Novel pharmacotherapy for burn wounds: what are the advancements

Nanotechnological Advances in Burn Wound Care: Silver Sulfadiazine-Loaded Nanosuspension-Based Chitosan-Incorporated Nanogel for Partial Thickness Burns

Burn lesions damage the skin's outermost defensive layer, allowing pathogenic microbes including Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli to infiltrate. Silver sulfadiazine (SSD) is an effective antibacterial agent approved by U.S. Food and Drug Administration (US-FDA) and is considered as the gold standard for burn wound treatment. Despite the high degree of efficacy of SSD in burn wound management, it possesses some drawbacks, such as poor solubility, low topical bioavailability and skin irritations. The present study endeavors to develop nanosuspension based SSD nanogel for improving the deliverability of SSD and its therapeutic outcomes for the management of partial thickness burn. The SSD nanosuspension was formulated employing controlled nanoprecipitation approach using various surfactants. The formulation was optimized utilizing one-factor-at-a-time approach and to fetch the optimized formulation of 134.6 nm size. The optimized nanosuspension was incorporated into chitosan gel that offer superior drug release potential, and also offered better spreadability (5.21 ± 0.38 g) and extrudability (152.27 ± 0.22 gm) that represents the easy application over the skin and extrusion of gel from the tube. The formulation was well tolerated as shown by skin irritation study and offered a superior burn lesion healing characteristics vis-à-vis the marketed product, even at a lower concentration. Hence, the formulation offers a huge potential in enhancing the clinical outcomes of SSD, especially in the management of partial thickness burn. The developed system with the above mentioned outcomes could be a promising delivery system for partial thickness burn wound management.

Potential therapeutic effects of topical recombinant human erythropoietin on burn wound healing: A preliminary randomized double-blind controlled clinical trial

BACKGROUND

Burn injuries can cause significant mortality and morbidity. This study aimed to evaluate the efficiency of topical recombinant human erythropoietin (rhEPO) on enhancing burn wound healing.

METHODS

In this randomized double-blind controlled clinical trial, we enrolled 40 participants aged 18 years and older who were referred to a burn center during the first 24 h of burning. The participants with no concurrent comorbidities had superficial and deep second-degree burns, no respiratory burns, no face and perineum burns, no keloid formation, or a healed, fully epithelialized, hypertrophic burn scar. Topical rhEPO or nitrofurazone/Vitamin A was administered every other day, and the patients were scheduled for follow-up visits to receive wound cleansing, debridement, and dressing changes. Burn wound healing response to treatment was measured as the study main outcome.

RESULTS

At the second follow-up visit, all parameters were significantly lower in the rhEPO group compared with the control group except for itchiness. The results of the next two follow-up sessions were also the same. The total value of the modified Vancouver Scar Scale (VSS) at days 5, 7, and 14 was significantly lower in the rhEPO group compared with the routine of care group. Trial Registry Date: 2022-03-02, Trial Registry number: IRCT20190810044500N23 CONCLUSIONS: The results of the present study suggested that topical rhEPO is a potential option in burn wounds and patient satisfaction, without causing intolerable side effects.

A single-center, open-labeled, randomized, 6-month, parallel-group study to assess the safety and efficacy of allogeneic cultured keratinocyte sheet transplantation for deep second-degree burn wounds: rationale and design of phase I/II clinical trial

BACKGROUND

Burn-related injuries are a major global health issue, causing 180,000 deaths per year. Early debridement of necrotic tissue in association with a split-thickness skin graft is usually administered for some of the 2nd- and 3rd-degree injuries. However, this approach can be complicated by factors such as a lack of proper donor sites. Artificial skin substitutes have attracted much attention for burn-related injuries. Keratinocyte sheets are one of the skin substitutes that their safety and efficacy have been reported by previous studies.

