Evaluation of Differentiated Bone Cells Proliferation by Blue Shark Skin Collagen via Biochemical for Bone Tissue Engineering

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.

Deepening in the understanding of the role of collagen subunits on the differential molecular arrangement of P. glauca and M. merluccius marine collagens

Decades of extensive efforts on marine collagen extraction and characterization allowed to recognize the unique and excellent characteristics of marine collagen offering advantages over that obtained from terrestrial sources. However, not all marine collagens have the same biochemical characteristics; understanding those at molecular and supramolecular level, is crucial for optimal design of applications. One relevant aspect of collagen characterization is the analysis of its different subunits (α-chains) and their intermolecular cross-links (β- and γ-components), which ultimately determine the specific functions of a particular collagen. Collagens from a teleost and an elasmobranch species were analyzed to understand the influence of their subunit composition and intermolecular crosslinking pattern on their different physicochemical behaviour. For comparative purposes a commercial mammal collagen was included in the study. Although electrophoretic profiles showed the typical composition of type I collagen for hake, blue shark and calf collagen, molar ratios of their α-chains were different indicating a different degree of dimerization of their α2-chains with implications in the presence of a different crosslinking degree pattern. Electrophoresis, amino acid composition, hydrophobicity (RP-HPLC) and molecular weight analysis (GPC-HPLC) results, besides a peptide mapping and an antioxidant activity study of the resultant peptides, would help to understand the role of different subunit collagen composition and different crosslinking pattern in the conformation of a differential quaternary supramolecular structure within different species and its biofunctional implications. The experiments developed would allow to progress in the valorization potential of fish discards and byproducts to explore commercial uses of collagens from marine origin.

The Role of Integrin Receptor's α and β Subunits of Mouse Mesenchymal Stem Cells on the Interaction of Marine-Derived Blacktip Reef Shark (Carcharhinus melanopterus) Skin Collagen

Marine collagen (MC) has recently attracted more attention in tissue engineering as a biomaterial substitute due to its significant role in cellular signaling mechanisms, especially in mesenchymal stem cells (MSCs). However, the actual signaling mechanism of MC in MSC growth, which is highly influenced by their molecular pattern, is poorly understood. Hence, we investigated the integrin receptors (α₁β₁, α₂β₁, α₁₀β₁, and α₁₁β₁) binding mechanism and proliferation of MCs (blacktip reef shark collagen (BSC) and blue shark collagen (SC)) compared to bovine collagen (BC) on MSCs behavior through functionalized collagen molecule probing for the first time. The results showed that BSC and SC had higher proliferation rates and accelerated scratch wound healing by increasing migratory rates of MSCs. Cell adhesion and spreading results demonstrated that MC had a better capacity to anchor MSCs and maintain cell morphology than controls. Living cell observations showed that BSC was gradually assembled by cells into the ECM network within 24 h. Interestingly, qRT-PCR and ELISA revealed that the proliferative effect of MC was triggered by interacting with specific integrin receptors such as α₂β₁, α₁₀β₁, and α₁₁β₁ of MSCs. Accordingly, BSC accelerated MSCs' growth, adhesion, shape, and spreading by interacting with specific integrin subunits (α₂ and β₁) and thereby triggering further signaling cascade mechanisms.

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.

Proliferative and Osteogenic Supportive Effect of VEGF-Loaded Collagen-Chitosan Hydrogel System in Bone Marrow Derived Mesenchymal Stem Cells

The use of hydrogel (HG) in regenerative medicine is an emerging field and thus several approaches have been proposed recently to find an appropriate hydrogel system. In this sense, this study developed a novel HG system using collagen, chitosan, and VEGF composites for culturing mesenchymal stem cells (MSCs), and investigated their ability for osteogenic differentiation and mineral deposition. Our results showed that the HG loaded with 100 ng/mL VEGF (HG-100) significantly supported the proliferation of undifferentiated MSCs, the fibrillary filament structure (HE stain), mineralization (alizarin red S and von Kossa stain), alkaline phosphatase, and the osteogenesis of differentiated MSCs compared to other hydrogels (loaded with 25 and 50 ng/mL VEGF) and control (without hydrogel). HG-100 showed a higher VEGF releasing rate from day 3 to day 7 than other HGs, which substantially supports the proliferative and osteogenic properties of HG-100. However, the HGs did not increase the cell growth in differentiated MSCs on days 14 and 21 due to the confluence state (reach stationary phase) and cell loading ability, regardless of the VEGF content. Similarly, the HGs alone did not stimulate the osteogenesis of MSCs; however, they increased the osteogenic ability of MSCs in presence of osteogenic supplements. Accordingly, a fabricated HG with VEGF could be used as an appropriate system to culture stem cells for bone and dental regeneration.

