Publications by Georges Wagnières

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Autofluorescence (AF) imaging is a powerful tool for the detection of (pre-)neoplastic lesions in the bronchi. Several endoscopic imaging systems exploit the spectral and intensity contrast of AF between healthy and (pre-)neoplastic bronchial tissues, yet, ...

The design and characterization of optical phantoms which have the same absorption and scattering characteristics as biological tissues in a broad spectral window (between 400 and 650 nm) are presented. These low cost phantoms use agarose dissolved in water as the transparent matrix. The latter is loaded with various amounts of silicon dioxide, intralipid, ink, bovine serum, blood, azide, penicillin and fluorochromes. The silicon dioxide and intralipid particles are responsible for the light scattering wher

Autofluorescence bronchoscopy is a promising approach to detect and characterize precancerous and early cancerous lesions. Nevertheless, many spectral features of photodetection systems remain unclear and sub-optimal at the present time. We report here a comprehensive study of the autofluorescence of the human healthy, metaplastic, dysplastic and cancerous bronchial tissues, covering a range of excitation wavelengths going from 350 nm to 480 nm. Moreover, the absolute values of these tissue autofluorescence

Background: Low-density lipoproteins (LDL) were used as a natural drug delivery system for the transport of hypericin (Hyp) in the bloodstream of the chicken's chorioallantoic membrane model (CAM). Hyp was chosen as a model for hydrophobic drug used in pho ...

Fluorescence imaging for detection of non-muscle-invasive bladder cancer is based on the selective production and accumulation of fluorescing porphyrins-mainly, protoporphyrin IX-in cancerous tissues after the instillation of Hexvix (R). Although the sensi ...

Time-resolved measurements of tissue autofluorescence (AF) excited at 405 nm were carried out with an optical-fiber-based spectrometer in the bronchi of 11 patients. The objectives consisted of assessing the lifetime as a new tumor/normal (T/N) tissue cont ...

The determination of the oxygen partial pressure (pO(2)) in real time in living biological tissues is of high interest for numerous therapeutics, including photodynamic therapy (PDT) and radiotherapy. The minimally invasive and real-time measurement of the ...

Converging lines of evidence indicate that near-infrared light treatment, also known as photobiomodulation (PBM), may exert beneficial effects and protect against cellular toxicity and degeneration in several animal models of human pathologies, including n ...

The pharmacokinetics (PK) of the photosensitizer tetra(m-hydroxyphenyl)chlorin (mTHPC) was measured by optical fiber-based light-induced fluorescence spectroscopy (LIFS) in the normal and tumoral cheek pouch mucosa of 29 Golden Syrian hamsters with chem. i ...

Golden Syrian hamsters are evaluated as an animal model for light induced fluorescence (LIF) photodetection and phototherapy of early squamous cell carcinomas of the upper aerodigestive tract, the esophagus, and the traecheo-bronchial tree. Carcinomas of this type are induced on the hamster cheek pouch mucosa by the application of the carcinogen 7,12-DMBA. For phototherapeutic experiments on the animals we utilized meso-(tetrahydoxyphenyl) chlorin (mTHPC). This drug is currently in phase I and II clinical t

Meta(tetrahydroxyphenyl)chlorin (m-THPC) is a new photosensitizer currently undergoing clin. trials at Lausanne's CHUV hospital for photodynamic therapy (PDT) of early cancer in the upper aerodigestive tract. The illumination of m-THPC with light at 650 nm ...

Significance: Side effects of many cancer treatments are associated with the production of reactive oxygen species (ROS) in normal tissues. This explains why patients treated by photodynamic therapy (PDT) often suffer from skin photosensitization, whereas ...

A major step in the development of photodynamic therapy (PDT) is the clinical optimization and evaluation of new photosensitizers (PS). Ideally, new compounds should be more effective and/or induce fewer side effects than the first generation PS such as he ...

The measurement of Protoporphyrin IX delayed fluorescence lifetime is a minimally invasive method for monitoring the levels of oxygen in cells and tissues. The excitation of Protoporphyrin IX during this measurement can lead to the formation of photoproduc ...

