Overview: acute and chronic wounds

Electrical hydrogel: electrophysiological-based strategy for wound healing

Wound healing remains a significant challenge in clinical practice, driving ongoing exploration of innovative therapeutic approaches. In recent years, electrophysiological-based wound healing strategies have gained considerable attention. Specifically, electrical hydrogels combine the synergistic effects of electrical stimulation and hydrogel properties, offering a range of functional benefits for wound healing, including antibacterial activity, real-time wound monitoring, controlled drug release, and electrical treatment. Despite significant progress made in electrical hydrogel research for wound healing, there is a lack of comprehensive, systematic reviews summarizing this field. In this review, we survey the latest advancements in electrical hydrogel technology. After analyzing the mechanisms of electrical stimulation in promoting wound healing, we establish a novel classification framework for electrical hydrogels based on their operational principles. The review further provides an in-depth evaluation of the therapeutic efficacy of these hydrogels in various types of wounds. Finally, we propose future directions and challenges for the development of electrical hydrogels for wound healing.

Skin and Wound Healing: Conventional Dosage versus Nanobased Emulsions Forms

The skin plays a crucial role in the body's homeostasis through its thermoregulation functions, metabolic activity, and, mainly, its barrier function. Once this system has its homeostasis disturbed, through the promotion of tissue discontinuity, an injury happens and a restoration process starts. Different products can be used to promote, accelerate, or stimulate the healing process, such as hydrogels, emulsions, and ointments (main conventional formulations). Despite the historical use and wide market and consumer acceptance, new systems emerged for wound management with the main challenge to overcome conventional form limitations, in which nanosystems are found, mainly nanobased emulsion forms (nano- and microemulsions, NE and ME). Here, we discuss the skin function and wound healing process, highlighting the cellular and molecular processes, the different wound classifications, and factors that affect physiological healing. We also investigated the recent patents (2012-2023) filed at the United States Patent and Trademark Office, where we found few patents for conventional forms (hydrogels = 5; emulsions = 4; ointments = 6) but a larger number of patents for nanobased emulsions filed in this time (NE = 638; ME = 4,072). Furthermore, we address the use of nanobased emulsions (NE and ME) and their particularities, differences, and application in wound treatment. This work also discusses the challenges, bottlenecks, and regulatory framework for nanosystems, industrial, academic, and government interest in nanotechnology, and future perspectives about this key factor for the nanosystems market and consumer acceptance.

Sequential Applications of Adipose Tissue-derived Stem Cells Enhance Healing in Complex Wounds: Experimental Model

Background

Complex wounds represent a challenge to global health, incurring significant healthcare costs and compromising patients' quality of life. Recently, research has investigated the potential of adipose tissue-derived stem cells (ASC) for therapeutic stem cells' immunomodulatory properties. This study aimed to evaluate the effect of sequential applications of ASC in an experimental model of a complex wound.

Methods

Thirty male Wistar rats were subjected to a complex wound model of enterocutaneous fistula. After 4 weeks, the rats were divided into 3 groups: control, 2 applications of culture medium, and 2 applications of 1 × 106 allogeneic ASC. The animals were euthanized and analyzed 4 weeks after the first application regarding the macroscopic reduction of the wound, histopathologic changes, and gene expression related to wound healing (Cd68, Il1rap, Il10, Mmp3, Mmp9, and Tnf).

Results

Animals treated with ASC showed a reduction in wound diameter of 68% compared with the control group (P = 0.002) and a reduction of 65% compared with the culture medium group (P = 0.011). The ASC group also showed a more than 100% increase in blood vessel count compared with the control group (P = 0.02). Gene expression analysis showed a decrease in the Mmp9 levels in the ASC group compared with the control group.

Conclusions

This study demonstrated that the treatment with ASC improves the healing of enterocutaneous fistula wounds.

Revealing the promising era of silk-based nanotherapeutics: a ray of hope for chronic wound healing treatment

Chronic wounds significantly contribute to disability and affect the mortality rate in diabetic patients. In addition, pressure ulcers, diabetic foot ulcers, arterial ulcers, and venous ulcers pose a significant health burden due to their associated morbidity and death. The complex healing process, environmental factors, and genetic factors have been identified as the rate-limiting stages of chronic wound healing. Changes in temperature, moisture content, mechanical strain, and genetics can result in slow wound healing, increased susceptibility to bacterial infections, and poor matrix remodelling. These obstacles can be addressed with natural biomaterials exhibiting antimicrobial, collagen synthesis, and granulation tissue formation properties. Recently, silk proteins have gained significant attention as a natural biomaterial owing to good biocompatibility, biodegradability, reduced immunogenicity, ease of sterilization, and promote the wound healing process. The silk components such as sericin and fibroin in combination with nano(platforms) effectively promote wound repair. This review emphasises the potential of sericin and fibroin when combined with nano(platforms) like nanoparticles, nanofibers, and nanoparticles-embedded films, membranes, gels, and nanofibers.

Nano-Delivery Revolution: Harnessing Mesenchymal Stem Cell-Derived Exosomes' Potential for Wound Healing

Stem cell transplantation has proven effective in treating acute and chronic wounds, but its limitations, such as low cellular viability and the need for specialized transportation, highlight the necessity for alternative approaches. This review explores the potential of engineered exosomes, containing identified miRNAs/peptides, as a more stable and efficient cell-free therapy for regenerative medicine, particularly in wound healing. The discussion emphasizes the benefits of exosomes, including their stability, reduced damage, and consistent biological activity, paving the way for innovative applications like lyophilized exosomes, mist spray delivery, and exosome-based scaffolds. The exploration of cell-free therapy in this review holds promising implications for advancing wound-healing strategies.

Molecular characterization of chronic cutaneous wounds reveals subregion- and wound type-specific differential gene expression

A limited understanding of the pathology underlying chronic wounds has hindered the development of effective diagnostic markers and pharmaceutical interventions. This study aimed to elucidate the molecular composition of various common chronic ulcer types to facilitate drug discovery strategies. We conducted a comprehensive analysis of leg ulcers (LUs), encompassing venous and arterial ulcers, foot ulcers (FUs), pressure ulcers (PUs), and compared them with surgical wound healing complications (WHCs). To explore the pathophysiological mechanisms and identify similarities or differences within wounds, we dissected wounds into distinct subregions, including the wound bed, border, and peri-wound areas, and compared them against intact skin. By correlating histopathology, RNA sequencing (RNA-Seq), and immunohistochemistry (IHC), we identified unique genes, pathways, and cell type abundance patterns in each wound type and subregion. These correlations aim to aid clinicians in selecting targeted treatment options and informing the design of future preclinical and clinical studies in wound healing. Notably, specific genes, such as PITX1 and UPP1, exhibited exclusive upregulation in LUs and FUs, potentially offering significant benefits to specialists in limb preservation and clinical treatment decisions. In contrast, comparisons between different wound subregions, regardless of wound type, revealed distinct expression profiles. The pleiotropic chemokine-like ligand GPR15L (C10orf99) and transmembrane serine proteases TMPRSS11A/D were significantly upregulated in wound border subregions. Interestingly, WHCs exhibited a nearly identical transcriptome to PUs, indicating clinical relevance. Histological examination revealed blood vessel occlusions with impaired angiogenesis in chronic wounds, alongside elevated expression of genes and immunoreactive markers related to blood vessel and lymphatic epithelial cells in wound bed subregions. Additionally, inflammatory and epithelial markers indicated heightened inflammatory responses in wound bed and border subregions and reduced wound bed epithelialization. In summary, chronic wounds from diverse anatomical sites share common aspects of wound pathophysiology but also exhibit distinct molecular differences. These unique molecular characteristics present promising opportunities for drug discovery and treatment, particularly for patients suffering from chronic wounds. The identified diagnostic markers hold the potential to enhance preclinical and clinical trials in the field of wound healing.

