Collagen-based sponge hastens wound healing via decrease of inflammatory cytokines

Recent advancements in natural polymers-based self-healing nano-materials for wound dressing

The field of wound healing has witnessed remarkable progress in recent years, driven by the pursuit of advanced wound dressings. Traditional dressing materials have limitations like poor biocompatibility, nonbiodegradability, inadequate moisture management, poor breathability, lack of inherent therapeutic properties, and environmental impacts. There is a compelling demand for innovative solutions to transcend the constraints of conventional dressing materials for optimal wound care. In this extensive review, the therapeutic potential of natural polymers as the foundation for the development of self-healing nano-materials, specifically for wound dressing applications, has been elucidated. Natural polymers offer a multitude of advantages, possessing exceptional biocompatibility, biodegradability, and bioactivity. The intricate engineering strategies employed to fabricate these polymers into nanostructures, thereby imparting enhanced mechanical robustness, flexibility, critical for efficacious wound management has been expounded. By harnessing the inherent properties of natural polymers, including chitosan, alginate, collagen, hyaluronic acid, and so on, and integrating the concept of self-healing materials, a comprehensive overview of the cutting-edge research in this emerging field is presented in the review. Furthermore, the inherent self-healing attributes of these materials, wherein they exhibit innate capabilities to autonomously rectify any damage or disruption upon exposure to moisture or body fluids, reducing frequent dressing replacements have also been explored. This review consolidates the existing knowledge landscape, accentuating the benefits and challenges associated with these pioneering materials while concurrently paving the way for future investigations and translational applications in the realm of wound healing.

Hyaluronan: Sources, Structure, Features and Applications

Hyaluronan (HA) is a non-sulfated glycosaminoglycan that is present in a variety of body tissues and organs. Hyaluronan has a wide range of biological activities that are frequently influenced by molar mass; however, they also depend greatly on the source, purity, and kind of impurities in hyaluronan. High-molar-mass HA has anti-inflammatory, immunosuppressive, and antiangiogenic properties, while low-molar-mass HA has opposite properties. A number of chemical modifications have been performed to enhance the stability of HA and its applications in medical practice. Hyaluronan is widely applied in medicine, such as viscosupplementation, ophthalmology, otolaryngology, wound healing, cosmetics, and drug delivery. In this review, we summarized several medical applications of polymers based on the hyaluronan backbone.

Reactive oxygen species (ROS) scavenging biomaterials for anti-inflammatory diseases: from mechanism to therapy

Inflammation is a fundamental defensive response to harmful stimuli, but the overactivation of inflammatory responses is associated with most human diseases. Reactive oxygen species (ROS) are a class of chemicals that are generated after the incomplete reduction of molecular oxygen. At moderate levels, ROS function as critical signaling molecules in the modulation of various physiological functions, including inflammatory responses. However, at excessive levels, ROS exert toxic effects and directly oxidize biological macromolecules, such as proteins, nucleic acids and lipids, further exacerbating the development of inflammatory responses and causing various inflammatory diseases. Therefore, designing and manufacturing biomaterials that scavenge ROS has emerged an important approach for restoring ROS homeostasis, limiting inflammatory responses and protecting the host against damage. This review systematically outlines the dynamic balance of ROS production and clearance under physiological conditions. We focus on the mechanisms by which ROS regulate cell signaling proteins and how these cell signaling proteins further affect inflammation. Furthermore, we discuss the use of potential and currently available-biomaterials that scavenge ROS, including agents that were engineered to reduce ROS levels by blocking ROS generation, directly chemically reacting with ROS, or catalytically accelerating ROS clearance, in the treatment of inflammatory diseases. Finally, we evaluate the challenges and prospects for the controlled production and material design of ROS scavenging biomaterials.

