Fig. 5.

In vivo evaluation of this starvation therapy in inhibiting PANC-1 pancreatic tumors on nude mice. a Schematic of in vivo experimental process, and hydrogel–GNR was simultaneously injected into both tumor and its periphery where 808 nm laser irradiation was carried out. b, c Time-dependent tumor volume variation (b) and survival rate (c) of PANC-1 tumor-bearing nude mice experiencing different treatments, i.e., control, Laser+GNR, Laser+hydrogel–GNR (1), Laser+hydrogel–GNR (2) and pNIPAAm, wherein (1) and (2) represent tumor injection alone and co-injection of tumor and its periphery, respectively, and pNIPAAm was also injected into both tumor and its periphery. Data are expressed as mean ± SD (n = 6); *P < 0.05, **P < 0.01 and ***P < 0.001, and the statistical significances were calculated via unpaired Student’s t test in comparison to control. d–f Microscopic images of PANC-1 tumor slices stained by H&E immumohistochemical staining (d), PCNA immumohistochemical staining (e) and CD 31 immumohistochemical staining (f) that were harvested after sacrificing of PANC-1-bearing nude mice treated with aforementioned different treatments (G1-G5) on the 10th day post-treatment, scale bar: 200 μm. Notes: H&E, PCNA and CD31 immumohistochemical assays were employed to evaluate cell structure, cell proliferation, and neovascularization, respectively. g Western blot analysis for analyzing different proteins including Bcl-2, Caspase 3, HSP70, P53, CD34 and CD31 and HIF 1α in PANC-1 tumors receiving aforementioned different treatments (G1–G5) on the 10th day post-treatment. Note: G1–G5 represent control, Laser+GNR, Laser+hydrogel–GNR (1), Laser+hydrogel–GNR (2) and pNIPAAm, respectively.