Marine origin collagens and its potential applications

Preparation, structural and morphological characterization of cartilage type II collagen peptide assemblies from sturgeon head

BACKGROUND

Sturgeon cartilage type II collagen peptides (SHCPs) can self-assemble and be used to prepare collagen peptide assemblies. Self-assembled peptides have great potential for applications in the food industry. In the present study, self-assembled peptides were prepared from sturgeon cartilage and then characterized.

RESULTS

The SHCPs self-assembled and formed collagen peptide assemblies. After response surface experiment optimization, the optimal enzyme digestion process comprised 43.1 °C, 3.37 h and 0.96% enzyme addition, and the peptide yield was 78.46%. Physicochemical analysis showed that the SHCPs were amphiphilic, with an average molecular weight of 1081 Da, and were rich in hydrophobic amino acids. Peptide sequence identification showed that the peptides of SHCPs with polar amino acids followed by hydrophobic amino acids could be self-assembled through hydrogen bonding and hydrophobic interaction. Through turbidity experiments, Fourier transform infrared spectroscopy and scanning electron microscopy, we demonstrated that SHCPs can self-assemble into reticular and tubular structures under specific conditions. Furthermore, both the SHCPs-Ca and SHCPs-Mg assemblies were stabilized within a pH range consistent with that of the human gastrointestinal tract.

CONCLUSION

The present study provides a simple and safe method for preparing novel self-assembled peptide materials from sturgeon by-products, providing a scientific basis for the exploitation of sturgeon cartilage and potentially reducing resource wastage. © 2024 Society of Chemical Industry.

Age and sex effects on histological features and in vitro culturing of Antillean manatee (Trichechus manatus manatus, Linnaeus 1758) dermis

The biobanks from dermal biopsies represent an interesting strategy for biodiversity conservation. Nevertheless, the morphological and cellular patterns of the dermis can be influenced by the age and sex of the individual. Therefore, evaluating these factors is interesting for forming biobanks of Antillean manatees. These animals, representatives of marine fauna, have had their population reduced, and biobanks are essential for their conservation. Then, we evaluated the effects of age (3.5 years vs. 3.6-16 years vs. 23.6 years) and sex (males vs. females) on morphological and cellular parameters using histological and in vitro culture techniques. Regardless of age, no differences were observed for dermal thickness, collagen fibres, tissue proliferative activity and viable cell recovery. Nonetheless, fibroblast reduction was observed in groups aged 23.6 years compared to other animals (p < 0.05). Additionally, cells from animals aged 3.6-16 years showed more significant mitochondrial damage than the other groups (p < 0.05). Regardless of sex, no differences were observed for dermal thickness, collagen fibres, tissue proliferative activity and viable cell recovery; however, females had fewer fibroblasts than males (p < 0.05). Cells from females showed lower mitochondrial damage when compared to cells from males. In summary, although age and sex do not influence dermal thickness and cell recovery, variations in the number of fibroblasts and mitochondrial characteristics were observed among the groups. These differences may be significant for understanding the dermis aspects to be correlated to biobank systems.

Enriched characteristics of poultry collagen over other sources of collagen and its extraction methods: A review

Collagen is the most abundant protein in animals and is extensively studied for its structural and thermal stability, biocompatibility, and healing properties which enables them to be widely applied in various fields. Collagen extracted from poultry sources have shown improved structural stability and reduced risk of triggering allergic responses and transmitting animal diseases onto humans. Furthermore, poultry collagen is widely accepted by consumers of diverse beliefs in comparison to collagen extracted from bovine and porcine sources. The review aims to compare different sources of collagen, focusing on the various beneficial characteristics of poultry collagen over the other sources. Moreover, the review explains various pre-treatment and extraction methods of poultry collagen and its versatile applications in different industrial sectors.

Enhancing Guided Bone Regeneration with a Novel Carp Collagen Scaffold: Principles and Applications

Bone defects resulting from trauma, surgery, and congenital, infectious, or oncological diseases are a functional and aesthetic burden for patients. Bone regeneration is a demanding procedure, involving a spectrum of molecular processes and requiring the use of various scaffolds and substances, often yielding an unsatisfactory result. Recently, the new collagen sponge and its structural derivatives manufactured from European carp (Cyprinus carpio) were introduced and patented. Due to its fish origin, the novel scaffold poses no risk of allergic reactions or transfer of zoonoses and additionally shows superior biocompatibility, mechanical stability, adjustable degradation rate, and porosity. In this review, we focus on the basic principles of bone regeneration and describe the characteristics of an "ideal" bone scaffold focusing on guided bone regeneration. Moreover, we suggest several possible applications of this novel material in bone regeneration processes, thus opening new horizons for further research.

Electrospun skin dressings for diabetic wound treatment: a systematic review

Abstract

Diabetes mellitus is a metabolic disease characterized by persistent hyperglycemia associated with a lack of insulin production or insulin resistance. In diabetic patients, the capacity for healing is generally decreased, leading to chronic wounds. One of the most common treatments for chronic wounds is skin dressings, which serve as protection from infection, reduce pain levels, and stimulate tissue healing. Furthermore, electrospinning is one of the most effective techniques used for manufacturing skin dressings.

Objective

The purpose of this study was to perform a systematic review of the literature to examine the effects of electrospun skin dressings from different sources in the process of healing skin wounds using in vivo experiments in diabetic rats.

Methods

The search was carried out according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), and the Medical Subject Headings (MeSH) descriptors were defined as "wound dressing," "diabetes," "in vivo," and "electrospun." A total of 14 articles were retrieved from PubMed and Scopus databases.

Results

The results were based mainly on histological analysis and macroscopic evaluation, demonstrating moderate evidence synthesis for all experimental studies, showing a positive effect of electrospun skin dressings for diabetic wound treatment.

Conclusion

This review confirms the significant benefits of using electrospun skin dressings for skin repair and regeneration. All the inks used were demonstrated to be suitable for dressing manufacturing. Moreover, in vivo findings showed full wound closure in most of the studies, with well-organized dermal and epidermal layers.

Fabrication of atelocollagen-coated bioabsorbable suture and the evaluation of its regenerative efficacy in Achilles tendon healing using a rat experimental model

Recently, the incidence of Achilles tendon ruptures (ATRs) has become more common, and repair surgery using a bioabsorbable suture is generally preferred, particularly in the case of healthy patients. Sutures composed of poly(lactic-co-glycolic acid) (PLGA) are commonly used in ATR surgeries. Nevertheless, owing to the inherent limitations of PLGA, novel bioabsorbable sutures that can accelerate Achilles tendon healing are sought. Recently, several studies have demonstrated the beneficial effects of atelocollagen on tendon healing. In this study, poly(3,4-dihydroxy-L-phenylalanine) (pDOPA), a hydrophilic biomimetic material, was used to modify the hydrophobic surface of a PLGA suture (Vicryl, VC) for the stable coating of atelocollagen on its surface. The main objective was to fabricate an atelocollagen-coated VC suture and evaluate its performance in the healing of Achilles tendon using a rat model of open repair for ATR. Structural analyses of the surface-modified suture indicated that the collagen was successfully coated on the VC/pDOPA suture. Postoperative in vivo biomechanical analysis, histological evaluation, ultrastructural/morphological analyses, and western blotting confirmed that the tendons in the VC/pDOPA/Col group exhibit superior healing than those in the VC and VC/pDOPA groups after 1 and 6 weeks following the surgery. The this study suggests that atelocollagen-coated PLGA/pDOPA sutures are preferable for future medical applications, especially in the repair of ATR.

