World Aquaculture 2023

May 29 - June 1, 2023

Darwin, Northern Territory, Australia


Chamilani Nikapitiya*, E. H. T. Thulshan Jayathilaka and Mahanama De Zoysa

College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungnam National University, Yuseong-gu, Daejeon 34134, Republic of Korea.



Extracellular vesicles (EVs) are lipid-bound membranes (ranging in diameter from ~30 to 1000 nm) secreted by cells into the extracellular space. They exist in body fluids, and tissues, and contain various biological cargo molecules, such as nucleic acids (DNA, mRNA, miRNAs), proteins, lipids, enzymes, etc. EVs can mediate intercellular communication and immune regulation, and they are considered biomarkers for disease. The wide array of functions and biomedical applications of EVs as therapeutic agents (e.g cancer therapy, wound healing, etc.) have been reported. Moreover, as a nanoscale vesicle with a lipid bilayer membrane, exosomes are considered biocompatible drug carriers released by cells. Therefore, EVs can consider as a potential biomaterial for fish medicine, but the area of utilization has not been applied with well-defined strategies or approaches. Although EVs from fish have been isolated, characterized, and investigated the composition (miRNA, protein, etc.), it still lacks sufficient experimental data for EVs used for therapeutic application in the aquaculture field (e.g. vaccine candidates, wound healing agents, etc.).

Bacteria Edwardsiella piscicida (Gram-negative) and Streptococcus parauberis (Gram-positive) are two major causative agents for diseases of Edwardsiellosis and Streptococcosis, respectively. They frequently affecting to the aquaculture industry and resulting high mortality in economically important fish including olive flounder (Paralichthys olivaceus). Plasma is one of the most frequently studied biological fluids in fish, and the most promising source of biomarkers. It may contain a collection of EVs from different cells. We hypothesize that EVs could be one of the efficient and promising biomaterials to discover novel proteins expressed in EVs against pathogenic bacteria and viruses. These EVs have unique proteins for specific immune activation, thus it could be used as a tool for multi-functional bioactivities, such as immunomodulatory, disease resistance, and wound healing for therapeutic uses.

Our target is to develop plasma-derived immunogenic and biocompatible EVs from immune-modulated olive flounder as a multifunctional biomaterial for application in fish medicine. Finally, we will ensure that the functionally characterized plasma-derived EVs can be applied in a wide spectrum of therapeutic applications as vaccine candidates, antimicrobial, immunomodulatory, and wound healing agents.

Acknowledgments: This work was supported by the National Research Foundation of Korea (NRF) grant funded by  the Korea government (MSIT) 2021R1A2C1004431.