Application of Hydrogels in fisheries Sector.pptx

Hydrogels types, natural, synthetic and semi natural or integrated with artificial ingredients for multiple and specific functional and focus on aquatic ecosystems systems as source of hydrogels, and integrated applications in fish food spoilage quality monitoring and testing during transportation.

1. Application of various Hydrogels, special focus on monitoring of freshness of f in fishes and shell fishes during transportation and quality testing By B. BHASKAR Fisheries Ref: Nan Ding et al, 2022)

2. Introduction Food spoilage is a critical thing during improper food processing and transportation. Food spoilage is prone to occur due to long transportation distances and complex storage environments between food production areas and consumers. According to the characteristics of fish, easy to rot, and short shelf life, the study of accurate detection of fish freshness is an essential basis to guarantee food quality and safety.   Many research have highlighted that fish will be affected by bacteria and microorganisms to decompose proteins or amino acids during storage and transportation, producing ammonia, amines, and other alkaline nitrogenous compounds, such as trimethylamine (TMA), dimethylamine (DMA), etc. These alkaline nitrogenous compounds have volatile properties and are collectively referred to as the total volatile basic nitrogen (TVB-N) content. TVB-N is an important indicator to reflect the freshness of fish. Hydrogels can be categorized as natural, synthetic, or a combination of both . Hydrogels obtained from natural polymers are classified as natural polymer hydrogels. These natural polymers include polysaccharides, polynucleotides, and polypeptides.

3. Cont … Gelatin -based hydrogel derived from fish have shown some advantages such as swelling capacity, biocompatibility, biodegradability, and commercial availability. In recent years, studies related to fish gelatin extraction and its application has increased due to its advantages over mammalian gelatin . Therefore, salmon gelatin (SG) and tilapia gelatin (TG) are promising sources of gelatin for the development of hydrogels. In the air environment of fish packaging, the content of volatile compounds is highly consistent with the TVB-N content of fish meat. Detecting volatile compounds in the air can enable non-contact and non-destructive monitoring of fish meat quality . Traditional detection methods of volatile compounds mainly include headspace gas chromatography detection, gas sensor array-based electronic nose, colour indicator, etc . Headspace gas chromatography is currently one of the most reliable methods for measuring volatile organic compounds, but this method is characterized by complex operation, high cost, etc . They usually involve invasive damage to the packaging, rendering individual products useless.

4. gas sensing array electronic nose can qualitatively detect and identify various gas components by forming an array of specific gas sensors. However, gas sensors are still dominated by semiconductor metal oxides. These sensors are based on a metal oxide semiconductor ( MOS) mechanism and require considerable energy consumption, so they need an additional power supply or battery power. The rigid gas sensor array and the traditional power supply make the electronic nose large and stiff, which is difficult to be applied to food quality monitoring in food packaging . With the gradual deterioration of fish, ammonia, amine, and other nitrogenous compounds accumulate in fish and volatilize into the air, which will cause changes in the pH value of fish and food packaging.   In addition to directly detecting the content of TVB-N to judge the quality of fish, it is also a feasible method to detect the pH of fish and the pH of air in food packaging to reflect the freshness of fish.

5. Hydrogel coating flexible pH sensor system for fish spoilage monitoring: Potential for monitoring fish spoilage in real-time. A hydrogel coating flexible pH sensor system is described for real-time wireless monitoring of fish spoilage. On absorption of the acidic or basic volatiles the hydrogel pH changes, which in turn changes the voltage across the pH-sensitive electrode pair shifting the response potential of the sensor. Developing a hydrogel coated flexible pH sensor system for TVB-N. Fabricating flexible pH sensor by facile process with laser direct scribing. Realizing accurate, convenient and long-term wireless monitoring for fish spoilage. Ensuring quality and safety of fish in storage and transport process .