In vivo assessment of marine vs bovine origin collagen-based composite scaffolds promoting bone regeneration in a New Zealand rabbit model

The ability of human tissues to self-repair is limited, which motivates the scientific community to explore new and better therapeutic approaches to tissue regeneration. The present manuscript provides a comparative study between a marine-based composite biomaterial, and another composed of well-established counterparts for bone tissue regeneration. Blue shark skin collagen was combined with bioapatite obtained from blue shark's teeth (mColl:BAp), while bovine collagen was combined with synthetic hydroxyapatite (bColl:Ap) to produce 3D composite scaffolds by freeze-drying. Collagens showed similar profiles, while apatite particles differed in their composition, being the marine bioapatite a fluoride-enriched ceramic. The marine-sourced biomaterials presented higher porosities, improved mechanical properties, and slower degradation rates when compared to synthetic apatite-reinforced bovine collagen. The in vivo performance regarding bone tissue regeneration was evaluated in defects created in femoral condyles in New Zealand rabbits twelve weeks post-surgery. Micro-CT results showed that mColl:BAp implanted condyles had a slower degradation and an higher tissue formation (17.9 ± 6.9 %) when compared with bColl:Ap implanted ones (12.9 ± 7.6 %). The histomorphometry analysis provided supporting evidence, confirming the observed trend by quantifying 13.1 ± 7.9 % of new tissue formation for mColl:BAp composites and 10.4 ± 3.2 % for bColl:Ap composites, suggesting the potential use of marine biomaterials for bone regeneration.

Association of a Skin Dressing Made With the Organic Part of Marine Sponges and Photobiomodulation on the Wound Healing in an Animal Model

The present study aims to characterize and to evaluate the biological effects of a skin dressing manufactured with the organic part of the Chondrilla caribensis marine sponge (called spongin-like collagen (SC)) associated or not to photobiomodulation (PBM) on the skin wound healing of rats. Skin dressings were manufactured with SC and it was characterized using scanning electron microscopy (SEM) and a tensile assay. In order to evaluate its biological effects, an experimental model of cutaneous wounds was surgically performed. Eighteen rats were randomly distributed into three experimental groups: control group (CG): animals with skin wounds but without any treatment; marine collagen dressing group (DG): animals with skin wounds treated with marine collagen dressing; and the marine collagen dressing + PBM group (DPG): animals with skin wounds treated with marine collagen dressing and PBM. Histopathological, histomorphometric, and immunohistochemical evaluations (qualitative and semiquantitative) of COX2, TGFβ, FGF, and VEGF were done. SEM demonstrates that the marine collagen dressing presented pores and interconnected fibers and adequate mechanical strength. Furthermore, in the microscopic analysis, an incomplete reepithelialization and the presence of granulation tissue with inflammatory infiltrate were observed in all experimental groups. In addition, foreign body was identified in the DG and DPG. COX2, TGFβ, FGF, and VEGF immunostaining was observed predominantly in the wound area of all experimental groups, with a statistically significant difference for FGF immunostaining score of DPG in relation to CG. The marine collagen dressing presented adequate physical characteristics and its association with PBM presented favorable biological effects to the skin repair process.

Use of Collagen in Cosmetic Products

Collagen (CLG) belongs to the family of fibrillar proteins and is composed of left-handed α polypeptide chains, which, twisting around themselves and their axis, form a right-handed superhelix. In the chemical structure, it contains mainly proline, hydroxyproline, glycine, and hydroxylysine. It occurs naturally in the dermis in the form of fibers that provide the skin with proper density and elasticity. The review aimed to present the types of collagen protein, factors affecting its structure and its unusual role in the functioning of the human body. Also, an overview of cosmetic products containing collagen or its derivatives, the characteristics of the formulas of these products, and the effects of their use were presented. Throughout the market, there are many cosmetic and cosmeceutical products containing CLG. They are in the form of fillers administered as injections, belonging to the group of the oldest tissue fillers; products administered orally and for topical use, such as creams, gels, serums, or cosmetic masks. Analyzed studies have shown that the use of products with collagen or its peptides improves the general condition of the skin and delays the aging process by reducing the depth of wrinkles, improving hydration (in the case of oral preparations), reducing transepithelial water loss (TEWL), as well as improving skin density and elasticity. In addition, oral application of bioactive CLG peptides has shown a positive effect on the nails, reducing the frequency of their breakage.

Combination of fractional carbon dioxide laser with recombinant human collagen in periocular skin rejuvenation

BACKGROUND

The most visible sign of facial aging is often seen in the periocular area. However, periocular rejuvenation remains challenging due to the particularity of periocular anatomic locations.

AIMS

We aimed to evaluate the efficacy and safety of the fractional-ablative CO2 laser-facilitated recombinant human collagen permeation in periocular rejuvenation.

PATIENTS/METHODS

This 3-month prospective single-blinded and self-controlled trial enrolled 26 patients with periocular aging who underwent the treatments of fractional-ablative CO2 laser along with laser-facilitated recombinant human collagen permeation. Following the treatments, the patients were quantitatively assessed by various periocular skin aging indices before and after the treatment and monitored for any related adverse events.

RESULTS

The patients showed significant improvements with the periocular skin aging indices 3 months after the treatments, which were detailed with a 47.3% decrease in lower eyelid skin rhytids, a 41.4% decrease in the lower eyelid skin texture, a 35.0% decrease in the static crow's feet, a 29.3% decrease in the amount of upper eyelid laxity, and a 20.2% increase in the MRD1 as compared with baseline (p < 0.05). Moreover, total skin thickness under ultrasound was increased in both upper and lower eyelids (5.6% and 3.3%, p < 0.05, respectively). Moreover, six patients (23.1%, 6/26) had erythema for 2 weeks, and two (2/26, 7.7%) had mild hyperpigmentation for 3 months.

CONCLUSIONS

Fractional-ablative CO2 laser combined with laser-facilitated recombinant human collagen permeation can be a safe and effective treatment for periocular rejuvenation.

Collagen-Based Medical Devices for Regenerative Medicine and Tissue Engineering

Assisted reproductive technologies are key to solving the problems of aging and organ defects. Collagen is compatible with living tissues and has many different chemical properties; it has great potential for use in reproductive medicine and the engineering of reproductive tissues. It is a natural substance that has been used a lot in science and medicine. Collagen is a substance that can be obtained from many different animals. It can be made naturally or created using scientific methods. Using pure collagen has some drawbacks regarding its physical and chemical characteristics. Because of this, when collagen is processed in various ways, it can better meet the specific needs as a material for repairing tissues. In simpler terms, collagen can be used to help regenerate bones, cartilage, and skin. It can also be used in cardiovascular repair and other areas. There are different ways to process collagen, such as cross-linking it, making it more structured, adding minerals to it, or using it as a carrier for other substances. All of these methods help advance the field of tissue engineering. This review summarizes and discusses the current progress of collagen-based materials for reproductive medicine.

Green Extraction and Preliminary Biological Activity of Hydrolyzed Collagen Peptides (HCPs) Obtained from Whole Undersized Unwanted Catches (Mugil cephalus L.)

