Photodynamic therapy of U87 human glioma in nude rat using liposome-delivered photofrin

Background and Objective Liposomes as photosensitizer carriers may enhance the photodynamic effect on tumors. Study Design/Materials and Methods: To test this hypothesis, we treated U87 human glioma in rat brain with photodynamic therapy (PDT) using Photofrin encapsulated in a liposome carrier or Photofrin in dextrose. Nontumored brain was also treated and Photofrin content ratios were measured in tumor and nontumored brain. Results PDT using the liposome encapsulated photosensitizer significantly increased tumor destruction compared to PDT with Photofrin in dextrose (P = 0.007), whereas no difference in tissue damage was detected in nontumored brain with or without liposome carrier. Photofrin uptake was also significantly elevated in the liposome vehicle group compared to the dextrose (P < 0.05) group. Conclusions Our data suggest that Photofrin encapsulated in a liposome may enhance the PDT treatment of human brain tumors. Lasers Surg. Med. 22:74–80, 1998. © 1998 Wiley‐Liss, Inc.