Synthesis and Characterization of Biocompatible Manganese‐Doped Titania Nanoparticles and Its Application to Single‐Cell Nanoencapsulation

Abstract

Biocompatible metal oxide nanoparticles (NPs) are promising materials for biointerfaces, wound healing, and theranostic applications owing to their multifunctional properties. Here, we report manganese‐doped TiO2 (Mn‐doped TiO2) nanozymes that integrate the chemical stability and biocompatibility of TiO2 with the redox activity and biofunctional potential of manganese oxide within a single‐phase oxide platform. The Mn‐doped TiO2 nanoparticles synthesized via hydrothermal and PEG‐assisted solvothermal routes exhibit uniform size (10–15 nm), high hydrophilicity, and excellent colloidal stability as confirmed by dynamic light scattering (DLS), along with suppressed photocatalytic activity to minimize ROS‐mediated cytotoxicity. Structural analyses via X‐ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed uniform manganese doping into the TiO2 lattice. Biological evaluations demonstrated excellent compatibility in both encapsulation models (phosphate‐functionalized nanospheres and Al2O3 plates) and living systems including immortalized human T lymphocytes (Jurkat T cells), neuronal cells, and yeast, with consistently high cell viability. Importantly, Mn redox centers confer nanozyme activity, catalyzing dopamine polymerization at cell surfaces and enabling single‐cell nanoencapsulation (SCNE). These findings establish Mn‐doped TiO2 nanozymes as a multifunctional promising platform for cell‐surface engineering, bioencapsulation, and future applications in regenerative medicine and theranostics.