Exploring the Potential Role of Manganese-Based Zeolitic Imidazolate Framework Nanoparticles in Cancer Therapy: In...

Chemodynamic therapy (CDT) has emerged as a promising cancer treatment strategy leveraging tumor microenvironment conditions to generate reactive oxygen species (ROS) through Fenton-type reactions. This study reports the synthesis, in-depth characterization, and biological evaluation of novel manganese-based zeolitic imidazolate framework (ZIF) nanoparticles, ie, Mn-rods, as a carrier-free potential CDT platform with exceptionally high manganese loading.

Mn-rods were synthesized through coordination of Mn²⁺ ions with 2-methylimidazolate and characterized using transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), and inductively coupled plasma optical emission spectroscopy (ICP-OES). Two human non-small cell lung cancer lines (A549 and Calu-3) were used to evaluate nanoparticle internalization and therapeutic response was assessed using cell viability assays, ROS generation measurements, and rescue experiments with pathway-specific inhibitors.

The synthesized Mn-rods exhibited a rod-shaped morphology (226 ± 93 nm length x 26.5 ± 9.5 nm width) with an exceptional Mn²⁺ loading of 50 wt.%, surpassing existing manganese-based systems. Both A549 and Calu-3 cells internalized Mn-rods, however, only A549 cells exhibited marked dose-dependent cell viability reduction, highlighting the influence of cellular phenotype on therapeutic response. Mechanistic studies suggest that Mn-rods induce ferroptosis-like cell death in A549 cells through lipid peroxidation and redox imbalance, independent of apoptosis, necroptosis and iron-mediated pathways. Rescue experiments with ferroptosis inhibitors (ferrostatin-1 and liproxstatin-1) confirmed the lipid ROS-driven mechanism, further supported by increased intracellular ROS levels and progressive membrane damage.

These findings establish Mn-rods as potent CDT agents whose efficacy is dictated by tumor cell oxidative vulnerability. Understanding such cell-specific responses is critical for optimizing nanoparticle design and tailoring therapeutic strategies in heterogeneous tumor environments. Future studies should extend these investigations across diverse cancer models to refine their translational potential.