Wound healing grafts: Omega-3 fatty acid lipid content differentiates the lipid profiles of acellular Atlantic cod skin from traditional dermal substitutes

Decellularization of fish tissues for tissue engineering and regenerative medicine applications

Decellularization is the process of obtaining acellular tissues with low immunogenic cellular components from animals or plants while maximizing the retention of the native extracellular matrix structure, mechanical integrity and bioactivity. The decellularized tissue obtained through the tissue decellularization technique retains the structure and bioactive components of its native tissue; it not only exhibits comparatively strong mechanical properties, low immunogenicity and good biocompatibility but also stimulates in situ neovascularization at the implantation site and regulates the polarization process of recruited macrophages, thereby promoting the regeneration of damaged tissue. Consequently, many commercial products have been developed as promising therapeutic strategies for the treatment of different tissue defects and lesions, such as wounds, dura, bone and cartilage defects, nerve injuries, myocardial infarction, urethral strictures, corneal blindness and other orthopedic applications. Recently, there has been a growing interest in the decellularization of fish tissues because of the abundance of sources, less religious constraints and risks of zoonosis transmission between mammals. In this review, we provide a complete overview of the state-of-the-art decellularization of fish tissues, including the organs and methods used to prepare acellular tissues. We enumerated common decellularized fish tissues from various fish organs, such as skin, scale, bladder, cartilage, heart and brain, and elaborated their different processing methods and tissue engineering applications. Furthermore, we presented the perspectives of (i) the future development direction of fish tissue decellularization technology, (ii) expanding the sources of decellularized tissue and (iii) innovating decellularized tissue bio-inks for 3D bioprinting to unleash the great potential of decellularized tissue in tissue engineering and regenerative medicine applications.

Acellular fish skin grafts in the treatment of diabetic wounds: Advantages and clinical translation

Diabetic wounds cannot undergo normal wound healing due to changes in the concentration of hyperglycemia in the body and soon evolve into chronic wounds causing amputation or even death of patients. Diabetic wounds directly affect the quality of patients and social medical management; thus researchers started to focus on skin transplantation technology. The acellular fish skin grafts (AFSGs) are derived from wild fish, which avoids the influence of human immune function and the spread of the virus through low-cost decellularization. AFSGs contain a large amount of collagen and omega-3 polyunsaturated fatty acids and they have an amazing effect on wound regeneration. However, after our search in major databases, we found that there were few research trials in this field, and only one was clinically approved. Therefore, we summarized the advantages of AFSGs and listed the problems faced in clinical use. The purpose of this paper is to enable researchers to better carry out original experiments at various stages.

Exploring the wound-healing and antimicrobial potential of Dittrichia viscosa L lipidic extract: Chemical composition and in vivo evaluation

Dittrichia viscosa belongs to the Dittrichia genus, it grows abundantly in the east and northeast of Morocco, and traditionally its fresh leaves are crushed and given for topical application after burns, wounds, and infections. In this study, we examine the wound-healing activity of Dittrichia viscosa lipidic extract in vivo, assess its anti-microbial effect, and explore the specific compounds that contribute to these effects. To assess the effectiveness of wound healing, a burn-induced wound model was employed in Wistar rats, and the levels of hydroxyproline as well as histopathological changes in the skin tissues were evaluated. Furthermore, the antimicrobial potential against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Candida glabrata, and Malassezia furfur was investigated using the agar disc diffusion method. Gas Chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC) techniques were employed to analyze the composition of fatty acids, phytosterols, and tocopherols. Topical application of Dittrichia viscosa lipidic fraction ointment exhibited significant improvements in wound contraction, achieving an impressive rate of 82% within 21 days. Additionally, the lipidic extract of Dittrichia viscosa displayed notable efficacy against various microbial strains, including Candida albicans (25.07 ± 0.2), Candida glabrata (24 ± 0.6), and Malassezia furfur (22 ± 0.7). The primary fatty acids identified in the sample were linolenic acid (58.95% ± 0), oleic acid (16.75% ±0.04), and linoleic acid (11.97% ± 0.1). Notably, the sample contained significant amounts of γ-Tocopherols (732.08 ± 21mg/kg), while the sterol fraction primarily consisted of 7-Campesterol (1937 ± 0 mg/kg), 7-β-Sitosterol (1621 ± 0 mg/kg), and Stigmasterol (1439 ± 26 mg/kg). By its richness in active compound content, Dittrichia viscosa effectively accelerates wound healing while safeguarding against microbial infections.