Recovery of Bioactive Compounds from Marine Organisms: Focus on the Future Perspectives for Pharmacological, Biomedical and Regenerative Medicine Applications of Marine Collagen

Marine environments cover more than 70% of the Earth's surface and are among the richest and most complex ecosystems. In terms of biodiversity, the ocean represents an important source, still not widely exploited, of bioactive products derived from species of bacteria, plants, and animals. However, global warming, in combination with multiple anthropogenic practices, represents a serious environmental problem that has led to an increase in gelatinous zooplankton, a phenomenon referred to as jellyfish bloom. In recent years, the idea of "sustainable development" has emerged as one of the essential elements of green-economy initiatives; therefore, the marine environment has been re-evaluated and considered an important biological resource. Several bioactive compounds of marine origin are being studied, and among these, marine collagen represents one of the most attractive bio-resources, given its use in various disciplines, such as clinical applications, cosmetics, the food sector, and many other industrial applications. This review aims to provide a current overview of marine collagen applications in the pharmacological and biomedical fields, regenerative medicine, and cell therapy.

Growth Factor-Free Vascularization of Marine-Origin Collagen Sponges Using Cryopreserved Stromal Vascular Fractions from Human Adipose Tissue

The successful integration of transplanted three-dimensional tissue engineering (TE) constructs depends greatly on their rapid vascularization. Therefore, it is essential to address this vascularization issue in the initial design of constructs for perfused tissues. Two of the most important variables in this regard are scaffold composition and cell sourcing. Collagens with marine origins overcome some issues associated with mammal-derived collagen while maintaining their advantages in terms of biocompatibility. Concurrently, the freshly isolated stromal vascular fraction (SVF) of adipose tissue has been proposed as an advantageous cell fraction for vascularization purposes due to its highly angiogenic properties, allowing extrinsic angiogenic growth factor-free vascularization strategies for TE applications. In this study, we aimed at understanding whether marine collagen 3D matrices could support cryopreserved human SVF in maintaining intrinsic angiogenic properties observed for fresh SVF. For this, cryopreserved human SVF was seeded on blue shark collagen sponges and cultured up to 7 days in a basal medium. The secretome profile of several angiogenesis-related factors was studied throughout culture times and correlated with the expression pattern of CD31 and CD146, which showed the formation of a prevascular network. Upon in ovo implantation, increased vessel recruitment was observed in prevascularized sponges when compared with sponges without SVF cells. Immunohistochemistry for CD31 demonstrated the improved integration of prevascularized sponges within chick chorioalantoic membrane (CAM) tissues, while in situ hybridization showed human cells lining blood vessels. These results demonstrate the potential of using cryopreserved SVF combined with marine collagen as a streamlined approach to improve the vascularization of TE constructs.

Extraction of Biocompatible Collagen From Blue Shark Skins Through the Conventional Extraction Process Intensification Using Natural Deep Eutectic Solvents

The disposal of large amounts of skin waste resulting from the blue shark fishing industry presents several industrial and environmental waste management concerns. In addition, these marine subproducts are interesting sources of collagen, a fibrous protein that shows high social and economic interest in a broad range of biomedical, pharmaceutical, and cosmetic applications. However, blue shark wasted skins are a poorly explored matrix for this purpose, and conventional collagen recovery methodologies involve several pre-treatment steps, long extraction times and low temperatures. This work presents a new green and sustainable collagen extraction approach using a natural deep eutectic solvent composed of citric acid:xylitol:water at a 1:1:10 molar ratio, and the chemical characterization of the extracted collagen by discontinuous electrophoresis, thermogravimetric analysis, Fourier transformed infrared spectroscopy and circular dichroism. The extracted material was a pure type I collagen, and the novel approach presented an extraction yield 2.5 times higher than the conventional one, without pre-treatment of raw material and reducing the procedure time from 96 to 1 h. Furthermore, the in vitro cytotoxicity evaluation, performed with a mouse fibroblasts cell line, has proven the biocompatibility of the extracted material. Overall, the obtained results demonstrate a simple, quick, cheap and environmentally sustainable process to obtain marine collagen with promising properties for biomedical and cosmetic applications.

