Controlled Formation of MnO<inf>2</inf> Nanosheets for Cancer Treatment

Abstract

MnO2 nanostructures are synthesized using the solution plasma process (SPP) by initiating plasma in KMnO4 aqueous solutions. The investigation delves into manipulating plasma parameters, i.e., pulse width and frequency, which are converted to duty cycle (DC) to attain MnO2 with diverse sizes. A significant challenge of this study is the inherent instability in the resulting product properties due to the ultrafast reaction, rendering traditional end point determination methods ineffective. Hence, we propose real-time RGB intensity monitoring via a mobile application to determine the reaction end point precisely. Five specific conditions where the end point can be clearly defined are identified, corresponding to DC values of 2.20%, 2.25%, 2.55%, 2.80%, and 3.36%. MnO2 samples synthesized from these DCs predominantly exhibit sheet-like structures with varying sizes correlated with the DCs. Subsequently, cell studies are conducted on selected MnO2 samples, featuring notable differences in hydrodynamic sizes (51, 61, and 85 nm) to evaluate their influence on compatibility with healthy cells and therapeutic efficacy against cancer. This study provides valuable insights for two essential applications: (i) real-time monitoring of MnO2 synthesis via SPP using RGB intensity, applicable to other syntheses of nanomaterials exhibiting color changes, and (ii) preliminary evaluation of SPP-synthesized MnO2 with a focus on size variation for potential cancer therapy applications.