The high recurrence and lethality of ovarian cancer at advanced stages is problematic, especially due to the development of numerous micrometastases scattered throughout the abdominal cavity. Fluorescence photodetection (PD) used in combination with surgical resection of malignant tissues has been suggested to improve recovery. Based on promising in vivo results for the detection of bladder cancer, hypericin (Hy), a natural photosensitizer (PS), stands as a good candidate for the photodetection of ovarian cancer. However, due to its hydrophobicity, systemic administration of Hy is problematic. Polymeric nanoparticles (NPs) help to overcome these delivery and stability problems and enable intravenous administration of Hy. In this study, Hy-loaded NPs of polylactic acid were produced with the following properties: (i) mean size of 268 nm, (ii) negative zeta potential, (iii) low residual surfactant and (iv) drug loading of 3.7 % (w/w). The potential of hypericin-loaded nanoparticles for the fluorescence photodetection of ovarian metastases in Fischer 344 rats bearing ovarian tumours was compared to free drug. The selectivity of Hy administered with both formulations was assessed first by fluorescence endoscopy, and then quantified after tissue extraction. The results showed an improved selective accumulation of Hy in ovarian micrometastases when NPs were used.
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http://dx.doi.org/10.1016/j.ejpb.2008.10.005 | DOI Listing |
Cancer Biol Med
March 2012
Department of Biochemistry, School of Medicine, People's Friendship University of Russia, Moscow 117198, Russia.
Photodynamic therapy (PDT) is a minimally invasive and promising new method in cancer treatment. Cytotoxic reactive oxygen species (ROS) are generated by the tissue-localized non-toxic sensitizer upon illumination and in the presence of oxygen. Thus, selective destruction of a targeted tumor may be achieved.
View Article and Find Full Text PDFNanomedicine (Lond)
February 2009
Department of Pharmaceutics & Biopharmaceutics, School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, 30, Quai E Ansermet, CH-1211 Geneva 4, Switzerland.
Aims: In urology, fluorescence-based imaging methods have been proven to significantly improve the detection of small, barely visible tumors and reduce the recurrence rate. Under ethical and economical pressure, new effective screening systems have to be developed to exploit and assess novel strategies for fluorescence photodetection in other areas. For this purpose, the chorioallantoic membrane (CAM) of the developing chick embryo is an attractive alternative model to the mammalian models.
View Article and Find Full Text PDFEur J Pharm Biopharm
February 2009
Department of Pharmaceutics and Biopharmaceutics, School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Geneva, Switzerland.
The high recurrence and lethality of ovarian cancer at advanced stages is problematic, especially due to the development of numerous micrometastases scattered throughout the abdominal cavity. Fluorescence photodetection (PD) used in combination with surgical resection of malignant tissues has been suggested to improve recovery. Based on promising in vivo results for the detection of bladder cancer, hypericin (Hy), a natural photosensitizer (PS), stands as a good candidate for the photodetection of ovarian cancer.
View Article and Find Full Text PDFPhotomed Laser Surg
August 2007
Department of Gynecology and Obstetrics, Lille University Hospital, Lille, France.
Objectives: This study set out to compare the photodetection of peritoneal micrometastases in an ovarian cancer model following administration of two precursors of protoporphyrin IX (PpIX): 5-aminolevulinic acid (ALA) and hexylester aminolevulinate (He-ALA).
Methods: ALA or He-ALA (100 mg/kg) was injected into the peritoneal cavity of 16 rats with induced peritoneal metastases of ovarian cancer. Two hours later, the tumors were visualized laparoscopically using both white light for standard exploration and blue light for fluorescence.
Lasers Med Sci
September 2007
Department of Obstetrics and Gynecology, Medizinische Hochschule Hannover, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany.
The concept of intraoperative in vivo diagnosis and selective resection of infiltrated lymph nodes in ovarian cancer has not been evaluated despite the increased morbidity associated with pelvic and paraaortic lymph node dissection and its questionable therapeutic value. Fluorescence photodetection is based on the application of a photosensitizer relatively selective for malignant tissue, which after light activation of appropriate wavelength, shows fluorescence. Six hours after oral application of 10 mg/kg body weight 5-aminolevulinic acid, the abdominal cavity of a patient with suspicion of recurrent ovarian cancer was inspected using a laparoscope and blue light at 380-440 nm.
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