The research status and prospects of nanomaterials in wound healing: A scientometric study

Nanotechnology and nanomaterials have swiftly influenced wound healing, propelling the development of wound-healing nanomaterials. Therefore, it's crucial to gather essential information about prominent researches in this domain. Moreover, identifying primary directions and related frontiers in wound healing and nanomaterials is paramount. This will enhance our comprehension of the current research landscape and foster progress in this field. Retrieved from the Web of Science core database, a total of 838 relevant studies published from 2013 to 2022 were analyzed through bibliometric visualization tools such as CiteSpace, VOSviewer, and Bibliometrics Online Analysis Platform. The annual study count has been rising steadily, primary contributors to this field include China, India, and the United States. The author with the highest output is Zangeneh, Akram, while Grumezescu, Alexandru Mihai garners the most citations. Chinese Academy of Sciences emerges as the leading institution, with Nanomaterials as the predominant journal. The keyword "antibacterial" signals prevailing and forthcoming trends in this domain. This study presents the first scientometric study and bibliometric visualization for wound healing-related nanomaterials, shedding light on research hotspots and trends. Over the course of the decade from 2013 to 2022, enthusiasm for nanomaterials in wound healing research has surged, auguring well for upcoming investigations.

ROS-responsive hydrogels with spatiotemporally sequential delivery of antibacterial and anti-inflammatory drugs for the repair of MRSA-infected wounds

For the treatment of MRSA-infected wounds, the spatiotemporally sequential delivery of antibacterial and anti-inflammatory drugs is a promising strategy. In this study, ROS-responsive HA-PBA/PVA (HPA) hydrogel was prepared by phenylborate ester bond cross-linking between hyaluronic acid-grafted 3-amino phenylboronic acid (HA-PBA) and polyvinyl alcohol (PVA) to achieve spatiotemporally controlled release of two kinds of drug to treat MRSA-infected wound. The hydrophilic antibiotic moxifloxacin (M) was directly loaded in the hydrogel. And hydrophobic curcumin (Cur) with anti-inflammatory function was first mixed with Pluronic F127 (PF) to form Cur-encapsulated PF micelles (Cur-PF), and then loaded into the HPA hydrogel. Due to the different hydrophilic and hydrophobic nature of moxifloxacin and Cur and their different existing forms in the HPA hydrogel, the final HPA/M&Cur-PF hydrogel can achieve different spatiotemporally sequential delivery of the two drugs. In addition, the swelling, degradation, self-healing, antibacterial, anti-inflammatory, antioxidant property, and biocompatibility of hydrogels were tested. Finally, in the MRSA-infected mouse skin wound, the hydrogel-treated group showed faster wound closure, less inflammation and more collagen deposition. Immunofluorescence experiments further confirmed that the hydrogel promoted better repair by reducing inflammation (TNF-α) and promoting vascular (VEGF) regeneration. In conclusion, this HPA/M&Cur-PF hydrogel that can spatiotemporally sequential deliver antibacterial and anti-inflammatory drugs showed great potential for the repair of MRSA-infected skin wounds.

Nickel sulfide and dysprosium-doped nickel sulfide nanoparticles: Dysprosium-induced variation in properties, in vitro chemo-photothermal behavior, and antibacterial activity

Newer materials for utilization in multi-directional therapeutic actions are investigated, considering delicate design principles involving size and shape control, surface modification, and controllable drug loading and release. Multi-faceted properties are imparted to the engineered nanoparticles, like magnetism, near-infrared absorption, photothermal efficiency, and suitable size and shape. This report presents nickel sulfide and dysprosium-doped nickel sulfide nanoparticles with poly-β-cyclodextrin polymer coating. The nanoparticles belong to the orthorhombic crystal systems, as indicated by X-ray diffraction studies. The size and shape of the nanoparticles are investigated using Transmission Electron Microscope (TEM) and a particle-size analyzer. The particles show soft ferromagnetic characteristics with definite and moderate saturation magnetization values. The nickel sulfide nanoparticles' in vitro anticancer and antibacterial activities are investigated in free and 5-fluorouracil/penicillin benzathine-loaded forms. The 5-fluorouracil-encapsulation efficiency of the nanoparticles is around 87%, whereas it is above 92% in the case of penicillin benzathine. Both drugs are released slowly in a controlled fashion. The dysprosium-doped nickel sulfide nanoparticles show better anticancer activity, and the efficacy is more significant than the free drug. The nanoparticles are irradiated with a low-power 808 nm laser. The dysprosium-doped nickel sulfide nanoparticles attain a higher temperature on irradiation, i.e., above 59 °C. The photothermal conversion efficiency of this material is determined, and the significance of dysprosium doping is discussed. Contrarily, the undoped nickel sulfide nanoparticles show more significant antibacterial activity. This study presents a novel designed nanoparticle system and the exciting variation of properties on dysprosium doping in nickel sulfide nanoparticles.

Hydrogel with ROS scavenging effect encapsulates BR@Zn-BTB nanoparticles for accelerating diabetic mice wound healing via multimodal therapy

The strategies for eliminating excess reactive oxygen species (ROS) or suppressing inflammatory responses on the wound bed have proven effective for diabetic wound healing. In this work, a zinc-based nanoscale metal-organic framework (NMOF) functions as a carrier to deliver natural product berberine (BR) to form BR@Zn-BTB nanoparticles, which was, in turn, further encapsulated by hydrogel with ROS scavenging ability to yield a composite system of BR@Zn-BTB/Gel (denoted as BZ-Gel). The results show that BZ-Gel exhibited the controlled release of Zn²⁺ and BR in simulated physiological media to efficiently eliminated ROS and inhibited inflammation and resulted in a promising antibacterial effect. In vivo experiments further proved that BZ-Gel significantly inhibited the inflammatory response and enhanced collagen deposition, as well as to re-epithelialize the skin wound to ultimately promote wound healing in diabetic mice. Our results indicate that the ROS-responsive hydrogel coupled with BR@Zn-BTB synergistically promotes diabetic wound healing.

The role of probiotics as wound healers: an overall view

A wound is an injury to the skin or damage to the body tissue. The healing process differs between various kinds of wounds. Treatment of hard-to-heal (chronic) wounds becomes challenging for healthcare practitioners, especially if patients have underlying health complications such as diabetes. Infection of wounds is another factor that interferes with the healing process and extends its duration. Active research is being conducted into the development of advanced wound dressing technologies. These wound dressings are intended to manage the exudate, reduce bacterial infection and speed up the healing process. Probiotics have been receiving much attention because of their potential application in the clinical field, especially in diagnostics and treatment strategies of various infectious and non-infectious diseases. The host immune-modulatory response and antimicrobial activity of probiotics are expanding their role in the development of improved wound dressing technology.