6. Contt … The sensitivity of the flexible pH-sensitive electrode pair in different pH standard buffers is −49.184 mv/ pH. In the process of fish deterioration, ammonia is the main component of volatile gas. Therefore, we used ammonia gas as the detection object to explore the response law of the pH sensor to volatile gases. At the same time, we also investigated the effects of temperature and hydrogel coating thickness on sensor performance. Finally, we integrate the pH sensor with the flexible battery-free wireless electronic system (FBES) for wireless signal transmission. By comparing the gained sensor potential signal with the content of TVB-N in tilapia, the results demonstrate that the sensor response is closely related to the content of TVB-N in fish samples. Under storage conditions of 4 °C, 12 °C, and 20 °C, the sensor can clearly identify when the expiration of fish shelf life (15 mg/100 g) occurs. Potential for monitoring fish spoilage in real-time.

7. Portable silver-doped prussian blue nanoparticle hydrogels for colorimetric and photothermal monitoring of shrimp and fish freshness (Ref: Nan  Ding et al,2022) a colorimetric and photothermal readout strategy based on silver-doped prussian blue nanoparticles (SPB NPs) hydrogel for detection of trimethylamine (TMA) and monitoring of shrimp/fish freshness. The functional hydrogel is fabricated via the addition of SPB NPs to agarose hydrogel. TMA vapor can permeate into the functional hydrogel, thereby causing the decomposition of SPB NPs along with the color evolution (blue to colorless ) and the disappearance of photothermal effects . The color information was digitized by a smartphone combined with RGB (red/green/blue) analysis. The photothermal effects was recorded by a handheld thermal imager. The ∆R gray value and temperature evolutions of the functional hydrogel were all closely related to the concentration of TMA, making it successful in the assessment of shrimp/fish freshness. Both colorimetric and photothermal signals are linear response to TMA concentration from 0.21 to 0.54 ppm. The application of smartphone and handheld thermal imager greatly improves the portability and practicality of monitoring on-spot . More significantly, the photothermal signal can still be applied to assess food freshness, when the hydrogel is contaminated by the colored food substrates and the colorimetric signal cannot be used to assessment. As per their point of view this is the first time that a photothermal strategy has been developed to monitor food freshness. Therefore , this simple, cost-effective, nondestructive and sensitive dual-mode functional hydrogel will open up a new prospect for monitoring of food spoilage.

8. Marine Gelatin - Methacryloyl -Based Hydrogels as Cell Templates for Cartilage Tissue Engineering (Ref: Inês Machado et al, 2023) Marine-origin gelatin has been increasingly used as a safe alternative to bovine and porcine ones due to their structural similarity, avoiding the health-related problems and sociocultural concerns associated with using mammalian-origin materials. Another benefit of marine-origin gelatin is that it can be produced from fish processing-products enabling high production at low cost. Recent studies have demonstrated the excellent capacity of gelatin-methacryloyl ( GelMA )-based hydrogels in a wide range of biomedical applications due to their suitable biological properties and tunable physical characteristics, such as tissue engineering applications, including the engineering of cartilage. Their study, fish gelatin was obtained from Greenland halibut skins by an acidic extraction method and further functionalized by methacrylation using methacrylic anhydride, developing a photosensitive gelatin-methacryloyl ( GelMA ) with a degree of functionalization of 58%. The produced marine GelMA allowed the fabrication of photo-crosslinked hydrogels by incorporating a photoinitiator and UV light exposure. To improve the biological performance, GelMA was combined with two glycosaminoglycans (GAGs): hyaluronic acid (HA) and chondroitin sulfate (CS). GAGs methacrylation reaction was necessary, rendering methacrylated HA (HAMA) and methacrylated CS (CSMA). Three different concentrations of GelMA were combined with CSMA and HAMA at different ratios to produce biomechanically stable hydrogels with tunable physicochemical features. The 20% (w/v) GelMA -based hydrogels produced in this work were tested as a matrix for chondrocyte culture for cartilage tissue engineering with formulations containing both HAMA and CSMA showing improved cell viability. Their results suggested these hybrid hydrogels be used as promising biomaterials for cartilage tissue engineering applications.

