VNV International Research Desk
Research & Innovation | 7 November 2026
Original Research Published: 2 November 2026

MIT Develops Water-Resistant Silk Microneedles for Underwater Fish Vaccination

Cambridge, Massachusetts, USA: Researchers at the Massachusetts Institute of Technology (MIT) and the United States Department of Agriculture (USDA) have developed a new microneedle platform designed to deliver vaccine materials to farmed fish underwater.

The technology uses food-grade silk-based microneedles with a water-resistant coating, allowing them to penetrate wet fish skin, remain attached temporarily and release their contents in a controlled manner.

The research was published online on 2 November 2026 in the peer-reviewed journal ACS Nano.

Why Fish Vaccination Remains a Challenge

Disease outbreaks are a persistent challenge for aquaculture producers. Vaccination offers a preventive approach, but administering vaccines to large numbers of fish can be labour-intensive and technically demanding.

Conventional injection methods often require handling, sedation and removal of fish from water. These processes can increase operational costs and cause stress to the animals.

Vaccinating juvenile fish presents an additional challenge because their small size limits the practicality of traditional injection techniques.

How the New Silk Microneedle Technology Works

The researchers engineered microneedles using silk fibroin, a protein-based material, and developed water-resistant structures capable of functioning underwater.

A shellac-based protective coating helps limit premature exposure to water, allowing the microneedles to maintain their structure before delivering their contents.

The research investigated three microneedle designs: shell, solid-tip and hollow configurations. These were evaluated for mechanical performance, water resistance, material compatibility and release behaviour.

Experimental Delivery to Very Small Fish

In preliminary animal studies, the microneedles were evaluated using zebrafish and juvenile rainbow trout.

The researchers demonstrated underwater delivery of vaccine-related materials to rainbow trout weighing approximately 1 to 2 grams.

This is notable because conventional needle-based vaccination is difficult in very small juvenile fish and is typically more practical once fish reach substantially greater body weight.

However, successful delivery of vaccine materials should not be confused with demonstrated protection against disease.

Controlled Release and Material Stability

The researchers investigated microneedle configurations capable of releasing their contents over different periods, ranging from minutes to several hours.

The study also examined the stability of DNA plasmid material carried by the microneedles during dry storage.

Under the tested conditions, at least half of the loaded plasmid material retained its supercoiled structure after four weeks outside the cold chain.

This result suggests potential advantages for future vaccine distribution systems, although further studies will be required to establish practical storage requirements for commercial products.

Could the Technology Improve Aquaculture Health?

If further research confirms vaccine effectiveness, safety and operational feasibility, underwater microneedle delivery could provide an additional option for preventive fish health management.

Potential applications include juvenile fish vaccination, reduced handling requirements and more flexible delivery of selected biological materials.

Large-scale application will depend on further evaluation of vaccine-induced immunity, fish welfare, manufacturing costs, administration methods and environmental considerations.

Research Limitations

The technology remains experimental. The published findings establish important material and delivery capabilities but do not demonstrate commercial-scale disease prevention.

The results must not be interpreted as evidence that the microneedles provide complete protection against fish infections or eliminate the need for established biosecurity measures.

Additional controlled trials will be necessary before routine farm-level implementation can be considered.

VNV Insight: Relevance for Pakistan’s Aquaculture Sector

Pakistan’s aquaculture and fisheries sectors face increasing demands for better fish health management, improved production efficiency and sustainable disease prevention.

The MIT–USDA research offers a useful direction for veterinary universities, fisheries research institutes and aquaculture businesses interested in emerging vaccine delivery systems.

Local research would be needed to determine whether similar approaches could be suitable for commercially important species farmed in Pakistan, including carps and tilapia.

Differences in fish species, skin characteristics, farming conditions, pathogens and vaccination requirements must be considered before drawing conclusions about local applications.

Why This Research Matters

The broader significance of this study lies in its potential to connect biomaterials engineering with aquatic animal health and preventive veterinary medicine.

It also highlights opportunities for collaboration among materials scientists, fish health specialists, veterinary researchers and aquaculture producers.

Original Research Credits

Research paper: Design of Water-Resistant, Food-Grade Microneedles for Fish Injection and Underwater Cargo Delivery

Authors: Meng Li, Jad Raad, Yunteng Cao, Yue Hu, Colleen Wolfe, Doyoon Kim, Bradley D. Frank, Gregory D. Wiens and Benedetto Marelli.

Research institutions: Massachusetts Institute of Technology and USDA Agricultural Research Service, with collaborating researchers.

Journal: ACS Nano

Publisher: American Chemical Society

Published online: 2 November 2026

DOI: 10.1021/acsnano.6c06013

Research support: MIT Abdul Latif Jameel Water and Food Systems Lab and the US Department of Agriculture.

Researcher Contact

Professor Benedetto Marelli
Department of Civil and Environmental Engineering
Massachusetts Institute of Technology
Email: bmarelli@mit.edu

Original Research and External Sources

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Editorial and Rights Notice: This article is an independently written research news report and editorial analysis by The Veterinary News & Views (VNV). Original research findings are credited to their authors, institutions and publisher. The technology remains experimental. Publication does not imply institutional endorsement of VNV or commercial approval of the technology.