Droplet vitrification has emerged as a promising ice-free cryopreservation approach to provide a supply chain for off-the-shelf cell products in cell therapy and regenerative medicine applications. Translation of this approach requires the use of low concentration (i.e., low toxicity) permeable cryoprotectant agents (CPA) and high post cryopreservation viability (>90%), thereby demanding fast cooling and warming rates. Unfortunately, with traditional approaches using convective heat transfer, the droplet volumes that can be successfully vitrified and rewarmed are impractically small (i.e., 180 picoliter) for <2.5 m permeable CPA. Herein, a novel approach to achieve 90–95% viability in micro-liter size droplets with 2 m permeable CPA, is presented. Droplets with plasmonic gold nanorods (GNRs) are printed onto a cryogenic copper substrate for improved cooling rates via conduction, while plasmonic laser heating yields >400-fold improvement in warming rates over traditional convective approach. High viability cryopreservation is then demonstrated in a model cell line (human dermal fibroblasts) and an important regenerative medicine cell line (human umbilical cord blood stem cells). This approach opens a new paradigm for cryopreservation and rewarming of dramatically larger volume droplets at lower CPA concentration for cell therapy and other regenerative medicine applications.
Bibliographical noteFunding Information:
L.Z. and S.‐Z.G. contributed equally to this work. The authors are thankful for the financial support from NIH SBIR Phase I (1R41OD024430‐01) and Phase II (9R44MH122118‐02). L.Z. acknowledges the Doctoral Dissertation Fellowship from University of Minnesota. The authors thank Dr. Robert Evans III for the help with X‐ray diffraction measurement. The authors thank Dr. Michael Etheridge for the careful read and comments to the manuscript. This work was also supported by the National Institute of Biomedical Imaging and Bioengineering of the National Institutes of Health under Award Number DP2EB020537. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
© 2021 The Authors. Advanced Science published by Wiley-VCH GmbH
- cell therapy
- conduction cooling
- droplet vitrification
- plasmonic laser heating