Skip to main content

Non-invasive measurement of photosensitiser concentration using fluorescence differential path-length spectroscopy: validation for different liposomal formulations of m-THPC: Foscan, Foslip and Fospeg

As previously described, Fluorescence differential path length spectroscopy (FPDS) can determine chromophore concentrations non-invasively after injection with m-THPC (Foscan) in the rat liver [1]. Our first aim is to validate FDPS for two other, liposomal formulations of m-THPC; pegylated liposomes (Fospeg) and conventionel liposomes (Foslip), and compare them to Foscan. As a proof of principle we use the highly vascularised, optically homogenous liver of the rat [1] Validation of the FDPS-measurements was done by chemical extraction of the same liver [2].

Our second aim is to validate FDPS measurements of the tongue, which is optically less homogenous, but clinically more relevant. After successful validation in both liver and tongue tissue, the pharmacokinetic-profile in other tissue types could be assessed by FDPS alone. Therefore, FDPS can lower the need for labour-intensive chemical extraction. Fifty-four male Wistar rats were intravenously injected with one of the three formulations of m-THPC; eighteen rats for each formulation. All rats were injected with 0.15 mg kg m-THPC. FDPS measurements were performed on liver, palate, tongue, spleen and kidney 2, 4, 8, 24, 48, and 96 h after m-THPC administration. For validation of our FDPS measurements, liver and tongue were harvested for chemical extraction [2]. Concentration estimates in liver and tongue measured by FDPS are here compared with chemical extraction.

At the HNODS-meeting we will present the results of our first step in the validation of FDPS; the correlation of FDPS measurements with chemical extraction for the three different formulations in the liver.

References

  1. 1.

    Kruijt B, Kascakova S, de Bruijn HS, van der Ploeg-van den Heuvel A, Sterenborg HJ, Robinson DJ, Amelink A: In vivo quantification of chromophore concentration using fluorescence differential path length spectroscopy. J Biomed Opt. 2009, 14 (3): 034022-10.1117/1.3149862.

    Article  PubMed  Google Scholar 

  2. 2.

    Kascáková S, Kruijt B, de Bruijn HS, van der Ploeg-van den Heuvel A, Robinson DJ, Sterenborg HJ, Amelink A: Ex vivo quantification of mTHPC concentration in tissue: influence of chemical extraction on the optical properties. J Photochem Photobiol B. 2008, 91 (2-3): 99-107. 10.1016/j.jphotobiol.2008.02.003.

    Article  PubMed  Google Scholar 

Download references

Author information

Affiliations

Authors

Corresponding author

Correspondence to Sebastiaan de Visscher.

Rights and permissions

Open Access This article is published under license to BioMed Central Ltd. This is an Open Access article is distributed under the terms of the Creative Commons Attribution 2.0 International License (https://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Reprints and Permissions

About this article

Cite this article

de Visscher, S., Witjes, M., Kascáková, S. et al. Non-invasive measurement of photosensitiser concentration using fluorescence differential path-length spectroscopy: validation for different liposomal formulations of m-THPC: Foscan, Foslip and Fospeg. Head Neck Oncol 2, O46 (2010). https://doi.org/10.1186/1758-3284-2-S1-O46

Download citation

Keywords

  • Public Health
  • Path Length
  • Tissue Type
  • Homogenous Liver
  • Liposomal Formulation