Comparison of Physicochemical and Structural Properties of Acid-Soluble and Pepsin-Soluble Collagens from Blacktip Reef Shark Skin

Fish collagen has been widely used in tissue engineering (TE) applications as an implant, which is generally transplanted into target tissue with stem cells for better regeneration ability. In this case, the success rate of this research depends on the fundamental components of fish collagen such as amino acid composition, structural and rheological properties. Therefore, researchers have been trying to find an innovative raw material from marine origins for tissue engineering applications. Based on this concept, collagens such as acid-soluble (ASC) and pepsin-soluble (PSC) were extracted from a new type of cartilaginous fish, the blacktip reef shark, for the first time, and were further investigated for physicochemical, protein pattern, microstructural and peptide mapping. The study results confirmed that the extracted collagens resemble the protein pattern of type-I collagen comprising the α₁, α₂, β and γ chains. The hydrophobic amino acids were dominant in both collagens with glycine and hydroxyproline as major amino acids. From the FTIR spectra, α helix (27.72 and 26.32%), β-sheet (22.24 and 23.35%), β-turn (21.34 and 22.08%), triple helix (14.11 and 14.13%) and random coil (14.59 and 14.12%) structures of ASC and PSC were confirmed, respectively. Collagens retained their triple helical and secondary structure well. Both collagens had maximum solubility at 3% NaCl and pH 4, and had absorbance maxima at 234 nm, respectively. The peptide mapping was almost similar for ASC and PSC at pH 2, generating peptides ranging from 15 to 200 kDa, with 23 kDa as a major peptide fragment. The microstructural analysis confirmed the homogenous fibrillar nature of collagens with more interconnected networks. Overall, the preset study concluded that collagen can be extracted more efficiently without disturbing the secondary structure by pepsin treatment. Therefore, the blacktip reef shark skin could serve as a potential source for collagen extraction for the pharmaceutical and biomedical applications.

Protein by-products: Composition, extraction, and biomedical applications

Significant upsurge in animal by-products such as skin, bones, wool, hides, feathers, and fats has become a global challenge and, if not properly disposed of, can spread contamination and viral diseases. Animal by-products are rich in proteins, which can be used as nutritional, pharmacologically functional ingredients, and biomedical materials. Therefore, recycling these abundant and renewable by-products and extracting high value-added components from them is a sustainable approach to reclaim animal by-products while addressing scarce landfill resources. This article appraises the most recent studies conducted in the last five years on animal-derived proteins' separation and biomedical application. The effort encompasses an introduction about the composition, an overview of the extraction and purification methods, and the broad range of biomedical applications of these ensuing proteins.

Therapeutic Effect of Nile Tilapia Type II Collagen on Rigidity in CD8+ Cells by Alleviating Inflammation and Rheumatoid Arthritis in Rats by Oral Tolerance

Fibrillins are microfibril-associated macro glycoproteins found in connective tissues and structurally related to latent TGF-β-binding proteins (LTBPs). The special cellular immunity and blocking glycoprotein receptors IIb and IIIa of fibrillins are emerging topics in recent years. In this study, Nile Tilapia type IIcollagen (NTCII) was extracted and purified from the skull cartilages by a pepsin-soluble method. Amino acid analysis indicated that NTCII consisted of 315/1000 glycine residues, 72/1000 hydroxyproline residues and 108/1000 proline residues. SDS-PAGE analysis showed that NTCII was composed of three identical 130 kDa α-chains. The results of glycoprotein/carbohydrate assay indicated that the total polysaccharide content of NTCII was 5.6–19.0%. The IR spectrum of NTCII displayed five characteristic peaks of amide I, II, III, A, B. NTCII at 10–100 μg/mL concentration downregulated the content of cytokines in the presence or absence of LPS, especially the secretion of cytokines IL-6, IL-1β and TNF-α. Interestingly, NTCII promoted the secretion of Fas/Apo-1 compared to the control group and 25 μg/mL of NTCII resulted in a higher Fas/Apo-1 secretion level in CD8⁺ T cells. FITC-TCII fluorescence images confirmed that NTCII could bind to the membrane surface of CD8⁺ T cells, leading to the induction of rigidity. NTCII could bind to the membrane surface of CD8⁺ T cells that leads to the induction of rigidity, as evidenced by the FITC-NTCII fluorescence images. The qRT-PCR gene expression analysis of caspase-8 collected with Fas/Apo-1 was upregulated significantly in the 1 and 50 μg/mL NTCII-treated groups compared with the control group. Overall, the results conclude that the rigidity did not lead to an increase in inflammatory factors in CD8⁺ T cells treated with NTCII. The oral administration of NTCII 3 mg/kg dosage caused more prominent repair of damaged ankle cartilage than the 1 mg/kg dosage in Freund’s adjuvant-induced model of arthritis in rats. Therefore, this study disclosed the immunological and anti-arthritic effect of fibrillar collagen, which could be a potential biomaterial for practical applications with lower toxicity.

