Fish skin grafts versus standard of care on wound healing of chronic diabetic foot ulcers: A systematic review and meta-analysis

INTRODUCTION

This study will explore the effectiveness of fish skin grafts (FSG) in ulcer healing in diabetic foot disease compared to standard of care (SOC).

METHODS

The systematic review and meta-analysis were performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standard. The electronic databases of PubMed, EMBASE, and Web of Science (WoS) internet were searched for the outcome rate of complete ulcer healing. The risk of bias assessment was conducted using the tool recommended by the Cochrane Collaboration. Statistical analysis included the individual and combined result of the studies, heterogeneity test, the effect size, sensitivity analysis, and publication bias tests.

RESULTS

Five randomised controlled trials (RCTs) with a total of 411 patients were included in this study. This meta-analysis showed a higher rate of complete ulcer healing in groups receiving fish skin grafts (OR = 3.34, 95% CI 2.14-5.20, p < 0.01, I2 = 0%) compared to control groups.

CONCLUSION

Fish skin grafts have been shown to be more effective for achieving complete ulcer healing compared to current conventional treatments in diabetic foot disease.

New strategies for sterilization and preservation of fresh fish skin grafts

The introduction of fish skin as a biological dressing for treating burns and wounds holds great promise, offering an alternative to existing management strategies. However, the risk of disease transmission is a significant concern. Therefore, this study aimed to examine how established sterilization and preservation procedures affected fish skin grafts' microbiological and histological properties for long-term usage. Lyophilization of the fish skin graft followed by rehydration in normal saline for 15 min did not change the collagen content. Furthermore, gamma irradiation of the lyophilized fish skin graft at different lengths 5, 10, and 25 KGy showed a significant reduction in microbial growth (aerobic bacteria, aerobic yeasts, and fungi) at 15- and 30 days after the irradiation. However, exposure to 10 KGy was found to be the most effective intensity among the different gamma irradiation lengths since it preserved the collagen fiber content and intensity in the lyophilized fish skin grafts at 15- and 30 days after the irradiation. These findings provide efficient preservation and sterilization methods for long-term usage of the fresh Tilapia skin grafts used for biological dressings.

Processing and post-processing of fish skin as a novel material in tissue engineering

As a natural material, fish skin contains significant amounts of collagen I and III, and due to its biocompatible nature, it can be used to regenerate various tissues and organs. To use fish skin, it is necessary to perform the decellularization process to avoid the immunological response of the host body. In the process of decellularization, it is crucial to conserve the extracellular matrix (ECM) three-dimensional (3D) structure. However, it is known that decellularization methods may also damage ECM strands arrangement and structure. Moreover, after decellularization, the post-processing of fish skin improves its mechanical and biological properties and preserves its 3D design and strength. Also, sterilization, which is one of the post-processing steps, is mandatory in pre-clinical and clinical settings. In this review paper, the fish skin decellularization methods performed and the various post-processes used to increase the performance of the skin have been studied. Moreover, multiple applications of acellular fish skin (AFS) and its extracted collagen have been reviewed.

The clinical outcomes of xenografts in the treatment of burn patients: a systematic review and meta-analysis

BACKGROUND

Although autografts are not feasible in patients with extensive burn wounds, allografts and xenografts can be used for temporary coverage. In this systematic review and meta-analysis, we compared the outcomes of xenografts and the standard treatment of burn wounds.

METHODS

International online databases were searched for English articles comparing xenografts with routine treatment in the burn patients. The random-effects model was used to estimate standardized mean differences (SMD) or odds ratios (OR) with a 95% confidence interval (CI).

RESULTS

From a total of 7144 records, 14 studies were included in our review after screening by title and abstracts followed by full-texts. No significant difference in hospital stays was found between the mammalian xenografts and control groups (SMD [95% CI] = - 0.18 [- 0.54-0.18]). The mean number of dressing changes was significantly lower in both mammalian xenografts compared to the controls (SMD [95% CI] = - 1.01 [- 1.61-- 0.41]) and fish xenografts compared to controls (SMD [95% CI] = - 6.16 [- 7.65-- 4.66]). In the fish xenografts, re-epithelialization time was significantly lower compared to controls (SMD [95% CI] = - 1.18 [- 2.23-- 0.14]).

CONCLUSIONS

Xenografts showed a significantly lower number of dressing changes and fish xenografts showed significant benefit in re-epithelialization compared to routine treatment. The beneficial results of xenografts suggest further research in the use of different types of xenografts in patients with extensive burn.

Evaluation of the healing potential of Nile tilapia skin collagen in traumatic oral ulcers in male rats

OBJECTIVE

To evaluate the healing potential of Nile tilapia skin collagen using a rat model with experimentally induced traumatic oral ulcers.

