Tetra‐p‐aminophenylporphyrin conjugated with Gd‐DTPA: Tumor‐specific contrast agent for MR imaging

Publisher Website
Google Scholar
Abstract
Tetra-P-aminophenylporphyrin (TPP) was conjugated with gadolinium diethylenetriaminepen-taacetic acid (DTPA) and used as a contrast agent in magnetic resonance (MR) imaging to achieve tumor selectivity in nude mice. A substantial decrease in T1 was measured in excised tissues (kidneys, tumor, and liver) from mice that received the porphy-rin derivative Gd2(DTPA)4 TPP. Toxicity and photo-toxicity were less than those obtained with hematoporphyrin derivative in both L1210 lym-phoblastic leukemia cells and HT 29 human co-lonic cancer cells, as determined with in vitro assays. MR images showed an enhancement of contrast between the tumor and adjacent tissue after injection of this agent. The results indicate that Gd2(DTPA)4TPP could be a useful prototype paramagnetic porphyrin MR imaging contrast agent with an affinity for tumors.