Meso-tetraphenylporphyrin in liposomes as a suitable photosenzitizer for photodynamic therapy of tumors.
نویسندگان
چکیده
The suitability of a liposomal form of hydrophobic nonsulfonated meso-tetraphenyl porphyrin (TPP) for the photodynamic therapy of tumors was investigated. TPP was solubilized in small unilamellar lipid vesicles prepared by extrusion on a LIPOSOFAST apparatus. These samples were studied by laser-excited time resolved luminescence and triplet-triplet absorption spectroscopy. In this lipid environment TPP was still an efficient singlet oxygen producer, as indicated by the characteristic singlet oxygen phosphorescence at 1270 nm in D2O, when excited with a 28 ns laser pulse at 412 nm. Moreover, unlike with sulfonated TPP (TPPS4), liposomal TPP showed the reduced decay rates of TPP triplet-states with the increasing time of pre-illumination by a Xenon lamp. This was shown in an indirect way, based upon the appearance of a second component of the luminescence decay at 1270 nm in D2O; and by direct TPP triplet state monitoring, detecting triplet-triplet absorption at 440 nm in H2O. The deactivation of higher triplet states was delayed upon pre-illumination. This reflects an irreversible interaction of singlet oxygen with membrane lipids, thus demonstrating the potential of the liposomal form of TPP to efficiently disintegrate tumor cell membranes and to be a suitable preparation for the photodynamic therapy.
منابع مشابه
Photodynamic Therapy: A New Approach to Remove Embryos of the Wistar Rat
Background Photodynamic therapy (PDT) is a promising new cancer treatment strategy which inactivates tumor cells by simultaneoulsy using light and a photosensitizer. The similarity between tumors and newly implanted embryos is notable. Extrauterine pregnancy (EUP) does not have a definite treatment and previous therapeutic options (medical and surgical) have not been effective or suitable. Ther...
متن کاملSpectroscopic Study of the Complexation of Meso-Tetraphenylporphyrin with -Acceptors DDQ and TCNE in Chloroform Solution
Formation of the molecular complexes between meso-tetraphenylporphyrin (TPP) and the p-acceptors 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) and tetracyanothylene (TCNE) in chloroform solution was investigated spectrophotometrically. The formation constants of the resulting 1:1 molecular complexes were determined using the Benesi-Hildebrand and Nash methods. The TPP-DDQ pro...
متن کاملState of the art of stimuli-responsive liposomes for cancer therapy
Specific delivery of therapeutic agents to solid tumors and their bioavailability at the target site are the most clinically important and challenging goals in cancer therapy. Liposomes are promising nanocarriers and have been well investigated for cancer therapy. In spite of preferred accumulation in tumors via the enhanced permeability and retention (EPR) effect, inefficient drug release at t...
متن کاملState of the art of stimuli-responsive liposomes for cancer therapy
Specific delivery of therapeutic agents to solid tumors and their bioavailability at the target site are the most clinically important and challenging goals in cancer therapy. Liposomes are promising nanocarriers and have been well investigated for cancer therapy. In spite of preferred accumulation in tumors via the enhanced permeability and retention (EPR) effect, inefficient drug release at t...
متن کاملEvaluation of the Combined Effects of Sonodynamic and Photodynamic Therapies in a Colon Carcinoma Tumor Model (CT26)
Introduction: Photodynamic therapy is a noninvasive therapeutic method for tumors with a maximum depth of 5 mm. On the other hand, most photosensitizers are also susceptible to ultrasound waves (the basis of sonodynamic therapy). Therefore, it is expected that a combination of the two therapeutic methods will increase effectiveness of photodynamic therapies for lower doses of sensitizer and cur...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- General physiology and biophysics
دوره 18 2 شماره
صفحات -
تاریخ انتشار 1999