DESIGN

Male Wistar rats were segregated into three experimental groups (n = 8/group/euthanasia day). Ulcers were induced using a dermatological punch on the left buccal mucosa. The rats were then euthanized on days 1, 5, 10, 15, and 20 (ntotal=120 rats). Each group received topical treatment, 2x/day, with 1 % Nile tilapia skin collagen orabase (experimental group), only orabase (negative control), or Oncilom-A® orabase (positive control). Ulcer area, closure percentage, and body mass variation were measured. Slides were prepared for histological analysis, which included Picrosirius red staining (collagen analysis), and immunohistochemistry (platelet endothelial cell adhesion molecule, alpha-smooth muscle actin, and transforming growth factor-beta).

RESULTS

On day 15, the experimental and positive control groups displayed smaller ulcer areas, a higher percentage of closure, complete re-epithelialization, superior histological repair scores, and a reduced count of polymorphonuclear cells in comparison to the negative control group (p < 0.05). Additionally, the experimental group exhibited an increased number of blood vessels, total collagen (types I and III) and expression of platelet endothelial cell adhesion molecule, alpha-smooth muscle actin, and transforming growth factor-beta relative to the negative and positive control groups (p < 0.05). By day 20, the experimental group showed a more significant weight gain compared to the other groups (p < 0.0001).

CONCLUSIONS

Nile tilapia skin collagen orabase optimizes the healing of traumatic ulcers by stimulating re-epithelialization, angiogenesis, and collagenesis. Transforming growth factor-beta plays a significant role in this process.

Tilapia Fish Skin Treatment of Third-Degree Skin Burns in Murine Model

This study explored the feasibility of using fish skin bandages as a therapeutic option for third-degree skin burns. Following the California wildfires, clinical observations of animals with third-degree skin burns demonstrated increased comfort levels and reduced pain when treated with tilapia fish skin. Despite the promises of this therapy, there are few studies explaining the healing mechanisms behind the application of tilapia fish skin. In this study, mice with third-degree burns were treated with either a hydrocolloid adhesive bandage (control) (n = 16) or fish skin (n = 16) 7 days post-burn. Mice were subjected to histologic, hematologic, molecular, and gross evaluation at days 7, 16, and 28 post-burn. The fish skin offered no benefit to overall wound closure compared to hydrocolloids. Additionally, we detected no difference between fish skin and control treatments in regard to hypermetabolism or hematologic values. However, the fish skin groups exhibited 2 times more vascularization and 2 times higher expression of antimicrobial defensin peptide in comparison to controls. Proteomic analysis of the fish skin revealed the presence of antimicrobial peptides. Collectively, these data suggest that fish skin can serve as an innovative and cost-effective therapeutic alternative for burn victims to facilitate vascularization and reduce bacterial infection.

Outcomes of Apert Syndrome Hand Reconstruction With Tilapia Skin: A Prospective Study

BACKGROUND

Tilapia skin has already been used in various medical scenarios, but there are no studies showing the use of tilapia skin for hand reconstruction in Apert syndrome. The objective of this study is to determine whether the use of tilapia skin during graft bed preparation for children with Apert syndrome can shorten wound reepithelialization intervals, reduce the number of dressing changes, and decrease patient discomfort.

METHODS

This is a prospective study on consecutive patients with Apert syndrome who underwent hand reconstruction at our Hospital. Patients were divided into 2 groups: (1) a control group consisting of patients who underwent conventional digit separation hand reconstruction surgery (2) an experimental group consisting of patients who underwent similar digit separation hand reconstruction surgery that commenced with the placement of a thin layer of tilapia skin at the raw commissures during a first operation, which was subsequently replaced by an autologous skin graft during a second operation staged 10 days postoperatively. Pain assessment was performed using the Visual Analog Scale. The number of dressing changes was also assessed. A T test compared the total number of dressings changes and pain data.

RESULTS

Experimental group patients (n = 8) required an average of 9.4 days of daily dressing changes, and control group patients (n = 5) required an average of 20.8 days of daily dressing changes ( P < 0.05) and tended to experience significantly less pain when compared with patients in the control group ( P = 0.079).

CONCLUSION

Tilapia skin can shorten wound reepithelialization intervals by reducing the total number of dressing changes.

Neovaginoplasty With Nile Tilapia Skin: Cytological and Microbiota Evaluation

OBJECTIVES

To study the clinical, cytological, and vaginal microbiota findings in patients with Mayer-Rokitansky-Küster-Hauser syndrome who underwent neovaginoplasty using Nile tilapia fish skin.

METHODS

This is a cross-sectional study with 7 cisgender women with Mayer-Rokitansky-Küster-Hauser syndrome who had previously undergone neovagina reconstruction using Nile tilapia fish skin at a university hospital. Local institutional review board approval and written permission from the patient were obtained. Between August 2019 and November 2021, within 12 to 24 months after surgery, vaginal specimens were obtained for conventional oncotic and hormonal cytology, and for Gram staining. The Nugent scores were calculated. Colposcopy was also performed.