Considering the global increase in fish consumption, the growing side-streams coming from the fish supply chain (e.g., skin, fins, tail, heads…), also including undersized or "unwanted catches", have been recently proposed as source of high-value bioactive compounds (e.g., peptides and fatty acids). In this case study, hydrolyzed collagen peptides (HCPs) were extracted from different parts of Mugil cephalus L. using environmentally friendly techniques such as ultrasounds and enzymatic treatments. Both a mixed biomass derived from the skin, fins, and tail, and a whole fish, were considered as starting biomass, simulating the unsorted processing side-streams and an undersized/unwanted catch, respectively. The extracted HCPs were purified in fractions (<3 KDa and >3 KDa) whose yields (about 5% and 0.04-0.3%, respectively) demonstrated the efficiency of the hydrolysis process. The extraction protocol proposed allowed us to also isolate the intermediate products, namely the lipids (about 8-10%) and the non-collagenous proteins (NCs, 16-23%), whose exploitation could be considered. Each sample was characterized using Sircol, UltraViolet-Spectra, and hydroxyproline assay, and the viability of their collagen fractions was tested on human endothelial cells. Significant effects were obtained at a fraction of <3 KDa, in particular at a concentration of 0.13 µg/mL. The T-scratch test was also performed, with positive results in all fractions tested.

Recent Advances in the Development of Biomimetic Materials

In this review, we focused on recent efforts in the design and development of materials with biomimetic properties. Innovative methods promise to emulate cell microenvironments and tissue functions, but many aspects regarding cellular communication, motility, and responsiveness remain to be explained. We photographed the state-of-the-art advancements in biomimetics, and discussed the complexity of a "bottom-up" artificial construction of living systems, with particular highlights on hydrogels, collagen-based composites, surface modifications, and three-dimensional (3D) bioprinting applications. Fast-paced 3D printing and artificial intelligence, nevertheless, collide with reality: How difficult can it be to build reproducible biomimetic materials at a real scale in line with the complexity of living systems? Nowadays, science is in urgent need of bioengineering technologies for the practical use of bioinspired and biomimetics for medicine and clinics.

Harnessing value and sustainability: Fish waste valorization and the production of valuable byproducts

The valorization of by-products, that are residual materials resulting from commercial product manufacturing, holds significant potential in various industries such as food, agrochemical, medical, and pharmaceutical sectors. This chapter explores the utilization of fish waste as a means to achieve sustainability in fish resources and enhance the production of profitable products. By developing cost-effective technologies, the abundant global supply of fish by-products can be transformed into low-cost sources of proteins and functional hydrolysates. This alternative approach in the food industry utilizes fish and seafood waste to generate valuable compounds with nutritional and functional properties, surpassing those found in traditional mammal products. Despite being commonly discarded, fish heads, viscera, skin, tails, blood, and seafood shells contain a wealth ofminerals, lipids, amino acids, polysaccharides, and proteins suitable for human health applications. This chapter presents an exploration of the various products and bioactive compounds that can be derived from seafood waste, contributing to a more sustainable and value-driven future.

Macro, Micro, and Nano-Inspired Bioactive Polymeric Biomaterials in Therapeutic, and Regenerative Orofacial Applications

Introducing dental polymers has accelerated biotechnological research, advancing tissue engineering, biomaterials development, and drug delivery. Polymers have been utilized effectively in dentistry to build dentures and orthodontic equipment and are key components in the composition of numerous restorative materials. Furthermore, dental polymers have the potential to be employed for medication administration and tissue regeneration. To analyze the influence of polymer-based investigations on practical medical trials, it is required to evaluate the research undertaken in this sector. The present review aims to gather evidence on polymer applications in dental, oral, and maxillofacial reconstruction.

Mutable Collagenous Tissue Isolated from Echinoderms Leads to the Production of a Dermal Template That Is Biocompatible and Effective for Wound Healing in Rats

The mutable collagenous tissue (MCT) of echinoderms possesses biological peculiarities that facilitate native collagen extraction and employment for biomedical applications such as regenerative purposes for the treatment of skin wounds. Strategies for skin regeneration have been developed and dermal substitutes have been used to cover the lesion to facilitate cell proliferation, although very little is known about the application of novel matrix obtained from marine collagen. From food waste we isolated eco-friendly collagen, naturally enriched with glycosaminoglycans, to produce an innovative marine-derived biomaterial assembled as a novel bi-layered skin substitute (Marine Collagen Dermal Template or MCDT). The present work carried out a preliminary experimental in vivo comparative analysis between the MCDT and Integra, one of the most widely used dermal templates for wound management, in a rat model of full-thickness skin wounds. Clinical, histological, and molecular evaluations showed that the MCDT might be a valuable tool in promoting and supporting skin wound healing: it is biocompatible, as no adverse reactions were observed, along with stimulating angiogenesis and the deposition of mature collagen. Therefore, the two dermal templates used in this study displayed similar biocompatibility and outcome with focus on full-thickness skin wounds, although a peculiar cellular behavior involving the angiogenesis process was observed for the MCDT.

Preparation of Nanoemulsions with Low-Molecular-Weight Collagen Peptides from Sturgeon Fish Skin and Evaluation of Anti-Diabetic and Wound-Healing Effects in Mice

This study aims to isolate collagen peptides from waste sturgeon fish skin, and prepare nanoemulsions for studying their anti-diabetic and wound-healing effects in mice. Collagen peptides were extracted and purified by acetic acid with sonication, followed by two-stage hydrolysis with 0.1% pepsin and 5% flavourzyme, and ultrafiltration with 500 Da molecular weight (MW) cut-off dialysis membrane. Animal experiments were performed with collagen peptides obtained by pepsin hydrolysis (37 kDa) and pepsin plus flavourzyme hydrolysis (728 Da) as well as their nanoemulsions prepared at two different doses (100 and 300 mg/kg/day). The mean particle size of low-MW and low-dose nanoemulsion, low-MW and high-dose nanoemulsion, high-MW and low-dose nanoemulsion and high-MW and high-dose nanoemulsion was, respectively, 16.9, 15.3, 28.1 and 24.2 nm, the polydispersity index was 0.198, 0.215, 0.231 and 0.222 and zeta potential was -61.2, -63.0, -41.4 and -42.7 mV. These nanoemulsions were highly stable over a 90-day storage period (4 °C and 25 °C) and heating at 40-100 °C (0.5-2 h). Experiments in mice revealed that the low-MW and high-dose nanoemulsion was the most effective in decreasing fasting blood glucose (46.75%) and increasing wound-healing area (95.53%). Collectively, the sturgeon fish skin collagen peptide-based nanoemulsion is promising for development into a health food or wound-healing drug.

3D Printing Type 1 Bovine Collagen Scaffolds for Tissue Engineering Applications-Physicochemical Characterization and In Vitro Evaluation

Collagen, an abundant extracellular matrix protein, has shown hemostatic, chemotactic, and cell adhesive characteristics, making it an attractive choice for the fabrication of tissue engineering scaffolds. The aim of this study was to synthesize a fibrillar colloidal gel from Type 1 bovine collagen, as well as three dimensionally (3D) print scaffolds with engineered pore architectures. 3D-printed scaffolds were also subjected to post-processing through chemical crosslinking (in N-(3-Dimethylaminopropyl)-N'-ethylcarbodiimide) and lyophilization. The scaffolds were physicochemically characterized through Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis, Differential Scanning Calorimetry, and mechanical (tensile) testing. In vitro experiments using Presto Blue and Alkaline Phosphatase assays were conducted to assess cellular viability and the scaffolds' ability to promote cellular proliferation and differentiation. Rheological analysis indicated shear thinning capabilities in the collagen gels. Crosslinked and lyophilized 3D-printed scaffolds were thermally stable at 37 °C and did not show signs of denaturation, although crosslinking resulted in poor mechanical strength. PB and ALP assays showed no signs of cytotoxicity as a result of crosslinking. Fibrillar collagen was successfully formulated into a colloidal gel for extrusion through a direct inkjet writing printer. 3D-printed scaffolds promoted cellular attachment and proliferation, making them a promising material for customized, patient-specific tissue regenerative applications.