METHODS

Two consecutive clinical trials were designed, one of them is phase I, a non-randomized, open-label trial with 5 patients, and phase II is a randomized and open-label trial with 35 patients. A total number of 40 patients diagnosed with 2nd-degree burn injury will receive allogenic keratinocyte sheet transplantation. The safety and efficacy of allogeneic skin graft with autograft skin transplantation and conventional treatments, including Vaseline dressing and topical antibiotic, will be compared in different wounds of a single patient in phase II. After the transplantation, patients will be followed up on days 3, 7, 10, 14, 21, and 28. In the 3rd and 6th months after the transplantation scar, a wound closure assessment will be conducted based on the Vancouver Scar Scale and the Patient and Observer Scar Assessment Scale.

DISCUSSION

This study will explain the design and rationale of a cellular-based skin substitute for the first time in Iran. In addition, this work proposes this product being registered as an off-the-shelf product for burn wound management in the country.

TRIAL REGISTRATION

Iranian Registry of Clinical Trials (IRCT) IRCT20080728001031N31, 2022-04-23 for phase I and IRCT20080728001031N36, 2024-03-15 for phase II.

Advantage effect of Dalbergia pinnata on wound healing and scar formation of burns

ETHNOPHARMACOLOGICAL RELEVANCE

Dalbergia pinnata, as a natural and ethnic medicine in China, has been used for burns and wounds with a long history, which has the effect of invigorating blood and astringent sores. However, there were no reports on the advantage activity of burns.

AIM OF STUDY

The purpose of this study was to screen out the best active extract part of Dalbergia pinnata and investigate its therapeutic effect on wound healing and scar resolution.

MATERIALS AND METHODS

Rat burn model was established and the healing effects of extracts from Dalbergia pinnata on burn wounds were evaluated by the percentage of wound contraction and period of epithelialization. Histological observation, immunohistochemistry, immunofluorescence and ELISA were used for the examination of inflammatory factors, TGF-β1, neovascularization and collagen fibers through the period of epithelialization. In addition, the effect of the optimal extraction site on fibroblast cells was evaluated by cell proliferation and cell migration assays. The extracts of Dalbergia pinnata were analyzed by UPLC-Q/TOF-MS or GC-MS technique.

RESULTS

Compared to the model group, there were better wound healing, suppressed inflammatory factors, more neovascularization as well as newly formed collagen in the ethyl acetate extract (EAE) and petroleum ether extract (PEE) treatment groups. The ratio of Collagen I and Collagen III was lower in the EAE and PEE treatment groups, suggesting a potential for reduced scarring. Furthermore, EAE and PEE could repair wounds by up-regulating TGF-β1 in the early stage of wound repair and down-regulating TGF-β1 in the late stage. In vitro studies showed that both EAE and PEE were able to promote NIH/3T3 cells proliferation and migration compared with the control group.

CONCLUSIONS

In this study, EAE and PEE were found to significantly accelerate wound repair and might have an inhibitory effect on the generation of scars. It was also hypothesized that the mechanism might be related to the regulation of TGF-β1 secretion. This study provided an experimental basis for the development of topical drugs for the treatment of burns with Dalbergia pinnata.

Myco-Synthesized Selenium Nanoparticles as Wound Healing and Antibacterial Agent: An In Vitro and In Vivo Investigation

Bacterial-associated wound infections are an obstacle for individuals and the medical industry. Developing versatile, antibiotic-free therapies helps heal wounds more quickly and efficiently. In the current study, fungal metabolites were employed as a reducing agent in fabricating selenium nanoparticles (SeNPs) for improved antibacterial and wound healing properties. Utilizing UV-visible spectroscopy, dynamic light scattering (DLS), zeta potential, X-ray diffraction (XRD), and electron microscopic examination, the properties of the synthesized nanoparticles were extensively evaluated. Myco-synthesized SeNPs demonstrated strong antibacterial activity against Staphylococcus aureus ATCC 6538 with a minimum inhibitory concentration of 0.3125 mg/mL, reducing cell number and shape distortion in scanning electron microscope (SEM) images. SeNPs' topical administration significantly reduced wound area and healing time, exhibiting the least bacterial load after six days compared to controls. After six and 11 days of treatment, SeNPs could decrease proinflammatory cytokines IL-6 and TNF-α production. The histopathological investigation showed a healed ulcer with moderate infiltration of inflammatory cells after exposing mice's skin to SeNPs for six and 11 days. The docking interaction indicated that SeNPs were highly efficient against the IL-6 and TNF-α binding receptors. These findings imply that myco-fabricated SeNPs might be used as topically applied antimicrobial agents for treating skin infections and wounds.

