Wound healing ability of acellular fish skin and bovine collagen grafts for split-thickness donor sites in burn patients: Characterization of acellular grafts and clinical application

Resolution of a chronic occipital wound with exposed skull bone with a fish skin graft: a successful treatment approach

Chronic skin defects in the head, face and neck pose challenges for closure, especially after multiple surgeries or radiation therapy. We report the case of a woman in her 70s with a chronic occipital wound following squamous cell carcinoma resections, resulting in exposed skull bone. Despite various options, we successfully treated the 4 cm x 5 cm wound with a Kerecis fish skin graft (FSG), observing significant improvement within a week. The FSG promoted granulation tissue formation, enabling subsequent full-thickness skin grafting from the patient's groin. Complete wound closure was achieved within 2 weeks, indicating FSG's efficacy in complex wound management. Our experience highlights FSG's potential as a valuable tool in wound healing and reconstruction, particularly in challenging cases involving the head and neck.

Acellular Fish Skin Grafts for Treatment of Periocular Skin Defects

PURPOSE

To describe the outcomes of acellular fish skin grafts for repair of periocular anterior lamella skin defects after Mohs surgery for skin cancers.

METHODS

Following the institutional review board approval, we conducted a retrospective chart review of patients treated with acellular fish skin grafts between January 2022 and December 2023. Indication was to repair defects after Mohs excision of basal cell carcinoma and squamous cell carcinoma. Demographics, smoking and diabetes status, diagnosis, defect location, graft size, and complications were evaluated. Outcomes were analyzed using the scar cosmesis assessment and rating scale.

RESULTS

Six patients (3 females and 3 males) with a mean age of 60.8 (range 44-80) had Mohs surgery for basal cell carcinoma (4) and squamous cell carcinoma (2). Location of defects included eyebrow (3 cases), lateral nasal wall (1 case), lower eyelid (1 case), and medial lower eyelid/nasal wall (1 case). Defect size ranged from 8 × 10 mm to 30 × 40 mm. Two patients had more than 1 application of xenograft. One patient developed a mild cicatricial ectropion. No other postoperative complications were seen, and all had good wound healing and cosmetically acceptable results.

CONCLUSIONS

In this pilot study, acellular fish skin xenografts are shown to be promising skin graft substitutes in patients with Mohs defects and decrease the need for autologous skin harvesting or allogenic skin donation.

Metabolic reprogramming in skin wound healing

Metabolic reprogramming refers to the ability of a cell to alter its metabolism in response to different stimuli and forms of pressure. It helps cells resist external stress and provides them with new functions. Skin wound healing involves the metabolic reprogramming of nutrients, such as glucose, lipids, and amino acids, which play vital roles in the proliferation, differentiation, and migration of multiple cell types. During the glucose metabolic process in wounds, glucose transporters and key enzymes cause elevated metabolite levels. Glucose-mediated oxidative stress drives the proinflammatory response and promotes wound healing. Reprogramming lipid metabolism increases the number of fibroblasts and decreases the number of macrophages. It enhances local neovascularization and improves fibrin stability to promote extracellular matrix remodelling, accelerates wound healing, and reduces scar formation. Reprogramming amino acid metabolism affects wound re-epithelialization, collagen deposition, and angiogenesis. However, comprehensive reviews on the role of metabolic reprogramming in skin wound healing are lacking. Therefore, we have systematically reviewed the metabolic reprogramming of glucose, lipids, and amino acids during skin wound healing. Notably, we identified their targets with potential therapeutic value and elucidated their mechanisms of action.

The Use of Acellular Tissue Matrices in Gender-Affirming Surgery: Review of the Literature and Institutional Experience

Wound healing complications are not uncommon after genital gender-affirming surgery and can pose significant challenges for the reconstructive surgeon. Acellular tissue matrices are products that contain extracellular matrix compounds without living cells and are used to expedite and improve wound healing. Some of these products have been described for a variety of different indications in gender-affirming surgery.  In this paper, the authors present a review of the current literature on the use of acellular tissue matrices in gender-affirming surgery as well as the authors' institutional experience in using these products.

