Collagen Extraction Research Articles

Biomedical Applications Based on Marine Collagen Obtained from the Jellyfish Species Rhizostoma Pulmo Extracted from the Black Sea

Abstract Due to its unique properties, collagen is used in various emerging fields such as the pharmaceutical and biomedical device industries, as well as in related fields: nutraceuticals, cosmetics, food, beverages and nutritional supplements. Marine gelatin, one of the biomaterials involved in food and medicinal research, is denatured collagen produced from acid, alkaline, or enzyme hydrolysis. Gelatin is a crucial ingredient for the food, pharmaceutical, medical, biomedical focusing on versatile applications. Jellyfish collagen is a valuable resource for bioplastics and biomaterials used in various health sectors. Recently, marine organisms have been considered viable sources of collagen because they do not harbor transmissible diseases. In particular, fish biomass, as well as the catches of other types of organisms, such as small fish, jellyfish, starfish, sea urchins, sponges, possess a significant content of collagen. The collagen extracted from the species Rhizostoma pulmo from the Black Sea basin is also part of the bioresources that can be used to obtain natural marine collagen from this type of invertebrates. The use of discarded or hither to unused biomass could contribute to the development of a sustainable collagen extraction process with a positive impact on the ecosystem. In the future it is desired to approach a world strategy that minimizes the amount of waste and that supports all three general objectives of sustainability: sustainable economic well-being, social well-being and environmental protection.

Seasonal Molecular Difference in Fibrillar Collagen Extracts Derived from the Marine Sponge Chondrosia reniformis (Nardo, 1847) and Their Impact on Its Derived Biomaterials.

Chondrosia reniformis (Nardo, 1847) is a marine sponge of high biotechnological interest both for its natural compound content and for its peculiar collagen, which is suitable for the production of innovative biomaterials in the form, for instance, of 2D membranes and hydrogels, exploitable in the fields of tissue engineering and regenerative medicine. In this study, the molecular and chemical-physical properties of fibrillar collagen extracted from specimens collected in different seasons are studied to evaluate the possible impact of sea temperature on them. Collagen fibrils were extracted from sponges harvested by the Sdot Yam coast (Israel) during winter (sea temperature: 17 °C) and during summer (sea temperature: 27 °C). The total AA composition of the two different collagens was evaluated, together with their thermal stability and glycosylation level. The results showed a lower lysyl-hydroxylation level, lower thermal stability, and lower protein glycosylation level in fibrils extracted from 17 °C animals compared to those from 27 °C animals, while no differences were noticed in the GAGs content. Membranes obtained with fibrils deriving from 17 °C samples showed a higher stiffness if compared to the 27 °C ones. The lower mechanical properties shown by 27 °C fibrils are suggestive of some unknown molecular changes in collagen fibrils, perhaps related to the creeping behavior of C. reniformis during summer. Overall, the differences in collagen properties gain relevance as they can guide the intended use of the biomaterial.

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.

Comparing the performance of demineralization agents (HCl and EDTA) for stable isotope analysis of bone collagen with implications for quality control criteria and collagen yield

AbstractStable isotope analysis of ancient bone collagen is a powerful technique for studying diet, migration, and ecology in archeological contexts. These analyses are, however, limited by collagen preservation and prohibitively low collagen yields. Harsh chemical demineralization is required to isolate the collagen from the mineral component of the bone, which in turn reduces the yield of material available for analysis. Demineralization is typically performed using hydrochloric acid (HCl), which reduces collagen yield via acid hydrolysis of peptide bonds. An alternative to a strong acid (HCl) treatment is the neutral chelating agent ethylenediaminetetraacetic acid (EDTA). To our knowledge, it has never been empirically tested whether EDTA treatment reduces collagen loss relative to HCl in samples that are known to be poorly preserved (i.e., low yields and/or collagen extracts failing other collagen quality control [QC] criteria). We tested the effect of the demineralization agent on collagen yield, stable isotope, and elemental composition of poorly preserved ancient bone samples. Collagen yield was significantly higher in EDTA‐treated samples; however, this did not translate into a greater number of samples passing relevant quality control criteria. Stable isotope compositions (SIC) were also not significantly different between treatments. The atomic C:N ratio of samples treated with EDTA was significantly lower than equivalent samples treated with HCl, which is likely a product of increased deamidation of asparagine and glutamine residues when collagen is demineralized with HCl relative to EDTA. We conclude that although EDTA treatment may reduce collagen loss relative to HCl treatment, this does not necessarily increase the probability of producing reliable–stable isotope data from bone samples yielding low amounts of collagen. Based on our isotopic data, we suggest the following provisional collagen QC criteria for EDTA‐demineralized samples: collagen yield > 2%, wt% C > 4%, wt% N > 2%, and atomic C:N ratio between 2.80 and 3.25.

