and re-epithelialization than that of phosphate-buffered saline (PBS)-treated group. In conclusion, our lab-made rhFGF-2 could be a potentially therapeutic protein for burn treatment as well as a bioequivalent drug for other commercial applications using FGF-2.

Growth factors-based therapeutic strategies and their underlying signaling mechanisms for peripheral nerve regeneration

Peripheral nerve injury (PNI), one of the most common concerns following trauma, can result in a significant loss of sensory or motor function. Restoration of the injured nerves requires a complex cellular and molecular response to rebuild the functional axons so that they can accurately connect with their original targets. However, there is no optimized therapy for complete recovery after PNI. Supplementation with exogenous growth factors (GFs) is an emerging and versatile therapeutic strategy for promoting nerve regeneration and functional recovery. GFs activate the downstream targets of various signaling cascades through binding with their corresponding receptors to exert their multiple effects on neurorestoration and tissue regeneration. However, the simple administration of GFs is insufficient for reconstructing PNI due to their short half‑life and rapid deactivation in body fluids. To overcome these shortcomings, several nerve conduits derived from biological tissue or synthetic materials have been developed. Their good biocompatibility and biofunctionality made them a suitable vehicle for the delivery of multiple GFs to support peripheral nerve regeneration. After repairing nerve defects, the controlled release of GFs from the conduit structures is able to continuously improve axonal regeneration and functional outcome. Thus, therapies with growth factor (GF) delivery systems have received increasing attention in recent years. Here, we mainly review the therapeutic capacity of GFs and their incorporation into nerve guides for repairing PNI. In addition, the possible receptors and signaling mechanisms of the GF family exerting their biological effects are also emphasized.

Collagen extract obtained from Nile tilapia (Oreochromis niloticus L.) skin accelerates wound healing in rat model via up regulating VEGF, bFGF, and α-SMA genes expression

BACKGROUND

Collagen is the most abundant structural protein in the mammalian connective tissue and represents approximately 30% of animal protein. The current study evaluated the potential capacity of collagen extract derived from Nile tilapia skin in improving the cutaneous wound healing in rats and investigated the underlying possible mechanisms. A rat model was used, and the experimental design included a control group (CG) and the tilapia collagen treated group (TCG). Full-thickness wounds were conducted on the back of all the rats under general anesthesia, then the tilapia collagen extract was applied topically on the wound area of TCG. Wound areas of the two experimental groups were measured on days 0, 3, 6, 9, 12, and 15 post-wounding. The stages of the wound granulation tissues were detected by histopathologic examination and the expression of vascular endothelial growth factor (VEGF), and transforming growth factor (TGF-ß1) were investigated using immunohistochemistry. Moreover, relative gene expression analysis of transforming growth factor-beta (TGF-ß1), basic fibroblast growth factor (bFGF), and alpha-smooth muscle actin (α-SMA) were quantified by real-time qPCR.

RESULTS

The histopathological assessment showed noticeable signs of skin healing in TCG compared to CG. Immunohistochemistry results revealed remarkable enhancement in the expression levels of VEGF and TGF-β1 in TCG. Furthermore, TCG exhibited marked upregulation in the VEGF, bFGF, and α-SMA genes expression. These findings suggested that the topical application of Nile tilapia collagen extract can promote the cutaneous wound healing process in rats, which could be attributed to its stimulating effect on recruiting and activating macrophages to produce chemotactic growth factors, fibroblast proliferation, and angiogenesis.

CONCLUSIONS

The collagen extract could, therefore, be a potential biomaterial for cutaneous wound healing therapeutics.

The Japanese Experience with Basic Fibroblast Growth Factor in Cutaneous Wound Management and Scar Prevention: A Systematic Review of Clinical and Biological Aspects

INTRODUCTION

Basic fibroblast growth factor (bFGF) plays several key roles in wound healing. Over the last 2 decades, clinical and basic research on bFGF has been actively conducted in Japan with reports on its potent efficacy in accelerating the healing of chronic ulcers and burn wounds by stimulating key cellular players in the skin. However, its efficacy remains unrecognized internationally. Thus, this study reviews current knowledge about the therapeutic value of bFGF in wound management and scar prevention accumulated in Japan over the last 2 decades.

