The SK-MEL-2 cells with GFP tagged on one endogenous DNM2 allele28 (link) were provided by Dr. David G. Drubin (University of California, Berkeley). Lipofectamine RNAiMAX (ThermoFisher, Cat# 13778030) was used to transfect the siRNA of dynamin-2 (siDNM2, ThermoFisher, Cat# S4212) into SK-MEL-2 cells. The sequence of siDNM2 is 5′-ACAUCAACACGAACCAUGA-3′. Lipofectamine RNAiMAX and siDNM2 were complexed for transfection based on the ThermoFisher manual. Details are available in the Section 2.8. of the Supporting Information. The lipid-RNA complex containing Opti-MEM was added into each well and incubated for 48 hours or 72 hours. After washing with phosphate buffer saline, the siDNM2-treated SK-MEL-2 cells are ready to be further evaluated for the cellular uptake of polymers.