Effects of ultrasound on the structural and functional properties of sheep bone collagen

The study evaluated the effect of an ultrasound-assisted treatment on the structural and functional properties of sheep bone collagen (SBC). The type and distribution of SBC were analyzed by proteome (shotgun) technology combined with liquid chromatography-tandem mass spectrometry. Compared with pepsin extraction, the ultrasound-assisted treatment significantly increased the collagen extraction rate by 17.4 pp (P < 0.05). The characteristic functional groups and structural integrity of collagen extracted by both methods were determined via Fourier transform infrared spectroscopy, ultraviolet absorption spectroscopy, and fluorescence spectroscopy. Circular dichroism spectra revealed that the ultrasound-assisted pretreatment reduced α-helix content by 1.6 pp, β-sheet content by 21.9 pp, and random coils content by 28.4 pp, whereas it increased β-turn content by 51.9 pp (P < 0.05), compared with pepsin extraction. Moreover, ultrasound-assisted treatment collagen had superior functional properties (e.g., solubility, water absorption, and oil absorption capacity) and foaming and emulsion properties, compared with pepsin extraction. Furthermore, the relative content of type I collagen in ultrasound-assisted extracted SBC was highest at 79.66%; only small proportions of type II, VI, X, and XI collagen were present. Peptide activity analysis showed that SBC had potential antioxidant activity, dipeptidyl peptidase 4 inhibitory activity, and angiotensin-converting enzyme inhibitory activity; it also had anticancer, antihypertensive, anti-inflammatory, and immunomodulatory effects.

The expression of BMP4 and FGF2 in Wistar rats (Rattus norvegicus) post application of gourami fish (Osphronemus goramy) collagen

Background: Periodontitis is a chronic inflammatory disease of the periodontal tissue that is characterized by alveolar bone resorption. This occurs due to an imbalance of osteoblast and osteoclast during the bone formation and resorption processes. In order to obtain complete regeneration of periodontal tissue, bone grafting is frequently used in periodontal surgical therapy. Although each material has disadvantages, safe graft materials derived from animal sources can be employed as an alternative to bone graft materials. Osteoblast, osteoclast, calcified bone matrix, type I collagen, osteonectin, and hydroxyapatite can all be found in gourami scales, a form of food waste. BMP4 has osteoinduction functions, which are important in bone metabolism. Through angiogenic activity, FGF2 also contributes to periodontal regeneration. Purpose: The aim of the study was to assess the expression of BMP4 and FGF2 after the treatment group had been given gourami fish scale extract. Methods: Thirty-two experimental three-month-old male Wistar rats (150-200g) were randomly divided into four groups: a seven-day control group, a seven-day treatment group, a 14-day control group, and a 14-day treatment group. One mandibular incisor was extracted from each Wistar rat. The post-extraction socket was filled with blood for the control group and collagen extract for the treatment. Results: The one-way ANOVA test showed a significance level of 0.000 (p = &lt;0.05). Conclusion: The expression of BMP4 and FGF2 increased after the application of collagen extract from gourami scales.