METHODS

We review the Japanese literature that demonstrates the anti-scarring effects of bFGF and exhaustively assess how these effects are exerted. Using the search terms "bFGF OR growth factors AND wound healing in Japan" and "bFGF AND scar prevention in Japan," we conducted a search of the PubMed database for publications on the role of bFGF in wound and scar management in Japan. All eligible papers published between 1988 and December 2019 were retrieved and reviewed.

RESULTS

Our search yielded 208 articles; 82 were related to the application of bFGF for dermal wound healing in Japan. Of these, 27 fulfilled all inclusion criteria; 11 were laboratory studies, 7 were case reports, 4 were clinical studies, and 5 were randomized controlled trials.

CONCLUSION

Further research, with recognition of the therapeutic value of bFGF in wound and scar management and its clinical applications, is needed to provide additional clinical advantages while improving wound healing and reducing the risk of post-surgical scar formation.

The immunologic changes during different phases of intestinal anastomotic healing

Intestinal anatomosis is a complex and multicellular process that involving three overlapped phases: exudative phase, proliferative phase, and reparative phase. Undisturbed anastomotic healings are crucial for the recovery of patients after operations but unsuccessful healings are linked with a considerable mortality. This time, we concentrate on the immunologic changes during different phases of intestinal anastomotic healing and select several major immune cells and cytokines of each phase to get a better understanding of these immunologic changes in different phases, which will be significant for more precise therapy strategies in anastomoses.

Visible Light-Curable Hydrogel Systems for Tissue Engineering and Drug Delivery

Visible light-curable hydrogels have been investigated as tissue engineering scaffolds and drug delivery carriers due to their physicochemical and biological properties such as porosity, reservoirs for drugs/growth factors, and similarity to living tissue. The physical properties of hydrogels used in biomedical applications can be controlled by polymer concentration, cross-linking density, and light irradiation time. The aim of this review chapter is to outline the results of previous research on visible light-curable hydrogel systems. In the first section, we will introduce photo-initiators and mechanisms for visible light curing. In the next section, hydrogel applications as drug delivery carriers will be emphasized. Finally, cellular interactions and applications in tissue engineering will be discussed.

Topical ozonated virgin coconut oil improves wound healing and increases HSP90α, VEGF-A, EGF, bFGF and CD34 in diabetic ulcer mouse model of wound healing

Background: Diabetes is a disease that affects people worldwide, including in Indonesia. The prevalence of diabetes in Indonesia is increasing from year to year. One of the most devastating complications of diabetes mellitus is diabetic ulcers, which is a limb-threatening complication. Over the past few decades, ozone generated using plasma medical technology has been investigated as an agent that helps wound healing. This study aims to evaluate the effects of topical ozonated virgin coconut oil (VCO) in a diabetic wound mouse model. Methods: This study was an experimental study with a post-test control design. An ulcer wound model was made in 50 diabetic male Wistar mice, divided into five groups, and a control group of 10 non-diabetic mice. The control groups were given conventional therapy only and the treatment groups were also given topical ozonated VCO with different flow durations (0 min, 90 min, 7 h, 14 h). Macroscopic appearance and wound contraction were observed. HSP90β, VEGF-A, EGF, bFGF and CD34 levels were measured from the immunostained slices of wound margins. Results: The reduction of wound length was proportionally related to the duration of ozone flow. Ozonated VCO with a longer duration of ozone flow healed the wound more quickly and had the shortest wound length. VCO with ozone flow for 14 hours (16837.10 µm) had the biggest reduction in wound length compared to other groups. The wounds treated with ozonated VCO showed an increase in HSP90β, VEGF-A, EGF, bFGF and CD34 levels that correlated to improved wound healing. A longer period of treatment resulted in higher levels of wound healing biomarkers compared to shorter therapeutic durations. Conclusions: Topical ozonated VCO improved the wound healing process in a diabetic ulcer mouse model by improving macroscopic wound appearance and increasing levels of wound healing biomarkers.

