Drug delivery system composed of mesoporous silica and hollow mesoporous silica nanospheres for chemotherapeutic drug delivery

Mesoporous silica nanoparticles (MSN) and hollow mesoporous silica nanoparticles (HMSN) of the size of ∼200 nm have been synthesized from iron silicate via selective etching of iron oxide and were used to deliver a prominent anticancer drug doxorubicin under external stimuli. The facile synthesis of MSN and HMSN involves synthesis of iron silicate coated by iron oxide and silica in a layer by layer (LbL) fashion followed by selective etching of iron oxide under mild conation. Among all the particles, HMSN has less surface area (100 m2/g) and larger pore size (4.62 nm). We demonstrated that both MSN and HMSN release the drug over a period of 4 h under external stimuli (acidic pH). The release profile reveals that HMSN release comparatively less amount of drug as compared to MSN. This could be attributed to the larger pore volume (0.52 cc/g) of MSN as compared to HMSN (0.20 cc/g). The particles neither show any cytotoxicity towards the HeLa cells up to 350 μg/ml nor any morphological change to the nucleus of the cells. The cytotoxicity value was much higher compared to the literature reports on MSN. This implies a better biocompatibility of the particles prepared through this methodology.