Dual Anticancer and Antibacterial Properties of Silica-Based Theranostic Nanomaterials Functionalized with Coumarin343, Folic Acid and a Cytotoxic Organotin(IV) Metallodrug

Five different silica nanoparticles functionalized with vitamin B12, a derivative of coumarin found in green plants and a minimum content of an organotin(IV) fragment (1-MSN-Sn, 2-MSN-Sn, 2-SBA-Sn, 2-FSPm-Sn and 2-FSPs-Sn), were identified as excellent anticancer agents against triple negative breast cancer, one of the most diagnosed and aggressive cancerous tumors, with very poor prognosis. Notably, compound 2-MSN-Sn shows selectivity for cancer cells and excellent luminescent properties detectable by imaging techniques once internalized. The same compound is also able to interact with and nearly eradicate biofilms of Staphylococcus aureus, the most common bacteria isolated from chronic wounds and burns, whose treatment is a clinical challenge. 2-MSN-Sn is efficiently internalized by bacteria in a biofilm state and destroys the latter through reactive oxygen species (ROS) generation. Its internalization by bacteria was also efficiently monitored by fluorescence imaging. Since silica nanoparticles are particularly suitable for oral or topical administration, and considering both its anticancer and antibacterial activity, 2-MSN-Sn represents a new dual-condition theranostic agent, based primarily on natural products or their derivatives and with only a minimum amount of a novel metallodrug.

Nanomaterials and nanomaterials-based drug delivery to promote cutaneous wound healing

Various factors could damage the structure and integrity of skin to cause wounds. Nonhealing or chronic wounds seriously affect the well-being of patients and bring heavy burdens to the society. The past few decades have witnessed application of numerous nanomaterials to promote wound healing. Owing to the unique physicochemical characteristics at nanoscale, nanomaterials-based therapy has been regarded as a potential approach to promote wound healing. In this review, we first overview the wound categories, wound healing process and critical influencing factors. Then applications of nanomaterials with intrinsic therapeutic effect and nanomaterials-based drug delivery systems to promote wound healing are addressed in detail. Finally, current limitations and future perspectives of nanomaterials in wound healing are discussed.

Fabrication and Bioactivity of Peptide-Conjugated Biomaterial Tissue Engineering Constructs

Tissue engineering combines materials engineering, cells and biochemical factors to improve, restore or replace various types of biological tissues. A nearly limitless combination of these strategies can be combined, providing a means to augment the function of a number of biological tissues such as skin tissue, neural tissue, bones, and cartilage. Compounds such as small molecule therapeutics, proteins, and even living cells have been incorporated into tissue engineering constructs to influence biological processes at the site of implantation. Peptides have been conjugated to tissue engineering constructs to circumvent limitations associated with conjugation of proteins or incorporation of cells. This review highlights various contemporary examples in which peptide conjugation is used to overcome the disadvantages associated with the inclusion of other bioactive compounds. This review covers several peptides that are commonly used in the literature as well as those that do not appear as frequently to provide a broad scope of the utility of the peptide conjugation technique for designing constructs capable of influencing the repair and regeneration of various bodily tissues. Additionally, a brief description of the construct fabrication techniques encountered in the covered examples and their advantages in various tissue engineering applications is provided.

Effect of stem cell treatment on burn wounds: A systemic review and a meta-analysis

A meta-analysis was performed to evaluate the effect of stem cells treatment in managing burn wounds. A systematic literature search up to March 2022 incorporated 24 studies reported between 2013 and 2021 including 400 animals with burn wounds at the beginning of the study; 211 were using stem cells treatment, and 189 controlled. Statistical tools like the contentious method were used within a random or fixed-influence model to establish the mean difference (MD) with 95% confidence intervals (CIs) to evaluate the influence of stem cells treatment in managing burn wounds. Stem cells treatment had a significantly higher burn wound healing rate (MD, 15.18; 95% CI, 11.29-19.07, P < .001), higher blood vessel number (MD, 12.28; 95% CI, 10.06-14.51, P < .001), higher vascular endothelial growth factor (MD, 10.24; 95% CI, 7.19-13.29, P < .001), lower interleukin-1 level (MD, -98.48; 95% CI, -155.33 to -41.63, P < .001), and lower tumour necrosis factor α level (MD, -28.71; 95% CI, -46.65 to -10.76, P < .002) compared with control in animals' models with burn wounds. Stem cells treatment had a significantly higher burn wound healing rate, higher blood vessel number, higher vascular endothelial growth factor, lower interleukin-1 level, and lower tumour necrosis factor α level compared with control in animals' models with burn wounds. Further studies are required to validate these findings.

Photodynamic therapy for treating infected skin wounds: A systematic review and meta-analysis from randomized clinical trials

BACKGROUND

Infected skin wounds represent a public health problem that effects 20 million people worldwide. Photodynamic therapy (PDT) is a treatment option with excellent results against several infections.

OBJECTIVE

This study aimed to perform a systematic review and meta-analysis on PDT efficacy for treating infected wounds based on randomized clinical trials (RCTs).

METHODS

PubMed, Scopus, Web of Science, SciELO, and the Cochrane library were searched. The Delphi List criteria and the Revised Cochrane risk-of-bias (Rob 2) were used for evaluating the quality of clinical trials. Meta-analyses were performed with the random-effect model. The odds ratio was the effect measure for binary outcomes, while the standard mean difference was used for continuous outcomes. The trim-and-fill method was used to detect small-study effects. The quality of evidence was verified for each outcome.

RESULTS

Only four out of 573 articles were selected for the qualitative and quantitative analyses. The most frequent cause of infected wounds was impaired venous circulation (75%). All studies used red LED light. PDT reduced healing time and improved the healing process and wound oxygenation. Patients treated with PDT showed 15% to 17% (p = 0.0003/ I²=0%) lower microbial cell viability in the wound and a significantly smaller wound size (0.72 cm²/p = 0.0187/I²=0%) than patients treated with placebo or red-light exposure. There was a high level of evidence for each meta-analysis outcome.

CONCLUSION

PDT can be an excellent alternative treatment for infected skin wounds, though larger trials are needed.

Nano-material utilization in stem cells for regenerative medicine

The utilization of nanotechnology in regenerative medicine has been globally proven to be the main solution to many issues faced with tissue engineering today, and the theoretical and empirical investigations of the association of nanomaterials with stem cells have made significant progress as well. For their ability to self-renew and differentiate into a variety of cell types, stem cells have become popular candidates for cell treatment in recent years, particularly in cartilage and Ocular regeneration. However, there are still several challenges to overcome before it may be used in a wide range of therapeutic contexts. This review paper provides a review of the various implications of nanomaterials in tissue and cell regeneration, the stem cell and scaffold application in novel treatments, and the basic developments in stem cell-based therapies, as well as the hurdles that must be solved for nanotechnology to be used in its full potential. Due to the increased interest in the continuously developing field of nanotechnology, demonstrating, and pinpointing the most recognized and used applications of nanotechnology in regenerative medicine became imperative to provide students, researchers, etc. who are interested.