Adsorption and Release of Growth Factors from Four Different Porcine-Derived Collagen Matrices

Xenogeneic acellular collagen matrices represent a safe alternative to autologous soft tissue transplants in periodontology and implant dentistry. Here, we aimed to investigate the adsorption and release of growth factors from four porcine-derived collagen matrices using enzyme-linked immunosorbent assay. Non-crosslinked collagen matrix (NCM), crosslinked collagen matrix (CCM), dried acellular dermal matrix (DADM), and hydrated acellular dermal matrix (HADM) adsorbed each of the following growth factors, TGF-β1, FGF-2, PDGF-BB, GDF-5 and BMP-2, with an efficiency close to 100%. Growth factor release for a 13-day period was in the range of 10-50% of the adsorbed protein, except for the BMP-2 release that was in the range of 5-7%. Generally, protein release occurred in two phases. Phase I was arbitrary defined by the highest release from the matrices, usually within 24 h. Phase II, spanning the period immediately after the peak release until day 13, corresponded to the delayed release of the growth factors from the deeper layers of the matrices. HADM showed significantly (P < 0.001) higher TGF-β1, FGF-2, and PDGF-BB release in phase II, compared to the rest of the matrices. NCM exhibited significantly (P < 0.001) higher FGF-2 release in phase II, compared to CCM and DADM as well as a characteristic second peak in PDGF-BB release towards the middle of the tested period. In contrast to NCM and HADM, CCM and DADM showed a gradual and significantly higher release of GDF-5 in the second phase. Several burst releases of BMP-2 were characteristic for all matrices. The efficient adsorption and sustained protein release in the first 13 days, and the kinetics seen for HADM, with a burst release within hours and high amount of released growth factor within a secondary phase, may be beneficial for the long-term tissue regeneration following reconstructive periodontal surgery.

Towards advanced wound regeneration

Wound management is a major contributor towards the economic burden placed upon the national health service (NHS), serving as an important target for the development of advanced therapeutic interventions. The economic expenditure of wound care for the NHS exceeds £5 billion per annum, thus presenting a significant opportunity for the introduction of alternative treatments in regards to their approach in tackling the ever increasing prevalence of wound management associated problems. As most wounds typically fall under the acute or chronic category, it is therefore necessary to design a therapeutic intervention capable of effectively resolving the pathologies associated with each problem. Such an intervention should be of increased economic viability and therapeutic effectiveness when compared to standardized treatments, thus helping to alleviate the financial burden imposed upon the NHS. The purpose of this review is to critically analyse the various aspects associated with wound management, detailing the fundamental concepts of dermal regeneration, whilst also providing an evaluation of the different materials and methods that can be utilised to achieve maximal wound regeneration. The primary aspects of this review revolve around the three concepts of antibacterial methodology, enhancement of dermal regeneration and the utilisation of a carrier medium to facilitate the regenerative process. Each aspect is explored, conveying its justifications as a target for dermal regeneration, whilst offering various solutions towards the fulfilment of a therapeutic design that is both effective and financially feasible.

Basic fibroblast growth factor promotes human dental pulp stem cells cultured in 3D porous chitosan scaffolds to neural differentiation

AIM/PURPOSE

Dental pulp stem cells (DPSCs) were widely used as seed cells in the field of tissue engineering and regenerative medicine, including spinal cord injury (SCI) repair and other neuronal degenerative diseases, due to their easy isolation, multiple differentiation potential, low immunogenicity and low rates of rejection during transplantation. Various studies have shown that bFGF can enhance peripheral nerve regeneration after injury, and phospho-ERK (p-ERK) activation as a major mediator may be involved in this process. Previous studies also have proved that a suitable biomaterial scaffold can carry and transport the therapeutic cells effectively to the recipient area. It has showed in our earlier experiments that 3D porous chitosan scaffolds exhibited a suitable circumstance for survival and neural differentiation of DPSCs in vitro. The purpose of the study was to evaluate the influence of chitosan scaffolds and bFGF on differentiation of DPSCs.

MATERIALS AND METHODS

In current study, DPSCs were cultured in chitosan scaffolds and treated with neural differentiation medium for 7 days. The neural genes and protein markers were analyzed by western blot and immunofluorescence. Meanwhile, the relevant signaling pathway involved in this process was also tested.

