U. Schmidterfurth et al., PHOTODYNAMIC THERAPY OF EXPERIMENTAL CHOROIDAL MELANOMA USING LIPOPROTEIN-DELIVERED BENZOPORPHYRIN, Ophthalmology, 101(1), 1994, pp. 89-99
Background: Benzoporphyrin derivative monoacid (BPD) is a new photosen
sitizer currently undergoing clinical trial for cutaneous malignancies
. Compared with the clinically most frequently used sensitizer, Photof
rin, BPD may offer higher tumor phototoxicity, better tissue penetrati
on, and absence of significant skin sensitization. Low-density lipopro
tein (LDL) carriers heighten efficiency and selectivity of BPD because
neovascular and tumor cells express an increased number of LBL recept
ors. Hence, in addition to the vaso-occlusive effects similar to most
other photosensitizers, LDL-BPD also has been shown to cause direct tu
mor cell damage. Methods: Benzoporphyrin derivative monoacid was compl
exed with human LDL and used in photodynamic treatment of choroidal me
lanomas experimentally induced in eight albino rabbits. Five rabbits s
erved as controls. Three hours after intravenous injection of 2 mg/kg
body weight of LDL-BPD, eight tumors were irradiated at 692 nm and 100
J/cm(2) via an argon-pumped dye laser coupled into a slit lamp. Resul
ts: Angiography and histologic findings showed immediate photothrombos
is after disintegration of endothelial membranes. After complete necro
sis of tumor cells within 24 hours, a small fibrotic scar slowly devel
oped. No tumor regrowth was noted up to 6 weeks when animals were kill
ed. Conclusion: These data suggest that photodynamic treatment with LD
L-BPD may be a promising modality for multiple clinical applications,
including tumors and neovascularizations II.