9. Protein-based hydrogel from fish industrialization wastes (Ref: Carlos Prentice& Vilásia G. Martins, 2012) Chemical modification of proteins has been largely used with the subject of expose functional groups "hidden" before into the protein chains, determinate functional groups of enzymes and also help in understanding of drug action. Animal proteins are rich in lysine, which is an essential amino acid with many functional properties, to the opposite of vegetal proteins, such as soybean. The fish proteins tend to be very big, with an inherent capacity of water uptake. For the application in hydrogel, the physical properties of the fish polymers are more superior to vegetable polymers . Hydrogel is a light and wet class material, whose properties depend on the polymer net constructed and the water content. Many synthetic polymers have limited structural and functional properties, while the natural polymers are unique, with various functional and structural properties . The mechanical properties and swelling properties of hydrogel made by using natural polymers can be improved by chemical or physical modification of the functional groups. Modification does not alter the biodegradable and biocompatible characteristics of the proteins. Therefore , if suitable functionality can be imparted, the natural polymers could replace some potentially toxic synthetic polymers, which are unsuitable for many biological applications. The hydrogel with high water retention capacity has a great number of attributes that make them attractive in several applications. The basic property of uptake water has been suggesting the use of absorbent materials in many applications, such as towel paper, surgery sponge, meat tray, bath rug and medical wound. One of the greatest challenges that confront the science nowadays is the development of a new generation of biomaterials for human organism repair and also to combat environmental problems relate with pollution.

10. Update on Chitosan-Based Hydrogels: Preparation, Characterization, and Its Antimicrobial and Antibiofilm Applications (Ref:   Kokila Thirupathi , et al) Chitosan is a prominent biopolymer in research for of its physicochemical properties and uses. Each year, the number of publications based on chitosan and its derivatives increases. Because of its comprehensive biological properties, including antibacterial, antioxidant, and tissue regeneration activities, chitosan and its derivatives can be used to prevent and treat soft tissue diseases. Chitosan can be employed as a nanocarrier for therapeutic drug delivery. In this review, we will first discuss chitosan and chitosan-based hydrogel polymers . The structure, functionality, and physicochemical characteristics of chitosan-based hydrogels are addressed. Second , a variety of characterization approaches were used to analyze and validate the physicochemical characteristics of chitosan-based hydrogel materials. Finally , we discuss the antibacterial, antibiofilm , and antifungal uses of supramolecular chitosan-based hydrogels. They revelled that this review can be used as a base for future research into the production of various types of chitosan-based hydrogels in the antibacterial and antifungal fields.

11. Synthesis, modification and application of fish skin gelatin -based hydrogel as sustainable and versatile bioresource of antidiabetic peptide (Ref: Heli Siti Halimatul   Munawaroh et al, 2023) Gelatin hydrogel is widely employed in various fields, however, commercially available gelatin hydrogels are mostly derived from mammalian which has many disadvantages due to the supply and ethical issues. In this study, the properties of hydrogels from fish-derived collagen fabricated with varying  Glutaraldehyde  (GA) determined. The   antidiabetic  properties of salmon gelatin (SG) and  tilapia   gelatin (TG) was also evaluated against α-glucosidase. Glutaraldehyde-crosslinked salmon gelatin and  tilapia   gelatin were used, and compared with different concentrations of GA by 0.05 %, 0.1 %, and 0.15 %. Water absorbency, swelling, porosity, pore size and water retention of the hydrogels were dependent on the degree of crosslinking. The synthesis of hydrogels was confirmed by FTIR study. Scanning electron microscope (SEM) observation showed that all hydrogels have a porous structure with irregular shapes and heterogeneous morphology . Their study Performance tests showed that gelatin -GA 0.05 % mixture had the best performance. Antidiabetic bioactivity  in vitro  and  in silico  tests showed that the active peptides of SG and TG showed a high binding affinity to α-glucosidase enzyme . They concluded that SG and TG cross-linked GA 0.05 % have the potential as an  antidiabetic  agent and as a useful option over mammalian-derived gelatin . • Hydrogel from salmon and tilapia skin hydrolysates was crosslinked with glutaraldehyde. •The glutaraldehyde of 0.05 % improved the storage of the gelatin -hydrogels. •Salmon and tilapia gelatins showed potential bioactivity as antidiabetic agents against α- glucosidase. •The type of inhibition was predicted as competitive inhibition against α- glucosidase. • Fish peptides predicted to be potentially employed as sustainable ingredients for antidiabetic .

