A Universal Biomimetic Approach for Making Artificial Antigen‐Presenting Cells for T Cell Activation

Abstract T cells based‐adoptive therapy has emerged as an effective therapy for treating various diseases. It involves the activation of T cells in vitro via artificial antigen presenting cells (aAPCs). However, conventional aAPC systems face limitations such as poor biodegradability, limited cargo capacity, and complex fabrication procedures. In this context, microcapsule systems offer a promising alternative for creating artificial cells, thanks to their distinctive core‐shell architecture and straightforward functionalization. Despite their potential, existing microcapsule systems often rely on toxic chemicals or harsh conditions for fabrication. Inspired by how marine organisms use biomolecules to create silica structure, the study develops a universal biomimetic strategy to fabricate silica microcapsules (SMCs) using emulsion templates under benign conditions. These SMCs are loaded with hydrophobic fluorescent dyes for tracking and magnetic nanoparticles for easy separation and manipulation, and they can be surface‐modified with antibodies to function as aAPCs. The novel SMC‐based aAPC (SMC‐aAPC) demonstrates superior T cell activation compared to commercially available Dynabeads. This innovation opens up exciting new possibilities for advanced immunotherapy and cell‐based treatments.