FTIR-based prediction of collagen content in hydrolyzed protein samples

Fourier transform infrared spectroscopy (FTIR) is a powerful analytical tool that has been used for protein and peptide characterization for decades. In the present study, the objective was to investigate if FTIR can be used to predict collagen content in hydrolyzed protein samples. All samples were obtained from enzymatic protein hydrolysis (EPH) of poultry by-products providing a span in collagen content from 0.3% to 37.9% (dry weight), and the FTIR analysis was performed using dry film FTIR. Since nonlinear effects were revealed by calibration using standard partial least squares (PLS) regression, Hierarchical Cluster-based PLS (HC-PLS) calibration models were constructed. The HC-PLS model provided a low prediction error when validated using an independent test set (RMSE = 3.3% collagen), while validation using real industrial samples also showed satisfying results (RMSE = 3.2%). The results corresponded well with previously published FTIR-based studies of collagen, and characteristic spectral features for collagen were well identified in the regression models. Covariance between collagen content and other EPH related processing parameters could also be ruled out in the regression models. To the authors' knowledge, this is the first time that collagen content has been systematically studied in solutions of hydrolysed proteins using FTIR. This is also one of few examples where FTIR is successfully used to quantify protein composition. The dry-film FTIR approach presented in the study is expected to be an important tool in the growing industrial segment that is based on sustainable utilization of collagen-rich biomass.

Flounder fish (Paralichthys sp.) collagen a new tissue regeneration: genotoxicity, cytotoxicity and physical-chemistry characterization

Collagen dressings have been widely used as effective treatments for chronic wounds acting as barrier, protecting the area from infections and participating in the healing process. Collagen from fish skin is biocompatible, presents low immunogenicity and is able of stimulating wound healing. In this scenario, skin of flounder fish (Paralichthys sp.) may constitute a promising source for collagen. Then, our hypothesis is that fish collagen is able of increasing cell proliferation, with no cytotoxicity. In this context, the aim of the present study was to investigate the physicochemical and morphological properties of collagen using scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDS), mass loss and pH. Moreover, the cytotoxicity and genotoxicity of collagen were studied using in vitro studies (cell viability, comet assay and micronucleus assay). Fish collagen showed no variation of pH and mass weight, with characteristic peaks of collagen in FTIR. Furthermore, all the extracts presented cell viability at least over 50% and no cytotoxicity was observed. Regarding genotoxicity data, the results showed that only the extract of 100% showed higher values in comparison with negative control group for CHO-K1 cell line as depicted by comet and micronucleus assays. Based on the results, it is suggested that fish collagen is biocompatible and present non-cytotoxicity in the in vitro studies, being considered a suitable material for tissue engineering proposals.

Understanding the Molecular Conformation and Viscoelasticity of Low Sol-Gel Transition Temperature Gelatin Methacryloyl Suspensions

For biomedical applications, gelatin is usually modified with methacryloyl groups to obtain gelatin methacryloyl (GelMA), which can be crosslinked by a radical reaction induced by low wavelength light to form mechanically stable hydrogels. The potential of GelMA hydrogels for tissue engineering has been well established, however, one of the main disadvantages of mammalian-origin gelatins is that their sol-gel transitions are close to room temperature, resulting in significant variations in viscosity that can be a problem for biofabrication applications. For these applications, cold-water fish-derived gelatins, such as salmon gelatin, are a good alternative due to their lower viscosity, viscoelastic and mechanical properties, as well as lower sol-gel transition temperatures, when compared with mammalian gelatins. However, information regarding GelMA (with special focus on salmon GelMA as a model for cold-water species) molecular conformation and the effect of pH prior to crosslinking, which is key for fabrication purposes since it will determine final hydrogel's structure, remains scarce. The aim of this work is to characterize salmon gelatin (SGel) and salmon methacryloyl gelatin (SGelMA) molecular configuration at two different acidic pHs (3.6 and 4.8) and to compare them to commercial porcine gelatin (PGel) and methacryloyl porcine gelatin (PGelMA), usually used for biomedical applications. Specifically, we evaluated gelatin and GelMA samples' molecular weight, isoelectric point (IEP), their molecular configuration by circular dichroism (CD), and determined their rheological and thermophysical properties. Results showed that functionalization affected gelatin molecular weight and IEP. Additionally, functionalization and pH affected gelatin molecular structure and rheological and thermal properties. Interestingly, the SGel and SGelMA molecular structure was more sensitive to pH changes, showing differences in gelation temperatures and triple helix formation than PGelMA. This work suggests that SGelMA presents high tunability as a biomaterial for biofabrication, highlighting the importance of a proper GelMA molecular configuration characterization prior to hydrogel fabrication.

Marine collagen-chitosan-fucoidan/chondroitin sulfate cryo-biomaterials loaded with primary human cells envisaging cartilage tissue engineering

Cartilage repair after a trauma or a degenerative disease like osteoarthritis (OA) continues to be a big challenge in current medicine due to the limited self-regenerative capacity of the articular cartilage tissues. To overcome the current limitations, tissue engineering and regenerative medicine (TERM) and adjacent areas have focused their efforts on new therapeutical procedures and materials capable of restoring normal tissue functionalities through polymeric scaffolding and stem cell engineering approaches. For this, the sustainable exploration of marine origin materials has emerged in the last years as a natural alternative to mammal sources, benefiting from their biological properties (e.g., biocompatibility, biodegradability, no toxicity, among others) for the development of several types of scaffolds. In this study, marine collagen(jCOL)-chitosan(sCHT)-fucoidan(aFUC)/chondroitin sulfate(aCS) were cryo-processed (-20 °C, -80 °C, and -196 °C) and a chemical-free crosslinking approach was explored to establish cohesive and stable cryogel materials. The cryogels were intensively characterized to assess their oscillatory behavior, thermal structural stability, thixotropic properties (around 45 % for the best formulations), injectability, and surface structural organization. Additionally, the cryogels demonstrate an interesting microenvironment in in vitro studies using human adipose-derived stem cells (hASCs), supporting their viability and proliferation. In both physic-chemical and in vitro studies, the systems that contain fucoidan in their formulations, i.e., C₁ (jCOL, sCHT, aFUC) and C₃ (jCOL, sCHT, aFUC, aCS), submitted at -80 °C, are those that demonstrated most promising results for future application in articular cartilage tissues.

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.

3D Printed Scaffolds Manufactured with Biosilica from Marine Sponges for Bone Healing in a Cranial Defect in Rats

The inorganic part of marine sponges, called Biosilica (BS), presents an osteogenic potential and the ability of consolidating fractures. Moreover, 3D printing technique is highly effective for manufacturing scaffolds for tissue engineering proposals. Thus, the aims of this study were to characterize the 3D rinted scaffolds, to evaluate the biological effects in vitro and to investigate the in vivo response using an experimental model of cranial defects in rats. The physicochemical characteristics of 3D printed BS scaffolds were analyzed by FTIR, EDS, calcium assay, evaluation of mass loss and pH measurement. For in vitro analysis, the MC3T3-E1 and L929 cells viability was evaluated. For the in vivo evaluation, histopathology, morphometrical and immunohistochemistry analyses were performed in a cranial defect in rats. After the incubation, the 3D printed BS scaffolds presented lower values in pH and mass loss over time. Furthermore, the calcium assay showed an increased Ca uptake. The FTIR analysis indicated the characteristic peaks for materials with silica and the EDS analysis demonstrated the main presence of silica. Moreover, 3D printed BS demonstrated an increase in MC3T3-E1 and L929 cell viability in all periods analyzed. In addition, the histological analysis demonstrated no inflammation in days 15 and 45 post-surgery, and regions of newly formed bone were also observed. The immunohistochemistry analysis demonstrated increased Runx-2 and OPG immunostaining. Those findings support that 3D printed BS scaffolds may improve the process of bone repair in a critical bone defect as a result of stimulation of the newly formed bone.