Noordin WN, Huda N. Biochemical analysis of collagens from the bone of lizardfish (Saurida tumbil Bloch, 1795) extracted with different acids

Background

Lizardfish (Saurida tumbil Bloch, 1795) bone is a fish by-product generated during industrial surimi processing. This by-product is an important source of collagen production since the use of terrestrial animal-based collagens no longer sought due to concern regarding the transfer of infectious diseases and religious issues. Hence, this study was carried out to determine the biochemical analysis of collagens from the bone of lizardfish extracted with different acids.

Methods

Lizardfish bone collagens were extracted with various acids (i.e., acetic, lactic and citric acids). All extraction processes were conducted in a chiller room (4 °C). The extracted collagens were biochemically characterized, such as hydroxyproline content, Ultraviolet (UV) absorption, X-ray diffraction (XRD), Fourier transform infrared spectroscopy spectra (FTIR), Differential scanning calorimetry (DSC) and solubility in different pH values and NaCl concentrations.

Results

The yield of extracted collagens ranged between 1.73% and 2.59%, with the highest (p < 0.05) observed in citric acid-extracted collagen (CaEC). Protein patterns confirmed that all-collagen samples had two identical subunits, α1 and α2, representing type I collagen. The highest whiteness value was found in acetic acid-extracted collagen (AaEC), but there was no significant difference (p ≥ 0.05) compared to lactic acid-extracted collagen (LaEC). UV absorption and XRD analysis reflected the characteristics of the collagen, as reported in the literature. For the FTIR, all acid-extracted collagen samples presented a triple helical structure. The thermal transition temperature (T _max = 77.92-89.04 °C) was in accordance with collagen extracted from other fish species. All extracted collagens were highly soluble in acidic pH and low concentrations of NaCl (0-20 g/L). In conclusion, collagens extracted from lizardfish bone may be used as alternative sources of collagen in industrial settings, and AaEC would be considered superior in terms of the characteristics evaluated in this study.

A comparative assessment of collagen type 1 from silver carp (fresh water) and milk shark(marine) fish waste

In this study, a comparative structural and bioactive analysis of collagen extracted from the skin of bony and cartilaginous fishes. The acid-soluble method was followed to extract the collagen from Hypophthalmichthys molitrix (silver carp) and Rhizoprionodon acutus (milk shark) followed by purification using Ion exchange chromatography. A higher yield of collagen was obtained from the skin of SCsk (69.45%) as compared to SHsk (55.29%). SDS PAGE displayed the characteristic α, β bands of the collagen type1. The native conformation and secondary structure stability of collagen were confirmed by FTIR, XRD and CD studies. The SEM micrographs exhibited the layered and fibrillar nature of the collagen from SHsk and SCsk, respectively. Relative solubility and thermal denaturation analysis showed SCsk to be more stable, but SHsk could withstand higher temperatures. 53.65% of antioxidant activity was observed in SCsk collagen as compared to SHsk (45.9%). Haemocompatibility, cell viability and adhesion results also displayed silvercarp skin to be a better source than Shark skin collagen. The results establish the potential of silver carp collagen as a biomaterial that can have many commercial applications in tissue engineering, cosmetics and food industries.

Collagens from Marine Organisms towards Biomedical Applications

Collagen is the main fibrous structural protein in the extracellular matrix and connective tissue of animals [...]