RESULTS

Squamous cells without atypia were found in all patients. Five patients had intermediate vaginal microbiota (Nugent score of 4), which was determined by the presence of few lactobacilli on Gram staining. In hormonal cytology, 4 patients presented with findings compatible with menacme. No colposcopic change was observed. When postsurgical dilation was performed correctly, a mean vaginal length of 8.3 cm was maintained after 1 year of follow-up.

CONCLUSIONS

Squamous cells without atypia were present in neovaginas with Nile tilapia fish skin. Most vaginal contents revealed intermediate microbiota and hormonal results compatible with menacme. Studies with a greater number of patients are necessary for a more comprehensive understanding of the microbiome in neovaginas with this new technique, thereby providing support for the treatment and prevention of associated pathologies.

Comparison of Type I and Type III Collagen Concentration between Oreochromis mossambicus and Oreochromis niloticus in Relation to Skin Scaffolding

Background and Objectives: Skin scaffolding can be done using allografts and autografts. As a biological allograft, the skin of Oreochromis niloticus (ON) has been used due to its high type I and III collagen content. Oreochromis mossambicus (OM) is also a member of the Oreochromis family, but not much is known regarding its collagen content. As such, this study aimed to assess and compare the collagen content of the two fish species. Materials and Methods: This is a crossover study comparing the skin collagen contents of the two fish. Young fish were chosen, as they tend to have higher collagen concentrations. The skin samples were sterilized in chlorhexidine and increasing glycerol solutions and analyzed histochemically with Sirius red picrate under polarized light microscopy. Results: 6 young ON and 4 OM specimens were used. Baseline type I collagen was higher for OM, but at maximum sterilization it was higher for ON, with no differences in between Type III collagen was higher for OM across all comparisons with the exception of the last stage of sterilization. Generally, collagen concentrations were higher in highly sterilized samples. Conclusions: OM skin harvested from young fish, with its greater collagen III content may be a better candidate for use as a biological skin scaffold in the treatment of burn wounds, compared to ON.

Current state of clinical trials on xenograft

BACKGROUND

Xenotransplantation is a worth investing branch of science, since it aims to fulfil the demand on human cells, tissues and organs. Despite decades of consistent work in preclinical assessments, clinical trials on xenotransplantation are far from reaching the targeted goal. Our study aims to track the characteristics, assess the content and summarize the plan of each trial on skin, beta-island, bone marrow, aortic valve and kidney xenografts, leading to a clear sorting of efforts made in this field.

METHODS

In December 2022, we searched clinicaltrial.gov for interventional clinical trials related to xenograft of skin, pancreas, bone marrow, aortic valve and kidney. A total of 14 clinical trials are included in this study. Characteristics on each trial were gathered. Linked publications were searched using Medline/PubMed and Embase/Scopus. Content of trials was reviewed and summarized.

RESULTS

Only 14 clinical trials met our study's criteria. The majority were completed, and most of the trials' enrolment was between 11 and 50 participants. Nine trials used a xenograft of porcine origin. Six trials targeted skin xenotransplantation, four targeted β-cells, two targeted bone marrow and one trial targeted each of the kidney and aortic valve. The average length of trials was 3.38 years. Four trials were conducted in the United States and two trials in each of Brazil, Argentina and Sweden. Of all the included trials, none had any results provided and only three had published work. Phases I, III, and IV had only one trial each. A total of 501 participants were enrolled in these trials.

CONCLUSION

This study sheds the light on the current state of clinical trials on xenograft. Characteristically, trials on this field are of low number, low enrolment, short duration, few related publications and no published results. Porcine organs are the most used in these trials, and skin is the most studied organ. An extension of the literature is highly needed due to the variety of conflicts mentioned. Overall, this study sheds the light on the necessity of managing research efforts, leading to the initiation of more trials targeting the field of xenotransplantation.

Fish Skin Grafts Versus Alternative Wound Dressings in Wound Care: A Systematic Review of the Literature

Wound healing poses a variety of challenges making it a vital subject in medicine. With the advancement of science, we have seen the use of a new xenograft known as acellular fish skin (AFS) grafts that are derived from either Atlantic cod or Nile Tilapia. Fish skin has shown anti-inflammatory and anti-bacterial properties that support and improve wound healing in a variety of wounds including burns and diabetic foot ulcers (DFU). There is ongoing research that evaluates the efficacy of fish skin grafts in comparison to alternative wound healing techniques. A literature search was conducted through the National Library of Medicine with search terms fish skin graft, AFS, xenograft, dehydrated human amnion/chorion, ulcer, burns, and wounds. A total of ten studies that investigate the efficacy of fish skin grafts either in comparison to a different wound healing technique or by simply observing wound healing with fish skin grafts and recording the results were chosen. AFS showed superior healing in comparison to collagen alginate dressings, silver sulfadiazine cream 1%, and allografts. Although there is no one specific gold standard technique for wound healing, fish skin grafts demonstrated overall improved and quicker wound healing, fewer dressing changes, less pain, and lower costs.