Carbon monoxide combined with artificial blood cells acts as an antioxidant for tissues thermally-damaged by dye laser irradiation

Artificial red blood cells [i.e., hemoglobin vesicles (HbVs)] can be used as photosensitizers in pulsed-dye laser (PDL) treatment for port wine stains in animal models. Small HbVs are distributed in the vicinity of the endothelial cells of the blood vessels. In our previous in vivo experiments, both HbVs and red blood cells absorbed photons of the laser and generated heat, contributing to removal of very small blood vessels and large deeper subcutaneous blood vessels with PDL irradiation. Herein, we tested carbon monoxide-bound HbVs (CO-HbVs) that would produce heat energy while releasing CO in vessels after dye laser irradiation in a rabbit auricle model. We conducted this experiment to confirm secondary progression of thermal injury being reduced with the antioxidative property of CO. We histopathologically evaluated the damages to the large vessels and surrounding dermal tissue following PDL irradiation alone or subsequent to the intravenous injection of the qualified HbVs. The soft tissue damages were graded on a five-point scale and compared statistically. Intravenous CO-HbVs significantly reduced damage to the surrounding tissue after subsequent PDL irradiation; however, the degree of damage to the larger vessel wall resulted in a variety of changes, including a slight increase in our histopathological grades. This beneficial effect in dye laser treatment for port wine stains may be the result of the antioxidative property of CO against free radicals in the zone of stasis that may still be theoretically viable in burns. This effect of CO protecting tissues from thermal damage is consistent with previous reports of CO as a reducing agent. If the reducing agent can be delivered directly to the affected area immediately after the burn injury, even in a small amount, the complex inflammatory cascade may be reduced and unnecessary inflammation after laser treatment that lowers the patient's quality of life can be avoided.

Research advances in prevention and treatment of burn wound deepening in early stage

The burn wound is a dynamic living environment that is affected by many factors. It may present a progressive expansion of necrosis into the initially viable zone of stasis within a short time postburn. Therefore, how to salvage of the zone of stasis is of crucial importance in prevention and treatment strategies of burn wound progressive deepening. This review focuses on the cellular basis of tissue injury and the current progress of prevention and treatment strategies of burn wound progressive deepening, in order to provide references for the treatment of burn wounds in the early phase.

Therapeutic Strategies to Reduce Burn Wound Conversion

Burn wound conversion refers to the phenomenon whereby superficial burns that appear to retain the ability to spontaneously heal, convert later into deeper wounds in need of excision. While no current treatment can definitively stop burn wound conversion, attempts to slow tissue damage remain unsatisfactory, justifying the need for new therapeutic interventions. To attenuate burn wound conversion, various studies have targeted at least one of the molecular mechanisms underlying burn wound conversion, including ischemia, inflammation, apoptosis, autophagy, generation of reactive oxygen species, hypothermia, and wound rehydration. However, therapeutic strategies that can target various mechanisms involved in burn wound conversion are still lacking. This review highlights the pathophysiology of burn wound conversion and focuses on recent studies that have turned to the novel use of biologics such as mesenchymal stem cells, biomaterials, and immune regulators to mitigate wound conversion. Future research should investigate mechanistic pathways, side effects, safety, and efficacy of these different treatments before translation into clinical studies.

