Functional roles of fish collagen peptides on bone regeneration

Impact of boiling on the allergens in fish bone samples identified by microfluidic chips and MALDI-TOF MS

Fish bones hold significant potential in the food industry. Investigating the allergenic characteristics of fish bone food products can enhance our understanding of fish allergies. In this study, the allergenic proteins in aqueous extracts from large yellow croaker (Larimichthys crocea) bones boiled for various durations were analyzed and identified using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and protein database searches. Tryptic products of potential allergens were detected using MALDI-TOF MS and further identified through analysis with Bruker's FlexAnalysis software and the FindMod tool available on the ExPASy proteomics server of the SIB (http://expasy.org/). 25 proteins related to allergy were identified. Two proteins reported as allergens were identified, along with twenty-three (23) proteins that, to the best knowledge of the authors, have not been reported as allergens. At least one aligned tryptic peptide were detected for 17 of the 25 proteins. The 17 potentially allergenic proteins exhibit peptide coverage ranging from 6.72 % to as high as 80 %. The results indicate that boiling the bones for 10 min releases many potentially allergenic proteins. However, the sensitization of most proteins diminishes when the bones are boiled for 30 to 120 min. Despite this, boiling does not completely eliminate the allergenicity of proteins in large yellow croaker bone samples. It is recommended to boil large yellow croaker fish bones for 30 min or longer to reduce most of the protein allergenicity when processing fish bones. Boiling may affect the allergenicity of proteins in fish bones by modifying their structure. These findings provide valuable guidance for monitoring allergens in aquatic food by-products, promisingly assisting to ensure the safety of allergy sufferers. Additionally, this research offers a reference for allergy management and the development of diagnostic reagents derived from aquatic food by-products.

Comparative transcriptome analysis of albino northern snakehead (Channa argus) reveals its various collagen-related DEGs in caudal fin cells

The albino northern snakehead (Channa argus) is an aquaculture species characterized by heritable albino body color, in contrast to the typical coloration. Additionally, there are gray- and golden-finned individuals, which exhibit distinct coloration in their caudal fins. We performed RNA-seq to profile the transcriptome of caudal fin tissues in albino gray-finned and golden-finned C. argus, contrasting these with normal morphs to elucidate the differences between the two groups. A total of 137,130 unigenes were identified in this study. Gene Ontology (GO) analysis showed that the identified DEGs were significantly enriched in cellular components related to cytoplasm. So far, 379 common DEGs have been identified in all three groups. Notably, we observed more DEGs in golden-finned individuals compared to gray-finned individuals. We also revealed that golden-finned individuals were enriched in collagen-related pathways compared with normal individuals. The enriched DEGs of collagen components include collagen I of COL1A1 and COL1A2, collagen II of COL2A1, collagen V of COL5A1 and COL5A2, collagen VI of COL6A1 and COL6A3, collagen IX of COL9A3, collagen X of COL10A1, collagen XI of COL11A2, collagen XII of COL12A1, collagen XVI of COL16A1, collagen XVIII of COL18A1 and decorin (DCN), all of which play a role in modulating the collagen matrix. In golden-finned albino fish, collagen-related genes were downregulated, suggesting that despite the abundance of collagen types in their caudal fin cells, gene expression was slightly limited. This work provides valuable genetic insights into collagen variation in albino C. argus, lays the foundation for research on collagen genes and is crucial for the development and utilization of fish-derived collagen as a biomaterial for tissue engineering and biomedical applications.

Deciphering the Wound-Healing Potential of Collagen Peptides and the Molecular Mechanisms: A Review

Collagen peptides have been reported to display various bioactivities and high bioavailability. Recently, increasing evidence has revealed the excellent wound-healing activity of collagen peptides, but their molecular mechanisms remain incompletely elucidated. This review systematically evaluates the therapeutic efficacy of collagen peptides from diverse sources based on various wound models. Furthermore, the structure-activity relationships of collagen peptides and wound-healing mechanisms are discussed and summarized. Characterized by their low molecular weight and abundant imino acids, collagen peptides facilitate efficient absorption by the body to deliver nutrition throughout the wound-healing process. The specific mechanism of collagen peptide for wound healing is mainly through up-regulation of related cytokines and participation in the activation of relevant signaling pathways, such as TGF-β/Smad and PI3K/Akt/mTOR, which can promote cell proliferation, angiogenesis, collagen synthesis and deposition, re-epithelialization, and ECM remodeling, ultimately achieving the effect of wound healing. Collagen peptides can offer a potential therapeutic approach for treating incision and excision wounds, mucosal injuries, burn wounds, and pressure ulcers, improving the efficiency of wound healing by about 10%-30%. The present review contributes to understanding of the wound-healing potential of collagen peptides and the underlying molecular mechanisms.

