Single-Cell Nanoencapsulation of Saccharomyces cerevisiae by Cytocompatible Layer-by-Layer Assembly of Eggshell Membrane Hydrolysate and Tannic Acid

Single-cell nanoencapsulation (SCNE) demands cytocompatible materials and processes to ensure the maintenance of cell viability and prefers the degradation-on-demand and postfunctionalization of the cytoprotective shells. Although the layer-by-layer (LbL) method has intensively been used for SCNE, there have been few reports on the cytocompatible LbL shells that are postfunctionalizable under mild conditions. Herein, the use of nature-derived eggshell membrane hydrolysate (ESMH) as a counter component to tannic acid (TA) for hydrogen bonding-based LbL shell formation on Saccharomyces cerevisiae is proposed. In addition to the great cytocompatibility of the LbL process and protective capability of the ESMH/TA shell (e.g., 18-fold increase in survival against Cu²⁺), the shell is postfunctionalizable, benefitting from the presence of various functional groups in the ESMH, as demonstrated by reactions with N-hydroxysuccinimide- or maleimide-conjugated fluorescent probes and bioinspired silicification. This work suggests that ESMH would be an advanced biomaterial for chemically interfacing with living cells in a controlled fashion.