An Overview of Recent Developments in the Management of Burn Injuries

According to the World Health Organization (WHO), around 11 million people suffer from burns every year, and 180,000 die from them. A burn is a condition in which heat, chemical substances, an electrical current or other factors cause tissue damage. Burns mainly affect the skin, but can also affect deeper tissues such as bones or muscles. When burned, the skin loses its main functions, such as protection from the external environment, pathogens, evaporation and heat loss. Depending on the stage of the burn, the patient's condition and the cause of the burn, we need to choose the most appropriate treatment. Personalization and multidisciplinary collaboration are key to the successful management of burn patients. In this comprehensive review, we have collected and discussed the available treatment options, focusing on recent advances in topical treatments, wound cleansing, dressings, skin grafting, nutrition, pain and scar tissue management.

Osteogenic differentiation and reconstruction of mandible defects using a novel resorbable membrane: An in vitro and in vivo experimental study

To evaluate the cellular response of both an intact fish skin membrane and a porcine-derived collagen membrane and investigate the bone healing response of these membranes using a translational, preclinical, guided-bone regeneration (GBR) canine model. Two different naturally sourced membranes were evaluated in this study: (i) an intact fish skin membrane (Kerecis Oral®, Kerecis) and (ii) a porcine derived collagen (Mucograft®, Geistlich) membrane, positive control. For the in vitro experiments, human osteoprogenitor (hOP) cells were used to assess the cellular viability and proliferation at 24, 48, 72, and 168 h. ALPL, COL1A1, BMP2, and RUNX2 expression levels were analyzed by real-time PCR at 7 and 14 days. The preclinical component was designed to mimic a GBR model in canines (n = 12). The first step was the extraction of premolars (P1-P4) and the 1st molars bilaterally, thereby creating four three-wall box type defects per mandible (two per side). Each defect site was filled with bone grafting material, which was then covered with one of the two membranes (Kerecis Oral® or Mucograft®). The groups were nested within the mandibles of each subject and membranes randomly allocated among the defects to minimize potential site bias. Samples were harvested at 30-, 60-, and 90-days and subjected to computerized microtomography (μCT) for three-dimensional reconstruction to quantify bone formation and graft degradation, in addition to histological processing to qualitatively analyze bone regeneration. Neither the intact fish skin membrane nor porcine-based collagen membrane presented cytotoxic effects. An increase in cell proliferation rate was observed for both membranes, with the Kerecis Oral® outperforming the Mucograft® at the 48- and 168-hour time points. Kerecis Oral® yielded higher ALPL expression relative to Mucograft® at both 7- and 14-day points. Additionally, higher COL1A1 expression was observed for the Kerecis Oral® membrane after 7 days but no differences were detected at 14 days. The membranes yielded similar BMP2 and RUNX2 expression at 7 and 14 days. Volumetric reconstructions and histologic micrographs indicated gradual bone ingrowth along with the presence of particulate bone grafts bridging the defect walls for both Kerecis Oral® and Mucograft® membranes, which allowed for the reestablishment of the mandible shape after 90 days. New bone formation significantly increased from 30 to 60 days, and from 60 to 90 days in vivo, without significant differences between membranes. The amount of bovine grafting material (%) within the defects significantly decreased from 30 to 90 days. Collagen membranes led to an upregulation of cellular proliferation and adhesion along with increased expression of genes associated with bone healing, particularly the intact fish skin membrane. Despite an increase in the bone formation rate in the defect over time, there was no significant difference between the membranes.

The Use of Intact Fish Skin Grafts in the Treatment of Necrotizing Fasciitis of the Leg: Early Clinical Experience and Literature Review on Indications for Intact Fish Skin Grafts

BACKGROUND

Necrotizing fasciitis (NF) is a serious infectious disease that can initially place the patient's life in danger and, after successful surgical and antibiotic treatment, leaves extensive wounds with sometimes even exposed bones and tendons. Autologous skin grafts are not always possible or require adequate wound bed preparation. Novel intact fish skin grafts (iFSGs; Kerecis® Omega3 Wound, Kerecis hf, Isafjördur, Iceland) have already shown their potential to promote granulation in many other wound situations. Faster wound healing rates and better functional and cosmetic outcomes were observed due to their additionally postulated anti-inflammatory and analgesic properties. Therefore, iFSGs may also be essential in treating NF. We present our initial experience with iFSGs in treating leg wounds after NF and review the literature for the current spectrum of clinical use of iFSGs.