Ultrasound-assisted extraction of collagen from broiler chicken trachea and its biochemical characterization

Broiler chicken tracheas are a co-product from chicken slaughterhouses which are normally turned into low value animal feed despite their high levels of collagen. Typical collagen extraction by acid and/or pepsin usually results in relatively low yield. Ultrasound-assisted extraction (UAE) could be a means to improve collagen yield. The objectives of this study were to investigate the effects of ultrasonic parameters on the yield and biochemical properties of trachea collagen (TC). Conventional extraction using acetic acid and pepsin for 48 h resulted in acid-soluble (AS) and pepsin-soluble (PS) collagen with a yield of 0.65% and 3.10%, respectively. When an ultrasound with an intensity of 17.46 W·cm−2 was applied for 20 min, followed by acid extraction for 42 h (U-AS), the collagen yield increased to 1.58%. A yield of 6.28% was obtained when the ultrasound treatment was followed by pepsin for 36 h (U-PS). PS and U-PS contained collagen of 82.84% and 85.70%, respectively. Scanning electron microscopy images revealed that the ultrasound did not affect the collagen microstructure. All collagen samples showed an obvious triple helix structure as measured by circular dichroism spectroscopy. Fourier transform infrared spectroscopy indicated that the ultrasound did not disturb the secondary structure of the protein in which approximately 30% of the α-helix content was a major structure for all collagen samples. Micro-differential scanning calorimetry demonstrated that the denaturation temperature of collagen in the presence of deionized water was higher than collagen solubilized in 0.5 M acetic acid, regardless of the extraction method. All collagen comprised of α1 and α2-units with molecular weights of approximately 135 and 116 kDa, respectively, corresponding to the type I characteristic. PS and U-PS collagen possessed higher imino acids than their AS and U-AS counterparts. Based on LC-MS/MS peptide mapping, PS and U-PS collagen showed a high similarity to type I collagen. These results suggest that chicken tracheas are an alternative source of type I collagen. UAE is a promising technique that could increase collagen yield without damaging its structure.

Thermally crosslinked electrospun nanofibrous mat from chrome-tanned solid wastes for cationic dye adsorption in wastewater treatment

Chrome-tanned solid wastes from the tannery were used to extract collagen hydrolysate (CH) for the fabrication of electrospinning nanofibrous mat with polyvinyl alcohol (PVA) to remove cationic dye from wastewater. The nanofibrous mat was thermally crosslinked by heat curing to make it stable in neutral, acidic, and basic environments. The prepared nanofibrous mat was characterized by attenuated total reflectance infrared spectroscopy (ATR-IR), thermogravimetry (TGA), X-ray diffraction (XRD), and water dissolution properties. The detailed experimental results revealed that the nanomat prepared from CH: PVA (2:3) yielded better stability in an aqueous solution after thermal crosslinking. The nanofibrous mat was used as adsorbent and its adsorption properties were evaluated from the adsorption behaviour of methylene blue (MB), a common cationic dye. The adsorption results demonstrated that the nanomat showed maximum adsorption capacity of 99.9 mg g−1 with 88.8% removal efficiency at pH 12. The adsorption parameters were optimized and revealed to be highly pH sensitive, with 12.0 being the optimum pH for the highest dye removal. The experimental results revealed that the adsorption capacity of the nanofibrous mat grew with increasing initial dye concentration and decreased with increasing adsorbent doses. The thermodynamic study indicated that the adsorption kinetics (R2 > 0.99) followed pseudo-second-order equation, and the equilibrium data was the best suited by the Langmuir model (R2 > 0.99). On the other hand, the electrospun nanofibrous mat showed significantly better adsorption than the prepared CH-PVA composite film. The results for cationic dye adsorption suggest that the potential broader applications of collagen hydrolysate-based nanofibrous mat for pollution control may include its use as potential adsorbent for wastewater treatment.

