Provided herein are methods of inhibiting proliferation of one or more tumor cells comprising contacting the one or more tumor cells with a composition comprising one or more epigenetic drugs that inhibit one or more epigenetic mechanisms of the tumor cells, wherein the one or more epigenetic drugs are encapsulated in a nanogel. The invention is also directed to methods of treating a tumor, metastasis of a tumor or a combination thereof in an individual in need thereof. The invention is also directed to a method of sequentially delivering one or more epigenetic drugs that alter one or more epigenetic mechanisms of a tumor cell and one or more chemotherapeutic drugs to an individual that has a tumor. Compositions which comprise one or more epigenetic drugs that alter one or more epigenetic mechanisms of a tumor cell, wherein the one or more epigenetic drugs are encapsulated in a nanogel.