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.

Synergistic Use of Novel Technological Advances in Burn Care Significantly Reduces Hospital Length of Stay Below Predicted: A Case Series

Length of stay is an important metric in healthcare systems, primarily because it reflects the cost of care provided. In the US, as in many countries, inpatient hospital stays are significantly more expensive than outpatient care across all healthcare conditions [1], so earlier discharge and transition to outpatient care is crucial to help control the ever-increasing cost of healthcare. In burn patients, length of stay has traditionally been estimated at 1 day per 1% total body surface area of burn. This estimation was first described in a round table discussion in 1986.[2] However, since that time there has been significant evolution in the quality of care available to burn patients, in both the operating room and ICU. The use of new harvesting techniques, synthetic dermal substitution, and autologous epidermal skin cell suspension are allowing large, deep burns to be excised and covered in much quicker time frames than historically were possible. Examples include the skin harvesting and wound debridement device for grafting and excision, biodegradable temporizing matrix as a fully synthetic dermal template, and regenerative epidermal suspension concerning cell harvesting. Although these modalities can all be used separately, we believe that using them in conjunction has allowed us to shorten the length of stay in patients with severe partial and full-thickness burns. We present an initial case series of 3 patients with anticipated hospital lengths of stay of 54.5, 55, and 51 days, who were ready for discharge in 37, 35, and 43 days, respectively.

Bacterial Cellulose as a Versatile Biomaterial for Wound Dressing Application

Chronic ulcers are among the main causes of morbidity and mortality due to the high probability of infection and sepsis and therefore exert a significant impact on public health resources. Numerous types of dressings are used for the treatment of skin ulcers-each with different advantages and disadvantages. Bacterial cellulose (BC) has received enormous interest in the cosmetic, pharmaceutical, and medical fields due to its biological, physical, and mechanical characteristics, which enable the creation of polymer composites and blends with broad applications. In the medical field, BC was at first used in wound dressings, tissue regeneration, and artificial blood vessels. This material is suitable for treating various skin diseases due its considerable fluid retention and medication loading properties. BC membranes are used as a temporary dressing for skin treatments due to their excellent fit to the body, reduction in pain, and acceleration of epithelial regeneration. BC-based composites and blends have been evaluated and synthesized both in vitro and in vivo to create an ideal microenvironment for wound healing. This review describes different methods of producing and handling BC for use in the medical field and highlights the qualities of BC in detail with emphasis on biomedical reports that demonstrate its utility. Moreover, it gives an account of biomedical applications, especially for tissue engineering and wound dressing materials reported until date. This review also includes patents of BC applied as a wound dressing material.

The Use of Acellular Fish Skin Grafts in Burn Wound Management-A Systematic Review

Background and Objectives: Burn wound healing and management continues to be a major challenge for patients and health care providers resulting in a considerable socio-economic burden. Recent advances in the development of applicable xenografts as an alternative to split-thickness skin grafts have allowed for the development of acellular fish skin. Acellular fish skin acts as a skin substitute, reducing inflammatory responses and advancing proinflammatory cytokines that promote wound healing. Due to these beneficial wound healing properties, acellular fish skin might represent an effective treatment approach in burn wound management. Materials and Methods: A systematic review of the literature, up to March 2022, was conducted using the electronic databases PubMed and Web of Science. Titles and abstracts were screened for the following key terms (variably combined): "fish skin", "fish skin grafts", "acellular fish skin", "Omega3 Wound matrix", "xenograft", "burn injury", "burns". Results: In total, 14 trials investigating the effects of acellular fish skin in burn wounds or split-thickness donor sites were determined eligible and included in the present review. Existing evidence on the use of acellular fish skin indicates an acceleration of wound healing, reduction in pain and necessary dressing changes as well as treatment-related costs and improved aesthetic and functional outcomes compared to conventional treatment options. Conclusions: Acellular fish skin xenografts may represent an effective, low-cost alternative in treatment of superficial- and partial-thickness burns. However, results mainly originate from preclinical and small cohort studies. Future larger cohort studies are warranted to elucidate the full potential of this promising approach.