Swim Bladder of Farmed Totoaba macdonaldi: A Source of Value-Added Collagen

Finding strategies to use the swim bladder of farmed totoaba (Totoaba macdonaldi) is of the utmost need to reduce waste. Fish swim bladders are rich in collagen; hence, extracting collagen is a promising alternative with benefits for aquaculture of totoaba and the environment. The elemental biochemical composition of totoaba swim bladders, including their proximate and amino acid compositions, was determined. Pepsin-soluble collagen (PSC) was used to extract collagen from swim bladders, and its characteristics were analyzed. Alcalase and papain were used for the preparation of collagen hydrolysates. Swim bladders contained 95% protein, 2.4% fat, and 0.8% ash (on a dry basis). The essential amino acid content was low, but the functional amino acid content was high. The PSC yield was high, at 68% (dry weight). The amino acid composition profile, electrophoretic pattern, and structural integrity analyses of the isolated collagen suggested it is a typical type-I collagen with high purity. The denaturalization temperature was 32.5 °C, probably attributable to the imino acid content (205 residues/1000 residues). Papain-hydrolysates (≤3 kDa) of this collagen exhibited higher radical scavenging activity than Alcalase-hydrolysates. The swim bladder from the farmed totoaba could be an ideal source to produce high-quality type I collagen and may be considered an alternative to conventional collagen sources or bioactive peptides.

Application of steam explosion treatment on the collagen peptides extraction from cattle bone

In this study, steam explosion (SE) treatment was applied to extract collagen peptides from cattle bone. The SE treatment conditions included steam pressure: 1.5 MPa (200.43 °C), 2.0 MPa (213.85 °C), and 2.5 MPa (224.99 °C), and reaction time: 10 min, 20 min, and 30 min. With the increase of pressure and reaction time, the protein recovery rate improved, and reached to 60.5% at 2.0 MPa–30 min. SE significantly decreased the molecular weight of collagen peptides (P < 0.05) with increasing pressure and reaction time. However, at 2.5 MPa, SE darkened the sample color resulting in dark yellow. Particle size analysis and SEM images indicated that SE decreased the particle size and destroyed microstructure of cattle bone powder. FT-IR analysis showed that SE induced distinct characteristic peaks of hydroxyapatite in cattle bone powder. SE facilitated peptides release from collagen by destroying peptide bonds and enzymatic cross-links. Amino acid analysis indicated SE could not change the amino acid composition of collagen peptides. The calcium-binding ability and osteoblast proliferative activity of extracted collagen peptides were 44.7 μg/mg and 126.7% (200 μg/mL), respectively. The findings put forward data support and a scientific basis for the application and development of SE technology to collagen peptides extraction and high-value utilization of cattle bone.

Low-Molecular-Mass Fragments of Collagen Improve Parameters Related to Mass and Inflammation of the Adipose Tissue in the Obese Rat.

Despite clearly recognized links between increased body mass and increased risk for various pathological conditions, therapeutic options to treat obesity are still very limited. The aim of the present study is to explore the effect of low-molecular-mass collagen fragments obtained from the scales of Antarctic wild marine fish on rats' visceral and subcutaneous white adipose tissue in a high-calorie diet-induced obesity model. The study was conducted on outbred rats, which were divided into 3 experimental groups: (i) control, consuming standard food (3.81 kcal/g), (ii) obese group, consuming a high-calorie diet (5.35 kcal/g), and (iii) obese group, consuming a high-calorie diet (5.35 kcal/g) with intragastric administration of low-molecular-mass collagen fragments (at a dose 1 g/kg of body mass during 6 weeks). Low-molecular-mass collagen fragments were obtained by a procedure that included collagen extraction from fish scales and enzymatic hydrolysis with pepsin. Apart from hematoxylin and eosin staining, fibrosis level was assessed by histochemical Van Gieson's trichrome picrofuchsin staining, and mast cells were analysed by toluidine blue O staining. Group treated with low-molecular-mass fragments of collagen exhibited decreased rate of mass gain, relative mass, area occupied by collagen fibre of both visceral and subcutaneous adipose tissue, and cross-sectional area of both visceral and subcutaneous adipocytes. Treatment with low-molecular-mass fragments of collagen reduced the infiltration of immune cells, number of mast cells and their redistribution back to the septa. This was also accompanied by a decreased number of the crown-like structures formed by the immune cells, which are markers of chronic inflammation that accompanies obesity. This is the first study that reports the anti-obesity effect of low-molecular-mass fragments produced as a result of controlled hydrolysis of collagen from the scales of Antarctic wild marine fish in the in vivo model. Another novelty of this work is the observation that the tested collagen fragments not only reduce the body mass, but also improve the morphological and inflammatory parameters (decrease in the number of crown-like structures, immune cell infiltration, fibrosis and mast cells). Altogether, our work suggests that low-molecular-mass collagen fragments are a promising candidate for amelioration of some comorbidities linked to obesity.

