Mesoporous silica nanoparticles (MSNs) have attracted significant interest in drug delivery applications due to their good biocompatibility and high specific surface area. However, conventional MSNs typically have small pore sizes and low degradation rates, resulting in limited drug loading capacity and potential nanoparticle accumulation. This study focuses on the synthesis of novel magnesium (Mg) ion-doped silica nanoparticles (MgMSNs) using a chemical precipitation method followed by calcination. In contrast to the nanorod-shaped MSNs, the Mg ion-doped silica nanoparticles exhibited a nanosheet-shaped morphology. When the added Mg concentration was 5 mM, the prepared nanosheets (5MgMSNs) showed superior antibacterial activity and increased curcumin-loading capacity compared to pure silica nanoparticles. Additionally, the natural green fluorescence of curcumin allowed for the visualization of cellular uptake, confirming the efficient internalization of 5MgMSNs by L929 cells. Notably, under acidic conditions, the release of Mg ions and the degradability of the nanoparticles were enhanced, indicating pH-responsive release behavior. Overall, these results highlight the favorable degradability and improved cellular uptake capacity of nanosheet Mg-incorporated silica nanoparticles, suggesting their potential for loading polyphenol drugs such as curcumin and achieving efficient drug release within cells.