Fig. 2

T-iRGD showed improved tumor infiltration capacity and antitumor efficiency in 3D tumor spheroids and peritoneal metastasis tumor model. a Confocal microscopy images and surface plot images of HGC27 spheroids treated with CFSE-labeled T, T + iRGD, T-iRGD, or control peptide iRGE modified T cells (T-iRGE) for 20 h. 15 μg ml⁻¹ anti-NRP-1 antibody and control sheep anti-IgG were added 20 min before T cells incubation. Magnification, ×200; Scale bars, 100 μm. b, c T cell cytotoxicity against HGC27 tumor spheroids. Representative images of MCS treated with culture medium, T, T + iRGD, or T-iRGD for 20 h and then incubated in fresh culture medium for 24 h. scale bar, 100 μm (b). Growth inhibition assay in HGC27 MCS (c). Data are represented as mean ± s.e.m.; n = 5. Student’s t test. ***p < 0.001. d Near-infrared imaging of intraperitoneal tumor-bearing mice at 3 h post intraperitoneal injection of DiR-labeled T cells. e. Ex vivo images of tumor, liver, and spleen at 3 h after intraperitoneal T cells injection. White dashed lines, peritoneal tumors. f Semiquantification of T cells biodistribution at 3 h post-injection. Results are expressed as mean fluorescence intensity ± s.e.m. (n = 3). Student’s t test. ***p < 0.001. g Confocal images and immunohistochemistry analysis of resected tumor nodules at 3 h post intraperitoneal injection of T cells. Upper layer, T cells were labeled with CFSE before intraperitoneal injection; tumor blood vessels were stained with anti-CD31. T cell, green; vessel, red; nucleus, blue. Under layer, T cells were stained with anti-CD3. Scale bar, 100 μm. h Schematic illustration of treatment process of peritoneal metastasis tumor model. i, j Mice bearing disseminated MKN45 peritoneal tumors implanted 1 week earlier received intraperitoneal injection of PBS, IL-2, T, T + iRGD, or T-iRGD every 4 days for 3 times. Tumors are harvested after 2 weeks of treatment. Tumor nodules larger than 3 mm in diameter were weighed (i), and the numbers of remaining small tumor nodules (1–3 mm in general) were counted (j). Data represent mean ± s.e.m.; n = 8. Student’s t test. n.s, not significant; *p < 0.5; **p < 0.01; ***p < 0.001. Tu tumor, Li liver, Sp spleen