Extraction and Characterization of Collagen from Cattle Horns for Potential Wound Healing

Extraction and Characterization of Collagen from Cattle Horns for Potential Wound Healing

Functional Properties of Collagen Extracted From Catfish ( Silurus triostegus) Bone

Back ground: Collagen accounts for 25percent of all proteins found in vertebrates. The words &amp;quot;collagen&amp;quot;is created with Greek words &amp;quot;kolla&amp;quot; and &amp;quot;genos,&amp;quot; which respectively mean &amp;quot;glue&amp;quot; and &amp;quot;formation.&amp;quot; It hasa wide range of biological and pharmacological uses. Pig and cow skins provide the majority of thecollagen. Utilizing animal collagen has been restricted as a result of epidemics of certain animal diseasesincluding foot-and-mouth disease (FMD) and bovine spongiform encephalopathy (BSE) (FMD), whichpose a risk of transmission to humansObjective: The goal of this study is to extract collagen from catfish bone.Material and methods: Catfish (Silurus triostegus) bone was used to extract collagen that has beenpepsinized and acid-solubilized collagen (ASC) (PSC). The extracts&amp;#39; proximate composition (moisture,protein, fat, and ash) was measured, and dry weight was used to compute the yield of ASC and PSC. Themolecular weight of experimental collagen ranged from 97 to 200 KD, according to the SDS-PAGEpattern. In order to identify bone collagen, the Fourier Transform Infrared (FTIR) spectra analysis for theacquired ASC and PSC, as well as the standard collagen (type I, II), was used. Using a scanning electronmicroscope (SEM, the morphological structure of ASC and PSC was revealed), and the diffraction angles(2 θ) of ASC and PSC were determined using X-ray analysis. For quality control, the HPLC techniquewas used to determine the collagen.Rustles: The proximate composition of ASC and PSC bone of catfish. The ASC bone of catfish containedmoisture (75.22%), good amount of protein (16.65%) , fat (2.40%) and ash content (0.28 %), While thePSC bone had slightly lower moisture (68.50%) than ASC, it had higher protein (19.93%), fat (1.825%),and ash (0.58%) levels ,HPLC SEM ,FTIR ,Electrophoresis, X-ray.Conclusion: Fish bone was promising sources for preparing collagen, acid soluble collagen (ASC),pepsin soluble collagen (PSC) were successfully extracted by two methods. The collagen extracted frombone catfish, was of type I collagen, which are composed two α1, one α2 chains, and β chains as shownby SDS-PAGE patterns.

AMS 14C dating of bioapatite: Advantage and disadvantage

Most methods of bone preparation for 14C dating are designed to extract collagen or individual compounds. The problem becomes acute for poorly preserved bones, since they have no collagen. The bioapatite is stable against microbiological decomposition and dissolution over millennium scales. However, it may be exposed to isotopic exchange with environmental carbonates.We are reviewing our research during the last decades comparing the dating different fractions of bones of different ages and differing preservation degrees. The results have shown that preservation of bioapatite depends on the conditions of the environment in which samples were buried. The wet environment affects bioapatite by enriching it with 14C due to isotopic exchange with environmental carbonates. 14C depletion of bone bioapatite deposited in caves and in limestone is possible. The results for the samples from arid, semi-arid and non-carbonate environments are in a good agreement with dates on other materials.

