Publications by Georges Wagnières

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Background: In specific conditions, photodynamic therapy (PDT) can enhance the distribution of macromolecules across the endothelial barrier in solid tumors. It was recently postulated that tumor neovessels were more responsive to PDT than the normal vascu ...

The fluorescence lifetime of living tissues is, in certain cases, related to their pathol. state and is therefore of interest for cancer detection. Measuring fluorescence lifetime in vivo during an endoscopic examn. has thus been a challenging objective fo ...

The objective of this study was to evaluate the ability of meso-tetra(hydroxyphenyl)chlorin (m-THPC) encapsulated into liposomal formulations to occlude neovascularization. Two m-THPC formulations including conventional or plain liposomes (Foslip) based on ...

Photobiomodulation (PBM) is a promising approach to treat Parkinson's disease (PD) symptoms in cellular or animal models. Unfortunately, little information is available on the optical parameters playing a role in the light dosimetry during PBM. We conducted a study to determine the effective attenuation coefficient mu(eff) of PD-relevant human deep brain tissues at 671 and 808 nm, using a multichannel fluence rate-meter comprising sub-millimeter isotropic detectors. The first step involved measurements of t

In vivo spectrofluorometric analysis during photodynamic therapy (PDT) is a tool to obtain information about fluorophore bleaching kinetics in tissue. Using a cylindrical esophageal light distributor for PDT with an integrated sensing fiber, together with a fluorescence detection setup, we can obtain tissue fluorescence spectra endoscopically in a clinical environment. This study was performed on patients with early squamous cell carcinomas in the esophagus. Patients were injected intravenously with 0.15 mg

Phototoxicity is a side-effect of in vitro and in vivo oxygen partial pressure (pO(2)) detection by luminescence lifetime measurement methods. Dichlorotris(1,10-phenanthroline)-ruthenium(II) hydrate (Ru(Phen)(3)) is a water soluble pO(2) probe associ ...

Nowadays, photobiomodulation (PBM) in combination with chemotherapy or other therapeutic approaches is an attractive adjuvant modality for cancer treatment. Targeted destruction of cancer cells is one of the main ad-vantages of photodynamic therapy (PDT). ...

Background. To optimize photodynamic therapy (PDT) and photodetection of cancer, two important variables that must be considered are the uptake of the dye and the dye contrast between normal and neoplastic tissue after injection. Methods. To study these va ...

Delayed fluorescence (DF) is a long-lived luminescence process used in a variety of applications ranging from oxygen sensing in biological tissues to organic Light Emitting Diodes. In common cases, DF results from the deexcitation of the first excited trip ...

Photodynamic therapy (PDT) and/or photodetection (PDD) based on protoporphyrin IX (PpIX) are used in many medical fields. However, the endogenous production of PpIX in tissues after administration of its precursor, 5-aminolevulinic acid (ALA) or derivative ...

Head and neck (H&N) cancer patients have a high incidence of second primary tumors in the tracheobronchial tree. Diagnostic autofluorescence endoscopy (DAFE) has shown promising results in the detection of early neoplastic and pre-neoplastic changes in the bronchi. We have investigated the medical impact of DAFE in a population of H&N cancer patients. The bronchoscopies were performed using a modified commercially available DAFE system, allowing both white light (WL) and autofluorescence (AF) bronchoscopy.

Measuring tissue oxygenation in vivo is of interest in fundamental biological as well as medical applications. One minimally invasive approach to assess the oxygen partial pressure in tissue (pO(2)) is to measure the oxygen-dependent luminescence lifetime ...

The chicken embryo's chorioallantoic membrane (CAM) is widely used as an in vivo model to study the vascular effects induced by agents administrated topically or intravenously. Hence, in the vascular plexus of this respiratory membrane, angiogenic and anti-angiogenic agents, as well as phototoxic effects have been studied. The main goal of this study was to characterize the capillary network of the CAM after topical administration of dimethyl sulfoxid (DMSO), a frequently used solvent of lipophylic drugs, i

Fluorescence cystoscopy has been recently acknowledged as a useful method to detect early superficial bladder cancer, even flat lesions. After the instillation of hexaminolevulinic acid (Hexvix®) in the bladder for about an hour, photoactivable porphyrins (PaP), mainly protoporphyrin IX (PpIX) accumulate in the cancerous cells. Although we observe a selective production of PpIX and an outstanding sensitivity of this method, false positive (FP) lesions negatively impact its specificity. Carcinogenesis often

Photodynamic therapy (PDT) is an interesting and promising approach to tackle a broad spectrum of cancer. With the combination of a photosensitizer, light and oxygen, PDT achieves a unique selectivity by the production of localized reactive oxygen species ...

