Thus, PDA NPs•Tmab@PTX and PDA NPs@Tmab@PTX reduced BT474 and SKBR3 cell viability rates between 5–15% more than PDA NPs@PTX (depending on the NP concentration and treatment time), a fact that revealed that Tmab loading could enhance NP endocytosis in HER2+ tumor cells. This evidence concerns the gene ERBB2 and neoplasm.