12. A nanofiber hydrogel derived entirely from ocean biomass for wound healing (Ref: Tian- Cai Sun et al, 2023) Crustaceans and fish scales in the marine food industry are basically thrown away as waste. This not only wastes resources but also causes environmental pollution. While reducing pollution and waste, biological activity and storage of materials are urgent issues to be solved. In their study, by first preparing dry fibers and then making hydrogels, they prepared a fish scale/sodium alginate/chitosan nanofiber hydrogel (FS-P) by cross-linking the nanofibers in situ. From fish and other organisms, fish gelatin (FG), collagen and CaCO3 were extracted. Fish scale (FS)/sodium alginate/chitosan nanofibers were cross-linked with copper sulfide nanoparticles prepared by a one-step green method to obtain FS-P nanofiber hydrogels under mild conditions without catalyst and additional procedures. These fiber hydrogels not only have good tissue adhesion and tensile properties, but also have the antibacterial effect of natural antibacterial and CuS photothermal synergism, which can achieve 51.32% and 49.96% of the antibacterial effect against Staphylococcus aureus and Escherichia coli respectively, avoiding the generation of superbacteria . The nanofiber hydrogels have 87.56% voidage and 52.68% degradability after 14 days. The combined strategy of using marine bio-based fibers to prepare gels promoted angiogenesis and tissue repair.

13. Fish scale/sodium alginate/chitosan nanofiber hydrogels based on a marine ecosystem & Synthesis of FS-P Hydrogel (Ref: Tian- Cai Sun et al, 2023) Synthesis schematic diagram of FS-P hydrogel. (B) X-ray diffraction (XRD) pattern. (C) FT-IR spectra. (D) SEM images of FS-P nanofibers and FS-P hydrogel.   Fish scale/sodium alginate/chitosan nanofiber hydrogels based on a marine ecosystem

14. Morphology and properties of the hydrogels The FS-P hydrogel was obtained by regulating the cross-linked FS-P fiber through CuS , because we accidentally found that it was not only related to the concentration of CuS , but also to the diameter of the fiber . Three fibers of uniform diameter and concentration were set up for the study. The SEM image and DES surface scan image of FS-P-2. It can be seen that there are many pore sizes, and it is obvious that the O element comes from macromolecules such as collagen, chitosan and sodium alginate. Ca element is derived from CaCO3 in fish scales, while Cu and S elements are derived from FG- CuS . CuS was successfully extracted and synthesized from fish scale solution, and CuS was introduced into the hydrogel. As shown in Fig. S5,† the pore size distribution of fiber hydrogels obtained for FS-P-1 and FS-P-3 fiber membranes was poor. In order to study the causes, rheological shear tests were carried out, and FS-P-2 hydrogels showed stable moduli compared with FS-P-1 and FS-P-3 hydrogels, which may be one of the reasons for the difference in SEM morphology. Porosity statistics were conducted and it was found that the porosity of FS-P-2 hydrogel was greater than that of FS-P-1 and FS-P-3 hydrogels, which resulted in the difference in swelling capacity. The swelling rate statistics over time, FS-P-2 hydrogel has the highest swelling rate. Considering that medical excipients should have good compressive and cutting resistance, compression cutting and adhesion tests were carried out. It can remain intact after heavy compression and knife cutting. Medical excipients must have a certain adhesion to satisfy the filling of geometric tissue. Natural macromolecule CS and collagen have good adhesion to the FS-P fiber hydrogel due to their active groups such as amino, carboxyl and hydroxyl groups, especially to the skin of animal tissues. The shear stretch curve of hydrogel adhesion to pig skin. It can be seen that hydrogels can withstand stresses of 0.23 MPa. Finally, FS-P-1, FS-P-2 and FS-P-3 hydrogels all degraded about 40% within 14 days. In conclusion, marine waste-based FS-P-2 nanofiber hydrogels have great advantages as tissue repair materials for medical purposes.

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