Mineralized collagen as a bioactive ink to support encapsulation of human adipose stem cells: A step towards the future of bone regeneration

Bioprinting - printing with incorporated living cells - has earned special attention on tissue engineering approaches, aiming to closer reproduce the 3D microenvironment of the target tissue. However, it raises extra complexity related to the need to use cell-friendly printing conditions that still comply with material printing fidelity. Inspired by the composite nano structural organization of mineralized tissues, this work reports the efficiency of the chemical approach followed to in situ mineralize blue shark skin collagen, at a nano scale level, to ultimately produce stable inks. The influence of initial cellular density was evaluated by assessing three different concentrations (2.5, 5 and 7.5 × 10⁶ cells·ml^-1) of human adipose stem cells (hASC), with the higher density of encapsulated cells presenting improved viability in a long culture term. Immunodetection of osteogenic-related markers, like RUNX2 and osteopontin, 21 days after cell culture in basal conditions confirmed the potential of the ink to be applied for osteogenic purposes, which may be associated with the success of the cell-to-ink interaction and the Ca²⁺ ions released from the co-precipitated hydroxyapatite. A combination of mineralized shark collagen, alginate and hASC is thus proposed as a bioactive bioink with potential properties for regeneration of bone tissue.

Biomaterials from the sea: Future building blocks for biomedical applications

Marine resources have tremendous potential for developing high-value biomaterials. The last decade has seen an increasing number of biomaterials that originate from marine organisms. This field is rapidly evolving. Marine biomaterials experience several periods of discovery and development ranging from coralline bone graft to polysaccharide-based biomaterials. The latter are represented by chitin and chitosan, marine-derived collagen, and composites of different organisms of marine origin. The diversity of marine natural products, their properties and applications are discussed thoroughly in the present review. These materials are easily available and possess excellent biocompatibility, biodegradability and potent bioactive characteristics. Important applications of marine biomaterials include medical applications, antimicrobial agents, drug delivery agents, anticoagulants, rehabilitation of diseases such as cardiovascular diseases, bone diseases and diabetes, as well as comestible, cosmetic and industrial applications.

Marine-Derived Collagen as Biomaterials for Human Health

Collagen is a kind of biocompatible protein material, which is widely used in medical tissue engineering, drug delivery, cosmetics, food and other fields. Because of its wide source, low extraction cost and good physical and chemical properties, it has attracted the attention of many researchers in recent years. However, the application of collagen derived from terrestrial organisms is limited due to the existence of diseases, religious beliefs and other problems. Therefore, exploring a wider range of sources of collagen has become one of the main topics for researchers. Marine-derived collagen (MDC) stands out because it comes from a variety of sources and avoids issues such as religion. On the one hand, this paper summarized the sources, extraction methods and characteristics of MDC, and on the other hand, it summarized the application of MDC in the above fields. And on the basis of the review, we found that MDC can not only be extracted from marine organisms, but also from the wastes of some marine organisms, such as fish scales. This makes further use of seafood resources and increases the application prospect of MDC.

Application of marine collagen for stem-cell-based therapy and tissue regeneration (Review)

Tissue engineering and regenerative medicine is becoming an important component in modern biological scientific research. Tissue engineering, a branch of regenerative medicine, is a field that is actively developing to meet the challenges presented in biomedical applications. This particularly applies to the research area of stem cells and biomaterials, due to both being pivotal determinants for the successful restoration or regeneration of damaged tissues and organs. Recently, the development of innovative marine collagen-based biomaterials has attracted attention due to the reported environmentally friendly properties, the lack of zoonotic disease transmission, biocompatibility, bioactivity, the lack of ethics-related concerns and cost-effectiveness for manufacturing. The present review aimed to summarize the potential application and function of marine collagen in stem cell research in a medical and clinical setting. In addition, the present review cited recent studies regarding the latest research advances into using marine collagen for cartilage, bone, periodontal and corneal regeneration. It also characterized the distinct advantages of using marine collagen for stem cell-based tissue repair and regeneration. In addition, the present review comprehensively discussed the most up to date information on stem cell biology, particularly the possibility of treating stem cells with marine collagen to maximize their multi-directional differentiation capability, which highlights the potential use of marine collagen in regenerative medicine. Furthermore, recent research progress on the potential immunomodulatory capacity of mesenchymal stem cells following treatment with marine collagen to improve the understanding of cell-matrix interactions was investigated. Finally, perspectives on the possible future research directions for the application of marine collagen in the area of regenerative medicine are provided.