Oral Progenitor Cell Line-Derived Small Extracellular Vesicles as a Treatment for Preferential Wound Healing Outcome

Scar formation during wound repair can be devastating for affected individuals. Our group previously documented the therapeutic potential of novel progenitor cell populations from the non-scarring buccal mucosa. These Oral Mucosa Lamina Propria-Progenitor Cells (OMLP-PCs) are multipotent, immunosuppressive, and antibacterial. Small extracellular vesicles (sEVs) may play important roles in stem cell-mediated repair in varied settings; hence, we investigated sEVs from this source for wound repair. We created an hTERT immortalized OMLP-PC line (OMLP-PCL) and confirmed retention of morphology, lineage plasticity, surface markers, and functional properties. sEVs isolated from OMLP-PCL were analyzed by nanoparticle tracking analysis, Cryo-EM and flow cytometry. Compared to bone marrow-derived mesenchymal stromal cells (BM-MSC) sEVs, OMLP-PCL sEVs were more potent at driving wound healing functions, including cell proliferation and wound repopulation and downregulated myofibroblast formation. A reduced scarring potential was further demonstrated in a preclinical in vivo model. Manipulation of OMLP-PCL sEVs may provide novel options for non-scarring wound healing in clinical settings.

An active ingredient isolated from Ganoderma lucidum promotes burn wound healing via TRPV1/SMAD signaling

The mushroom Ganoderma lucidum is a traditional Chinese medicine and G. lucidum spore oil (GLSO) is the lipid fraction isolated from Ganoderma spores. We examined the effect of GLSO on burn wound healing in mice. Following wounding, GLSO was applied on the wounds twice daily. Repair analysis was performed by Sirius-Red-staining at different time points. Cell proliferation and migration assays were performed to verify the effect of GLSO on growth. Network pharmacology analysis to identify possible targets was also carried out, followed by Western blotting, nuclear translocation, cell proliferation, and immunofluorescence assays for in-depth investigation of the mechanism. Our study showed that GLSO significantly promoted cell proliferation, and network pharmacology analysis suggested that GLSO might act through transient receptor potential vanilloid receptor 1 (TRPV1)/SMAD signaling. Furthermore, GLSO elevated SMAD2/3 expression in skin burn and promoted its nuclear translocation, and TRPV1 expression was also increased upon exposure to GLSO. Cell proliferation and immunofluorescence assays with TRPV1 inhibitor showed that GLSO accelerated skin burn wound healing through TRPV1 and SMADs signaling, which provides a foundation for clinical application of GLSO in the healing of deep skin burns.

[Research advances on the prevention and treatment strategies of burn wound progressive deepening]

The progressive deepening of burn wounds is one of the common clinical problems and difficulties in early burn treatment. At the present, it is believed that local ischemia and hypoxia, persistent inflammation, infection, unbalanced local microenvironment, cell necrosis, apoptosis, and autophagy are the main mechanisms of progressive deepening of burn wounds. In recent years, basic and clinical studies have proposed various new strategies for prevention and treatment of progressive deepening of burn wounds, mainly including correct cooling, improving blood perfusion of the wound, early debridement, improving the wound microenvironment, preventing and treating wound infection, reducing wound inflammation, and inhibiting the oxidative stress in the wound. This review focuses on the current progress of prevention and treatment strategies of burn wound progressive deepening, in order to provide references for the treatment of burn wounds.

Intelligent Nanoparticle-Based Dressings for Bacterial Wound Infections

Conventional wound dressing materials containing free antibiotics for bacterial wound infections are presented with several limitations, that is, lack of controlled and triggered release capabilities, and may often not be adequate to address the complex bacteria microenvironment of such infections. Additionally, the improper usage of antibiotics may also result in the emergence of drug resistant strains. While delivery systems (i.e., nanoparticles) that encapsulate antibiotics may potentially overcome some of these limitations, their therapeutic outcomes are still less than desirable. For example, premature drug release or unintended drug activation may occur, which would greatly reduce treatment efficacy. To address this, responsive nanoparticle-based antimicrobial therapies could be a promising strategy. Such nanoparticles can be functionalized to react to a single stimulus or multi stimulus within the bacteria microenvironment and subsequently elicit a therapeutic response. Such "intelligent" nanoparticles can be designed to respond to the microenvironment, that is, an acidic pH, the presence of specific enzymes, bacterial toxins, etc. or to an external stimulus, for example, light, thermal, etc. These responsive nanoparticles can be further incorporated into wound dressings to better promote wound healing. This review summarizes and highlights the recent progress on such intelligent nanoparticle-based dressings as potential wound dressings for bacteria-infected wounds, along with the current challenges and prospects for these technologies to be successfully translated into the clinic.