Management of Pediatric Facial Burns with Zinc-Hyaluronan Gel

Zinc-hyaluronan-containing burn dressings have been associated with enhanced reepithelialization and low infection rates, although their effectiveness has not yet been investigated in pediatric facial thermal injuries. This single-arm, retrospective cohort study assessed the characteristics of 23 children (≤17-year-old) with facial superficial partial-thickness burns and the wound closure capabilities of the applied zinc-hyaluronan gel. Patients were admitted consecutively to the Pediatric Surgery Division in Pécs, Hungary, between 1 January 2016 and 15 October 2021. The mean age of the children was 6.2 years; 30.4% of them were younger than 1 year. An average of 3% total body surface was injured in the facial region and 47.8% of the patients had other areas damaged as well, most frequently the left upper limb (30.4%). The mean time until complete reepithelialization was 7.9 days and the children spent 2 days in the hospital. Wound cultures revealed normal bacterial growth in all cases and follow-up examinations found no hypertrophic scarring. In conclusion, pediatric facial superficial partial-thickness burns are prevalent during infancy and coincide with left upper limb injuries. Rapid wound closure and low complication rates are accountable for the moderate amount of hospitalization. These benefits, along with the gel’s ease of applicability and spontaneous separation, are linked to child-friendly burn care.

Therapeutic Treatment of 2A Grade Burns with Decellularized Bovine Peritoneum as a Xenograft: Multicenter Randomized Clinical Trial

Background and Objectives: Homogeneous and xenogenic bioengineering structures are actively used as wound coatings in treatment of burns and have already shown their effectiveness. Nevertheless, the disadvantage of such dressings is their high cost. This issue is particularly challenging for developing countries in which the incidence of burns is the highest one. With such needs taken into account, the research team developed and clinically tested a new wound coating based on decellularized bovine peritoneum (DBP). Materials and Methods: A multicenter randomized clinical trial was conducted to evaluate DBP. The following variables were considered in the research study: the number of inpatient days, the number of dressing changes, the level of pain experienced during dressing changes, and the condition of wounds at the time of the follow-up examination. Results: The research involved 68 participants. It was found that the patients who were treated with a DBP experienced less pain with less changes of dressings. However, the number of inpatient days and wound healing failed to demonstrate statistically significant difference compared to the control group. Conclusions: In the given research, DBP showed efficacy in improving patients' quality of life by reducing pain and the number of dressings' changes. However, when comparing this research study with the studies of other animal-derived wound coverings, there were a number of differences and limitations in the parameters. Thus, the results requires further study for a greater comparability of data. Given the above, we expect that DBP will become an inexpensive and effective treatment for burns in developing countries.

Fish collagen for skin wound healing: a systematic review in experimental animal studies

Collagen extracted from fishes has been appearing as an alternative for commercial porcine and bovine collagen and it has been considered interesting especially for membrane manufacturing in tissue engineering. Despite the positive in vitro effects of fish collagen membranes, there is still no understanding of all the benefits that this natural biomaterial plays in the wound healing process, due to the lack of compilation of the results obtained in animal studies. In this sense, the purpose of this study was to perform a systematic review of the literature to examine the effects of fish collagen membranes for skin wound healing in experimental models of skin wound. The search was carried out according to the orientations of Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA), and the descriptors of the Medical Subject Headings (MeSH) were defined: "fish," collagen," "skin," and "in vivo". A total of 10 articles were retrieved from the databases PubMed and Scopus. After the elegibility analyses, this review covers the different origins of fish collagen reported in the different papers from the beginning of 2015 through the middle of 2021. The results were based mainly on histological analysis and macroscopic evaluation, and fish skin collagen was responsible for improving the wound healing rate and the process of reepithelization and collagen deposition. In conclusion, fish skin collagen has shown positive results in in vivo studies and may be a potential biomaterial in tissue engineering.

Paediatric Partial-Thickness Burn Therapy: A Meta-Analysis and Systematic Review of Randomised Controlled Trials

Background: Paediatric second-degree burn injuries are a significant source of medical challenges to the population that may cause severe, lifelong complications. Currently, there are dozens of therapeutic modalities and we aimed to summarise their reported outcomes and determine their effectiveness, compared to the widely used silver sulphadiazine (SSD). Methods: We conducted the meta-analysis and systematic review of randomised controlled trials (RCTs), which investigated the performance of dressings in acute paediatric partial-thickness burns. The evaluated endpoints were time until wound closure, grafting and infection rate, number of dressing changes and length of hospitalisation. Results: Twenty-nine RCTs were included in the qualitative and 25 in the quantitative synthesis, but only three trials compared SSD directly to the same intervention (Biobrane). Data analysis showed a tendency for faster healing times and a reduced complication rate linked to biosynthetic, silver foam and amnion membrane dressings. A substantial difference was found between the number of dressing changes associated with less pain, narcosis and treatment duration. Conclusions: Considerable between-study heterogeneity was caused by the unequal depth subcategory ratio and surface area of the injuries; therefore, no significant difference was found in the main outcomes. Further research is necessary to establish the most effective treatment for these burns.