Applications of marine collagens in bone tissue engineering

For decades, collagen has been among the most widely used biomaterials with several biomedical applications. Recently, researchers have shown a keen interest in collagen obtained from marine sources because of its biocompatibility, biodegradability, ease of extractability, safety, low immunogenicity, and low production costs. A wide variety of marine collagen-based scaffolds have been developed for bone tissue engineering, and these scaffolds display excellent biological effects. This review aims to provide an overview of the biological effects of marine collagen in bone engineering, such as promoting osteogenesis and collagen synthesis, inhibiting inflammation, inducing the differentiation of cartilage, and improving bone mineral density. Marine collagen holds great promise as a biomaterial in bone tissue engineering.

Does Subunit Composition Influence the Intermolecular Crosslinking of Fish Collagen? A Study with Hake and Blue Shark Skin Collagens

Acid-soluble collagens from European hake and Blue shark skin were isolated, characterized, and compared. As the structure of collagen determines its function, the final objective of this study was to investigate biochemical differences between both collagens to identify future potential applications. Chromatographic behavior revealed differences in collagen from both species. Increases of temperature and stirring time produced no effect on European hake collagen solubility in the mobile phase, resulting in the same chromatographic profiles. Conversely, the application of temperature and stirring-time increments showed a positive effect on Blue shark collagen solubility, resulting in different chromatographic profiles and observing higher molecular weight components when sample is incubated at 50 °C (15 min) after 48 h stirring. To test if the different chromatographic behavior exhibited by both collagens could be influenced by differences in subunit composition (alpha-chains), cation exchange chromatography was employed to separate collagen subunits. The electrophoretic patterns and gel permeation chromatography with light-scattering detection (GPC-LS) results of the obtained cation exchange peak fractions revealed differences regarding subunit composition between both species, influencing the crosslinking pattern. This is the first comparative study using GPC-LS to provide information of European hake and Blue shark collagen subunit composition.

Characterization of fish collagen from blue shark skin and its application for chitosan- collagen composite coating to preserve red porgy (Pagrus major) meat

Pepsin soluble collagen (PSC) was extracted from blue shark (Prionace glauca) skin and was used for chitosan-collagen composite coating to investigate coating effects on fresh red porgy (Pagrus major) fillet quality during storage at 4°C. Total volatile basic nitrogen (TVB-N), thiobarbituric acid (TBA), pH, K value, drip loss, and sensory evaluation scores were measured as deterioration indexes. Results show that coating by 1% of chitosan solutions containing 0.0%-0.8% of PSC significantly improved most deterioration indexes. Coating by 1% of chitosan solution containing 0.8% of PSC yielded the best results for K value, drip loss, and sensory evaluation, although the other indexes show no clear PSC concentration dependence. These results indicate 1% of chitosan solution containing 0.8% of PSC as the best coating formulation examined in this study. PRACTICAL APPLICATIONS: Aquatic products have high contents of water and protein. Their qualities are likely to decline because of endogenous chemical and enzyme reactions, and also because of the role of spoilage and pathogenic microorganisms during storage. The edible collagen and chitosan coating suggested by this research is biodegradable, biocompatible, cost effective, and is able to meet the requirements for food quality and storage duration. Pepsin soluble collagen (PSC) is an aquatic product processing by-product that makes the maximum use of resources. As described herein, a composite formulation comprising collagen and chitosan improves preservation effects of different types of coatings. A more high-quality and effective edible coating formulation was obtained, thereby extending the red porgy fillet shelf life.

Cell-Laden Biomimetically Mineralized Shark-Skin-Collagen-Based 3D Printed Hydrogels for the Engineering of Hard Tissues