Development and characterization of mupirocin encapsulated in animal bone-derived hydroxyapatite for management of chronic wounds

Background

Hydroxyapatite is an important biomedical material used in drug delivery owing to its excellent bioactivity and biocompatibility. In this study, hydroxyapatite isolated from bovine and caprine bones was capped and used as a drug carrier to encapsulate mupirocin as an active pharmaceutical product in hydrogel formulations which were utilized in wound healing application using animal model (Wistar Rats).

Results

Characterization of the mupirocin-encapsulated hydroxyapatite using Fourier transform infrared spectroscopy, and X-ray diffractometer revealed the active presence of mupirocin after encapsulation. The in-vitro drug release study revealed that the capped hydroxyapatite obtained from caprine bone loaded with mupirocin gave drug release rate of 84.67% of the drug within 75 min while conventional mupirocin ointment had the lowest at 27.04% within the same time. The capped hydroxyapatite obtained from bovine bone loaded with mupirocin had the highest encapsulation efficiency of 73.67%. However, the animals treated with formulation prepared from capped hydroxyapatite obtained from caprine bone loaded with mupirocin had the highest wound closure area of 377.8 mm2, while conventional mupirocin ointment had 231.5 mm2 in 16 days of treatment. All the formulations with mupirocin except the ointment showed excellent resistance against Klebsiella pneumonia and Staphylococcus aureus of about 40 mm of inhibition zone.

Conclusions

The mupirocin encapsulated in hydroxyapatite extracted from bovine and caprine bones has been demonstrated to be more superior to the conventional ointment in the management of chronic wound conditions.

A review of wound dressing materials and its fabrication methods: emphasis on three-dimensional printed dressings

A wound is a trauma caused by some adverse external or blunt forces that can damage the body tissues. Wound healing is a complex process that occurs post-injury which involves the revamping of the structure and function of damaged tissues. Scaffolds are engineered tissue structures manufactured using different materials and methods for facilitating the wound healing process. For external wounds, the antimicrobial property and ability to absorb moisture play an important role in the material selection of the scaffold. Among different methods that exist for designing scaffolds, three-dimensional printing has emerged as a promising technique wherein customised scaffolds can be designed. However, the literature on three-dimensional printed dressings is very much limited compared to conventional ones. Therefore, this review specifically focuses on the methods used to design the scaffolds with special emphasis on different three-dimensional printing techniques. It covers the process of external wound healing, different materials used in the fabrication of scaffolds, and their advantages and drawbacks.

Advancement in Nanoformulations for the Management of Diabetic Wound Healing

People with diabetes have a very slow tendency for wound healing. Wound healing is a vast process where several factors inhibit the sequence of healing. Nano formulation plays a major role during acute and chronic wound healing. The present manuscript aims to discuss the role of nanoformulation in the treatment of diabetic wound healing. Diabetes is a common disease that has harmful consequences which lead to bad health. During the literature survey, it was observed that nanotechnology has significant advantages in the treatment of diabetic wound healing. The present manuscript summarized the role of nanomaterials in wound healing, challenges in diabetic wound healing, physiology of wound healing, a limitation that comes during wound repair, and treatments available for wound healing. After a comprehensive literature survey, it can be concluded that health worker needs more focus on the area of wound healing in diabetic patients. Medical practitioners, pharmaceutical and biomedical researchers need more attention towards the utilization of nanoformulations for the treatment of wound healing, specifically in the case of diabetes.

Nanotechnology-based therapeutic applications: in vitro and in vivo clinical studies for diabetic wound healing

Diabetic wounds often indicate chronic complications that are difficult to treat. Unfortunately, existing conventional treatment modalities often cause unpremeditated side effects, given the need to develop alternative therapeutic phenotypes that are safe or have minimal side effects and risks. Nanotechnology-based platforms, including nanotherapeutics, nanoparticles (NPs), nanofibers, nanohydrogels, and nanoscaffolds, have garnered attention for their groundbreaking potential to decipher the biological environment and offer personalized treatment methods for wound healing. These nanotechnology-based platforms can successfully overcome the impediments posed by drug toxicity, existing treatment modalities, and the physiology and complexity of the wound sites. Furthermore, studies have shown that they play an essential role in influencing angiogenesis, collagen production, and extracellular matrix (ECM) synthesis, which are integral in skin repair mechanisms. In this review, we emphasized the importance of various nanotechnology-based platforms for healing diabetic wounds and report on the innovative preclinical and clinical outcomes of different nanotechnology-based platforms. This review also outlined the limitations of existing conventional treatment modalities and summarized the physiology of acute and chronic diabetic wounds.

Differential Capability of Clinically Employed Dermal Regeneration Scaffolds to Support Vascularization for Tissue Bioengineering

The loss of skin integrity has always represented a major challenge for clinicians dealing with dermal defects, such as ulcers (diabetic, vascular and chronic), postoncologic resections (i.e., radical vulvectomy) or dermatologic disorders. The introduction in recent decades of acellular dermal matrices (ADMs) supporting the repair and restoration of skin functionality represented a significant step toward achieving clean wound repair before performing skin grafts. Hard-to-heal ulcers generally depend on local ischemia and nonadequate vascularization. In this context, one possible innovative approach could be the prevascularization of matrices with vessel-forming cells (inosculation). This paper presents a comparative analysis of the most widely used dermal templates, i.e., Integra^® Bilayer Matrix Wound Dressing, PELNAC^®, PriMatrix^® Dermal Repair Scaffold, Endoform^® Natural Dermal Template, and Myriad Matrix^®, testing their ability to be colonized by human adult dermal microvascular endothelial cells (ADMECs) and to induce and support angiogenesis in vitro and in vivo. By in vitro studies, we demonstrated that Integra^® and PELNAC^® possess superior pro-adhesive and pro-angiogenetic properties. Animal models allowed us to demonstrate the ability of preseeded ADMECs on Integra^® to promote the engraftment, integration and vascularization of ADMs at the site of application.

Collagen-Containing Fish Sidestream-Derived Protein Hydrolysates Support Skin Repair via Chemokine Induction

Restoring homeostasis following tissue damage requires a dynamic and tightly orchestrated sequence of molecular and cellular events that ensure repair and healing. It is well established that nutrition directly affects skin homeostasis, while malnutrition causes impaired tissue healing. In this study, we utilized fish sidestream-derived protein hydrolysates including fish collagen as dietary supplements, and investigated their effect on the skin repair process using a murine model of cutaneous wound healing. We explored potential differences in wound closure and histological morphology between diet groups, and analyzed the expression and production of factors that participate in different stages of the repair process. Dietary supplementation with fish sidestream-derived collagen alone (Collagen), or in combination with a protein hydrolysate derived from salmon heads (HSH), resulted in accelerated healing. Chemical analysis of the tested extracts revealed that Collagen had the highest protein content and that HSH contained the great amount of zinc, known to support immune responses. Indeed, tissues from mice fed with collagen-containing supplements exhibited an increase in the expression levels of chemokines, important for the recruitment of immune cells into the damaged wound region. Moreover, expression of a potent angiogenic factor, vascular endothelial growth factor-A (VEGF-A), was elevated followed by enhanced collagen deposition. Our findings suggest that a 5%-supplemented diet with marine collagen-enriched supplements promotes tissue repair in the model of cutaneous wound healing, proposing a novel health-promoting use of fish sidestreams.