Evaluation of the use of sitagliptin for insulin resistance in burn patients

BACKGROUND

Following severe burn injury, patients undergo profound metabolic changes, including insulin resistance and hyperglycemia. Hyperglycemia has been linked to impaired wound healing, increased risk of skin graft loss, increased muscle catabolism, increased infections, and mortality. Sitagliptin is a dipeptidyl peptidase-4 (DPP-4) inhibitor that improves glycemic control by slowing the inactivation of incretin hormones, increasing insulin synthesis and release from pancreatic beta cells and lowering glucagon secretion from pancreatic alpha cells. The objective of this study was to describe our institution's experience with using sitagliptin to help mitigate insulin resistance after burn injury.

METHODS

This was a retrospective chart review that included 22 adult burn patients. Burn patients were prescribed sitagliptin regardless of their previous medical history of type 2 diabetes mellitus. Patients were included in this analysis if they were adults admitted for burn injury during a 13-month period and received at least 3 consecutive doses of sitagliptin. Patients were excluded if they did not have insulin use data 3 days pre- and 3 days post-sitagliptin initiation. The first day of sitagliptin initiation was considered day 0; data from day 0 were not included in either the pre- or post-sitagliptin analysis.

RESULTS

In the 3 days prior to sitagliptin initiation, patients received a median of 114.3 units per day (IQR 49.1, 228) in an attempt to maintain a blood glucose goal of less than 180 mg/dL. In the 3 days after sitagliptin was started, exogenous insulin requirements significantly decreased to a median to 36.3 units per day (IQR 11.7, 95) (P=0.009). Seven patients were on insulin infusions at the time of sitagliptin initiation. After sitagliptin was started, it took a median of 3 days (IQR 2, 3.25) to be liberated from the insulin infusion. In terms of safety, there were two episodes of hypoglycemia (BG<70 mg/dL) after sitagliptin initiation, compared to three episodes prior to sitagliptin initiation (P=0.7).

CONCLUSION

The addition of sitagliptin to burn patients' medication regimens significantly reduced insulin requirements over a 3-day period and allowed liberation from insulin drips.

Effects of Carnosine, Ankaferd, and Silver Sulfadiazine on an Experimental Burn Model: Roles of Irisin and HSP70

In this study, the effects of carnosine, ankaferd, and 1% silver sulfadiazine applied topically on second-degree burns were investigated and the roles of irisin and Heat shock protein 70 (HSP70) in this healing process were evaluated. Ninety male albino rats were used and divided into five groups. The groups were classified as control, burn, burn + carnosine (CAR), burn + ankaferd (ABS), and burn + silver sulfadiazine (SS). It was found that level of irisin increased in the first week and decreased in the second week in the burn and CAR groups. In the ABS and SS groups, the level of irisin was determined that started to increase in the first week and continued to increase in the second week. The level of HSP70 was found to increased in the first week in burn and CAR groups and decreased in the second week, but started to increase in the second week in ABS and SS groups. Both levels of irisin and HSP70 were observed to decreased in all treatment groups in the third week. In this study, it was shown that ankaferd and silver sülfadiazine treatments cause an increase in the irisin levels in the early period and a gradually increase in HSP70 levels in the later period in burns. The inflammatory response was observed to be limited in the early period in the ankaferd and sulfadiazin groups. It was concluded that these findings were effective in early wound healing in burns.