The Efficiency of the Natural Collagen Coating in the Treatment of Extensive Chronic Defects of the Skin and Surrounding Tissues in Dogs

The occurrence of extensive non-healing and chronic skin defects with loss of tissue substance in companion animals are a frequently solved problem. The management of the therapy of large-area defects and absent tissues is a challenge for setting up successful therapeutic management and achieving wound closure, satisfactory cosmetic effect, and restoration of the functionality of the damaged area. In veterinary medicine, we often encounter the failure of wound therapy methods commonly used in closing defects, as a result of which the defect closure time is prolonged. The longer the time required to close the defect, the greater the risk of microbial infection and complications associated with healing in the case of extensive damage to the surrounding soft tissues. Direct influence of the individual phases of healing with supportive alternative therapy appears to be a very suitable solution for the treatment of chronic wounds. To overcome the shortcomings related to partially efficient conventional wound dressings, efforts are oriented toward developing new and effective platforms for wound healing applications. Five patients referred to the Small Animal Clinic of the University Veterinary Hospital were included in this clinical study.

Patients were referred to the clinic with extensive long-term non-healing wounds, necrosis and secernation, or ongoing infection, with loss of tissue substance, which showed signs of chronicity. After assessing the patient’s state of health and subsequent cleaning of the wound bed from contaminants and damaged tissues, collagen sponge Suprasorb® C was applied to the surface of the cleaned wound bed. The average time for the complete closure of the defect was 24.6 days since the introduction of the primary treatment. In all patients, we observed the complete closure of the defect, restoration of functionality of the damaged tissues, and achievement of a cosmetic effect without complications in the recovery process, which points to the excellent effectiveness of the collagen covering in the wound healing process.

Effect of Absorbable Collagen sponge and Steroid Injectionfor One or Two Segment Anterior Cervical Discectomy and fusion: A Retrospective comparison study

BACKGROUND

Dysphagia, mostly resulting from prevertebral soft tissue swelling (PSTS), is a common and refractory complication of anterior cervical discectomy and fusion (ACDF). Although the symptoms are mild and moderate in most cases, severe dysphagia can incur significant mental burdens and morbidity in some patients. This retrospective study aims to analyze the effect of absorbable collagen sponge and steroid injection (ACS-SI) for patients with ACDF.

METHOD

150 patients in the ACS-SI group and 175 in the ANCS-SI group were enrolled in this study from the Affiliated Lihuili Hospital of Ningbo University from January 2018 to November 2020. Baseline characteristics and operation parameters were collected from medical records. The swallowing function was evaluated by the Swallowing-Quality of Life (SWAL-QOL) survey, odynophagia was assessed by visual analog scale (VAS), and prevertebral soft tissue swelling index (PSTSI) was measured.

RESULTS

There was no significant difference in baseline characteristics and operation parameters between the two groups. The improvement of PSTSI and recovery of swallowing function in the ACS-SI group was better than that in the ANCS-SI group at 1 day and 1 month follow-up visit (P<0.05). The VAS score was significantly higher at 2 and 7 days after operation in the ANCS-SI group than that in the ACS-SI group (6.61±0.68 VS 5.52±0.74 and 4.23±0.90 VS 2.08±0.56, P<0.05). There was no significant difference in clinical outcomes between the two groups after 1 month (P>0.05).

CONCLUSION

The use of ACS-SI is beneficial to relieve postoperative odynophagia, reduce PSTS and recover swallow function.

Secreted PEDF modulates fibroblast collagen synthesis through M1 macrophage polarization under expanded condition

Tissue expansion is widely used to obtain new skin tissue for repairing defects in the clinical practice of plastic surgery. One major complication can be dermal thinning during expansion, which usually leads to skin rupture. Collagen synthesis can determine dermal thickness and can be influenced by macrophage polarization during expansion. The aim of the study was to test whether pigment epithelium-derived factor (PEDF) could be a modulator of collagen synthesis in fibroblasts by regulating macrophage polarization during skin expansion. Our results showed that PEDF mRNA expression was increased in expanded human and mouse epidermis. PEDF protein levels were elevated in the subcutaneous exudates of a rat skin expansion model. Increased PEDF mRNA expression was accompanied by dermal thinning during a three-week expansion protocol. Subcutaneous injection of PEDF in vivo further resulted in dermal thinning and cell number increase of M1 macrophage in the expanded skin. PEDF also promoted macrophage polarization in vitro to the M1 subtype under hypoxic conditions. PEDF did not influence collagen gene expression in fibroblasts directly, but attenuated collagen synthesis in a macrophage-mediated manner. Additionally, blockage of PEDF receptors on macrophages with inhibitors rescued collagen synthesis in fibroblasts. Our research demonstrated PEDF elevation in expanded skin leads to dermal thinning through M1 macrophage-mediated collagen synthesis inhibition in fibroblasts. Our results could form a basis for the development of novel strategies to improve skin integrity in expanded skin by using PEDF.