Jellyfishes—Significant Marine Resources with Potential in the Wound-Healing Process: A Review

The wound-healing process is a significant area of interest in the medical field, and it is influenced by both external and patient-specific factors. The aim of this review paper is to highlight the proven wound-healing potential of the biocompounds found in jellyfish (such as polysaccharide compounds, collagen, collagen peptides and amino acids). There are aspects of the wound-healing process that can benefit from polysaccharides (JSPs) and collagen-based materials, as these materials have been shown to limit exposure to bacteria and promote tissue regeneration. A second demonstrated benefit of jellyfish-derived biocompounds is their immunostimulatory effects on growth factors such as (TNF-α), (IFN-γ) and (TGF), which are involved in wound healing. A third benefit of collagens and polysaccharides (JSP) is their antioxidant action. Aspects related to chronic wound care are specifically addressed, and within this general theme, molecular pathways related to tissue regeneration are explored in depth. Only distinct varieties of jellyfish that are specifically enriched in the biocompounds involved in these pathways and live in European marine habitats are presented. The advantages of jellyfish collagens over mammalian collagens are highlighted by the fact that jellyfish collagens are not considered transmitters of diseases (spongiform encephalopathy) or various allergic reactions. Jellyfish collagen extracts stimulate an immune response in vivo without inducing allergic complications. More studies are needed to explore more varieties of jellyfish that can be exploited for their biocomponents, which may be useful in wound healing.

Marine Natural Products as Innovative Cosmetic Ingredients

Over the course of the last 20 years, numerous studies have identified the benefits of an array of marine natural ingredients for cosmetic purposes, as they present unique characteristics not found in terrestrial organisms. Consequently, several marine-based ingredients and bioactive compounds are under development, used or considered for skin care and cosmetics. Despite the multitude of cosmetics based on marine sources, only a small proportion of their full potential has been exploited. Many cosmetic industries have turned their attention to the sea to obtain innovative marine-derived compounds for cosmetics, but further research is needed to determine and elucidate the benefits. This review gathers information on the main biological targets for cosmetic ingredients, different classes of marine natural products of interest for cosmetic applications, and the organisms from which such products can be sourced. Although organisms from different phyla present different and varied bioactivities, the algae phylum seems to be the most promising for cosmetic applications, presenting compounds of many classes. In fact, some of these compounds present higher bioactivities than their commercialized counterparts, demonstrating the potential presented by marine-derived compounds for cosmetic applications (i.e., Mycosporine-like amino acids and terpenoids’ antioxidant activity). This review also summarizes the major challenges and opportunities faced by marine-derived cosmetic ingredients to successfully reach the market. As a future perspective, we consider that fruitful cooperation among academics and cosmetic industries could lead to a more sustainable market through responsible sourcing of ingredients, implementing ecological manufacturing processes, and experimenting with inventive recycling and reuse programs.

Different Species of Marine Sponges Diverge in Osteogenic Potential When Therapeutically Applied as Natural Scaffolds for Bone Regeneration in Rats

A highly porous structure, and an inorganic (biosilica) and collagen-like organic content (spongin) makes marine sponges potential candidates to be used as natural scaffolds in bone tissue engineering. The aim of this study was to characterize (through SEM, FTIR, EDS, XRD, pH, mass degradation and porosity tests) scaffolds produced from two species of marine sponges, Dragmacidon reticulatum (DR) and Amphimedon viridis (AV), and to evaluate the osteogenic potential of these scaffolds by using a bone defect model in rats. First, it was shown that the same chemical composition and porosity (84 ± 5% for DR and 90 ± 2% for AV) occurs among scaffolds from the two species. Higher material degradation was observed in the scaffolds of the DR group, with a greater loss of organic matter after incubation. Later, scaffolds from both species were surgically introduced in rat tibial defects, and histopathological analysis after 15 days showed the presence of neo-formed bone and osteoid tissue within the bone defect in DR, always around the silica spicules. In turn, AV exhibited a fibrous capsule around the lesion (19.9 ± 17.1%), no formation of bone tissue and only a small amount of osteoid tissue. The results showed that scaffolds manufactured from Dragmacidon reticulatum presented a more suitable structure for stimulation of osteoid tissue formation when compared to Amphimedon viridis marine sponge species.

Preparation of fish decalcified bone matrix and its bone repair effect in rats

Decalcified bone matrix has great potential and application prospects in the repair of bone defects due to its good biocompatibility and osteogenic activity. In order to verify whether fish decalcified bone matrix (FDBM) has similar structure and efficacy, this study used the principle of HCl decalcification to prepare the FDBM by using fresh halibut bone as the raw material, and then degreasing, decalcifying, dehydrating and freeze-drying it. Its physicochemical properties were analyzed by scanning electron microscopy and other methods, and then its biocompatibility was tested by in vitro and in vivo experiments. At the same time, an animal model of femoral defect in rats was established, and commercially available bovine decalcified bone matrix (BDBM) was used as the control group, and the area of femoral defect in rats was filled with the two materials respectively. The changes in the implant material and the repair of the defect area were observed by various aspects such as imaging and histology, and its osteoinductive repair capacity and degradation properties were studied. The experiments showed that the FDBM is a form of biomaterial with high bone repair capacity and lower economic cost than other related materials such as bovine decalcified bone matrix. FDBM is simpler to extract and the raw materials are more abundant, which can greatly improve the utilization of marine resources. Our results show that FDBM not only has a good repair effect on bone defects, but also has good physicochemical properties, biosafety and cell adhesion, and is a promising medical biomaterial for the treatment of bone defects, which can basically meet the clinical requirements for bone tissue repair engineering materials.

Suitability of R. pulmo Jellyfish-Collagen-Coated Well Plates for Cytocompatibility Analyses of Biomaterials

Cytocompatibility analyses of new implant materials or biomaterials are not only prescribed by the Medical Device Regulation (MDR), as defined in the DIN ISO Norm 10993-5 and -12, but are also increasingly replacing animal testing. In this context, jellyfish collagen has already been established as an alternative to mammalian collagen in different cell culture conditions, but a lack of knowledge exists about its applicability for cytocompatibility analyses of biomaterials. Thus, the present study was conducted to compare well plates coated with collagen type 0 derived from Rhizostoma pulmo with plates coated with bovine and porcine collagen. The coated well plates were analysed in vitro for their cytocompatibility, according to EN ISO 10993-5/-12, using both L929 fibroblasts and MC3T3 pre-osteoblasts. Thereby, the coated well plates were compared, using established materials as positive controls and a cytotoxic material, RM-A, as a negative control. L929 cells exhibited a significantly higher viability (#### p < 0.0001), proliferation (## p < 0.01), and a lower cytotoxicity (## p < 0.01 and # p < 0.05)) in the Jellagen® group compared to the bovine and porcine collagen groups. MC3T3 cells showed similar viability and acceptable proliferation and cytotoxicity in all collagen groups. The results of the present study revealed that the coating of well plates with collagen Type 0 derived from R. pulmo leads to comparable results to the case of well plates coated with mammalian collagens. Therefore, it is fully suitable for the in vitro analyses of the cytocompatibility of biomaterials or medical devices.

