Biodistribution Assessment of a Lutetium(III) Texaphyrin Analogue in Tumor-bearing Mice Using NIR Fourier-transform Raman Spectroscopy


  • Posted on the website on 29 March 2004.

*To whom correspondence should be addressed (VK): Department of Analytical Chemistry, Institute of Chemical Technology, Technická 5, 166 28 Prague 6, Czech Republic. Fax: 402-224310352; e-mail:

*To whom correspondence should be addressed (JLS): Department of Chemistry and Biochemistry, Institute for Cellular and Molecular Biology, 1 University Station, The University of Texas at Austin, Austin, TX 78712-1065, USA. Fax: 512-471-7550; e-mail:


The use of near-infrared (NIR)-excited Fourier-transform (FT) Raman spectroscopy as a technique for evaluating the extent of photosensitizer localization in tumor (human pancreatic adenocarcinomas)-bearing mice has been tested using lutetium(III) texaphyrin analogue Ln-T2B2Tex. The complex was injected subcutaneously in the form of three injections given during the course of 3 days. The kinetics of biodistribution were then followed over a time scale of 1–6 days. The NIR-FT-Raman spectra of tissue samples obtained from the xenographic tumor, muscle, heart, brain, liver, spleen, kidney and blood were recorded and used to identify the presence of Lu-T2B2Tex in these tissues. Five Raman sensitizer markers were used to estimate the relative content of Lu-T2B2Tex in tumor at various postinjection times. UV-Visible (Vis) absorption spectroscopic detection of this sensitizer in tissue extracts was applied as a conventional method. Both spectroscopic methods were in good agreement with each other and confirm that Lu-T2B2Tex localizes well in tumor tissue. Maximal drug content was observed 3 days after the final injection. This time delay seems to be optimal for tumor irradiation in photodynamic therapy.