Development of Mitochondria-Targeted Imaging Nanoplatforms by Incorporation of Fluorescent Carbon Quantum Dots

Multifunctional nanoplatforms are promising scaffolds for biomedical applications such as bioimaging, chemical/biological sensors, drug delivery, and cancer diagnosis and/or treatments. Mitochondria play crucial roles in metabolism of eukaryotic cells; therefore, mitochondria-targeting molecule such as triphenylphosphonium (TPP) is attached onto the magnetic mesoporous silica nanoparticle (Fe₃O₄@mSiO₂). In order to track the nanoparticles, fluorescent carbon quantum dots (CDs) were conjugated to the Fe₃O₄@mSiO₂. The as-constructed Fe₃O₄@mSiO₂-TPP/CQD nanoplatform showed minimal cytotoxicity in various cell lines such as A549, CHO, HeLa, SH-SY5Y, HFF, and HMEC-1. External magnetic field-assisted uptake of the nanoplatform by tumor cell has been achieved promptly. More importantly, conjugation with CQDs endows the nanoplatform multicolored fluorescence that can remain bright and stable inside cells for a long time. This nanoplatform provides a multifunctional platform in targeting, imaging, and agent delivery for mitochondria-related disease diagnosis and treatment.