# Gold nanoparticle laser warming of cryopreserved zebrafish embryos

> **NIH NIH R44** · NANOCOMPOSIX, INC. · 2020 · $728,101

## Abstract

Project Summary/Abstract
 Laboratories around the world have produced tens of thousands of distinct zebrafish lines
that serve as model organisms for genetic and biomedical research that applies to human
genetics and diseases. Maintaining all these valuable genotypes is expensive and beyond the
capacity of even the largest stock centers. One solution is the cryopreservation of zebrafish
sperm, eggs and embryos, an approach that would enable the strategy of increased multi-
institutional research using animal models envisioned by the NIH Division of Comparative
Medicine. Zebrafish sperm and eggs have been successfully cryopreserved, but technical
challenges had prevented the cryopreservation of zebrafish embryos until recent success
demonstrated by nanoComposix and Prof. John Bischof at the University of Minnesota. The
main challenge with zebrafish embryo cryopreservation is the large embryo size, which limits
the rate at which the embryo can be externally cooled and warmed. The innovative approach
used by the applicants utilizes an injected formulation of gold nanoparticles that act as ultra-
efficient heaters to generate heat internally when illuminated with an infrared laser. This
technology demonstrated, for the first time, the successful cooling, cryogenic stabilization and
rewarming of zebrafish embryos. Further development and commercialization of this successful
proof-of-concept will address a critical need for zebrafish researchers and will form the basis for
other genetic preservation applications in aquaculture and human reproduction, improving
reproduction for societal, environmental and biodiversity needs.
 This project will further optimize the zebrafish embryo laser warming reagents, protocols,
and equipment developed during the Phase I contract. The equipment will be beta tested by
zebrafish research centers and a commercial system will be manufactured. The system will
consist of a reagent formulation composed of a cryoprotectant agent and a gold nanoparticle,
optimized to provide high photothermal conversion efficiency and minimal toxicity, and will be
manufactured under a ISO 13485-compliant quality system. Reagent microinjection into the
embryos and freezing and laser rewarming protocols will be refined to further improve embryo
survival rates and will form the basis of training materials for end users. Finally, first-generation
equipment will be developed, along with testing of automated, high-throughput methods for
embryo cooling. Further technology development will provide a universal high throughput
platform for preserving germplasm of other vertebrate and non-vertebrate organisms.

## Key facts

- **NIH application ID:** 10016844
- **Project number:** 5R44MH122118-03
- **Recipient organization:** NANOCOMPOSIX, INC.
- **Principal Investigator:** JOHN C BISCHOF
- **Activity code:** R44 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $728,101
- **Award type:** 5
- **Project period:** 2017-05-01 → 2022-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10016844

## Citation

> US National Institutes of Health, RePORTER application 10016844, Gold nanoparticle laser warming of cryopreserved zebrafish embryos (5R44MH122118-03). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10016844. Licensed CC0.

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