Evaluation of a hydroxyapatite-crosslinked fish gelatin membranes

Background/purpose

Porcine collagen is widely used in regenerative therapies to generate membranes for bone augmentation. However, porcine or bovine gelatin or collagen is often not appropriate for patients with creed and religious beliefs or for allergic reasons. In this study, we evaluated the potential of fish gelatin to generate membranes.

Materials and methods

Fish gelatin and hydroxyapatite (HAp) were used at three different ratios (2:0, 2:1, 2:1.5, and 2:2) to prepare gelatin-hydroxyapatite (G-HAp) membranes via freeze-drying and heat-crosslinking. The surface morphology and cell attachment of G-HAp membranes were observed using scanning electron microscopy and confocal laser microscopy. G-HAp membrane was placed at the bottom of a well plate, and MC3T3-E1 cells were seeded on it. Cell viability and cytotoxicity were tested after 1 and 3 days of culture. Alkaline phosphatase (ALP) and alizarin red staining was performed at 10 and 21 days, respectively.

Results

Viability of cells on G-HAp membrane with the gelatin:HAp ratio of 2:1.5 was significantly higher than that on membranes with other gelatin:HAp ratios. ALP and alizarin red staining showed that ALP-positive areas and calcium deposition were the highest on G-HAp membrane with the gelatin:HAp ratio of 2:1. These membranes showed negligible cytotoxicity.

Conclusion

Fish-derived G-HAp membranes have the potential to promote osteogenic differentiation of MC3T3-E1 cells with negligible cytotoxicity.

Delivery of bone morphogenetic protein-2 by crosslinking heparin to nile tilapia skin collagen for promotion of rat calvaria bone defect repair

Collagen has been widely used as a biomaterial for tissue regeneration. At the present, aqua-collagen derived from fish is poorly explored for biomedical material applications due to its insufficient thermal stability. To improve the bone repair ability and thermal stability of fish collagen, the tilapia skin collagen was crosslinked by EDC/NHS with heparin to bind specifically to BMP-2. The thermal stability of tilapia skin collagen crosslinked with heparin (HC-COL) was detected by differential scanning calorimetry (DSC). Cytotoxicity of HC-COL was assessed by detecting MC3T3-E1 cell proliferation using CCK-8 assay. The specific binding of BMP-2 to HC-COL was tested and the bioactivity of BMP-2-loaded HC-COL (HC-COL-BMP-2) was evaluated in vitro by inducing MC3T3-E1 cell differentiation. In vivo, the bone repair ability of HC-COL-2 was evaluated using micro-CT and histological observation. After crosslinking by EDC/NHS, the heparin-linked and the thermostability of the collagen of Nile Tilapia were improved simultaneously. HC-COL has no cytotoxicity. In addition, the binding of BMP-2 to HC-COL was significantly increased. Furthermore, the in vitro study revealed the effective bioactivity of BMP-2 binding on HC-COL by inducing MC3T3-E1 cells with higher ALP activity and the formation of mineralized nodules. In vivo studies showed that more mineralized and mature bone formation was achieved in HC-COL-BMP-2 group. The prepared HC-COL was an effective BMP-2 binding carrier with enough thermal stability and could be a useful biomaterial for bone repair.

Research Progress on Nutritional Value, Preservation and Processing of Fish-A Review

The global population has rapidly expanded in the last few decades and is continuing to increase at a rapid pace. To meet this growing food demand fish is considered a balanced food source due to their high nutritious value and low cost. Fish are rich in well-balanced nutrients, a good source of polyunsaturated fatty acids and impose various health benefits. Furthermore, the most commonly used preservation technologies including cooling, freezing, super-chilling and chemical preservatives are discussed, which could prolong the shelf life. Non-thermal technologies such as pulsed electric field (PEF), fluorescence spectroscopy, hyperspectral imaging technique (HSI) and high-pressure processing (HPP) are used over thermal techniques in marine food industries for processing of most economical fish products in such a way as to meet consumer demands with minimal quality damage. Many by-products are produced as a result of processing techniques, which have caused serious environmental pollution. Therefore, highly advanced technologies to utilize these by-products for high-value-added product preparation for various applications are required. This review provides updated information on the nutritional value of fish, focusing on their preservation technologies to inhibit spoilage, improve shelf life, retard microbial and oxidative degradation while extending the new applications of non-thermal technologies, as well as reconsidering the values of by-products to obtain bioactive compounds that can be used as functional ingredients in pharmaceutical, cosmetics and food processing industries.