In vitro experiments showed that CRISPR/Cas9-3NLS/sgHMGA2@PDA can achieve efficient delivery of CRISPR/Cas9-3NLS/sgHMGA2 and efficient HMGA2 gene editing in gastric cancer cells, with delivery and gene editing efficiencies as high as 95% and 82%, respectively. This evidence concerns the gene HMGA2 and gastric cancer.