Successful Treatment Outcomes for Partial Thickness Burns by Innovative Bovine Peritoneum Dressing

In the world practice of treating burns, acellular matrices have been used for quite a long time. However, the budget for treating one burn patient in Kazakhstan does not exceed $1000. This amount does not cover the costs for procurement of foreign-made xenograft dressings. Because the cattle breeding sector is very well-developed in the country, a domestic xenograft is produced by decellularization and sterilization of the cattle peritoneum, which costs only $10. This case report outlines how we used this matrix in a patient with partial thickness burns. A 45-year-old woman was admitted to the burn department with second stage burns on her back and right shoulder. The burn area comprised 10%, according to the Lund Browder chart. Once formal consent was obtained from the patient, an occlusive dressing was applied from the decellularized cattle peritoneum. Good adhesion of the dressing to the wound bed was noted. The patient was discharged from the hospital on the tenth day. It took 23 days to reach complete epithelialization. No adverse effects were noted. We believe that further studies conducted by our research team will allow this innovative, low-cost, easy-to-apply biologic dressing to be widely used in the therapeutic treatment of burns.

Stem Cell-Based Tissue Engineering for the Treatment of Burn Wounds: A Systematic Review of Preclinical Studies

Burn wounds are a devastating type of skin injury leading to severe impacts on both patients and the healthcare system. Current treatment methods are far from ideal, driving the need for tissue engineered solutions. Among various approaches, stem cell-based strategies are promising candidates for improving the treatment of burn wounds. A thorough search of the Embase, Medline, Scopus, and Web of Science databases was conducted to retrieve original research studies on stem cell-based tissue engineering treatments tested in preclinical models of burn wounds, published between January 2009 and June 2021. Of the 347 articles retrieved from the initial database search, 33 were eligible for inclusion in this review. The majority of studies used murine models with a xenogeneic graft, while a few used the porcine model. Thermal burn was the most commonly induced injury type, followed by surgical wound, and less commonly radiation burn. Most studies applied stem cell treatment immediately post-burn, with final endpoints ranging from 7 to 90 days. Mesenchymal stromal cells (MSCs) were the most common stem cell type used in the included studies. Stem cells from a variety of sources were used, most commonly from adipose tissue, bone marrow or umbilical cord, in conjunction with an extensive range of biomaterial scaffolds to treat the skin wounds. Overall, the studies showed favourable results of skin wound repair in animal models when stem cell-based tissue engineering treatments were applied, suggesting that such strategies hold promise as an improved therapy for burn wounds.

Treatment of severe extravasation injury in a newborn by using tilapia fish skin: A case report

Introduction and importance

Peripheral venous catheterizations in newborns are associated with complications such as infections, phlebitis, vessel rupture and drug leaks or serum. Extravasation injury refers to the leakage of injected drugs from blood vessels causing damage to the surrounding tissues, skin necrosis, and sometimes amputation. Using tilapia fish skin (TFS) is one of the new strategies that have been used in wound management.

Case presentation

This case is a 36-week- and 4-day-old male fetus with a birth weight of 1600 g, height of 40 cm, and head circumference of 31 cm who was born to a 25-year-old mother by cesarean section at Mahzad Obstetrics and Gynecology Hospital, Urmia, Iran. On the third day of hospitalization at neonatal intensive care unit (NICU), an extravasation injury occurred in the infant's left hand in size approximately 1 × 1 cm by peripheral catheter. Despite extensive intravenous antibiotic therapy and rinsing with normal saline, wound healing was not achieved. The necrotic area was bandaged by using of the tilapia skin. For this purpose, the area was first washed with normal saline for 5 min and then the tilapia skin was placed on the damaged skin for 10 days. After a month, the newborn's wound had completely healed.

Clinical discussion

Infants are more prone to extravasation injury than adults due to being more sensitive and thinner peripheral vessel walls.

Conclusion

This case illustrates that tilapia fish skin may be a suitable alternative to other temporary skin cover dressings in premature newborns suffering from extravasation injury.

•

Peripheral venous catheterizations are associated with complications such as extravasation.

•

Tilapia fish dressing is one of the new strategies that have been used in wound management.

•

Tilapia fish dressing may be used as a suitable alternative method for routine dressings, even in premature neonates

Marine collagen scaffolds in tissue engineering

Collagen is the primary component of the extracellular matrix in humans. Traditionally commercial collagen is confined to bovine and porcine sources which have concerns of pathogenic transfer. Marine wastage accounts up to 85% by weight in the fishing industry. Extraction of collagen from these wastes for economic value and environmental sustainability is clear. Marine collagens have several advantages such as excellent biocompatibility, lower zoonotic risks, less immunological risk for patients allergic to mammalian products, and less religious restrictions. However, the properties of marine collagen-based constructs are highly dependent on the methods of fabrication. This article reviews advances in the design and fabrication of marine collagen-based constructs for medical applications. The potential applications of marine collagen in the regeneration of skin, bone and cartilage were also highlighted.

