Bioorthogonal Assembly of Cell-Nanoparticle Hybrids Enables Synergistic Cancer Therapy

Integrating nanoparticles (NPs) with living cells into a unified therapeutic system remains a major methodological challenge. Here, we describe a robust and modular bioorthogonal strategy for constructing cell-nanoparticle hybrids (CNHs) via sequential thiazolidine formation and SpyCatcher/SpyTag ligation. This two-step chemical assembly enables highly specific and covalent conjugation of structurally diverse NP payloads─including ferritin nanocages, lipid micelles, and amphiphilic polymers─onto aldehyde-presenting cell surfaces without genetic modification, ensuring broad applicability while preserving cellular functionality. The resulting CNHs exhibit enhanced nanoparticle retention and tumor penetration both in vitro and in vivo. In a colorectal cancer xenograft model, CNHs demonstrate superior antitumor efficacy compared with free drugs, unconjugated NPs, or unmodified macrophages. Mechanistic studies indicate that the enhanced tumor inhibition arises from the combined effects of chemotherapeutic drug-loaded NPs and the intrinsic properties of macrophages. Collectively, these results demonstrate a versatile chemical framework for bioorthogonal cell-nanoparticle assembly and the rational design of functional living hybrid systems.