Fig. 8.

Evaluations on inhibited tumor metastasis using this starvation therapy. a In vitro anti-metastasis apparatus schematic that is used to evaluate the ability of hydrogel–GNR to occluding the migration passage of cell invasion, wherein S0 is the primary site of PANC-1 tumor cells, and S1–S4 represent four objective metastasis sites and are separated from S0 with hydrogel–GNR with varied thicknesses. b Optical microscopic images of S0–S4 after different incubation periods (scale bar: 200 µm). c, d The number of time-dependent cells in S0 (c) and S1–S4 (d). *P < 0.05, **P < 0.01, and ***P < 0.001, which were obtained using student's t test in comparison to 0 h. Data are expressed as mean ± SD (n = 3). e Principle schematic of in vivo tumor anti-metastasis using such an extravascular gelation shrinkage-induced internal stress to squeeze blood vessels, reduce vascular density and occlude the migration passage of tumor cells; notes: Zone A represents the treated zone with Laser+hydrogel–GNR (2) and Zone B represents the control group without gel occlusion. f The underlying anti-metastasis mechanism of this special starvation therapy on the orthotopic mammary adenocarcinomas-bearing transgenic mouse model. g Digital photos of lungs acquired from transgenic mice-bearing orthotopic mammary adenocarcinomas in treated and control groups to assess lung metastasis at the end of experiment (day 28). h The statistical number of distant tumors in lungs in both control (G1) and treated groups (G4). Values are mean ± SD (n = 7) and statistical significances were calculated via unpaired Student’s t test. Notes: mice in treated group received Laser+hydrogel–GNR (2) treatment which mean co-injection of hydrogel–GNR in tumor and its periphery and subsequent 808 nm laser irradiation on the 1st day.