Novel synthesis of ZnO nanoparticles and their enhanced anticancer activity: Role of ZnO as a drug carrier

In this work, a simple and versatile technique was developed to prepare highly crystalline ZnO nanoparticles (ZnO NPs) by organic precursor method using 5, 6 dimethyl benzimidazole and Zn(CH3COO)2·2H2O followed by calcination. These synthesized ZnO NPs were used as a drug carrier to form 5-Fluorouracil (5 Fu) encapsulated ZnO NPs by varying the molar ratio (100–300:1) of ZnO NPs to 5-Fu. X-ray diffraction (XRD) results indicated that the ZnO NPs had single phase nature with the wurtzite structure. Field emission scanning electron microscopy (FESEM) and Transmission electron microscopy (TEM) results showed nanometer dimension of the NPs. FTIR analysis further reaffirmed the formation/encapsulation of ZnO NPs. UV–vis spectroscopy determined the encapsulation efficiency (EE) and loading capacity (LC) of 5-Fu drug on ZnO NPs. HPLC analysis of encapsulated NPs indicated release of 5-Fu was higher at tumor cell pH (pH 6.0) than physiological pH. Moreover, the anti-tumor activity of ZnO NPs and 5-Fu-encapsulated ZnO NPs investigated using flow cytometry demonstrated that 5-Fu encapsulated ZnO NPs have more anti-tumor activities than 5-Fu itself toward MCF-7 (Breast cancer) cell line. Also, cytotoxicity of MCF-7 increased with the increase of ZnO NPs: 5-Fu ratio. This research will introduce a new concept to synthesize 5-fluorouracil encapsulated ZnO NPs and its application towards the cancer cell line. Thus, the ZnO NPs could not only apply as the drug carrier to deliver 5-Fluorouracil into the cancer cells, but also enhances anti-tumor activity.