title: Distribution of aluminum phthalocyanine disulfonate in an oral squamous cell carcinoma model. In vivo fluorescence imaging compared with ex vivo analytical methods.
abstract: Photosensitizer-induced fluorescence is studied as a technique for the detection of cancer. Therefore we investigated the ability of a photosensitizer, aluminum phthalocyanine disulfonate (AIPcS2), to localize in tumor tissue. In vivo endoscopic fluorescence imaging, fluorescence microscopy, conventional spectrofluorometry and high performance liquid chromatograpy combined with diode laser-induced fluorescence (HPLC-Dio-LIF) were used. Squamous cell carcinomas were induced with 4-nitro-quinoline-1-oxide (4NQO) in the mucosa of the palate of the rat. In vivo fluorescence images, taken after injection of 1.5 mumol/kg AIPcS2 intravenously, showed that 4NQO-treated palates had higher fluorescence signals than normal palates. Areas displaying locally high amounts of AIPcS2 fluorescence (hot spots) were present only in 4NQO-treated rats 2-8 h but had disappeared 24 h after injection. However, HPLC-Dio-LIF showed that the relative AIPcS2 content was highest at 24/48 h in biopsies taken in the areas of the hot spots. Fluorescence microscopy revealed that AIPcS2 was present only between 2 and 8 h in the epithelial layer, while in biopsies the connective tissue contained large quantities of AIPcS2 at 24/48 h. In vivo fluorescence imaging appears to show mainly fluorescence from the epithelial layer and the ex vivo analytical techniques mainly show the connective tissue fluorescence. Care should be taken when interpreting data using one technique only.
authors.affiliation: Department of Oral & Maxillofacial Surgery, University Hospital Groningen, The Netherlands. MHK@MED.RUG.NL
authors.forename: M J
authors.initials: MJ
authors.lastname: Witjes
authors.forename: A J
authors.initials: AJ
authors.lastname: Mank
authors.forename: O C
authors.initials: OC
authors.lastname: Speelman
authors.forename: R
authors.initials: R
authors.lastname: Posthumus
authors.forename: C A
authors.initials: CA
authors.lastname: Nooren
authors.forename: J M
authors.initials: JM
authors.lastname: Nauta
authors.forename: J L
authors.initials: JL
authors.lastname: Roodenburg
authors.forename: W M
authors.initials: WM
authors.lastname: Star
mesh_terms: D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D007211:Indoles / Q000493:pharmacokinetics*; D008297:Male; D008856:Microscopy, Fluorescence; D009062:Mouth Neoplasms / Q000175:diagnosis / Q000378:metabolism*; D009942:Organometallic Compounds / Q000493:pharmacokinetics*; D017319:Photosensitizing Agents / Q000493:pharmacokinetics*; D051381:Rats; D017208:Rats, Wistar; D013050:Spectrometry, Fluorescence
chemical_list: D007211:Indoles; D009942:Organometallic Compounds; D017319:Photosensitizing Agents; C064331:aluminum phthalocyanine disulfonate