Improving collagen processing towards a greener approach: current progress

AbstractThe high market demand for collagen as a biomaterial has prompted additional studies into improved methods of collagen extraction without sacrificing the overall quality of collagen. The use of clean technology for sustainable collagen extraction has recently gained popularity due to its efficiency and minimal waste production. This review focuses on improving collagen processing based on three essential steps: pre‐treatment (fermentation, high shear mechanical homogenisation, ultrasound), extraction (ultrasound‐assisted extraction, microwave‐assisted extraction, physical‐aided extraction, and supercritical fluid technology), and recovery (ultrafiltration). This review also summarises the benefits and drawbacks of the emerging green technologies used in each step to obtain collagen. This study shows that these clean technologies eliminate the need for excessive chemicals and shortens processing time. However, each collagen‐processing step must be carefully controlled to preserve structural integrity, which influences collagen's properties and hence its uses for further applications. © 2023 Society of Chemical Industry (SCI).

Collagen Derived from Fish Industry Waste: Progresses and Challenges.

Fish collagen garnered significant academic and commercial focus in the last decades featuring prospective applications in a variety of health-related industries, including food, medicine, pharmaceutics, and cosmetics. Due to its distinct advantages over mammalian-based collagen, including the reduced zoonosis transmission risk, the absence of cultural-religious limitations, the cost-effectiveness of manufacturing process, and its superior bioavailability, the use of collagen derived from fish wastes (i.e., skin, scales) quickly expanded. Moreover, by-products are low cost and the need to minimize fish industry waste's environmental impact paved the way for the use of discards in the development of collagen-based products with remarkable added value. This review summarizes the recent advances in the valorization of fish industry wastes for the extraction of collagen used in several applications. Issues related to processing and characterization of collagen were presented. Moreover, an overview of the most relevant applications in food industry, nutraceutical, cosmetics, tissue engineering, and food packaging of the last three years was introduced. Lastly, the fish-collagen market and the open technological challenges to a reliable recovery and exploitation of this biopolymer were discussed.

Age-Related Properties of Aquaponics-Derived Tilapia Skin (Oreochromis niloticus): A Structural and Compositional Study.

In the last two decades, fisheries and fish industries by-products have started to be recovered for the extraction of type I collagen because of issues related to the extraction of traditional mammalian tissues. In this work, special attention has been paid to by-products from fish bred in aquaponic plants. The valorization of aquaponic fish wastes as sources of biopolymers would make the derived materials eco-friendlier and attractive in terms of profitability and cost effectiveness. Among fish species, Nile Tilapia is the second-most farmed species in the world and its skin is commonly chosen as a collagen extraction source. However, to the best of our knowledge, no studies have been carried out to investigate, in depth, the age-related differences in fish skin with the final aim of selecting the most advantageous fish size for collagen extraction. In this work, the impact of age on the structural and compositional properties of Tilapia skin was evaluated with the aim of selecting the condition that best lends itself to the extraction of type I collagen for biomedical applications, based on the known fact that the properties of the original tissue have a significant impact on those of the final product. Performed analysis showed statistically significant age-related differences. In particular, an increase in skin thickness (+110 µm) and of wavy-like collagen fiber bundle diameter (+3 µm) besides their organization variation was observed with age. Additionally, a preferred collagen molecule orientation along two specific directions was revealed, with a higher fiber orientation degree according to age. Thermal analysis registered a shift of the endothermic peak (+1.7 °C) and an increase in the enthalpy (+3.3 J/g), while mechanical properties were found to be anisotropic, with an age-dependent brittle behavior. Water (+13%) and ash (+0.6%) contents were found to be directly proportional with age, as opposed to protein (-8%) and lipid (-10%) contents. The amino acid composition revealed a decrease in the valine, leucine, isoleucine, and threonine content and an increase in proline and hydroxyproline. Lastly, fatty acids C14:0, C15:0, C16:1, C18:2n6c, C18:3n6, C18:0, C20:3n3, and C23:0 were revealed to be upregulated, while C18:1n9c was downregulated with age.