Nanomaterials in Skin Regeneration and Rejuvenation

Skin is the external part of the human body; thus, it is exposed to outer stimuli leading to injuries and damage, due to being the tissue mostly affected by wounds and aging that compromise its protective function. The recent extension of the average lifespan raises the interest in products capable of counteracting skin related health conditions. However, the skin barrier is not easy to permeate and could be influenced by different factors. In the last decades an innovative pharmacotherapeutic approach has been possible thanks to the advent of nanomedicine. Nanodevices can represent an appropriate formulation to enhance the passive penetration, modulate drug solubility and increase the thermodynamic activity of drugs. Here, we summarize the recent nanotechnological approaches to maintain and replace skin homeostasis, with particular attention to nanomaterials applications on wound healing, regeneration and rejuvenation of skin tissue. The different nanomaterials as nanofibers, hydrogels, nanosuspensions, and nanoparticles are described and in particular we highlight their main chemical features that are useful in drug delivery and tissue regeneration.

Surgical Strategies to Promote Cutaneous Healing

Usually, cutaneous wound healing does not get impeded and processes uneventfully, reaching wound closure easily. The goal of this repair process is to restore the integrity of the body surface by creating a resilient and stable scar. Surgical practice and strategies have an impact on the course of wound healing and the later appearance of the scar. By considering elementary surgical principles, such as the appropriate suture material, suture technique, and timing, optimal conditions for wound healing can be created. Wounds can be differentiated into clean wounds, clean–contaminated wounds, contaminated, and infected/dirty wounds, based on the degree of colonization or infection. Furthermore, a distinction is made between acute and chronic wounds. The latter are wounds that persist for longer than 4–6 weeks. Care should be taken to avoid surgical site infections in the management of wounds by maintaining sterile working conditions, using antimicrobial working techniques, and implementing the principles of preoperative antibiotics. Successful wound closure is influenced by wound debridement. Wound debridement removes necrotic tissue, senescent and non-migratory cells, bacteria, and foreign bodies that impede wound healing. Additionally, the reconstructive ladder is a viable and partially overlapping treatment algorithm in plastic surgery to achieve successful wound closure.

Antioxidant Properties of Plant-Derived Phenolic Compounds and Their Effect on Skin Fibroblast Cells

Plants are rich sources of a diverse range of chemicals, many of which have significant metabolic activity. One large group of secondary compounds are the phenolics, which act as inter alia potent reactive oxygen scavengers in cells, including fibroblasts. These common dermis residue cells play a crucial role in the production of extracellular matrix components, such as collagen, and maintaining the integrity of connective tissue. Chronic wounds or skin exposure to UV-irradiation disrupt fibroblast function by the generation of reactive oxygen species, which may damage cell components and modify various signaling pathways. The resulting imbalance may be reversed by the antioxidant activity of plant-derived phenolic compounds. This paper reviews the current state of knowledge on the impact of phenolics on fibroblast functionality under oxidative stress conditions. It examines a range of compounds in extracts from various species, as well as single specific plant-derived compounds. Phenolics are a good candidate for eliminating the causes of skin damage including wounds and aging and acting as skin care agents.

Biopolymer-based Scaffolds for Tissue Engineering Applications

Tissue engineering is governed by the use of cells and polymers. The cells may be accounted for the type of tissue to be targeted, while polymers may vary from natural to synthetic. The natural polymers have advantages such as non-immunogenic and complex structures that help in the formation of bonds in comparison to the synthetic ones. Various targeted drug delivery systems have been prepared using polymers and cells, such as nanoparticles, hydrogels, nanofibers, and microspheres. The design of scaffolds depends on the negative impact of material used on the human body and they have been prepared using surface modification technique or neo material synthesis. The dermal substitutes are a distinctive array that aims at the replacement of skin parts either through grafting or some other means. This review focuses on biomaterials for their use in tissue engineering. This article shall provide the bird's eye view of the scaffolds and dermal substitutes, which are naturally derived.

Efficacy of stem cell therapy for burn wounds: a systematic review and meta-analysis of preclinical studies

BACKGROUND

Burns remain a serious public health problem with high morbidity and mortality rates worldwide. Although there are various treatment options available, there is no consensus on the best treatment for severe burns as of yet. Stem cell therapy has a bright prospect in many preclinical studies of burn wounds. The systematic review was performed for these preclinical studies to assess the efficacy and possible mechanisms of stem cells in treating burn wounds.

METHODS

Twenty-two studies with 595 animals were identified by searching PubMed, EMBASE, Web of Science, and Cochrane Library databases from inception to 13 May 2020. In addition, a manual search of references of studies was performed to obtain potential studies. No language or time restrictions were enforced. RevMan 5.3 was used for all data analysis.

RESULTS

The overall meta-analysis showed that stem cell therapy significantly improved burn healing rate (SMD 3.06, 95% CI 1.98 to 4.14), irrespective of transplant type, burn area, and treatment method in the control group. Subgroup analyses indicated that hair follicle stem cells seemed to exert more beneficial effects on animals with burn wounds (SMD 7.53, 95% CI 3.11 to 11.95) compared with other stem cells. Furthermore, stem cell therapy seemed to exert more beneficial effects on burn wounds with second-degree (SMD 7.53, 95% CI 3.11 to 11.95) compared with third-degree (SMD 2.65, 95% CI 1.31 to 4.00).

CONCLUSIONS

Meta-analysis showed that stem cell therapy exerts a healing function for burn wounds, mainly through angiogenesis and anti-inflammatory actions. These findings also demonstrate the need for considering variations in future clinical studies using stem cells to treat a burn wound in order to maximize the effectiveness. In general, stem cells can potentially become a novel therapy candidate for burn wounds.

Commercial hydrogels for biomedical applications

Hydrogels are polymeric networks having the ability to absorb a large volume of water. Flexibility, versatility, stimuli-responsive, soft structure are the advantages of hydrogels. It is classified based on its source, preparation, ionic charge, response, crosslinking and physical properties. Hydrogels are used in various fields like agriculture, food industry, biosensor, biomedical, etc. Even though hydrogels are used in various industries, more researches are going in the field of biomedical applications because of its resembles to living tissue, biocompatibility, and biodegradability. Here, we are mainly focused on the commercially available hydrogels used for biomedical applications like wound dressings, contact lenses, cosmetic applications, tissue engineering, and drug delivery.

A systematic review of pharmacological activities and safety of Moringa oleifera

In the last few decades, Moringa oleifera, a multipurpose medicinal plant (MMP) has received increased research attention and commercial interest for its nutritional, therapeutic and pharmacological properties. Rigorous approaches including biological assays, animal and clinical trials are required towards safe usage as herbal therapy. We conducted a systematic review of the known pharmacological activities, toxicity, and safety of M. oleifera, usually used locally in the treatment and prevention of myriads of illnesses. Five major bibliographic databases (SCOPUS, Web of Science, Science Direct, PubMed, and Mendeley) were searched for studies reported on pharmacological activities, toxicity, and safety assessment of M. oleifera in the last 29 years (1990 – 2019). Studies on animals and humans involving aqueous leaf extracts and different preparations from M. oleifera seed and bark were also considered. All articles retained, and data collected were evaluated based on the period of the article, country where such studies were conducted and the document type. Our search results identified and analyzed 165 articles while 63 studies were eventually retained. Diverse pharmacological activities including neuroprotective, antimicrobial, antiasthmatic, anti-malaria, cardioprotective, antidiabetic, antiobesity, hepatoprotective and cytotoxic effects, amongst others, were recorded. Toxicity studies in animal models and few human studies showed that M. oleifera is safe with no adverse effect reported. The importance of the plant is highlighted in the search for new bioactive compounds to explore its therapeutic potentials towards drug discovery and development in the pharmaceutical and allied industries.