CASE PRESENTATIONS

We present two male patients (aged 60 and 69 years) with chronic or acute postsurgical extensive leg ulcers six weeks and six days after necrotizing fasciitis, respectively. Both suffered from diabetes mellitus without vascular pathologies of the lower limbs. A single application of one pre-meshed (Kerecis® Graftguide) and one self-meshed 300 cm2 iFSG (Kerecis® Surgiclose) was performed in our operation room after extensive surgical debridement and single circles of negative wound pressure therapy. Application and handling were easy. An excellent wound granulation was observed, even in uncovered tibia bone and tendons, accompanied by pain relief in both patients. Neither complications nor allergic reactions occurred. The patients received autologous skin grafting with excellent functional and cosmetic outcomes.

CONCLUSIONS

iFSGs have the potential to play a significant role in the future treatment of NF due to the fast promotion of wound granulation and pain relief. Our experience may encourage surgeons to use iFSGs in NF patients, although high-quality, large-sized studies are still required to confirm these results. The observed effects of iFSGs on wounds associated with NF may be transferred to other wound etiologies as well.

The Burn Wound

Skin serves as a protective barrier against infection, prevents excessive fluid and electrolyte losses, performs crucial thermoregulation, and provides tactile feedback of surroundings. The skin also plays an essential role in human perception of body image, personal appearance, and self-confidence. With these many diverse functions, understanding normal anatomic composition of skin is pivotal to evaluating the extent of its disruption from burn injury. This article discusses the pathophysiology, initial evaluation, subsequent progression, and healing of burn wounds. By delineating the various microcellular and macrocellular alterations of burn injury, this review also augments providers' capacity to deliver patient-centered, evidence-based burn care.

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.

Study on the preparation and properties of acellular matrix from the skin of silver carp (Hypophthalmichthys molitrix)

Acellular matrices are mainly composed of mammalian tissues, and aquatic tissues with lower biological risks and less religious restrictions are considered alternatives to mammalian tissues. The acellular fish skin matrix (AFSM) has been commercially available. Silver carp has the advantages of farmability, high yield and low price, but there are few studies on the silver carp acellular fish skin matrix (SC-AFSM). In this study, an acellular matrix with low DNA and endotoxin was prepared from the skin of silver carp. After treatment with trypsin/sodium dodecyl sulfate and Triton X-100 solutions, the DNA content in SC-AFSM reached 11.03 ± 0.85 ng/mg, and the endotoxin removal rate was 96.8%. The porosity of SC-AFSM was 79.64% ± 0.17%, which is favorable for cell infiltration and proliferation. The relative cell proliferation rate of SC-AFSM extract was 117.79% ± 15.26%. The wound healing experiment showed that SC-AFSM had no adverse acute pro-inflammatory response, which had a similar effect as commercial products in promoting tissue repair. Therefore, SC-AFSM has great application potential in biomaterials.

Cutting Edge Aquatic-Based Collagens in Tissue Engineering

Aquatic-based collagens have attracted much interest due to their great potential application for biomedical sectors, including the tissue engineering sector, as a major component of the extracellular matrix in humans. Their physical and biochemical characteristics offer advantages over mammalian-based collagen; for example, they have excellent biocompatibility and biodegradability, are easy to extract, and pose a relatively low immunological risk to mammalian products. The utilization of aquatic-based collagen also has fewer religious restrictions and lower production costs. Aquatic-based collagen also creates high-added value and good environmental sustainability by aquatic waste utilization. Thus, this study aims to overview aquatic collagen's characteristics, extraction, and fabrication. It also highlights its potential application for tissue engineering and the regeneration of bone, cartilage, dental, skin, and vascular tissue. Moreover, this review highlights the recent research in aquatic collagen, future prospects, and challenges for it as an alternative biomaterial for tissue engineering and regenerative medicines.

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.

Advanced application of collagen-based biomaterials in tissue repair and restoration

In tissue engineering, bioactive materials play an important role, providing structural support, cell regulation and establishing a suitable microenvironment to promote tissue regeneration. As the main component of extracellular matrix, collagen is an important natural bioactive material and it has been widely used in scientific research and clinical applications. Collagen is available from a wide range of animal origin, it can be produced by synthesis or through recombinant protein production systems. The use of pure collagen has inherent disadvantages in terms of physico-chemical properties. For this reason, a processed collagen in different ways can better match the specific requirements as biomaterial for tissue repair. Here, collagen may be used in bone/cartilage regeneration, skin regeneration, cardiovascular repair and other fields, by following different processing methods, including cross-linked collagen, complex, structured collagen, mineralized collagen, carrier and other forms, promoting the development of tissue engineering. This review summarizes a wide range of applications of collagen-based biomaterials and their recent progress in several tissue regeneration fields. Furthermore, the application prospect of bioactive materials based on collagen was outlooked, aiming at inspiring more new progress and advancements in tissue engineering research.

