Nanoparticle-Mediated Routing of Antibiotics into Mitochondria in Cancer Cells

In recent years, antibiotics have emerged as alternative medicines in cancer therapy due to their capability of mitochondrial dysfunction in cancer cells. However, antibiotics render collateral damage in noncancerous cells by targeting mitochondrial transcription and translational machinery. To address this, herein, we have engineered three different mitochondria-targeted cationic antibiotic (tigecycline)-loaded nanoparticles from cholesterol conjugates. Dynamic light scattering and electron microscopy confirmed the spherical morphology and a less than 200 nm hydrodynamic diameter for these nanoparticles. The triphenylphosphine-coated tigecycline-loaded nanoparticle (Mito-TPP-Tig-NP) was shown to be homed into the mitochondria of A549 lung cancer cells compared to the other cationic nanoparticles. These Mito-TPP-Tig-NPs indeed triggered mitochondrial morphology damage and generation of reactive oxygen species (ROS). All the mitochondria-targeted tigecycline-loaded nanoparticles showed improved cancer cell killing ability in A549 and HeLa cervical cancer cells compared to free tigecycline. Moreover, Mito-TPP-Tig-NPs showed much less toxicity toward noncancerous human embryonic kidney cells (HEK293) compared to free tigecycline. These antibiotic-loaded mitochondria-targeted nanoparticles can open up an avenue toward anticancer therapy.