Nano-drug delivery systems in wound treatment and skin regeneration

Skin damages are defined as one of most common lesions people suffer from, some of wounds are notoriously difficult to eradicate such as chronic wounds and deep burns. Existing wound therapies have been proved to be inadequate and far from satisfactory. The cutting-edge nanotechnology offers an unprecedented opportunity to revolutionize and invent new therapies or boost the effectiveness of current medical treatments. In particular, the nano-drug delivery systems anchor bioactive molecules to applied area, sustain the drug release and explicitly enhance the therapeutic efficacies of drugs, thus making a fine figure in field relevant to skin regeneration. This review summarized and discussed the current nano-drug delivery systems holding pivotal potential for wound healing and skin regeneration, with a special emphasis on liposomes, polymeric nanoparticles, inorganic nanoparticles, lipid nanoparticles, nanofibrous structures and nanohydrogel.

Electrospun Fibers as a Dressing Material for Drug and Biological Agent Delivery in Wound Healing Applications

Wound healing is a complex tissue regeneration process that promotes the growth of new tissue to provide the body with the necessary barrier from the outside environment. In the class of non-healing wounds, diabetic wounds, and ulcers, dressing materials that are available clinically (e.g., gels and creams) have demonstrated only a slow improvement with current available technologies. Among all available current technologies, electrospun fibers exhibit several characteristics that may provide novel replacement dressing materials for the above-mentioned wounds. Therefore, in this review, we focus on recent achievements in electrospun drug-eluting fibers for wound healing applications. In particular, we review drug release, including small molecule drugs, proteins and peptides, and gene vectors from electrospun fibers with respect to wound healing. Furthermore, we provide an overview on multifunctional dressing materials based on electrospun fibers, including those that are capable of achieving wound debridement and wound healing simultaneously as well as multi-drugs loading/types suitable for various stages of the healing process. Our review provides important and sufficient information to inform the field in development of fiber-based dressing materials for clinical treatment of non-healing wounds.

Acellular Gelatinous Material of Human Umbilical Cord Enhances Wound Healing: A Candidate Remedy for Deficient Wound Healing

Impaired wound healing is a severe clinical challenge and research into finding effective wound healing strategies is underway as there is no ideal treatment. Gelatinous material from the umbilical cord called Wharton's jelly is a valuable source of mesenchymal stem cells which have been shown to aid wound healing. While the cellular component of Wharton's jelly has been the subject of extensive research during the last few years, little is known about the de-cellularized jelly material of the umbilical cord. This is important as they are native niche of stem cells. We have isolated Wharton's jelly from umbilical cords and then fractionated acellular gelatinous Wharton's jelly (AGWJ). Here, we show for the first time that AGWJ enhances wound healing in vitro as well as in vivo for wounds in a murine model. In vivo staining of the wounds revealed a smaller wound length in the AGWJ treated wounds in comparison to control treatment by enhancing cell migration and differentiation. AGWJ significantly enhanced fibroblast cell migration in vitro. Aside from cell migration, AGWJ changed the cell morphology of fibroblasts to a more elongated phenotype, characteristic of myofibroblasts, confirmed by upregulation of alpha smooth muscle actin using immunoblotting. AGWJ treatment of wounds led to accelerated differentiation of cells into myofibroblasts, shortening the proliferation phase of wound healing. This data provides support for a novel wound healing remedy using AGWJ. AGWJ being native biological, cost effective and abundantly available globally, makes it a highly promising treatment option for wound dressing and skin regeneration.

A survey of herbal weeds for treating skin disorders from Southern Thailand: Songkhla and Krabi Province

ETHNOPHARMACOLOGICAL RELEVANCE

Skin diseases are common health problems which affecting to all ages. In Thailand, the number of patients diagnosed with skin diseases is increasing every year. Nowadays, The Ministry of Public Health is supporting and promoting herbs for treating various disorders, including disorders of the skin to reduce the problem of antibiotic resistance and adverse drug reactions. This study aimed to: (1) enumerate the herbal weeds for treating skin disorders; (2) study local knowledge of weed utilization for treating skin disorders according to the folk healers in Songkhla and Krabi province; and (3) study quantitative data by Informant consensus factor (ICF), Use value (UV) and Fidelity level (FL) value.

MATERIALS AND METHODS

Field surveys and Semi-structured interviews about the local names, parts of plants used, preparation and use method, as well as local properties were done. The data were further analyzed by descriptive statistics, interpretation and quantitative indexes (ICF, UV as well as FL).

RESULTS

The results discovered 44 herbal species of weeds belonging to 41 genera in 25 families. The most used plant families were Amaranthaceae (6 species). Most plants were used to treat abscess (18 species; 40.91%). The highest UV was recorded for Commelina benghalensis (0.65). The highest ICF values were found in vitiligo, ringworm, tinea versicolor and burns (1.00 each). The highest FL values were recorded for Cleome gynandra, Cleome viscosa, Sphenoclea zeylanica, Acmella oleracea, Leersia hexandra, Cyperus involucratus, Phyllanthus urinaria and Iresine herbstii (100.00 each). A review of the literatures revealed that 34 plant species had already been tested for their pharmacological activities. The biological activities associated with treatment of skin diseases can be divided into four categories: antimicrobial, anti-inflammatory, wound healing and antioxidant activity.

CONCLUSION

The information indicates that herbal weedy utilization is still importance to the treatment of traditional healers through accumulated experience for a long time. Therefore, this study is a guide to the conservation of folk medicinal knowledge. It might be implied as the basis for drug development and application of herbal weeds to treat skin disorders along with promoting sustainable use of natural resource.

Administration of adipose-derived stem cells enhances vascularity, induces collagen deposition, and dermal adipogenesis in burn wounds

Current treatment options for severe burn wounds are often insufficient in reconstructing skin and soft tissue defects. Adipose-derived stem cells (ASCs), a readily available source of multipotent stem cells, represent a promising therapy for the treatment of full-thickness burn wounds. Full-thickness burn wounds were created on the paraspinal region of athymic mice. A one-time, sub-eschar injection of 6.8×10(6) ASCs in PBS or PBS alone was administered at 24-h postoperatively. Time to healing was quantified using Image J analysis. At days 4, 7, 14, and 21, mice were sacrificed and tissues were excised for molecular and histological analysis. ASCs were able to survive in burn wounds as determined by the presence of PKH labeling and human PPARγ expression within the wounds. CD-31 staining demonstrated increased vascularity in ASC-treated wounds at POD 4 (p<0.05). Molecular studies showed enhanced adipogenesis, as well as type III and type I collagen deposition in the ASC treated group (p<0.05). An increase in the mRNA expression ratio of type III to type I collagen was also observed following ASC treatment (p<0.05). By enhancing vascularity, collagen deposition, and adipogenesis, ASCs show promise as an adjunctive therapy for the current treatment of full thickness burn wounds.