Use of Fish Skin Graft in Management of Combat Injuries Following Military Drone Assaults in Field-Like Hospital Conditions

INTRODUCTION

The 2020 Nagorno-Karabakh war was an armed conflict between Azerbaijan and Armenia over an ethnically and historically significant region. This manuscript is a report on the forward deployment of acellular fish skin graft (FSG) from Kerecis™, a biologic, acellular matrix derived from the skin of wild-caught Atlantic cod that contains intact epidermis and dermis layers. The usual intention of treatment under adverse circumstances is to temporize wounds until better treatment can be attained, although ideally, rapid coverage and treatment are necessary to prevent long-term complications and loss of life and limb. An austere environment, such as the one experienced during the conflict described here, presents considerable logistical barriers for the treatment of wounded soldiers.

MATERIALS AND METHODS

Dr H. Kjartansson from Iceland and Dr S. Jeffery from the United Kingdom traveled to Yerevan, near the heart of the conflict, to deliver and train on using FSG in wound management. The primary goal was to use FSG in patients where stabilization and improvement in the wound bed were needed before skin grafting. Other goals were to improve healing time, achieve earlier skin grafting, and have better cosmetic outcomes upon healing.

RESULTS

Over the course of two trips, several patients were managed with fish skin. Injuries included large-area full-thickness burn and blast injuries. Management with FSG induced wound granulation several days sooner in all cases, and even weeks in some instances, allowing a stepdown in the reconstruction ladder with earlier skin grafting procedures and a reduction in requirement of flap surgery.

CONCLUSIONS

This manuscript describes a successful first instance of forward deployment of FSGs to an austere environment. FSG, in this military context, has shown great portability, with easy transfer of knowledge. More importantly, management with fish skin has shown faster granulation rates in burn wounds for skin grafting, resulting in improved patient outcomes with no documented infections.

Fish Skin Graft: Narrative Review and First Application for Abdominal Wall Dehiscence in Children

Acellular fish skin grafts (FSGs) are tissue-based products created by minimally processing the skin of the Atlantic cod (Gadus morhua). The FSG is rich in omega-3 and facilitates tissue regeneration by supporting revascularization and ingrowth in the proliferation and remodeling phases of wound healing. FSG is structurally more similar to human skin than antiviral-processed skin substitutes such as amniotic membrane, and there are no known prion, bacterial, or viral diseases that can be transmitted from North-Atlantic cod to humans. The FSG is processed using a proprietary method that preserves the structure and lipid composition of the skin. FSG is CE marked, and US Food and Drug Administration cleared for multiple clinical applications in partial and full-thickness wounds. FSG is currently the only acellular dermal matrix product that does not originate from mammalian tissues. For this narrative review, Medline and UpToDate were used to include a total of 21 articles published from 2015 to 2022 about fish skin graft use. We also reported a case of a 7-year-old boy who underwent treatment with FSG for abdominal wall dehiscence at our department of pediatric surgery, IRCCS Sant'Orsola-Malpighi, Alma Mater Studiorum, University of Bologna, University Hospital of Bologna. FSG provides a valuable and sustainable treatment that improves wound healing in both adult and pediatric populations. We described the first application of an FSG for wound dehiscence of the abdominal wall in a pediatric patient, reporting how FSG was completely reabsorbed and improved the skin's repair.

Potential of Atlantic Codfish (Gadus morhua) Skin Collagen for Skincare Biomaterials

Collagen is the major structural protein in extracellular matrix present in connective tissues, including skin, being considered a promising material for skin regeneration. Marine organisms have been attracting interest amongst the industry as an alternative collagen source. In the present work, Atlantic codfish skin collagen was analyzed, to evaluate its potential for skincare. The collagen was extracted from two different skin batches (food industry by-product) using acetic acid (ASColl), confirming the method reproducibility since no significant yield differences were observed. The extracts characterization confirmed a profile compatible with type I collagen, without significant differences between batches or with bovine skin collagen (a reference material in biomedicine). Thermal analyses suggested ASColl's native structure loss at 25 °C, and an inferior thermal stability to bovine skin collagen. No cytotoxicity was found for ASColl up to 10 mg/mL in keratinocytes (HaCaT cells). ASColl was used to develop membranes, which revealed smooth surfaces without significative morphological or biodegradability differences between batches. Their water absorption capacity and water contact angle indicated a hydrophilic feature. The metabolic activity and proliferation of HaCaT were improved by the membranes. Hence, ASColl membranes exhibited attractive characteristics to be applied in the biomedical and cosmeceutical field envisaging skincare.

A Risk-Benefit Review of Currently Used Dermal Substitutes for Burn Wounds

While split-thickness autologous skin grafts remain the most common method of definitive burn wound closure, dermal substitutes have emerged as an attractive option. There are many advantages of utilizing a dermal substitute, notably reducing the need for donor tissue and subsequent iatrogenic creation of a secondary wound. However, there are disadvantages with each that most be weighed and factored into the decision. And most come at a high initial financial cost. There is little comparative literature of the various available and emerging products. This analysis was performed to objectively present risks and benefits of each option.

