Fig 1.
Fluorescence of CT26-KR cell line.
A) Flow cytometry of CT26 (R2 = 97.3%) and CT26-KR (R2 = 4.6%) cells. B) Fluorescence microscopy of CT26-KR cells: transmitted light, blue fluorescence of Hoechst 33342, red fluorescence of KR. Bar is 50 μm.
Fig 2.
Photobleaching of KR in CT26-KR tumors.
A) Fluorescence imaging of CT26-KR tumor in vivo during irradiation with the pulsed laser at 225 mW/cm2. Tumor is shown by the arrow. B) Photobleaching as a function of light dose for the five fluence rates. The results are expressed as mean ± SD (n = 3). The solid lines show exponential approximations (R2 = 0.91 and 0.99 for the CW and pulsed laser modes, respectively).
Table 1.
Temperature on the CT26-KR tumor surface after laser treatment.
Fig 3.
A histological view of CT26-KR tumors 24 hours after PDT with CW or pulsed lasers and untreated control.
Representative tissue sections stained with H&E are shown. The cellular disorders induced by PDT in pulsed mode are shown by the numerated arrows: 1—swollen hyperchromic nuclei, 2—chromatin condensation, 3—vacuolated cytoplasm, 4—apoptosis hallmarks.
Table 2.
Quantification of the cellular disorders induced by PDT with KR.
Fig 4.
Effect of PDT with KR on the growth of CT26 tumors in BALB/c mice.
Mean ± SD (n = 7). PDT was conducted on days 6, 7, and 8 (shown by arrows) after cancer cell inoculation. The tumors were irradiated at 260 J/cm2 (150 mW/cm2, 30 min) in CW mode or at 337 J/cm2 (225 mW/cm2, 25 min) in pulsed mode. *, P ≤ 0.01, compared with the control “CT26-KR, No treatment” group.