Work

Synergistic Photothermal Ice Inhibition Strategy for Scalable Cryopreservation of Macroscopic Spheroids and Immune Cells in Advanced Immunotherapy

Year: 2025

Type: article

Abstract: Scalable and effective cryopreservation of human immune cells and biological samples is challenging for advanced cellular therapeutics. However, current cryoprotectants are limited due to trade-offs between robust ice inhibition and uniform thermal management to mitigate Ostwald ripening. Herein, we develop a nonpermeable nanocryoprotectant (PVA@PPy) by combining antifreezing poly(vinyl alcohol) (PVA) with photothermal polypyrrole (PPy). The strong hydration of pendant PVA chains limits ice growth, while the photothermal PPy enables bulky heating to prevent devitrification. A low concentration of 0.05% nanocryoprotectant enables the recovery of 0.5 mm neural spheroids, outperforming traditional cryopreservation methods employing 10% DMSO. We achieve >95% recovery rates across all tested human immune cell populations, including CD4+, CD8+, NK cells, and αβ T cells. This work underscores the unprecedented potential of PVA@PPy for the effective preservation of macroscopic biological samples and immune cells for advanced therapeutics.

Source: ACS Applied Materials & Interfaces

DOI: 10.1021/acsami.5c10710