HIF1A and neoplasm: Methods: Generation 5 poly(amidoamine) dendrimers partially modified with 1,3-propanesultone were used for templated synthesis of Au NPs, and the created zwitterionic Au DENPs were adopted for serum-enhanced delivery of siRNA to lead to the knockdown of hypoxia-inducible factor-1α (HIF-1α) protein and downstream genes to relieve tumor invasion.