Fig. 2

Confocal images of tumor tissue sections showing intra-tumoral localization of FGFR1i- 5Fu- and CPT-AuNSs. a-c Untreated tumor tissue sections exhibited strong and diffuse fluorescent signal indicating strongly expressed FGFR1. d-f Tumor tissue sections treated with free-FGFR1i show decreased FGFR1 expression compared with control indicating successful tumor penetration and inhibition of FGFR1. g-i Tumor tissue section treated with FGFR1i-AuNSs shows total loss of FGFR1 expression as a function of enhanced FGFR1i-AuNSs tumor penetration and selective targeting. k Untreated tumor tissue section lacking any fluorescence signal. l, n, p, r) Tissue sections showing molecules of CPT and 5Fu localization on tumor cell plasma membranes rather than the nuclei. m, o, q, s Tissue sections treated with CPT-AuNSs or 5Fu-AuNSs showing drug localization within the nucleus, thus conjugating 5Fu and CPT to AuNSs enhanced tumor penetration and increased cellular uptake (CPT and 5Fu fluorescence emission at 405 nm and 495 nm, respectively). No nuclear fluorochrome was applied. Magnification × 63, Scale bar =25 μm except (M), which is 10 μm. j Percentage of nuclear localization denotes that 5Fu- and CPT- AuNSs significantly enhance nuclear accumulation by 2-fold and 3-fold, respectively; CPT-AuNSs shows marked intense intranuclear staining compared with 5Fu-AuNSs p< 0.001. (n=13)