Mineralization processes based on coprecipitation methods have been applied as a promising alternative to the most commonly used methods of polymer-ceramic combination, direct mixing, and incubation in simulated body fluid (SBF) or modified SBF. In the present study, for the first time, the in situ mineralization (ideally hydroxyapatite formation) of blue shark (Prionace glauca (PG)) collagen to fabricate 3D printable cell-laden hydrogels is proposed. In the first part, several parameters for collagen mineralization were tested until optimization. The hydroxyapatite formation was confirmed by FT-IR, XRD, and TEM techniques. In the second part, stable bioinks combining the biomimetically mineralized collagen with alginate (AG) (1:1, 1:2, 1:3, and AG) solution were used for 3D printing of hydrogels. The addition of Ca²⁺ ions into the system did present a synergistic effect: by one side, the in situ mineralization of the collagen occurred, and at same time, they were also useful to ionically cross-link the blends with alginate, avoiding the addition of any cytotoxic chemical cross-linking agent. Mouse fibroblast cell line survival during and after printing was favored by the presence of PG collagen as exhibited by the biological performance of the hydrogels. Inspired in a concept of marine byproduct valorization, 3D bioprinting of in situ mineralized blue shark collagen is thus proposed as a promising approach, envisioning the engineering of mineralized tissues.

Sequential Delivery of Dual Growth Factors from Injectable Chitosan-Based Composite Hydrogels

Local administration of platelet-derived growth factor-BB (PGDF-BB) and bone morphogenetic protein-2 (BMP-2) in a sequential release manner could substantially promote bone healing. To achieve this goal, a delivery system that could sustain the release of PGDF-BB and BMP-2 by way of temporal separation was developed. One type of PGDF-BB-encapsulated alginate microsphere and another type of BMP-2-encapsulated microsphere with a core-shell structure were respectively produced using emulsification methods. These two types of microspheres were then embedded into chitosan/glycerophosphate hydrogel for constructing composite gels. Some of them were found to be injectable at ambient temperature and had thermo-sensitive features near physiological temperature and pH. The optimally formulated composite gels showed the ability to control the release of PGDF-BB and BMP-2 in a sequential fashion in which PDGF-BB was released earlier than BMP-2. In vitro release patterns indicated that the release rates could be significantly regulated by varying the embedded amount of the factor-encapsulated microspheres, which can in turn mediate the temporal separation release interval between PGDF-BB and BMP-2. The released PDGF-BB and BMP-2 were detected to be bioactive based on their respective effects on Balb/c 3T3 and C2C12 cells. These results suggest that the presently developed composite gels have the potential for bone repair by synergistically utilizing the early chemotactic effect of PDGF-BB and the subsequent osteogenic and angiogenic functions of PDGF-BB and BMP-2.

Collagen Peptide Upregulates Osteoblastogenesis from Bone Marrow Mesenchymal Stem Cells through MAPK- Runx2

Collagen is the most abundant extracellular fibrous protein that has been widely used for biomedical applications due to its excellent biochemical and biocompatibility features. It is believed that the smaller molecular weight collagen, i.e., collagen peptide (CP), has more potent activity than native collagen. However, the preparation of CP from fish bone collagen is a complex and time-consuming process. Additionally, the osteogenic effect of CP depends on its molecular weight and amino acid composition. Considering the above concept, the present work was undertaken to extract the CP directly from Mahi mahi fish (Coryphaena hippurus) bones and test its osteogenic potential using bone marrow mesenchymal stem (BMMS) cells. The hydrolyzed collagen contained triple alpha chains (110 kDa) and a peptide (~1 kDa) and the peptide was successfully separated from hydrolyzed collagen using molecular weight cut-off membrane. CP treatment was up-regulated BMMS cells proliferation and differentiation. Interestingly, CP accrued the mineral deposition in differentiated BMMS cells. Protein and mRNA expression revealed that the osteogenic biomarkers such as collagen, alkaline phosphatase, and osteocalcin levels were significantly increased by CP treatment in differentiated BMMS cells and also further elucidated the hypothesis that CP was upregulated osteogenesis through activating Runx2 via p38MAPK signaling pathway. The above results concluded that the CP from Mahi mahi bones with excellent osteogenic properties could be the suitable biomaterial for bone therapeutic application.

Chitosan-Collagen 3D Matrix Mimics Trabecular Bone and Regulates RANKL-Mediated Paracrine Cues of Differentiated Osteoblast and Mesenchymal Stem Cells for Bone Marrow Macrophage-Derived Osteoclastogenesis