Characterization of Dual-Layer Hybrid Biomatrix for Future Use in Cutaneous Wound Healing

A skin wound without immediate treatment could delay wound healing and may lead to death after severe infection (sepsis). Any interruption or inappropriate normal wound healing, mainly in these wounds, commonly resulted in prolonged and excessive skin contraction. Contraction is a common mechanism in wound healing phases and contributes 40-80% of the original wound size post-healing. Even though it is essential to accelerate wound healing, it also simultaneously limits movement, mainly in the joint area. In the worst-case scenario, prolonged contraction could lead to disfigurement and loss of tissue function. This study aimed to fabricate and characterise the elastin-fortified gelatin/polyvinyl alcohol (PVA) film layered on top of a collagen sponge as a bilayer hybrid biomatrix. Briefly, the combination of halal-based gelatin (4% (w/v)) and PVA ((4% (w/v)) was used to fabricate composite film, followed by the integration of poultry elastin (0.25 mg/mL) and 0.1% (w/v) genipin crosslinking. Furthermore, further analysis was conducted on the composite bilayer biomatrix's physicochemical and mechanical strength. The bilayer biomatrix demonstrated a slow biodegradation rate (0.374967 ± 0.031 mg/h), adequate water absorption (1078.734 ± 42.33%), reasonable water vapour transmission rate (WVTR) (724.6467 ± 70.69 g/m² h) and porous (102.5944 ± 28.21%). The bilayer biomatrix also exhibited an excellent crosslinking degree and was mechanically robust. Besides, the elastin releasing study presented an acceptable rate post-integration with hybrid biomatrix. Therefore, the ready-to-use bilayer biomatrix will benefit therapeutic effects as an alternative treatment for future diabetic skin wound management.

Characterization of the Biophysical Properties and Cell Adhesion Interactions of Marine Invertebrate Collagen from Rhizostoma pulmo

Collagen is the most ubiquitous biomacromolecule found in the animal kingdom and is commonly used as a biomaterial in regenerative medicine therapies and biomedical research. The collagens used in these applications are typically derived from mammalian sources which poses sociological issues due to widespread religious constraints, rising ethical concern over animal rights and the continuous risk of zoonotic disease transmission. These issues have led to increasing research into alternative collagen sources, of which marine collagens, in particular from jellyfish, have emerged as a promising resource. This study provides a characterization of the biophysical properties and cell adhesion interactions of collagen derived from the jellyfish Rhizostoma pulmo (JCol). Circular dichroism spectroscopy and atomic force microscopy were used to observe the triple-helical conformation and fibrillar morphology of JCol. Heparin-affinity chromatography was also used to demonstrate the ability of JCol to bind to immobilized heparin. Cell adhesion assays using integrin blocking antibodies and HT-1080 human fibrosarcoma cells revealed that adhesion to JCol is primarily performed via β1 integrins, with the exception of α2β1 integrin. It was also shown that heparan sulfate binding plays a much greater role in fibroblast and mesenchymal stromal cell adhesion to JCol than for type I mammalian collagen (rat tail collagen). Overall, this study highlights the similarities and differences between collagens from mammalian and jellyfish origins, which should be considered when utilizing alternative collagen sources for biomedical research.

Isolation and Characterization of Collagen and Collagen Peptides with Hyaluronidase Inhibition Activity Derived from the Skin of Marlin (Istiophoridae)

Type I and V collagens are the major components of fibrillogenic proteins in fish skin, and their hydrolysis products possess hyaluronidase inhibitory activity. In this study, for the first time, type I and V collagens were isolated from the skin of shortbill spearfish and striped marlin. Type I (2α1[I]α2[I]) and type V (α1[V]α3[V]α2[V]) collagens composed of distinct α-peptide chains with comparable structures were investigated using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and UV spectrophotometric chromatography. After enzymatic digestion, the collagen peptides were purified by using ultrafiltration (30 KDa) and high-performance liquid chromatography (RP-HPLC) to yield CPI-F3 and CPV-F4 fractions with strong hyaluronidase inhibition rates (42.17% and 30.09%, respectively). Based on the results of simulated gastrointestinal fluid, temperature, and pH stability assays, CPI-F3 and CPV-F4 exhibited stability in gastric fluid and showed no significant changes under the temperature range from 50 to 70 °C (p > 0.05). The results of this first research on the bioactivity of type V collagen peptides provide valuable information for the biomedical industry and show the potential for future bioactivity investigations of type V collagen and its peptides.

Evaluating dried salted cod amino acid signature for nutritional quality assessment and discriminant analysis

Aim

Thus, the aim of this study was to answer three scientific questions: (1) Are the protein content and amino acid profile of dried salted cod influenced by species (Gadus morhua and Gadus macrocephalus)? (2) Are the protein content and amino acid profile of dried salted cod influenced by the geographical area of capture (Iceland and Norway)? and (3) Does the amino acid profile have the potential to be used as a discriminator of species and geographical areas of capture?

Methods

A total of 45 dried salted cods (2-3 kg of dry weight; n = 15 samples/origin) were used in this study. The Atlantic cod was fished in the Atlantic northeast (FAO 27 area) within the Exclusive Economic zones (EEZ) of Norway (n = 15) and Iceland (n = 15), while the Pacific cod was caught in the Pacific northeast (FAO 67 area) within the Alaska EEZ (n = 15). Total protein content was determined by the Kjeldahl method, in accordance with the AOAC procedures. The amino acid profile was analyzed by HPLC with fluorescence detection (at excitation and emission wavelengths of 338 and 425 nm, respectively).

Results

The Atlantic cod presented higher contents of total protein (33.90 versus 33.10 g/100 g of cod edible portion; p = 0.017) and total amino acid contents (32.52 versus 32.04 g/100 g of cod edible portion; p = 0.015) but displayed lower percentage of indispensable amino acids (32.16 versus 32.83 g/100 g of protein; p < 0.001) than Pacific cod. Among the Atlantic cod harvesting locations, the Norwegian cod displayed higher total amino acid contents (96.91 versus 96.81 g/100 g of protein; p = 0.012) and higher percentage of indispensable amino acids (35.38 versus 28.94 g/100 g of protein; p = 0.042) than the Icelandic counterpart. A correct classification of 100% was obtained for the Pacific and Icelandic cod varieties, but the classification accuracy in the Norwegian cod was of just 86.67%, since 2 samples out of 15 were incorrectly classified as Icelandic.

Conclusion

The comparison of cod species showed that the Atlantic cod had a significantly lower EAAI than the Pacific cod (p < 0.001; 88.23 versus 88.61). On the other hand, the comparison of the two origins in the Atlantic cod, showed that Norwegian cod displayed a significantly higher EAAI than the Icelandic cod (99.15 versus 77.32). The assessment of the EAAI allows the classification of the protein's nutritional quality, allowing us to classify both cod species as a good protein source to human diet. However, within the Atlantic cod, the Norwegian cod's protein is classified as high quality, while the Icelandic cod attain the classification of useful quality. Regarding the amino acid profile discriminatory potential to classify cod samples. The results show that the AA profile has 100% accuracy in the separation of cod species, but was not globally efficient in the differentiation of the Norwegian from the Icelandic cod.