The interplay of DAMPs, TLR4, and proinflammatory cytokines in pulmonary fibrosis

Pulmonary fibrosis is a chronic debilitating condition characterized by progressive deposition of connective tissue, leading to a steady restriction of lung elasticity, a decline in lung function, and a median survival of 4.5 years. The leading causes of pulmonary fibrosis are inhalation of foreign particles (such as silicosis and pneumoconiosis), infections (such as post COVID-19), autoimmune diseases (such as systemic autoimmune diseases of the connective tissue), and idiopathic pulmonary fibrosis. The therapeutics currently available for pulmonary fibrosis only modestly slow the progression of the disease. This review is centered on the interplay of damage-associated molecular pattern (DAMP) molecules, Toll-like receptor 4 (TLR4), and inflammatory cytokines (such as TNF-α, IL-1β, and IL-17) as they contribute to the pathogenesis of pulmonary fibrosis, and the possible avenues to develop effective therapeutics that disrupt this interplay.

A Prototype Skin Substitute, Made of Recycled Marine Collagen, Improves the Skin Regeneration of Sheep

Simple Summary

Marine ecosystems are a huge source of unexplored “blue” materials for different applications. The edible part of sea urchin is limited, and the vast majority of the product ends up as waste. Our studies intend to fully recycle wastes from the food industry and reconvert them in high added-value products, as innovative biocompatible skin substitutes for tissue regeneration. The aim of the present work is to apply the pioneering skin substitute in in vivo experimental wounds to test its regenerative potential and compare it, in a future study, to the available commercial membranes produced with collagen of bovine, porcine, and equine origin. Results are encouraging since the skin substitute made with marine collagen reduced inflammation, promoted the deposition of granulation tissue, and enhanced a proper re-epithelialization with the adequate development of skin appendages. In summary, our findings might be of great interest for processing industries and biotech companies which transform waste materials in high-valuable and innovative products for Veterinary advanced applications.

Abstract

Skin wound healing is a complex and dynamic process that aims to restore lesioned tissues. Collagen-based skin substitutes are a promising treatment to promote wound healing by mimicking the native skin structure. Recently, collagen from marine organisms has gained interest as a source for producing biomaterials for skin regenerative strategies. This preliminary study aimed to describe the application of a collagen-based skin-like scaffold (CBSS), manufactured with collagen extracted from sea urchin food waste, to treat experimental skin wounds in a large animal. The wound-healing process was assessed over different time points by the means of clinical, histopathological, and molecular analysis. The CBSS treatment improved wound re-epithelialization along with cell proliferation, gene expression of growth factors (VEGF-A), and development of skin adnexa throughout the healing process. Furthermore, it regulated the gene expression of collagen type I and III, thus enhancing the maturation of the granulation tissue into a mature dermis without any signs of scarring as observed in untreated wounds. The observed results (reduced inflammation, better re-epithelialization, proper development of mature dermis and skin adnexa) suggest that sea urchin-derived CBSS is a promising biomaterial for skin wound healing in a “blue biotechnologies” perspective for animals of Veterinary interest.

