The Food and Agriculture Organisation of the United States has reported that about 35% of the global aquaculture harvest is either lost or emaciated [1]. Significant economic losses are reported by pathogens in the water, responsible for inducing lethal diseases.[2]
From our Human Practice visits and Integrated Human Practice meetings, we found out that vibriosis is a disease that surges in commercial units due to higher impact of the stress factors. It is also quite prominent in cultivating setups and stages. Hence, ceasing this infection in its initial stages was necessary. Our solution, AMPifin, was created specifically for the aforementioned reasons.
Accessibility and affordability to a wide range of technologically advanced treatment methods is still an area of deficit. Antibiotics are no longer effective against numerous pathogenic diseases in aquaculture systems [3].
In an effort to prevent them from facing any future economic loss, we propose them to be one of the many end users of our product.
After successfully designing our peptide in-silico, we needed a delivery mechanism that could be implemented after successful Wet Lab testing.
Chitosan Nanoparticle Encapsulation
Chitosan nanoparticle encapsulation is our chosen delivery mechanism. Chitosan is an N-acetyl derivative of chitin. It has been widely explored in the field of drug delivery, food processing industry and has been reported to exhibit immunomodulatory properties [4].
Chitosan nanoparticles, in particular, have gained attention in drug delivery due to their properties like—enhanced stability, low toxicity, biocompatible and biodegradable [5], simple and mild preparation methods and flexible administration routes due to their sub-micron size [6].
The interaction studies would determine the nuances of the delivery mechanism, helping us obtain the optimum concentration of our peptide and subsequently decide the dosage parameters.
- Chitosan nanoparticles are usually incorporated with the drug in two ways:
- By addition of the drug to the chitosan solution
- By addition/loading of the drug onto the chitosan nanoparticles formed from ionic gelation
Various procedures exist for the making of CSNPs, such as—Ionic gelation, Microemulsion, Reverse micellar, Emulsification diffusion solvent, Polyelectrolyte complex method, etc [7].
Delivery Setup
RAS stands for Recirculatory Aquaculture System. The speciality of this system is that the water is recycled and reused after subjecting it to certain treatment steps. These steps are used for high-density culture of various species of fish which make use of minimum land area and water.
A standard RAS comprises several filter designs which remove metabolic wastes, excess nutrients, solids, etc in an effort to provide good water quality for aquatic life. India has seen a boom in the application of RAS in the industry in the past decade for sustainable practices [8]. This is where AMPifin finds its most appropriate application.
Given the standard design and features of an RAS, it is easy to integrate our peptide as a solution to vibriosis in the fish. We came up with a setup such that our peptide encapsulated chitosan nanoparticles would be immobilised onto a Polyvinyl chloride (PVC) mesh. This mesh would be subjected to the inlet of the pipe of the RAS.
Shown below is the design of the future implementation of our product:
Initially our design was going to be a single thin mesh covered with our peptide loaded chitosan nanoparticles. In the many HP visits that we had, we realised that it is difficult to make use of thin meshes as a filter due to the influence of the high flow rate. In such conditions, there are chances that the turbulent flow will wear off the mesh.
Hence, a sustainable way to integrate this mesh was by introducing a thicker mesh stack at the bypass. In accordance with the RAS systems widely used in the industry [9], we plan on integrating our mesh accordingly.
The mesh stack will be subjected to the bypass of the inlet pipe, connecting between the reservoir and the first tank. This would subject all the water flowing into the tanks for the fish, to interact with our peptide that will gradually be released into the water.
References
- [1] The State of World Fisheries and Aquaculture 2020. FAO, 2020. doi: 10.4060/ca9229en.
- [2] T. Håstein, A. D. Scarfe, and V. L. Lund, “Science-based assessment of welfare: aquatic animals.,” Rev. Sci. Tech., vol. 24, no. 2, pp. 529–47, Aug. 2005.
- [3] A. Assefa and F. Abunna, “Maintenance of Fish Health in Aquaculture: Review of Epidemiological Approaches for Prevention and Control of Infectious Disease of Fish,” Vet. Med. Int., vol. 2018, pp. 1–10, 2018, doi: 10.1155/2018/5432497.
- [4] G. Guan et al., “Biological Effects and Applications of Chitosan and Chito-Oligosaccharides,” Front. Physiol., vol. 10, May 2019, doi: 10.3389/fphys.2019.00516.
- [5] W. Paul and C. P. Sharma, “Enteric Coating of Polyclonal Antibody for Colon Delivery View project,” 2000, Accessed: Oct. 12, 2022. [Online]. Available: https://www.researchgate.net/publication/236898063
- [6] V. Mikušová and P. Mikuš, “Advances in Chitosan-Based Nanoparticles for Drug Delivery,” Int. J. Mol. Sci. 2021, Vol. 22, Page 9652, vol. 22, no. 17, p. 9652, Sep. 2021, doi: 10.3390/IJMS22179652.
- [7] A. Mesa, G. S. S. Mythatha, R. S. Lodi, S. Ravuri, and R. Balli, “Chitosan Nanoparticles: An Overview on Preparation, Characterization and Biomedical Applications,” 2021, pp. 393–427. doi: 10.1007/978-981-15-9916-3_17.
- [8] National Fisheries Development Board, “RECENT TRENDS IN AQUACULTURE Recirculatory Aquaculture System (RAS).”, Available: https://nfdb.gov.in/PDF/RAS%20RT.pdf
- [9] “RAS Roundtable: Feeding Strategies to Maintain Optimal Water Quality and Fish Performance.” https://www.innovasea.com/ras-roundtable-feeding-strategies-to-maintain-optimal-water-quality-and-fish-performance/ (accessed Oct. 11, 2022).