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.

Cosmeceutical Potential of Extracts Derived from Fishery Industry Residues: Sardine Wastes and Codfish Frames.

The fishery industry generates large amounts of waste (20-75% (w/w) of the total caught fish weight). The recovery of bioactive compounds from residues and their incorporation in cosmetics represents a promising market opportunity and may contribute to a sustainable valorisation of the sector. In this work, protein-rich extracts obtained by high-pressure technologies (supercritical CO2 and subcritical water) from sardine (Sardina pilchardus) waste and codfish (Gadus morhua) frames were characterized regarding their cosmeceutical potential. Antioxidant, anti-inflammatory and antibacterial activities were evaluated through chemical (ORAC assay), enzymatic (inhibition of elastase and tyrosinase), antimicrobial susceptibility (Klebsiella pneumoniae, Staphylococcus aureus and Cutibacterium acnes) and cell-based (in keratinocytes-HaCaT) assays. Sardine extracts presented the highest antibacterial activity, and the extract obtained using higher extraction temperatures (250 °C) and without the defatting step demonstrated the lowest minimum inhibitory concentration (MIC) values (1.17; 4.6; 0.59 mg/mL for K. pneumoniae, S. aureus and C. acnes, respectively). Codfish samples extracted at lower temperatures (90 °C) were the most effective anti-inflammatory agents (a concentration of 0.75 mg/mL reduced IL-8 and IL-6 levels by 58% and 47%, respectively, relative to the positive control). Threonine, valine, leucine, arginine and total protein content in the extracts were highlighted to present a high correlation with the reported bioactivities (R2 ≥ 0.7). These results support the potential application of extracts obtained from fishery industry wastes in cosmeceutical products with bioactive activities.

Potential Ophthalmological Application of Extracts Obtained from Tuna Vitreous Humor Using Lactic Acid-Based Deep Eutectic Systems.

A green technique was developed to extract hyaluronic acid (HA) from tuna vitreous humor (TVH) for its potential application in managing dry eye disease. Deep eutectic solvents (DES) were used to extract HA and were synthesized using natural compounds (lactic acid, fructose, and urea). The DES, the soluble fraction of TVH in DES (SF), and the precipitated extracts (PE) were evaluated for their potential use in dry eye disease treatment. In vitro experiments on human corneal epithelial cell lines and the effect on dry eye-associated microorganisms were performed. The influence of the samples on the HCE viability, their intracellular reactive oxygen species (ROS) scavenging capacity, inflammatory response, and antimicrobial properties were studied. According to the results, all samples displayed an antioxidant effect, which was significantly higher for PE in comparison to SF. Most of the tested samples did not induce an inflammatory response in cells, which confirmed the safety in ophthalmic formulations. In addition, the DES and SF proved to be efficient against the studied bacterial strains, while PE did not show an antimicrobial effect. Hence, both DES and SF at defined concentrations could be used as potential compounds in dry eye disease management.

Silver nanocomposites based on the bacterial fucose-rich polysaccharide secreted by Enterobacter A47 for wound dressing applications: Synthesis, characterization and in vitro bioactivity.

This study demonstrates the potential of a high molecular weight fucose-containing polysaccharide secreted by the bacterium Enterobacter A47, named FucoPol, and its silver nanocomposite as potential bioactive materials for wound dressings applications. A green, simple, light-assisted method was used for the synthesis of silver nanoparticles (AgNP) using FucoPol, as stabilizing and reducing agent. The synthesized nanoparticles were spherical, and the main population had a particle size in number ranging between 13 and 30 nm for percentiles 50 and 90, respectively. FucoPol, as well as the functionalized material, besides having no cytotoxicity towards human skin keratinocytes and mouse fibroblasts, also promoted in vitro keratinocytes migration. These observations not only show the safety of FucoPol and FucoPol/AgNP biocomposite, but also their wound healing ability. Moreover, the biocomposite had a strong antimicrobial activity against Staphylococcus aureus ATCC 6538 and Klebsiella pneumoniae CECT 8453, two representative strains of known skin commensal pathogens. These findings demonstrate for the first time the potential of FucoPol for the development of wound healing formulations. Additionally, the FucoPol/AgNP biocomposite might find use in antimicrobial biomaterials, including antibacterial wound healing formulations, which further strengthens the establishment of FucoPol as a bioactive biopolymer.

Development and validation of a multi-locus DNA metabarcoding method to identify endangered species in complex samples.

DNA metabarcoding provides great potential for species identification in complex samples such as food supplements and traditional medicines. Such a method would aid Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) enforcement officers to combat wildlife crime by preventing illegal trade of endangered plant and animal species. The objective of this research was to develop a multi-locus DNA metabarcoding method for forensic wildlife species identification and to evaluate the applicability and reproducibility of this approach across different laboratories. A DNA metabarcoding method was developed that makes use of 12 DNA barcode markers that have demonstrated universal applicability across a wide range of plant and animal taxa and that facilitate the identification of species in samples containing degraded DNA. The DNA metabarcoding method was developed based on Illumina MiSeq amplicon sequencing of well-defined experimental mixtures, for which a bioinformatics pipeline with user-friendly web-interface was developed. The performance of the DNA metabarcoding method was assessed in an international validation trial by 16 laboratories, in which the method was found to be highly reproducible and sensitive enough to identify species present in a mixture at 1% dry weight content. The advanced multi-locus DNA metabarcoding method assessed in this study provides reliable and detailed data on the composition of complex food products, including information on the presence of CITES-listed species. The method can provide improved resolution for species identification, while verifying species with multiple DNA barcodes contributes to an enhanced quality assurance.