Evaluation of the immunotoxicity of benzoporphyrin derivative (BPD-MA) in mice.

Photodynamic therapy has been shown to selectively eliminate activated lymphocytes in a number of experimental situations. These findings have important implications in therapies involving selective immunomodulation. In this study we report the effects of intravenous dosing with the photosensitizer benzoporphyrin derivative-monoacid A(BPD) on normal immunological function.

Accelerated myelopoietic recovery in irradiated mice treated with Photofrin.

The porphyrin photosensitizer, Photofrin porfimer sodium (Photofrin), has been widely studied for its capacity to evoke destruction of malignant tissues. In addition to its photosensitizing properties, Photofrin may exert myelostimulatory effects in normal and immunosuppressed mice in the absence of activating light. In the present set of experiments, we examined the effect of Photofrin upon the immunohematopoietic axis of sublethally irradiated DBA/2 mice.

Wavelength-dependent effects of benzoporphyrin derivative monoacid ring A in vivo and in vitro.

Benzoporphyrin derivative monoacid ring A (BPD-MA) is a chlorin-like photosensitizer currently in clinical trials for cancer and psoriasis. It has maximal absorption peaks at both 630 and 690 nm and can be activated at both these wavelengths. In vitro phototoxicity tests using the P815 murine mastocytoma cell lines conducted over wavelengths of light between 678 and 700 nm emitted by an argon-ion pumped dye laser showed that equivalent cell kill could be achieved between 682 and 690 nm.

Effect of porphyrins on the hematopoietic recovery of mice treated with gamma-radiation.

Porphyrins are a group of organic compounds involved in a wide spectrum of fundamental biological processes. Non-metallic, naturally occurring and synthetic porphyrin derivatives may produce cytotoxic effects in malignant or normal tissues exposed to visible light. Supra-clinical doses of the photosensitizing porphyrin, Photofrin are hematostimulatory when administered to normal and immunosuppressed inbred mice.

Liposomal delivery of a photosensitizer, benzoporphyrin derivative monoacid ring A (BPD), to tumor tissue in a mouse tumor model.

Biodistribution studies were carried out on 14C-labeled benzoporphyrin derivative monoacid ring A (BPD), which had been formulated as a unilamellar liposome or taken from a stock solution in dimethyl sulfoxide diluted into phosphate-buffered saline immediately before intravenous injection into DBA/2 mice. By and large the general distribution of BPD to various organs and tissues was comparable for both formulations. It was noted, however, that liposomal material appeared to enter tissues more rapidly and to be cleared more rapidly, as demonstrated by shorter half-lives for a number of tissues including skin, lung and fat, and generally lower levels in most tissues 24 h following administration.