Pepsin-Soluble Collagen from the Skin of Lophius litulo: A Preliminary Study Evaluating Physicochemical, Antioxidant, and Wound Healing Properties

The structure of pepsin-solubilized collagen (PSC) obtained from the skin of Lophius litulon was analyzed using the sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS-PAGE), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). SDS-PAGE results showed that PSC from Lophius litulon skin was collagen type I and had collagen-specific α1, α2, β, and γ chains. FTIR results indicated that the infrared spectrum of PSC ranged from 400 to 4000 cm^-1, with five main amide bands. SEM revealed the microstructure of PSC, which consisted of clear fibrous and porous structures. In vitro antioxidant studies demonstrated that PSC revealed the scavenging ability for 2,2-diphenyl-1-picrylhydrazyl (DPPH), HO·, O₂^-·, and ABTS·. Moreover, animal experiments were conducted to evaluate the biocompatibility of PSC. The collagen sponge group showed a good biocompatibility in the skin wound model and may play a positive role in the progression of the healing process. The cumulative results suggest that collagen from the skin of Lophius litulon has potential applications in wound healing due to its good biocompatibility.

Evaluation of Small Molecular Polypeptides from the Mantle of Pinctada Martensii on Promoting Skin Wound Healing in Mice

Skin wound healing, especially chronic wound healing, is a common challenging clinical problem. It is urgent to broaden the sources of bioactive substances that can safely and efficiently promote skin wound healing. This study aimed to observe the effects of small molecular peptides (SMPs) of the mantle of Pinctada martensii on wound healing. After physicochemical analysis of amino acids and mass spectrometry of SMPs, the effect of SMPs on promoting healing was studied through a whole cortex wound model on the back of mice for 18 consecutive days. The results showed that SMPs consisted of polypeptides with a molecular weight of 302.17-2936.43 Da. The content of polypeptides containing 2-15 amino acids accounted for 73.87%, and the hydrophobic amino acids accounted for 56.51%. Results of in vitro experimentation showed that SMPs possess a procoagulant effect, but no antibacterial activity. Results of in vivo experiments indicated that SMPs inhibit inflammatory response by secretion of anti-inflammatory factor IL-10 during the inflammatory phase; during the proliferative phase, SMPs promote the proliferation of fibroblasts and keratinocytes. The secretion of transforming growth factor-β1 and cyclin D1 accelerates the epithelialization and contraction of wounds. In the proliferative phase, SMPs effectively promote collagen deposition and partially inhibit superficial scar hyperplasia. These results show that SMPs promotes dermal wound healing in mice and have a tremendous potential for development and utilization in skin wound healing.

Physicochemical, antioxidant properties of giant croaker (Nibea japonica) swim bladders collagen and wound healing evaluation

Acid-solubilized collagen (ASC) and pepsin-solubilized collagen (PSC) were obtained from Nibea japonica swim bladders. The denaturation temperature (Td) of ASC and PSC was approximately 33.8 °C. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Fourier transform infrared spectroscopy (FTIR) analyses indicated that ASC and PSC contained triple-helical type I collagen when compared to rat tail collagen type I. Moreover, the microstructure of collagen sponges was uniform and porous. In addition, ASC and PSC exhibited antioxidant properties and in vitro scratch assays showed that PSC at various concentrations (0, 12.5, 25, and 50 μg/mL) had significant effects on the scratch closure rate. Furthermore, collagen sponge from Nibea japonica swim bladders exhibited an increased efficacy of wound healing when compared to the control mice. The levels of interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α in the collagen sponge treated mice were significantly decreased when compared to the control group. Thus, our results suggested that collagen sponge from Nibea japonica swim bladders has potential wound healing applications.

The wound healing potential of a pro-angiogenic peptide purified from Indian Russell's viper (Daboia russelii) venom

The cutaneous wound healing property of a pro-angiogenic venom peptide (RVVAP) in a cream-based formulation was evaluated using the excision wound healing model on Wistar strain rats. The wound healing potency and modest antibacterial activity of RVVAP was enhanced significantly (p < 0.05) when combined with Aloe vera extract. RVVAP was also found to be non-toxic at the tested dose of 1.0 mg/kg. Nevertheless, the release of inflammatory cytokines such as IL-1, IL-6, IL-10, and TNF-α in RVVAP-treated mice was suppressed, compared to the untreated controls. This is the first report assessing the wound healing potential of a low-molecular mass, non-enzymatic, pro-angiogenic peptide purified from snake venom.