Application of Long-Circulating Liposomes to Cancer Photodynamic Therapy.

Liposomal photosensitizers: potential platforms for anticancer photodynamic therapy

“…These investigators reported a higher accumulation rate of the PS coproporphyrin I incorporated into PEGylated liposomes and an improved response to PDT treatment in mice when compared to conventional liposomes and/or to free PS. Similarly, Oku et al (31) showed that 80% of mice bearing a subcutaneous sarcoma were cured after PDT treatment with intravenous injection of the benzoporphyrin derivative monoacid ring A (BPD-MA) incorporated into glucuronide-modified liposomes, while only a 20% cure rate was observed for injected PS-conventional liposomes.…”

“…For instance, Oku et al (31) reported that the PEGylation of BPD-MA-liposomes enhanced the passive accumulation of the liposomal drug in tumor tissues at 3 h after administration, but did not enhance the PDT efficacy, suggesting that the liposomes were not effectively taken up by the tumor cells before laser irradiation. Moreover, the low interaction of PEGylated liposomes with cells also reduces the amount of reactive oxygen species (ROS) that reach the targeted cells, since ROS are generated at the PS activation site and then diffuse through short distances (about 0.02 µm) due to their short half-life in biological tissues (3).…”

Can nanotechnology potentiate photodynamic therapy?

“…In active targeting, one or more molecules that have a high affi nity for specifi c membrane markers on malignant cells are bound to the surface of the liposome, resulting in increased interaction of the liposomes with target cells [24] . The molecule can be covalently bound to the liposome, either by using a spacer molecule or by binding directly to a hydrophobic anchor in the phospholipid bilayer.…”

PEGylation of Liposome Decreases the Susceptibility of Liposomal Drug in Cancer Photodynamic Therapy

“…10) In this case, the enhanced therapeutic efficacy may be explained by that 5 h is enough to allow BPD-MA-delivering to tumor cells, and/or that glucuronate-modification does not protect the interaction of liposome to tumor cells.…”