Recent studies have identified the regulatory mechanism of collagen in bone ossification and resorption. Due to its excellent bio-mimicry property, collagen is used for the treatment of several bone and joint disease such as arthritis, osteoporosis, and osteopenia. In bone, the biological action of collagen is highly influenced by the interactions of other bone materials such as glycosaminoglycan and minerals. In view of the above perceptions, collagen was crosslinked with chitosan, hydroxyapatite (H), and chondroitin sulfate (Cs), to produce a natural bone-like 3D structure and to evaluate its effect on bone homeostasis using bone marrow mesenchymal stem cells, osteoblast, and bone marrow macrophages. The XRD and micro-CT data confirmed the arrangement of H crystallites in the chitosan-collagen-H-Cs (CCHCs) three-dimensional (3D)-matrix and the three-dimensional structure of the matrix. The stimulatory osteoblastogenic and exploitive osteoclastogenic activity of 3D-matrices were identified using differentiated osteoblasts and osteoclasts, respectively. Besides, osteogenic progenitor’s paracrine cues for osteoclastogenesis showed that the differentiated osteoblast secreted higher levels of RANKL to support osteoclastogenesis, and the effect was downregulated by the CCHCs 3D-matrix. From that, it was hypothesized that the morphology of the CCHCs 3D-matrix resembles trabecular bone, which enhances bone growth, limits bone resorption, and could be a novel biomaterial for bone tissue engineering.

Physicochemical and Biocompatibility Properties of Type I Collagen from the Skin of Nile Tilapia (Oreochromis niloticus) for Biomedical Applications

The aim of this study is to investigate the physicochemical properties, biosafety, and biocompatibility of the collagen extract from the skin of Nile tilapia, and evaluate its use as a potential material for biomedical applications. Two extraction methods were used to obtain acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) from tilapia skin. Amino acid composition, FTIR, and SDS-PAGE results showed that ASC and PSC were type I collagen. The molecular form of ASC and PSC is (α₁)₂α₂. The FTIR spectra of ASC and PSC were similar, and the characteristic peaks corresponding to amide A, amide B, amide I, amide II, and amide III were 3323 cm-1, 2931 cm-1, 1677 cm-1, 1546 cm-1, and 1242 cm-1, respectively. Denaturation temperatures (Td) were 36.1 °C and 34.4 °C, respectively. SEM images showed the loose and porous structure of collagen, indicting its physical foundation for use in applications of biomedical materials. Negative results were obtained in an endotoxin test. Proliferation rates of osteoblastic (MC3T3E1) cells and fibroblast (L929) cells from mouse and human umbilical vein endothelial cells (HUVEC) were increased in the collagen-treated group compared with the controls. Furthermore, the acute systemic toxicity test showed no acute systemic toxicity of the ASC and PSC collagen sponges. These findings indicated that the collagen from Nile tilapia skin is highly biocompatible in nature and could be used as a suitable biomedical material.

Collagen of Extracellular Matrix from Marine Invertebrates and Its Medical Applications

The extraction and purification of collagen are of great interest due to its biological function and medicinal applications. Although marine invertebrates are abundant in the animal kingdom, our knowledge of their extracellular matrix (ECM), which mainly contains collagen, is lacking. The functions of collagen isolated from marine invertebrates remain an untouched source of the proteinaceous component in the development of groundbreaking pharmaceuticals. This review will give an overview of currently used collagens and their future applications, as well as the methodological issues of collagens from marine invertebrates for potential drug discovery.

Fish Collagen Surgical Compress Repairing Characteristics on Wound Healing Process In Vivo

The development of biomaterials with the potential to accelerate wound healing is a great challenge in biomedicine. In this study, four types of samples including pepsin soluble collagen sponge (PCS), acid soluble collagen sponge (ACS), bovine collagen electrospun I (BCE I) and bovine collagen electrospun II (BCE II) were used as wound dressing materials. We showed that the PCS, ACS, BCE I and BCE II treated rats increased the percentage of wound contraction, reduced the inflammatory infiltration, and accelerated the epithelization and healing. PCS, ACS, BCE I, and BCE II significantly enhanced the total protein and hydroxyproline level in rats. ACS could induce more fibroblasts proliferation and differentiation than PCS, however, both PCS and ACS had a lower effect than BCE I and BCE II. PCS, ACS, BCE I, and BCE II could regulate deposition of collagen, which led to excellent alignment in the wound healing process. There were similar effects on inducing the level of cytokines including EGF, FGF, and vascular endothelial marker CD31 among these four groups. Accordingly, this study disclosed that collagens (PCS and ACS) from tilapia skin and bovine collagen electrospun (BCE I and BCE II) have significant bioactivity and could accelerate wound healing rapidly and effectively in rat model.