A platinum(II) complex loaded on a mesosilicalite nanocarrier having a hierarchical silicalite characterized by a molar ratio of aluminum to silica in a range of 1:3000 to 1:1000. The hierarchical silicalite includes mesopores of a hexagonal structure, and micropores of silicalite structure with a microporous volume in the range of 0.05 cc/g to 0.1 cc/g. The mesosiliclite nanocarrier loaded with the platinum(II) complex is suitable for treatment of cancer, in particular, breast, cervical, and colon cancers.