PLLA-gelatin composite fiber membranes incorporated with functionalized CeNPs as a sustainable wound dressing substitute promoting skin regeneration and scar remodelling

The need of wound dressing material that can accelerate wound healing is increasing and will last a long time. In this study, Cerium Oxide Nanoparticles (CeNPs) incorporated poly-L-lactic acid (PLLA)-gelatin...

Lipid mediator profiles of burn wound healing: Acellular cod fish skin grafts promote the formation of EPA and DHA derived lipid mediators following seven days of treatment

The use of acellular fish skin grafts (FSG) for the treatment of burn wounds is becoming more common due to its beneficial wound healing properties. In our previous study we demonstarted that FSG is a scaffold biomaterial that is rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) conjugated to phosphatidylcholines. Here we investigated whether EPA and DHA derived lipid mediators are influenced during the healing of burn wounds treated with FSG. Deep partial and full thickness burn wounds (DPT and FT, respectively) were created on Yorkshire pigs (n = 4). DPT were treated with either FSG or fetal bovine dermis while FT were treated either with FSG or cadaver skin initially and followed by a split thickness skin graft. Punch biopsies were collected on days 7, 14, 21, 28 and 60 and analyzed in respect of changes to approximately 45 derivatives of EPA, DHA, arachidonic acid (AA), and linoleic acid (LA) employing UPLC-MS/MS methodology. Nine EPA and DHA lipid mediators, principally mono-hydroxylated derivatives such as 18-HEPE and 17-HDHA, were significantly higher on day 7 in the DPT when treated with FSG. A similar but non-significant trend was observed for the FT. The results suggest that the use of FSG in burn wound treatment can alter the formation of EPA and DHA mono hydroxylated lipid mediators in comparison to other grafts of mammalian origin. The differences observed during the first seven days after treatment indicates that FSG affects the early stages of wound healing.

EMT-Derived Alterations in Glutamine Metabolism Sensitize Mesenchymal Breast Cells to mTOR Inhibition

Epithelial-to-mesenchymal transition (EMT) is a fundamental developmental process with strong implications in cancer progression. Understanding the metabolic alterations associated with EMT may open new avenues of treatment and prevention. Here we used ¹³C carbon analogs of glucose and glutamine to examine differences in their utilization within central carbon and lipid metabolism following EMT in breast epithelial cell lines. We found that there are inherent differences in metabolic profiles before and after EMT. We observed EMT-dependent re-routing of the TCA-cycle, characterized by increased mitochondrial IDH2-mediated reductive carboxylation of glutamine to lipid biosynthesis with a concomitant lowering of glycolytic rates and glutamine-dependent glutathione (GSH) generation. Using weighted correlation network analysis, we identified cancer drugs whose efficacy against the NCI-60 Human Tumor Cell Line panel is significantly associated with GSH abundance and confirmed these in vitro. We report that EMT-linked alterations in GSH synthesis modulate the sensitivity of breast epithelial cells to mTOR inhibitors. IMPLICATIONS: EMT in breast cells causes an increased demand for glutamine for fatty acid biosynthesis, altering its contribution to glutathione biosynthesis, which sensitizes the cells to mTOR inhibitors.

Cerebrospinal Fluid C18 Ceramide Associates with Markers of Alzheimer's Disease and Inflammation at the Pre- and Early Stages of Dementia

Background:

Understanding how dysregulation in lipid metabolism relates to the severity of Alzheimer‘s disease (AD) pathology might be critical in developing effective treatments.

Objective:

To identify lipid species in cerebrospinal fluid (CSF) associated with signature AD pathology and to explore their relationships with measures reflecting AD-related processes (neurodegeneration, inflammation, deficits in verbal episodic memory) among subjects at the pre- and early symptomatic stages of dementia.

Methods:

A total of 60 subjects that had been referred to an Icelandic memory clinic cohort were classified as having CSF AD (n = 34) or non-AD (n = 26) pathology profiles. Untargeted CSF lipidomic analysis was performed using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS) for the detection of mass-to-charge ratio (m/z) features. CSF proteins reflecting neurodegeneration (neurofilament light [NFL]) and inflammation (chitinase-3-like protein 1 [YKL-40], S100 calcium-binding protein B [S100B], glial fibrillary acidic protein [GFAP]) were also measured. Rey Auditory Verbal Learning (RAVLT) and Story tests were used for the assessment of verbal episodic memory.

Results:

Eight out of 1008 features were identified as best distinguishing between the CSF profile groups. Of those, only the annotation of the m/z feature assigned to lipid species C18 ceramide was confirmed with a high confidence. Multiple regression analyses, adjusted for age, gender, and education, demonstrated significant associations of CSF core AD markers (Aβ₄₂: st.β= –0.36, p = 0.007; T-tau: st.β= 0.41, p = 0.005) and inflammatory marker S100B (st.β= 0.51, p = 0.001) with C18 ceramide levels.

Conclusion:

Higher levels of C18 ceramide associated with increased AD pathology and inflammation, suggesting its potential value as a therapeutic target.