TY - JOUR
T1 - Localization of Liposomal mTHPC Formulations within Normal Epithelium, Dysplastic Tissue, and Carcinoma of Oral Epithelium in the 4NQO-Carcinogenesis Rat Model
AU - de Visscher, SAHJ
AU - Witjes, MJH
AU - van der Vegt, B
AU - de Bruijn, Riëtte
AU - van den Heuvel, AV
AU - Amelink, Arjen
AU - Sterenborg, Dick
AU - Roodenburg, JLN
AU - Robinson, Dominic
PY - 2013
Y1 - 2013
N2 - Background and ObjectiveFoslip and Fospeg are liposomal formulations of the photosensitizer mTHPC (Foscan), which is used for photodynamic therapy (PDT) of malignancies. Literature suggests that liposomal mTHPC formulations have better properties and increased tumor uptake compared to Foscan. To investigate this, we used the 4NQO-induced carcinogen model to compare the localization of the different mTHPC formulations within normal, precancerous, and cancerous tissue. In contrast to xenograft models, the 4NQO model closely mimics the carcinogenesis of human oral dysplasia. Materials and MethodsFifty-four rats drank water with the carcinogen 4NQO. When oral examination revealed tumor, the rats received 0.15mg/kg mTHPC (Foscan, Foslip, or Fospeg). At 2, 4, 8, 24, 48, or 96hours after injection the rats were sacrificed. Oral tissue was sectioned for HE slides and for fluorescence confocal microscopy. The HE slides were scored on the severity of dysplasia by the epithelial atypia index (EAI). The calibrated fluorescence intensity per formulation or time point was corr ResultsFospeg showed higher mTHPC fluorescence in normal and tumor tissue compared to both Foscan and Foslip. Significant differences in fluorescence between tumor and normal tissue were found for all formulations. However, at 4, 8, and 24hours only Fospeg showed a significant difference. The Pearson's correlation between EAI and mTHPC fluorescence proved weak for all formulations. ConclusionIn our induced carcinogenesis model, Fospeg exhibited a tendency for higher fluorescence in normal and tumor tissue compared to Foslip and Foscan. In contrast to Foscan and Foslip, Fospeg showed significantly higher fluorescence in tumor versus normal tissue at earlier time points, suggesting a possible clinical benefit compared to Foscan. Low correlation between grade of dysplasia and mTHPC fluorescence was found. Lasers Surg. Med. 45:668-678, 2013. (c) 2013 Wiley Periodicals, Inc.
AB - Background and ObjectiveFoslip and Fospeg are liposomal formulations of the photosensitizer mTHPC (Foscan), which is used for photodynamic therapy (PDT) of malignancies. Literature suggests that liposomal mTHPC formulations have better properties and increased tumor uptake compared to Foscan. To investigate this, we used the 4NQO-induced carcinogen model to compare the localization of the different mTHPC formulations within normal, precancerous, and cancerous tissue. In contrast to xenograft models, the 4NQO model closely mimics the carcinogenesis of human oral dysplasia. Materials and MethodsFifty-four rats drank water with the carcinogen 4NQO. When oral examination revealed tumor, the rats received 0.15mg/kg mTHPC (Foscan, Foslip, or Fospeg). At 2, 4, 8, 24, 48, or 96hours after injection the rats were sacrificed. Oral tissue was sectioned for HE slides and for fluorescence confocal microscopy. The HE slides were scored on the severity of dysplasia by the epithelial atypia index (EAI). The calibrated fluorescence intensity per formulation or time point was corr ResultsFospeg showed higher mTHPC fluorescence in normal and tumor tissue compared to both Foscan and Foslip. Significant differences in fluorescence between tumor and normal tissue were found for all formulations. However, at 4, 8, and 24hours only Fospeg showed a significant difference. The Pearson's correlation between EAI and mTHPC fluorescence proved weak for all formulations. ConclusionIn our induced carcinogenesis model, Fospeg exhibited a tendency for higher fluorescence in normal and tumor tissue compared to Foslip and Foscan. In contrast to Foscan and Foslip, Fospeg showed significantly higher fluorescence in tumor versus normal tissue at earlier time points, suggesting a possible clinical benefit compared to Foscan. Low correlation between grade of dysplasia and mTHPC fluorescence was found. Lasers Surg. Med. 45:668-678, 2013. (c) 2013 Wiley Periodicals, Inc.
U2 - 10.1002/lsm.22197
DO - 10.1002/lsm.22197
M3 - Article
SN - 0196-8092
VL - 45
SP - 668
EP - 678
JO - Lasers in Surgery and Medicine
JF - Lasers in Surgery and Medicine
IS - 10
ER -