Bioactive Glasses: A Promising Therapeutic Ion Release Strategy for Enhancing Wound Healing

The morbidity, mortality, and burden of burn victims and patients with severe diabetic wounds are still high, which leads to an extensively growing demand for novel treatments with high clinical efficacy. Biomaterial-based wound treatment approaches have progressed over time from simple cotton wool dressings to advanced skin substitutes containing cells and growth factors; however, no wound care approach is yet completely satisfying. Bioactive glasses are materials with potential in many areas that exhibit unique features in biomedical applications. Today, bioactive glasses are not only amorphous solid structures that can be used as a substitute in hard tissue but also are promising materials for soft tissue regeneration and wound healing applications. Biologically active elements such as Ag, B, Ca, Ce, Co, Cu, Ga, Mg, Se, Sr, and Zn can be incorporated in glass networks; hence, the superiority of these multifunctional materials over current materials results from their ability to release multiple therapeutic ions in the wound environment, which target different stages of the wound healing process. Bioactive glasses and their dissolution products have high potency for inducing angiogenesis and exerting several biological impacts on cell functions, which are involved in wound healing and some other features that are valuable in wound healing applications, namely hemostatic and antibacterial properties. In this review, we focus on skin structure, the dynamic process of wound healing in injured skin, and existing wound care approaches. The basic concepts of bioactive glasses are reviewed to better understand the relationship between glass structure and its properties. We illustrate the active role of bioactive glasses in wound repair and regeneration. Finally, research studies that have used bioactive glasses in wound healing applications are summarized and the future trends in this field are elaborated.

Immunological approaches and therapy in burns (Review)

Burns have become an important public health problem in the last two decades, with just over a quarter of a million deaths annually. Major burns are accompanied by a strong inflammatory response, which will most often lead to systemic response inflammatory syndrome, followed by sepsis and finally induce multiple organ failure. The main mechanism involved in wound healing after burns is the inflammatory process, characterized by the recruitment of myeloid and T cells and by the involvement of numerous cytokines, chemokines, complement fractions, as well as various growth factors. Inflammasomes, protein-based cytosolic complexes, activated during metabolic stress or infection, play a role in modulating and improving the defense capacity of the innate immune system. Nucleotide-binding domain and leucine-rich repeat protein 3 (NLRP3) inflammasome has been studied predominantly and several hypotheses have been issued. Restoring the balance between the pro-inflammatory response and the anti-inflammatory activity is the key element to effective therapy in burns. Severe burns require nutritional support and pharmacotherapy not only for burn area but for different pathological complications of burn injury. In-depth research is required to find new ways to modulate the defense capacity, to prevent the complications of abnormal immune response and to treat burn injuries efficiently.

Review: Insulin resistance and mitochondrial dysfunction following severe burn injury

The insulin signaling pathway plays a pivotal role in glucose metabolism and metabolic homeostasis. Disruption of this pathway is commonly seen in critical illness such as following severe burn injuries where homeostatic control is lost, leading to "insulin resistance" with poor blood glucose control. The aberrant signaling pathways involved in insulin resistance following burn injury include increases in hyperglycemic stress hormones, pro-inflammatory cytokines and free radical production. Leakage of mitochondrial sequestered self-antigens and signaling between mitochondria and endoplasmic reticulum also contribute to insulin resistance. Greater understanding of molecular processes involved in burn-related insulin resistance could potentially lead to the development of novel therapeutic approaches to improve patient management.

Comprehensive physical domain care needs of burn patients: a qualitative study

INTRODUCTION

Burn patients have various physical needs. To provide full care for such patients, we need a broad range of services. The current study aims at showing the physical needs of burn patients.

METHODS

The current qualitative study has been done through content analysis. The data were collected from 20 in-depth, unstructured individual interviews with hospitalized patients with burns on more than 25% of their body, nurses, physiotherapists, and psychologists. The participants were selected by purposive sampling. The data were analyzed with a conventional content analysis approach using the Elo and Kyngas method.

RESULTS

By analyzing the data, 7 main categories were obtained from 932 primary codes: the necessity to provide optimal physiotherapy, the necessity of the patient's overall physical assessment, the necessity of monitoring and coordination in care, healthy nutrition for burn patients, the need for pharmacotherapy, the need for pain reliefs, and finally the theme for comprehensive physical care needs in burn patients.

CONCLUSION

According to the findings, by applying the extracted categories, it is possible to provide quality care based on the patient's individual needs. This can help speed up the treatment and shorten the length of hospitalization significantly.