RESULTS

Our study revealed that the viability of DPSCs was not influenced by co-culture with the chitosan scaffolds as well as bFGF. Compared with the control and DPSC/chitosan-scaffold groups, the levels of GFAP, S100β and β-tubulin III significantly increased in the DPSC/chitosan-scaffold+bFGF group.

CONCLUSION

Chitosan scaffolds were non-cytotoxic to the survival of DPSCs, and chitosan scaffolds combined with bFGF facilitated the neural differentiation of DPSCs. The transplantation of DPSCs/chitosan-scaffold+bFGF might be a secure and effective method of treating SCI and other neuronal diseases.

Bioactive borate glass triggers phenotypic changes in adipose stem cells

A bioactive borate glass, 13-93B3 (B3), has been used successfully in the clinic to treat chronic, nonhealing wounds without scarring. However, the mechanism by which B3 stimulates wound healing is poorly understood. Because adipose stem cells (ASCs) have been shown to have multiple roles in wound repair, we hypothesized that B3 triggers ASCs. In this study, we evaluate the effects of B3 on ASC survival, migration, differentiation, and protein secretion in vitro. In concentrations ≤10 mg/ml, B3 did not affect ASC viability under static conditions. B3 promoted the migration of ASCs but did not increase differentiation into bone or fat. B3 also decreased ASCs secretion of collagen I, PAI-1, MCP-1, DR6, DKK-1, angiogenin, IL-1, IGFBP-6, VEGF, and TIMP-2; increased expression of IL-1R and E-selectin; had a transient decrease in IL-6 secretion; and had a transient increase in bFGF secretion. Together, these results show that B3 alters the protein secretion of ASCs.

Novel Cryopreservation Approach Providing Off-the-Shelf Availability of Human Multipotent Mesenchymal Stromal Cells for Clinical Applications

Cryopreservation is the only established method to provide long-term storage and fast availability of cellular product for therapeutic applications. The overwhelming majority of cryopreservation media contain toxic concentrations of dimethyl sulfoxide (DMSO) limiting the possibility for the direct administration of cryopreserved cells to the patients. Here, we propose a novel approach for nontoxic xeno-free cryopreservation of human multipotent mesenchymal stromal cells (MSCs) aimed at ensuring high viability, ready-to-use availability, and localized delivery of the cell-based graft into damaged tissues. For MSC cryopreservation, we applied sucrose pretreatment procedure and xeno-free cryoprotective medium containing human platelet-poor blood plasma (PPP), sucrose, and nontoxic concentration of DMSO. Using the combination of PPP, 0.2 M sucrose, and 1% DMSO, the recovery rate of cryopreserved MSCs reached 73% of the values obtained for noncryopreserved cells. Moreover, the presence of PPP in the cryoprotective medium provided the possibility to create a ready-to-use 3D hydrogel for the localized delivery and additional support of MSCs in vivo. In a proof-of-concept study, we assessed the regenerative capacity of cryopreserved MSCs in a full-thickness wound model in mice. The positive impact of MSCs within 3D gel on wound healing rates was confirmed by morphometric and histological examinations. Our results demonstrate the possibility to apply cryopreserved cells immediately after thawing using a cryoprotective medium as the vehicle solution.

Treatment of venous ulcers with growth factors: systematic review and meta-analysis

OBJECTIVE

To identify evidence about the effects of growth factor application on venous ulcer healing.

METHOD

Systematic review and meta-analysis, including Randomized Clinical Trials. Searches: Ovid MEDLINE, EMBASE, CINAHL, Cochrane CENTRAL, LILACS, Web of Science, Digital Library of Theses and Dissertations; Google Scholar and list of references.

RESULTS

802 participants were recruited from the 10 included studies: 472 in the intervention group (growth factors) and 330 as control. The relative risk for the complete healing outcome was 1.06 [95% CI 0.92-1.22], p = 0.41. Participants who received Platelet-Rich Plasma and Epidermal Growth Factor showed a slight tendency to achieve complete healing, but without statistical relevance (p <0.05). Most of the studies were classified as moderate risk of bias.

CONCLUSION

The effect of the application of growth factors for complete healing in venous ulcers is not clear, and clinical trials with methodological quality are required for more accurate recommendations.