To improve the detectability of tumors by light-induced fluorescence, the use of monoclonal antibodies (MoAb) as carriers of fluorescent molecules was studied. As a model for this approach, the biodistribution of an anticarcinoembryonic antigen (CEA) MoAb ...

An excellent knowledge of histopathological risk factors of superficial bladder transitional cell carcinoma is mandatory to establish the prognosis of the disease. Presence or absence of carcinoma in situ (CIS) in superficial bladder cancer is one of the most powerful risk indicators. This study examines the usefulness of fluorescence photodetection of neoplastic urothelial foci in bladder cancer following intravesical instillation of delta-aminolevulinic acid (5-ALA). Following bladder instillation of an a

Crohn's disease is an inflammatory bowel disease originating from an overwhelming response of the mucosal immune system. Low dose photodynamic therapy (PDT) may modify the mucosal immune response and thus serve as a therapy for Crohn's disease. Most patients with Crohn's disease show inflammatory reactions in the terminal ileum or colon where PDT treatment is feasible by low-invasive endoscopic techniques. However, the tube like geometry of the colon, it's folding, and the presences of multiple foci of Croh

Early detection and localisation of bronchial cancer remains a challenging task. One approach is to exploit the changes in the autofluorescence characteristics of the bronchial tissue as a diagnostic tool with improved sensitivity. Evidence exists that this native fluorescence or autofluorescence of bronchial tissues changes when they turn dysplastic and to carcinoma in situ. There is agreement in the literature that the lesions display a decrease in autofluorescence in the green region of the spectrum unde

Zinc(II) phthalocyanine (ZnPC) is a new photosensitizer currently undergoing phase I and II clinical trials at Lausanne's CHUV hospital for the photodynamic therapy (PDT) of early cancer in the upper aerodigestive tract. Activated oxygen species other than ...

Georges Wagnières

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Photodynamic Therapy Selectively Enhances Liposomal Doxorubicin Uptake in Sarcoma Tumors to Rodent Lungs

Instrumentation for real-time fluorescence lifetime imaging in endoscopy

Photothrombic activity of m-THPC-loaded liposomal formulations: pre-clinical assessment on chick chorioallantoic membrane model

Optical properties of the deep brain in the red and NIR: changes observed under in-vivo, post-mortem, frozen and formalin-fixated conditions

In-vivo measurement of fluorescence bleaching of meso-tetra hydroxy phenyl chlorin (mTHPC) in the esophagus and the oral cavity

Endosomes: Guardians Against [Ru(Phen)3]2+ Photo-action In Endothelial Cells During In Vivo pO2 Detection?

Photobiomodulation and photodynamic therapy-induced switching of autophagy and apoptosis in human dermal fibroblasts

Clinical pharmacokinetic studies of photofrin by fluorescence spectroscopy in the oral cavity, the esophagus, and the bronchi

A general framework for non-exponential delayed fluorescence and phosphorescence decay analysis, illustrated on Protoporphyrin IX

Increase and homogenization of the endogenous production of protoporphyrin IX by photobiomodulation

Detection of early bronchial cancer by autofluorescence: Results in patients with H&N cancer

In vivo measurement of tissue oxygenation by time-resolved luminescence spectroscopy: advantageous properties of dichlorotris(1, 10-phenanthroline)-ruthenium(II) hydrate

Vascular effects induced by anti-VEGF agents in the CAM model: Effect of the DMSO

Bladder cancer detection by fluorescence imaging with Hexvix®: Analysis and processing of images obtained during high magnification cystoscopy

Porphyrin metalla-assemblies coupled to cellulose nanocrystals for PDT and imaging applications

Antibody-fluorescein conjugates for photoimmunodiagnosis of human colon carcinoma in nude mice

Usefulness of fluorescence photodetection of neoplastic urothelial foci in bladder cancer following intravesical instillation of delta-aminolevulinic acid (5-ALA)

Design of a light delivery system for the photodynamic treatment of the Crohn's disease

Detection of early bronchial carcinoma by imaging of the tissue autofluorescence

Production of the free radicals O-2(.-) and OH by irradiation of the photosensitizer zinc(II) phthalocyanine