M. Shopova et al., PHOTODYNAMIC THERAPY OF EXPERIMENTAL-TUMORS WITH ZN(II)-PHTHALOCYANINE AND PULSED-LASER IRRADIATION, Lasers in medical science, 10(1), 1995, pp. 43-46
The effectiveness of a pulsed dye laser (673 nm) for photodynamic ther
apy (PDT) of tumours in the presence of Zn(II)-phthalocyanine (ZnPc) w
as evaluated using Lewis lung carcinoma-bearing mice. The tumours were
irradiated with different pulse energies (from 0.4 to 10 mJ) at a con
stant fluence of 0.6 J cm(-2) at 24 h after administration of 0.25 mg
kg(-1) body weight liposome-incorporated ZnPc. Maximal PDT effect, as
evaluated by changes in mean tumour diameter, animal survival time and
histological evaluation of tumour necrosis, was observed after 3.0 mJ
pulse energy irradiation which appears to yield a deeper light penetr
ation and a more efficient sensitizer excitation when compared with lo
wer or higher pulse energies. Electron microscopic analysis of photo-t
reated tumour indicates preferential damage to malignant tissue as com
pared to endothelial cells.