In Vivo Skin Hydrating Efficacy of Fish Collagen from Greenland Halibut as a High-Value Active Ingredient for Cosmetic Applications.

The industrial processing of fish for food purposes also generates a considerable number of by-products such as viscera, bones, scales, and skin. From a value-added perspective, fish by-products can act also as raw materials, especially because of their collagen content (particularly in fish skin). Interestingly, the potential of marine collagen for cosmetic applications is enormous and, remarkably, the extraction of this protein from fish skins has been established for different species. Using this approach, we investigated the integration of marine collagen (COLRp_I) extracted from the skin of the Greenland halibut as an active ingredient in a cosmetic hydrogel formulation. In this study, extracts of marine collagen at concentrations up to 10 mg/mL showed a non-cytotoxic effect when cultured with fibroblast cells for 3 days. In addition, marine collagen extract, when incorporated into a cosmetic hydrogel formulation, met criterion A of ISO 11930:2019 regarding the efficacy of the preservative system (challenge test). In addition, the cosmetic formulations based on marine collagen at dosages of 0.1, 0.25 and 0.5% were tested in a clinical study on the skin of the forearms of 23 healthy volunteers, showing a sightly hydration effect, suggesting its potential for beauty applications. Moreover, this work illustrates that the circular economy concept applied to the fish processing industry can represent important benefits, at innovation, environmental and economic levels.

Solubility of Amino Acids in the Eutectic Solvent Constituted by Sodium Acetate Trihydrate and Urea and in Its Mixture with Water

Industrial fish and aquaculture processing leads to the generation of a huge quantity of by-products, whose accumulation and mismanagement involve serious environmental consequences as well as high economic losses. Taking advantage of these residues as a source of added-value compounds must be a priority in a circular economy. This work is a preliminary study to analyze the possibility of using the eutectic mixture of urea and sodium acetate trihydrate as a solvent for collagen extraction. To that end, the solid-liquid equilibrium of the system was determined in order to define the exact composition and temperature of the eutectic. The solubility in this solvent of the main amino acids that constitute fish collagen was studied at several temperatures and atmospheric pressure. At 308.15 K, solubilities of the major constituents of the target protein, namely L-proline, trans-4-hydroxy-L-proline, and glycine, were 0.19, 0.16, and 0.12 (mass fraction), respectively. These values increased with temperature. Dilution with water (50 wt%) allowed operation at lower temperature and led to an increase in the solubilities. The van 't Hoff model was satisfactorily used to correlate the experimental data and to calculate apparent properties of dissolution. All the dissolution processes studied herein are endothermic, non-spontaneous, and enthalpy-driven. Both the eutectic and its mixture with water are promising solvents for the design of an environmentally benign process for collagen extraction.

Exploring dog antler chews as a novel source of collagen supplementation: extraction and characterization of collagen from red deer antlers.

Collagen is the body's most abundant protein and is primarily found in the skin, bones, tendons, and ligaments of animals and fish. As the interest in collagen supplementation grows, new sources of this protein are continually being introduced. We have confirmed that red deer antlers are a source of type I collagen. We investigated the effects of chemical treatment, temperature, and time on the extractability of collagen from red deer antlers. The optimal conditions for obtaining the highest collagen yield were determined to be: 1) removing noncollagenous proteins at 25°C for 12 h in an alkaline solution, 2) defatting at 25°C using a 1:10 grounded antler:butyl alcohol ratio, and 3) acidic extraction lasting 36 h using a 1:10 antler:acetic acid ratio. Under these conditions, we obtained a collagen yield of 22.04%. The molecular characterization of red deer antler collagen revealed typical features of type I collagens, including the presence of three α-chains, high glycine content, and high levels of proline and hydroxyproline, as well as helical arrangements. This report suggests that red deer antlers have significant potential as a source of collagen supplements.