In accordance with the purpose(s) of the present disclosure, as embodied and broadly described herein, the disclosure, in one aspect, relates to methods for modifying cells such as, for example, changing shape, cell force, and/or modifying structural integrity of the cells. In a further aspect, the disclosure relates to controlling membrane permeability in cells by applying an electric current, where the cells are in contact with a polymeric nanofiber array and wherein direction and voltage of the electric current can be modified to induce the desired cellular response. In some aspects, the method results in higher survivability for cells during electroporation, greater permeability to molecules and/or drugs of different sizes, and greater transfection efficiencies for rare primary cells.