Biomaterials and host versus graft response: a short review

Biomaterials and biotechnology are increasing becoming an important area in modern medicine. The main aim in this area is the development of materials, which are biocompatible to normal tissue. Tissue-implant interactions with molecular, biological and cellular characteristics at the implant-tissue interface are important for the use and development of implants. Implantation may cause an inflammatory and immune response in tissue, foreign body reaction, systemic toxicity and imminent infection. Tissue-implant interactions determine the implant life-period. The aims of the study are to consider the biological response to implants. Biomaterials and host reactions to implants and their mechanisms are also briefly discussed.

Wound healing properties of ethyl acetate fraction of Moringa oleifera in normal human dermal fibroblasts

BACKGROUND/AIM

Wounds are the outcome of injuries to the skin that interrupt the soft tissue. Healing of a wound is a complex and long-drawn-out process of tissue repair and remodeling in response to injury. A large number of plants are used by folklore traditions for the treatment of cuts, wounds and burns. Moringa oleifera (MO) is an herb used as a traditional folk medicine for the treatment of various skin wounds and associated diseases. The underlying mechanisms of wound healing activity of ethyl acetate fraction of MO leaves extract are completely unknown.

MATERIALS AND METHODS

In the current study, ethyl acetate fraction of MO leaves was investigated for its efficacy on cell viability, proliferation and migration (wound closure rate) in human normal dermal fibroblast cells.

RESULTS

Results revealed that lower concentration (12.5 µg/ml, 25 µg/ml, and 50 µg/ml) of ethyl acetate fraction of MO leaves showed remarkable proliferative and migratory effect on normal human dermal fibroblasts.

CONCLUSION

This study suggested that ethyl acetate fraction of MO leaves might be a potential therapeutic agent for skin wound healing by promoting fibroblast proliferation and migration through increasing the wound closure rate corroborating its traditional use.

Reducing the pathogen burden and promoting healing with polyhexanide in non-healing wounds: a prospective study

OBJECTIVE

Polyhexamethylene biguanide (PHMB) is a novel wound antiseptic solution that has a broad antimicrobial spectrum and wound healing promoting effect, with minimal side effects. The aim of present study was to demonstrate the efficacy of the PHMB on the bacterial burden of non-healing wounds, the reduction in wound size or closure of the wound in comparison to Ringer's lactate solution (RLS) after 21 days of wound dressing. A second objective was to investigate the differences in the C-reactive protein (CRP) levels and white blood cell (WBC) counts between the two groups.

METHOD

In this prospective and open-cohort clinical study, patients who underwent cardiac surgery between July 2006 and August 2008 were included and placed in one of two groups, PHMB or RLS, by the block randomisation method. A wound care team, consisting of two surgeons, a wound care nurse and a microbiologist, was created. Classic moist dressings and wet compresses during dressing changes were applied at least once a day or as needed. During the 21 days of hospitalisation the team collected data on the wound healing status daily, on infection parameters every third day, and wound tissue for culture weekly.

RESULTS

There were 40 patients recruited of which 9 were excluded, leaving 31 in the intention-to-treat analysis. Of these 15 received PHMB and 16 received RLS. Overall 17 of 31 (66.7% PHMB group, 43.8% RLS group, p=0.181) patients were treated successfully by closure of surgically sutured wounds or healing by secondary intention, the wound tissue cultures of 19 of 31 patients (47.4% PHMB, 52.6% RLS, p=0.886) were negative, and wound size of all the patients were significantly reduced in clinical observations. Although the CRP levels were reduced significantly within group comparisons in both groups (p<0.001), it was significantly lower after 12 days (p<0.05) in the PHMB group compared with the RLS group.

CONCLUSION

The results of this study emphasise that the successful treatment of chronic non-healing wounds require a multidisciplinary team approach under the control of a wound care specialist. Whatever the disinfectant used, consistency in the approach to treatment may be more important. We suggest that increasing the use of PHMB and adoption of this team approach in other cardiac centres or other populations may decrease the healing period, especially in chronic non-healing wounds.

Genetic and epigenetic alterations in Toll like receptor 2 and wound healing impairment in type 2 diabetes patients

AIM

Persistent hyperglycemic microenvironment in type 2 diabetes mellitus (T2DM) leads to the development of secondary complications like wound healing impairment. Proper co-ordination of innate immune system plays an integral role in wound healing. Toll like receptors (TLRs) are prominent contributors for the induction of the innate immune and inflammation response. TLR2 is an important extracellular member in mammalian TLR family and has been shown to be a potent player in the wound healing mechanism.

METHODS

Expressional status of TLR2 was seen in wounds of T2DM cases with respect to the severity of wounds in 110 human lower extremity wounds. The methylation status of TLR2 promoter was also examined.

RESULTS

Although TLR2 transcripts were downregulated in T2DM wounds compared to control, their levels tend to increase with the severity of T2DM wounds. The methylation status of TLR2 gene promoter was not significantly different among different grades of wounds in T2DM subjects. The CpG sites investigated were totally or partially methylated in majority of DFU cases.

CONCLUSION

TLR2 down regulation in wounds of T2DM patients compared to non diabetic patients may lead to development of non healing chronic ulcers in them.

Helium generated cold plasma finely regulates activation of human fibroblast-like primary cells

Non-thermal atmospheric pressure plasmas are being developed for a wide range of health care applications, including wound healing. However in order to exploit the potential of plasma for clinical applications, the understanding of the mechanisms involved in plasma-induced activation of fibroblasts, the cells active in the healing process, is mandatory. In this study, the role of helium generated plasma in the tissue repairing process was investigated in cultured human fibroblast-like primary cells, and specifically in hepatic stellate cells and intestinal subepithelial myofibroblasts. Five minutes after treatment, plasma induced formation of reactive oxygen species (ROS) in cultured cells, as assessed by flow cytometric analysis of fluorescence-activated 2′,7′-dichlorofluorescein diacetate probe. Plasma-induced intracellular ROS were characterized by lower concentrations and shorter half-lives with respect to hydrogen peroxide-induced ROS. Moreover ROS generated by plasma treatment increased the expression of peroxisome proliferator activated receptor (PPAR)-γ, nuclear receptor that modulates the inflammatory responses. Plasma exposure promoted wound healing in an in vitro model and induced fibroblast migration and proliferation, as demonstrated, respectively, by trans-well assay and partitioning between daughter cells of carboxyfluorescein diacetate succinimidyl ester fluorescent dye. Plasma-induced fibroblast migration and proliferation were found to be ROS-dependent as cellular incubation with antioxidant agents (e.g. N-acetyl L-cysteine) cancelled the biological effects. This study provides evidence that helium generated plasma promotes proliferation and migration in liver and intestinal fibroblast-like primary cells mainly by increasing intracellular ROS levels. Since plasma-evoked ROS are time-restricted and elicit the PPAR-γ anti-inflammatory molecular pathway, this strategy ensures precise regulation of human fibroblast activation and can be considered a valid therapeutic approach for liver and gut lesions.