Preparation of Collagen/Hydroxyapatite Composites Using the Alternate Immersion Method and Evaluation of the Cranial Bone-Forming Capability of Composites Complexed with Acidic Gelatin and b-FGF

Bone-substitute materials are essential in dental implantology. We prepared collagen (Col)/hydroxyapatite (Hap)/acidic gelatin (AG)/basic fibroblast growth factor (b-FGF) constructs with enhanced bone-forming capability. The Col/Hap apatite composites were prepared by immersing Col sponges alternately in calcium and phosphate ion solutions five times, for 20 and 60 min, respectively. Then, the sponges were heated to 56 °C for 48 h. Scanning electron microscopy/energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy, and X-ray diffraction analyses showed that the Col/Hap composites contained poorly crystalline Hap precipitates on the Col matrix. Col/Hap composite granules were infiltrated by AG, freeze-dried, and immersed in b-FGF solution. The wet quaternary constructs were implanted in rat cranial bone defects for 8 weeks, followed by soft X-ray measurements and histological analysis. Animal studies have shown that the constructs moderately increase bone formation in cranial bone defects. We found that an alternate immersion time of 20 min led to the greatest bone formation (p < 0.05). Constructs placed inside defects slightly extend the preexisting bone from the defect edges and lead to the formation of small island-like bones inside the defect, followed by disappearance of the constructs. The combined use of Col, Hap, AG, and b-FGF might bring about novel bone-forming biomaterials.

A novel Atlantic salmon (Salmo salar) bone collagen peptide delays osteoarthritis development by inhibiting cartilage matrix degradation and anti-inflammatory

Nowadays, the biological activity of collagen peptides has been revealed, but the effect of Atlantic salmon (Salmo salar) bone-derived collagen peptide (CPs) on osteoarthritis remains unclear. In this study, CPs was identified as a small molecular weight peptide rich in Gly-X-Y structure. Meanwhile, interleukin-1β (IL-1β)-induced hypertrophic chondrocytes and partial medial meniscectomy (pMMx) surgery model in rats were performed. In IL-1β stimulated chondrocytes, CPs significantly increased the type-II collagen content, reduced the type-X collagen abundance and chondrocytes apoptosis. Meanwhile, CPs reversed the increased expression of matrix metalloproteinase, metalloproteinase with thrombospondin motifs and RUNX family transcription factor 2 in chondrocytes induced by IL-1β. In vivo, CPs increased pain tolerance of rats and without organ toxicity at 1.6 g/kg.bw. CPs significantly decreased the levels of COMP and Helix-II in serum. Furthermore, a significant decrease of IL-1β in synovial fluid and cartilage tissue were observed by CPs intervention. From Micro-CT, CPs (0.8 g/kg.bw) significantly decreased Tb.sp and SMI value. Meanwhile, the expression of tumor necrosis factor and interleukin-6 were reduced by CPs administration both in vitro and in vivo. Together, CPs showed potential to be a novel and safe dietary supplement for helping anti-inflammatory and cartilage regeneration, ultimately hindering osteoarthritis development. However, the clear mechanism of CPs's positive effect on osteoarthritis needs to be further explored.

Progressive Application of Marine Biomaterials in Targeted Cancer Nanotherapeutics

The marine microenvironment harbors many unique species of organisms that produce a plethora of compounds that help mankind cure a wide range of diseases. The diversity of products from the ocean bed serves as potentially healing materials and inert vehicles carrying the drug of interest to the target site. Several composites still lay undiscovered under the blue canopy, which can provide treatment for untreated diseases that keep haunting the earth periodically. Cancer is one such disease that has been of interest to several eminent scientists worldwide due to the heterogenic complexity involved in the disease's pathophysiology. Due to extensive globalization and environmental changes, cancer has become a lifestyle disease continuously increasing exponentially in the current decade. This ailment requires a definite remedy that treats by causing minimal damage to the body's normal cells. The application of nanotechnology in medicine has opened up new avenues of research in targeted therapeutics due to their highly malleable characteristics. Marine waters contain an immense ionic environment that succors the production of distinct nanomaterials with exceptional character, yielding highly flexible molecules to modify, thus facilitating the engineering of targeted biomolecules. This review provides a short insight into an array of marine biomolecules that can be probed into cancer nanotherapeutics sparing healthy cells.

Lactose Stabilization Prolongs In Vivo Retention of Cross-linked Fish Collagen Subcutaneous Grafts in Nude Mice

Bovine-derived collagen gel has been used in the medical field as an injection formulation, but there are concerns about cross-infection such as bovine spongiform encephalopathy. In this study, we attempted to use fish as a safe alternative to bovine collagen.

OBJECTIVE

Fish collagen has not been used in clinical settings, so we examined its potential by comparing its properties with those of bovine-derived collagen.

METHODS

Collagen was extracted from the ventral skin of flatfish. It was cross-linked with 1%, 3%, or 5% of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and treated with 1%, 5%, or 10% of lactose. Hydroxyproline contents and Young's modulus (elasticity) were measured. In addition, these were injected under the back of BALB/c nude mice and the amount of hydroxyproline was observed. Histological examination of the samples was also conducted.

RESULTS

The amount of hydroxyproline in fish collagen was 3.3 ± 0.3 μg/mg. The 3% collagen gel treated with 5% EDC and 5% lactose had the highest Young's modulus and was closest to the bovine-derived collagen injection formulation. When injected into mice, it was retained in vivo for about 90 days.

CONCLUSIONS

Fish collagen has a low denaturation temperature and is unstable and easily biodegrades in mammalian organisms. However, it is possible to approach the properties of conventional mammalian collagen by cross-linking and lactose treatment, suggesting that fish collagen can be used as a scaffold for cells in regenerative medicine.

Valorization of Fish Waste: Isolation and Characterization of Acid- and Pepsin-Soluble Collagen from the Scales of Mediterranean Fish and Fabrication of Collagen-Based Nanofibrous Scaffolds

In search of alternative and sustainable sources of collagenous materials for biomedical applications, the scales of five Mediterranean fish species-fished in high tonnage in the Mediterranean region since they represent popular choices for the local diet-as well as those of the Atlantic salmon for comparison purposes, were comparatively studied for their acid- and pepsin-soluble collagen content. Fish scales that currently represent a discarded biomass of no value could be efficiently exploited for the production of a high added-value biomaterial. The isolated collagenous materials, which showed the typical electrophoretic patterns of type I collagen, were morphologically and physicochemically characterized. Using scanning electron microscopy the fibrous morphology of the isolated collagens was confirmed, while the hydroxyproline content, in conjunction with infrared spectroscopy and X-ray diffraction studies verified the characteristic for collagen amino acid profile and its secondary structure. The acid- and pepsin-soluble collagens isolated from the fish scales were blended with the bioactive sulfated marine polysaccharide ulvan and polyethylene oxide and electrospun to afford nanofibrous scaffolds that could find applications in the biomedical sector.

A Comprehensive Review on Collagen Type I Development of Biomaterials for Tissue Engineering: From Biosynthesis to Bioscaffold

Collagen is the most abundant structural protein found in humans and mammals, particularly in the extracellular matrix (ECM). Its primary function is to hold the body together. The collagen superfamily of proteins includes over 20 types that have been identified. Yet, collagen type I is the major component in many tissues and can be extracted as a natural biomaterial for various medical and biological purposes. Collagen has multiple advantageous characteristics, including varied sources, biocompatibility, sustainability, low immunogenicity, porosity, and biodegradability. As such, collagen-type-I-based bioscaffolds have been widely used in tissue engineering. Biomaterials based on collagen type I can also be modified to improve their functions, such as by crosslinking to strengthen the mechanical property or adding biochemical factors to enhance their biological activity. This review discusses the complexities of collagen type I structure, biosynthesis, sources for collagen derivatives, methods of isolation and purification, physicochemical characteristics, and the current development of collagen-type-I-based scaffolds in tissue engineering applications. The advancement of additional novel tissue engineered bioproducts with refined techniques and continuous biomaterial augmentation is facilitated by understanding the conventional design and application of biomaterials based on collagen type I.