Photodynamic therapy (PDT) may modify the mucosal immune response and thus serve as a therapy for Crohn’s disease (CD). After evaluating safety in BALB/c mice and establishing an endoscopic index of colitis (EIC), we could demonstrate that a single «low dose» PDT with 15 mg/kg delta-aminolevulinic acid and 10 J/cm2 induced healing of the colitis and decreased the expression indices of pro-inflammatory cytokines. The effect of «low dose» PDT appeared more rapidly, was stronger and lasted longer in the contex

Fluorescence detection of early superficial bladder cancer has been well established over the last years. This technique exploits the selective production and accumulation within cancerous tissues of photoactive porphyrins (PaP), mainly protoporphyrin IX (PpIX), after the instillation of hexaminolevulinic acid (Hexvix (R)) in the bladder. Although the selective production of PpIX and the sensitivity of this procedure are outstanding, its specificity is still limited by a relatively important proportion of f

Golden Syrian hamsters are evaluated as an animal model for phototherapy of early squamous cell carcinomas of the mucosa of the upper aerodigestive tract, the esophagus and the tracheobronchial tree. Carcinomas of this type are induced on the hamster cheek pouch mucosa by the application of the carcinogen 7,12 DMBA. For phototherapeutic expts. on the animals the authors utilized meso-(tetrahydoxyphenyl)chlorin (mTHPC). The same drug is currently in phase I, II clin. trials for ENT patients with superficial

Protoporphyrin IX (PpIX) is used as a fluorescence marker and photosensitizing agent in photodynamic therapy (PDT). A temporary increase of PpIX in tissues can be obtained by administration of 5-aminolevulinic acid (ALA). Lipophilicity is one of the key pa ...

Time-resolved fluorescence spectroscopy has the potential to provide more information for the detection of early cancer than continuous wave spectroscopy. A new optical fiber-based spectrofluorometer for time-resolved fluorescence spectroscopy of biol. tis ...

The cutaneous phototoxic reaction induced by i.v. injection of 5,-10,-15,-20-tetra(m-hydroxyphenyl)chlorin (mTHPC) has been clin. evaluated in patients undergoing photodynamic therapy. These tests were performed on the backs of 23 patients with a solar sim ...

Georges Wagnières

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Blue-violet excited autofluorescence spectroscopy and imaging of normal and cancerous human bronchial tissue after formalin fixation

Design and characterization of a phantom that simultaneously simulates tissue optical properties between 400 and 650 nm

In vivo fluorescence spectroscopy to optimize the detection of early bronchial carcinoma by autofluorescence imaging

Hypericin can cross barriers in the chicken's chorioallantoic membrane model when delivered in low-density lipoproteins

High-magnification vascular imaging to reject false-positive sites in situ during Hexvix® fluorescence cystoscopy

In vivo time-resolved spectroscopy of the human bronchial early cancer autofluorescence

In vivo measurement of the tissue oxygenation by time-resolved luminescence spectroscopy of protoporphyrin IX: Strategies to minimize artefacts associated with photoproducts

Photobiomodulation Suppresses Alpha-Synuclein-Induced Toxicity in an AAV-Based Rat Genetic Model of Parkinson's Disease

Pharmacokinetics and pharmacodynamics of tetra(m-hydroxyphenyl)chlorin in the hamster cheek pouch tumor model: comparison with clinical measurements

Evaluation with mTHPC of early squamous cell carcinomas of the cheek pouch mucosa of Golden Syrian hamsters as a model for clinical PDT of early cancers in the upper aerodigestive tract, the esophagus

Spectroscopic studies of photobleaching and photoproduct formation of meta(tetrahydroxyphenyl)chlorin (m-THPC) used in photodynamic therapy. The production of singlet oxygen by m-THPC

Catechin reduces phototoxic effects induced by protoporphyrin IX-based photodynamic therapy in the chick embryo chorioallantoic membrane

Photodynamic Therapy for Cancer of the Upper Aerodigestive Tract Using Tetra(m-hydroxyphenyl)chlorin

Effect of PpIX photoproducts formation on pO2 measurement by time-resolved delayed fluorescence spectroscopy of PpIX in solution and in vivo

Photodynamic therapy as a novel therapeutic approach for the treatment of Crohn's disease

Detection of early bladder carcinoma by fluorescence cystoscopy with Hexvix: optical characterization of a high magnification cystoscope

Pharmacokinetics of meso-(tetrahydroxyphenyl)chlorin (mTHPC) studied by fluorescence spectroscopy on early cancer of the cheek pouch mucosa of Golden Syrian hamsters

5-Aminolevulinic acid and its derivatives: physical chemical properties and protoporphyrin IX formation in cultured cells

Time-resolved spectrofluorometer for clinical tissue characterization during endoscopy

Clinical evaluation of the cutaneous phototoxicity of 5, 10, 15, 20-tetra (m-hydroxyphenyl)chlorin