Graphical Abstract

The Discovery and Development of Natural-Based Biomaterials with Demonstrated Wound Healing Properties: A Reliable Approach in Clinical Trials

Current research across the globe still focuses strongly on naturally derived biomaterials in various fields, particularly wound care. There is a need for more effective therapies that will address the physiological deficiencies underlying chronic wound treatment. The use of moist bioactive scaffolds has significantly increased healing rates compared to local and traditional treatments. However, failure to heal or prolonging the wound healing process results in increased financial and social stress imposed on health institutions, caregivers, patients, and their families. The urgent need to identify practical, safe, and cost-effective wound healing scaffolding from natural-based biomaterials that can be introduced into clinical practice is unequivocal. Naturally derived products have long been used in wound healing; however, clinical trial evaluations of these therapies are still in their infancy. Additionally, further well-designed clinical trials are necessary to confirm the efficacy and safety of natural-based biomaterials in treating wounds. Thus, the focus of this review is to describe the current insight, the latest discoveries in selected natural-based wound healing implant products, the possible action mechanisms, and an approach to clinical studies. We explore several tested products undergoing clinical trials as a novel approach to counteract the debilitating effects of impaired wound healing.

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.

New Medical Device and Therapeutic Approvals in Otolaryngology: State of the Art Review of 2021

Objective

To evaluate new medical devices and drugs pertinent to otolaryngology–head and neck surgery that were approved by the Food and Drug Administration (FDA) in 2021.

Data Sources

Publicly available FDA device and drug approvals from ENT (ear, nose, and throat), anesthesia, neurosurgery, plastic surgery, and general surgery FDA committees.

Review Methods

FDA device and therapeutic approvals were identified and reviewed by members of the American Academy of Otolaryngology–Head and Neck Surgery’s Medical Devices and Drugs Committee. Two independent reviewers assessed the relevance of devices and drugs to otolaryngologists. Medical devices and drugs were then allocated to their respective subspecialty fields for critical review based on available scientific literature.

Conclusions

The Medical Devices and Drugs Committee reviewed 1153 devices and 52 novel drugs that received FDA approval in 2021 (67 ENT, 106 anesthesia, 618 general surgery and plastic surgery, 362 neurosurgery). Twenty-three devices and 1 therapeutic agent relevant to otolaryngology were included in the state of the art review. Advances spanned all subspecialties, including over-the-counter hearing aid options in otology, expanding treatment options for rhinitis in rhinology, innovative laser-safe endotracheal tubes in laryngology, novel facial rejuvenation and implant technology in facial plastic surgery, and advances in noninvasive and surgical treatment options for obstructive sleep apnea.

Implications for Practice

FDA approvals for new technology and pharmaceuticals present new opportunities across subspecialties in otolaryngology. Clinicians’ nuanced understanding of the safety, advantages, and limitations of these innovations ensures ongoing progress in patient care.

Fish Collagen Peptides Protect against Cisplatin-Induced Cytotoxicity and Oxidative Injury by Inhibiting MAPK Signaling Pathways in Mouse Thymic Epithelial Cells

Thymic epithelial cells (TECs) account for the most abundant and dominant stromal component of the thymus, where T cells mature. Oxidative- or cytotoxic-stress associated injury in TECs, a significant and common problem in many clinical settings, may cause a compromised thymopoietic capacity of TECs, resulting in clinically significant immune deficiency disorders or impairment in the adaptive immune response in the body. The present study demonstrated that fish collagen peptides (FCP) increase cell viability, reduce intracellular levels of reactive oxygen species (ROS), and impede apoptosis by repressing the expression of Bax and Bad and the release of cytochrome c, and by upregulating the expression of Bcl-2 and Bcl-xL in cisplatin-treated TECs. These inhibitory effects of FCP on TEC damage occur via the suppression of ROS generation and MAPK (p38 MAPK, JNK, and ERK) activity. Taken together, our data suggest that FCP can be used as a promising protective agent against cytotoxic insults- or ROS-mediated TEC injury. Furthermore, our findings provide new insights into a therapeutic approach for the future application of FCP in the prevention and treatment of various types of oxidative- or cytotoxic stress-related cell injury in TECs as well as age-related or acute thymus involution.