Functional proteins through green refining of seafood side streams

Scarcity of nutritive protein is a major global problem, the severity of which is bound to increase with the rising population. The situation demands finding additional sources of proteins that can be both safe as well as acceptable to the consumer. Food waste, particularly from seafood is a plausible feedstock of proteins in this respect. Fishing operations result in appreciable amounts of bycatch having poor food value. In addition, commercial processing results in 50 to 60% of seafood as discards, which consist of shell, head, fileting frames, bones, viscera, fin, skin, roe, and others. Furthermore, voluminous amounts of protein-rich effluents are released during commercial seafood processing. While meat from the bycatch can be raw material for proteinous edible products, proteins from the process discards and effluents can be recovered through biorefining employing upcoming, environmental-friendly, low-cost green processes. Microbial or enzyme treatments release proteins bound to the seafood matrices. Physico-chemical processes such as ultrasound, pulse electric field, high hydrostatic pressure, green solvent extractions and others are available to recover proteins from the by-products. Cultivation of photosynthetic microalgae in nutrient media consisting of seafood side streams generates algal cell mass, a rich source of functional proteins. A zero-waste marine bio-refinery approach can help almost total recovery of proteins and other ingredients from the seafood side streams. The recovered proteins can have high nutritive value and valuable applications as nutraceuticals and food additives.

Mechanically Enhanced Salmo salar Gelatin by Enzymatic Cross-linking: Premise of a Bioinspired Material for Food Packaging, Cosmetics, and Biomedical Applications

Marine animal by-products of the food industry are a great source of valuable biomolecules. Skins and bones are rich in collagen, a protein with various applications in food, cosmetic, healthcare, and medical industries in its native form or partially hydrolyzed (gelatin). Salmon gelatin is a candidate of interest due to its high biomass production available through salmon consumption, its biodegradability, and its high biocompatibility. However, its low mechanical and thermal properties can be an obstacle for various applications requiring cohesive material. Thus, gelatin modification by cross-linking is necessary. Enzymatic cross-linking by microbial transglutaminase (MTG) is preferred to chemical cross-linking to avoid the formation of potentially cytotoxic residues. In this work, the potential of salmon skin gelatin was investigated, in a comparative study with porcine gelatin, and an enzymatic versus chemical cross-linking analysis. For this purpose, the two cross-linking methods were applied to produce three-dimensional, porous, and mechanically reinforced hydrogels and sponges with different MTG ratios (2%, 5%, and 10% w/w gelatin). Their biochemical, rheological, and structural properties were characterized, as well as the stability of the material, including the degree of syneresis and the water-binding capacity. The results showed that gelatin enzymatically cross-linked produced material with high cross-linking densities over 70% of free amines. The MTG addition seemed to play a crucial role, as shown by the increase in mechanical and thermal resistances with the production of a cohesive material stable above 40 °C for at least 7 days and comparable to porcine and chemically cross-linked gelatins. Two prototypes were obtained with similar thermal resistances but different microstructures and viscoelastic properties, due to different formation dynamics of the covalent network. Considering these results, the enzymatically cross-linked salmon gelatin is a relevant candidate as a biopolymer for the production of matrix for a wide range of biotechnological applications such as food packaging, cosmetic patch, wound healing dressing, or tissue substitute.

Collagen Membrane Derived from Fish Scales for Application in Bone Tissue Engineering

Guided tissue/bone regeneration (GTR/GBR) is currently the main treatment for alveolar bone regeneration. The commonly used barrier membranes in GTR/GBR are collagen membranes from mammals such as porcine or cattle. Fish collagen is being explored as a potential substitute for mammalian collagen due to its low cost, no zoonotic risk, and lack of religious constraints. Fish scale is a multi-layer natural collagen composite with high mechanical strength, but its biomedical application is limited due to the low denaturation temperature of fish collagen. In this study, a fish scale collagen membrane with a high denaturation temperature of 79.5 °C was prepared using an improved method based on preserving the basic shape of fish scales. The fish scale collagen membrane was mainly composed of type I collagen and hydroxyapatite, in which the weight ratios of water, organic matter, and inorganic matter were 20.7%, 56.9%, and 22.4%, respectively. Compared to the Bio-Gide^® membrane (BG) commonly used in the GTR/GBR, fish scale collagen membrane showed good cytocompatibility and could promote late osteogenic differentiation of cells. In conclusion, the collagen membrane prepared from fish scales had good thermal stability, cytocompatibility, and osteogenic activity, which showed potential for bone tissue engineering applications.

Collagen Extraction from Animal Skin

Simple Summary

Collagen is useful in many applications including cosmetics, medicine, yarn production and packaging. Collagen can be recovered from skins of animals raised for meat. Here, we review methods for the extraction and purification of collagen from animal skins.

Abstract

Collagen is the most abundant structural protein in animals. It is the major component of skin. It finds uses in cosmetics, medicine, yarn production and packaging. This paper reviews the extraction of collagen from hides of most consumed animals for meat with the focus on literature published since 2000. The different pretreatment and extraction techniques that have been investigated for producing collagen from animal skins are reviewed. Pretreatment by enzymatic, acid or alkaline methods have been used. Extraction by chemical hydrolysis, salt solubilization, enzymatic hydrolysis, ultrasound assisted extraction and other methods are described. Post-extraction purification methods are also explained. This compilation will be useful for anyone wishing to use collagen as a resource and wanting to further improve the extraction and purification methods.

Characteristics of Marine Biomaterials and Their Applications in Biomedicine

Oceans have vast potential to develop high-value bioactive substances and biomaterials. In the past decades, many biomaterials have come from marine organisms, but due to the wide variety of organisms living in the oceans, the great diversity of marine-derived materials remains explored. The marine biomaterials that have been found and studied have excellent biological activity, unique chemical structure, good biocompatibility, low toxicity, and suitable degradation, and can be used as attractive tissue material engineering and regenerative medicine applications. In this review, we give an overview of the extraction and processing methods and chemical and biological characteristics of common marine polysaccharides and proteins. This review also briefly explains their important applications in anticancer, antiviral, drug delivery, tissue engineering, and other fields.

Suitability of Marine- and Porcine-Derived Collagen Type I Hydrogels for Bioprinting and Tissue Engineering Scaffolds

Collagens from a wide array of animals have been explored for use in tissue engineering in an effort to replicate the native extracellular environment of the body. Marine-derived biomaterials offer promise over their conventional mammalian counterparts due to lower risk of disease transfer as well as being compatible with more religious and ethical groups within society. Here, collagen type I derived from a marine source (Macruronus novaezelandiae, Blue Grenadier) is compared with the more established porcine collagen type I and its potential in tissue engineering examined. Both collagens were methacrylated, to allow for UV crosslinking during extrusion 3D printing. The materials were shown to be highly cytocompatible with L929 fibroblasts. The mechanical properties of the marine-derived collagen were generally lower than those of the porcine-derived collagen; however, the Young’s modulus for both collagens was shown to be tunable over a wide range. The marine-derived collagen was seen to be a potential biomaterial in tissue engineering; however, this may be limited due to its lower thermal stability at which point it degrades to gelatin.