Fig. 4. In vivo theranostic studies.
(a) Dynamic T2-weighted and OlsaCEST serial MRI of tumor-bearing mice after i.v. injection of 0.2 mmol/kg Olsa-RVRR or olsalazine (left: HCT116; right: LoVo). (b) MTRasym spectra of HCT116 and LoVo tumors before and 2 h after injection of Olsa-RVRR. (c) Time course of OlsaCEST signal for tumors after background correction by the subtraction of the MTRasym value at 0 h. Data are shown as mean±SD for n=4 mice; one-way ANOVA, followed by Dunnett's post-hoc test; ***P<0.001 vs. all other groups. (d) Ex vivo OlsaCEST images of various organs from tumor-bearing mice 2 h after i.v. injection of 0.2 mmol/kg Olsa-RVRR. (e) Organ distribution of OlsaCEST signal relative to muscle signal used as reference. Data are shown as mean±SD for n=4 mice. (f, g) Anti-tumor effects of olsalazine and Olsa-RVRR for HCT116 (f) and LoVo (g) tumors. Arrows indicate time points of repeated drug administration (QD3×8) after tumor cell injection. Data are shown as mean±SD (n=4 mice). (h) Relative tumor sizes at day 33 normalized to PBS group (set at 1.0). Data are shown as mean±SD for n= 4 mice; two-tailed Student’s t-test; *P=0.0179 vs. Olsa-RVRR group, **P<0.01 vs. control and olsalazine groups. (i) Measured mouse body weight over time time. Data are shown as mean±SD for n=4 mice. (j) Correlation between tumor OlsaCEST signal (HCT116 and LoVo) at 2h (Fig. 4c) and normalized tumor size (HCT116 and LoVo) at day 33 (Fig. 4h, n=4 mice). (k) 3D-SIM images of HCT116 and LoVo tumors after i.v. injection of 50 nmol Alexa-RVRR or Alexa 488. Green fluorescence represents self-assembled Alexa 488 nanoparticles. Cell nuclei were counterstained with DAPI (blue). The experiments in a-b, and d were repeated independently four times with similar results. The experiments in k were repeated independently three times with similar results.