Fabricating scalable, personalized wound dressings with customizable drug loadings via 3D printing

In recent times, 3D printing has been gaining traction as a fabrication platform for customizable drug dosages as a form of personalized medicine. While this has been recently demonstrated as oral dosages, there is potential to provide the same customizability and personalization as topical applications for wound healing. In this paper, the application of 3D printing to fabricate hydrogel wound dressings with customizable architectures and drug dosages was investigated. Chitosan methacrylate was synthesized and mixed with Lidocaine Hydrochloride and Levofloxacin respectively along with a photoinitiator before being used to print wound dressings of various designs. These designs were then investigated for their effect on drug release rates and profiles. Our results show the ability of 3D printing to customize drug dosages and drug release rates through co-loading different drugs at various positions and varying the thickness of drug-free layers over drug-loaded layers in the wound dressing respectively. Two scale-up approaches were also investigated for their effects on drug release rates from the wound dressing. The influence that each wound dressing design has on the release profile of drugs was also shown by fitting them with drug release kinetic models. This study thus shows the feasibility of utilizing 3D printing to fabricate wound dressings with customizable shapes, drug dosage and drug release rates that can be tuned according to the patient's requirements.

Nile tilapia skin (Oreochromis niloticus) for burn treatment: ultrastructural analysis and quantitative assessment of collagen

Nile tilapia (Oreochromis niloticus) skin is a well-known biomaterial used as an occlusive dressing for burn treatment. It is also an inexpensive and important source of collagen. This study aims to describe the ultrastructural aspects of Nile tilapia skin, assess its collagen amount and organization, and compare quantitative methods of histochemical and immunohistochemical analysis (in all sterilization steps for use in burn dressings). One sample (0.5 × 0.5 cm) of ten different fish skins was divided in four groups: in natura skin (IN), chemical sterilization (CH), additional irradiation (30 kGy) (IR), and skins used in burn treatment (BT) to compare histochemical and immunohistochemical findings of collagen amount and describe ultrastructural aspects through scanning electron microscopy. The amount of type I collagen decreased during sterilization and clinical use owing to gradual reduction of immunostaining (anti-collagen-I) and decreasing fiber thickness of the collagen, when compared to type III (Picrosirius-red-polarized light). The collagen fibers were rearranged at each sterilization step, with a low collagen percentage and large structural disorganization in BT. The amount of type-I collagen was further reduced after BT (p < 0.05). Both the methods did not exhibit a quantified value difference (p = 0.247), and a positive correlation (r = 0.927; 95 % CI = 0.720-0.983) was observed between them, with concordance for collagen quantification in similar samples, presenting a low systematic error rate (Dalberg coefficient: 6.70). A significant amount of type-I collagen is still observed despite sterilization, although clinical application further reduces type I collagen. Its quantification can be performed both by immunohistochemistry and/or Picrosirius Red reliably.

PCL/Andiroba Oil (Carapa guianensis Aubl.) Hybrid Film for Wound Healing Applications

Developing a biomimetic material to wound care is an emerging need for the healing process. Poly (ε-caprolactone) (PCL) is a polymer with the necessary dressing's requirements often used in medicine. Their surface, physic-chemical and biological properties can be modified by adding bioactive compounds, such as andiroba seed oil (Carapa guianensis). This Amazonian natural plant has medicinal and pharmacological properties. For this purpose, PCL polymeric films incorporated with andiroba oil were investigated. The synthesis of hybrids materials was carried out in the solvent casting method. Thermal properties were evaluated using thermogravimetric analysis (TGA/DTGA) and differential scanning calorimetry (DSC). The solvent type on the surface and hydrophilicity of samples was studied using a scanning electron microscope (SEM). Additionally, contact angle measurements, functional groups analysis, fluid absorption capacity, and cell viability were performed. The results demonstrated the influences of andiroba oil under the morphology and thermal properties of the polymeric matrix; the hydrophilicity of the hybrid film obtained by acetic acid was reduced by 13%; the porosity decreased as the concentration of oil increased, but its higher thermal stability. The L929 cell line's proliferation was observed in all materials, and it presented nontoxic nature. It was demonstrated the ability of PCL hybrid film as a matrix for cell growth. Then, the materials were proved potential candidates for biomedical applications.