Differential Expression of Matrix Metalloproteinase-9 Gene in Wounds of Type 2 Diabetes Mellitus Cases With Susceptible -1562C>T Genotypes and Wound Severity

Coordinated extracellular matrix deposition is a prerequisite for proper wound healing which is mainly orchestrated by matrix metalloproteinases (MMPs). Diabetic wounds generally show compromised wound healing cascade and abnormal MMP9 concentration is one of the cause. Our group have recently shown that the polymorphism -1562 C>T in the promoter region of MMP9 gene is associated with pathogenesis of wound healing impairment in T2DM patients. In present study we have done expression profiling of MMP9 gene in the wound biopsy of DFU cases. Expression level of MMP9 mRNA was then compared with susceptible -1562 C>T genotypes (TT and CT) as well as with different grades of wounds. We also screened the promoter region of MMP9 gene to see the methylation state of CpGs present there. Our study suggests that levels of MMP9 mRNA increase significantly with the wound grades. Moreover, the MMP9 levels in diabetic wounds were also dependent on -1562 C>T polymorphism in the promoter region of MMP9. Diabetic wounds also showed a significant unmethylated status of MMP9 promoter compared to control wounds. In conclusion, The risk genotypes of -1562 C>T polymorphism along with lack of methylation of CpG sites in MMP9 gene promoter may result in altered expression of MMP9 in wounds of T2DM cases resulting into nonhealing chronic ulcers in them.

A novel serine protease secreted by medicinal maggots enhances plasminogen activator-induced fibrinolysis

Maggots of the blowfly Lucilia sericata are used for the treatment of chronic wounds. As haemostatic processes play an important role in wound healing, this study focused on the effects of maggot secretions on coagulation and fibrinolysis. The results showed that maggot secretions enhance plasminogen activator-induced formation of plasmin and fibrinolysis in a dose- and time-dependent manner. By contrast, coagulation was not affected by secretions. Biochemical studies indicated that a novel serine protease within secretions, designated Sericase, cleaved plasminogen to several fragments. Recombinant Sericase degraded plasminogen leading amongst others to the formation of the mini-plasminogen like fragment Val454-plasminogen. In addition, the presence of a non-proteolytic cofactor in secretions was discovered, which plays a role in the enhancement of plasminogen activator-induced fibrinolysis by Sericase. We conclude from our in vitro studies that the novel serine protease Sericase, with the aid of a non-proteolytic cofactor, enhances plasminogen activator-induced fibrinolysis.

A functional single nucleotide polymorphism -1562C>T in the matrix metalloproteinase-9 promoter is associated with type 2 diabetes and diabetic foot ulcers

Impaired neovascularization is the hallmark of type 2 diabetes, which results in various macro- and microvascular complications and the development of foot ulcerations later in life. Matrix metalloproteinases (MMPs) are the key enzymes which influence matrix remodeling. Here, we aim to investigate that whether single nucleotide polymorphism (SNP -1562C>T) (rs3918242) in the promoter region of MMP-9 gene, which alters the transcriptional activity of MMP-9 is associated with type 2 diabetes and diabetic foot ulcers (DFUs). This case-control study was composed of 730 individuals, out of which 463 patients were with type 2 diabetes mellitus (T2DM) and 267 were nondiabetic healthy controls (non-DM controls). T2DM patients were subclassified as 149 cases without any secondary complications (T2DMNSC), 110 with DFUs, 204 T2DM patients having one or the other secondary complications. Genotyping for -1562C>T SNP in MMP-9 gene was done by polymerase chain reaction-restriction fragment length polymorphism method and sequencing. SNP -1562C>T of MMP-9 gene showed a significant association with T2DM and DFU. The allele distribution differed significantly between patients and normal control group (odds ratio = 1.82, P = .00005, 95% confidence interval = 1.36-2.42 for T2DM vs control and odds ratio = 2.112, P = .00048, 95% confidence interval = 1.38-3.126 for DFU vs control) indicating strong association of SNP -1562C>T of MMP-9 gene with T2DM and DFU in an Indian population. SNP -1562C>T in the promoter of the MMP-9 gene results in increased expression at the level of the transcription. To the best of our knowledge, this is the first report that suggests that SNP -1562C>T in the promoter of the MMP-9 gene is associated with T2DM and DFU. An increased MMP-9 production from high expressing T allele may promote matrix degradation.

Association of Toll-like receptor 4 polymorphisms with diabetic foot ulcers and application of artificial neural network in DFU risk assessment in type 2 diabetes patients

The Toll-Like receptor 4 (TLR4) plays an important role in immunity, tissue repair, and regeneration. The objective of the present work was to evaluate the association of TLR4 single nucleotide polymorphisms (SNPs) rs4986790, rs4986791, rs11536858 (merged into rs10759931), rs1927911, and rs1927914 with increased diabetic foot ulcer (DFU) risk in patients with type 2 diabetes mellitus (T2DM). PCR-RFLP was used for genotyping TLR4 SNPs in 125 T2DM patients with DFU and 130 controls. The haplotypes and linkage disequilibrium between the SNPs were determined using Haploview software. Multivariate linear regression (MLR) and artificial neural network (ANN) modeling was done to observe their predictability for the risk of DFU in T2DM patients. Risk genotypes of all SNPs except rs1927914 were significantly associated with DFU. Haplotype ACATC (P value = 9.3E − 5) showed strong association with DFU risk. Two haplotypes ATATC (P value = 0.0119) and ATGTT (P value = 0.0087) were found to be protective against DFU. In conclusion TLR4 SNPs and their haplotypes may increase the risk of impairment of wound healing in T2DM patients. ANN model (83%) is found to be better than the MLR model (76%) and can be used as a tool for the DFU risk assessment in T2DM patients.

Expression analysis of wound healing genes in human periapical granulomas of progressive and stable nature

INTRODUCTION

Wound healing process involves the activation of extracellular matrix components, remodeling enzymes, cellular adhesion molecules, growth factors, cytokines and chemokines genes. However, the molecular patterns underlying the healing process at the periapical environment remain unclear. Here we hypothesized that endodontic infection might result in an imbalance in the expression of wound healing genes involved in the pathogenesis of periapical lesions. Furthermore, we suggest that differential expression of wound healing markers in active and latent granulomas could account for different clinical outcomes for such lesions.

METHODS

Study samples consisted of 93 periapical granulomas collected after endodontic surgeries and 24 healthy periodontal ligament tissues collected from premolars extracted for orthodontic purposes as control samples. Of these, 10 periapical granulomas and 5 healthy periapical tissues were used for expression analysis of 84 wound healing genes by using a pathway-specific real-time polymerase chain reaction array. The remaining 83 granulomas and all 24 control specimens were used to validate the obtained array data by real-time polymerase chain reaction. Observed variations in expression of wound healing genes were analyzed according to the classification of periapical granulomas as active/progressive versus inactive/stable (as determined by receptor activator for nuclear factor kappa B ligand/osteoprotegerin expression ratio).

RESULTS

We observed a marked increase of 5-fold or greater in SERPINE1, TIMP1, COL1A1, COL5A1, VTN, CTGF, FGF7, TGFB1, TNF, CXCL11, ITGA4, and ITGA5 genes in the periapical granulomas when compared with control samples. SERPINE1, TIMP1, COL1A1, TGFB1, and ITGA4 mRNA expression was significantly higher in inactive compared with active periapical granulomas (P < .001), whereas TNF and CXCL11 mRNA expression was higher in active lesions (P < .001).

CONCLUSIONS

The identification of novel gene targets that curb the progression status of periapical lesions might contribute to a more accurate diagnosis and lead to treatment modalities more conducive to endodontic success.