Nile Tilapia Fish Skin-Based Wound Dressing Improves Pain and Treatment-Related Costs of Superficial Partial-Thickness Burns: A Phase III Randomized Controlled Trial

BACKGROUND

In a phase II study comparing Nile tilapia fish skin to silver sulfadiazine cream for outpatient management of superficial partial-thickness burns, the fish skin decreased reepithelialization time (average reduction, 1.43 days), dressing changes (average reduction, 3.72 dressings), and visual analogue scale pain scores. The present study aimed to further evaluate Nile tilapia fish skin efficacy for superficial partial-thickness burns. Unlike silver sulfadiazine cream, the fish skin has good adherence to the wound bed, which may prevent infections and decrease need for dressing changes. Thus, it could be a low-cost alternative to hasten healing and improve pain of burn patients.

METHODS

A phase III randomized controlled trial was conducted from April of 2017 to October of 2018 in Fortaleza, Brazil, and included 115 outpatients aged 18 to 70 years with superficial partial-thickness burns affecting 15 percent or less of body surface area and no previous treatment. Fifty-seven patients were treated with the glycerolized fish skin and 58 with silver sulfadiazine cream 1%. Primary outcomes were reepithelialization time, number of dressings, treatment-related costs, and pain intensity, assessed by means of visual analogue scale, Electronic von Frey, Burns Specific Pain Anxiety Scale, and analgesic use. Patients were evaluated every 48 hours.

RESULTS

Patients treated with fish skin required fewer days for reepithelialization (9.7 ± 0.6 days versus 10.2 ± 0.9 days; p = 0.001) and fewer dressings (1.6 ± 0.7 versus 4.9 ± 0.5; p < 0.001). They also had decreased analgesic needs and visual analogue scale, Burns Specific Pain Anxiety Scale, and Electronic von Frey measurements. Finally, fish skin use reduced the final average treatment-related cost per patient by 42.1 percent.

CONCLUSION

By hastening reepithelialization, improving burn-related pain, and decreasing treatment-related costs, Nile tilapia fish skin could benefit the resource-poor public health systems of developing countries.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, II.

Historical Evolution of Skin Grafting-A Journey through Time

Autologous skin grafting was developed more than 3500 years ago. Several approaches and techniques have been discovered and established in burn care since then. Great achievements were made during the 19th and 20th century. Many of these techniques are still part of the surgical burn care. Today, autologous skin grafting is still considered to be the gold standard for burn wound coverage. The present paper gives an overview about the evolution of skin grafting and its usage in burn care nowadays.

A Short History of Skin Grafting in Burns: From the Gold Standard of Autologous Skin Grafting to the Possibilities of Allogeneic Skin Grafting with Immunomodulatory Approaches

Due to groundbreaking and pioneering developments in the last century, significant improvements in the care of burn patients have been achieved. In addition to the still valid therapeutic standard of autologous split-thickness skin grafting, various commercially available skin substitutes are currently available. Significant progress in the field of tissue engineering has led to the development of promising therapeutic approaches. However, scientific advances in the field of allografting and transplant immunology are of great importance. The achievement of various milestones over the past decades has provided thought-provoking impulses in the field of skin allotransplantation. Thus, biologically viable skin allotransplantation is still not a part of the clinical routine. The purpose of this article is to review the achievements in burn surgery with regards to skin allotransplantation in recent years.

A Randomized Comparison Study of Lyophilized Nile Tilapia Skin and Silver-Impregnated Sodium Carboxymethylcellulose for the Treatment of Superficial Partial-Thickness Burns

Glycerolized Nile tilapia skin (NTS) showed promising results when used for burn treatment in phases II and III randomized controlled trials. This pilot study aims to evaluate the effectiveness of lyophilized NTS (LNTS) as a temporary skin substitute for superficial partial-thickness burns by comparing it with silver-impregnated sodium carboxymethylcellulose dressing. This was a randomized, prospective, open-label, and controlled pilot study conducted in Fortaleza, Brazil, from April 2019 to December 2019. The 24 participants had ≥18 and ≤70 years of age and superficial partial-thickness burns affecting up to 10% of TBSA. Primary outcomes were the number of dressings performed and pain intensity, assessed via the Visual Analogue Scale and the Electronic von Frey. Secondary outcomes were the level of pain-related anxiety, assessed via the Burns Specific Pain Anxiety Scale, and analgesic consumption. In the test group, the number of dressings and the patient-reported pain after dressing-related procedures were lower. Analgesic intake, pain-related anxiety, and both patient-reported and objectively measured pain before dressing-related procedures were similar for the treatment groups. No adverse effects were detected. LNTS shares the same characteristics of an "'ideal'" wound dressing demonstrated by glycerolized NTS in previous studies. Also, it demonstrated noninferiority for burn management when compared with silver-impregnated sodium carboxymethylcellulose dressing. The safety and efficacy of LNTS demonstrated in this pilot study may allow the development of larger phases II and III RCTs in a near future.