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See detailANTIBODY-COUPLED NANORODS AS BIOSENSOR PLATFORM FOR SPECIFIC CANCER DETECTION
Schol, Daureen ULg

Doctoral thesis (2013)

This work started as part of a Specific Targeted Research Project, ADONIS (FP-6 of the European Commission) and the aim of the project was the development of active targeting gold nanoparticles for ... [more ▼]

This work started as part of a Specific Targeted Research Project, ADONIS (FP-6 of the European Commission) and the aim of the project was the development of active targeting gold nanoparticles for optoacoustic imaging, from chemistry to biology. The establishment of a biosensor composed of antibody-functionalized gold nanorods is achieved on a model of tumor, in our case prostate cancer. Prostate cancer is a major public health problem in our industrialized countries, indeed it is the most frequent cancer and the second leading cause of death by cancer in men [1]. A major challenge in prostate cancer oncology is to develop more accurate, precise and less invasive tools for early stage diagnostic, including more accurate imaging assessments than those currently available. An efficient imaging technique which significantly improves the sensitivity and the specificity of the diagnostic and enables prediction of the cancer behavior would be extremely valuable to oncologists. Briefly the developed biosensor model consists of a gold nanorod – designed to convert a primary optical excitation into a detectable acoustic signal – coupled with a monoclonal antibody that targets prostate cancer cells for a specific recognition. Improved access to the target can be achieved by targeting accessible extracellular domain of a membrane protein, here the Prostate Specific Membrane Antigen (PSMA) [2]. PSMA is a transmembrane protein considered as a suitable biomarker for prostate cancer [3] and which is under intense investigation for use as an imaging and therapeutic target. PSMA is highly expressed in prostate cancers and also expressed in the tumor associated neovasculature of most solid cancers [4]. Before biological assessments the cytotoxic surfactant, essential to form rod-shaped nanoparticles, is exchanged by a mixture of two functionalized polyethylene glycol (PEG) molecules: HS-PEG-OMe for nanoparticle passivation and HS-PEG-NH2 for subsequent coupling with the antibody. The different cytotoxicity assays are achieved to establish the toxic threshold of the surfactant in order to know what CTAB concentration maybe tolerable on the cells. This argument is important during the displacement of the surfactant, based on successive centrifugations, because the whole discard of CTAB seem to be time-consuming or even routinely unfeasible. Once this threshold drawn up, the PEGylated GNRs can be assessed on cancer cells, what seems being a common in vitro investigation. However unexpected issues came up during the experiments and had to be considered due to the properties of the nanomaterial. Nevertheless, after cytotoxicity assessment of PEGylated nanoparticles, the biosensor binding on targeted cells was assessed by fluorescence and scanning electron microscopies, two straightforward and flexible techniques. The antibody coupled to the gold nanorod is specific to the human prostate carcinoma LNCaP cell line, reported to express PSMA which is an admitted biomarker of this cell line [5]. Finally, in order to complete the specific targeting of the biosensor, the antibody-coupled gold nanorods are injected in nude mice to evaluate their biodistribution and bioaccumulation for which inductively coupled plasma mass spectrometry (ICP/MS) is the technique of choice. Preliminary optoacoustic imaging is the ultimate step for the state-of-theart of the developed biosensor. Although the promising end results, particularly biodistribution assays, new questioning swarm and this is more and more discussed in publications due to the in vivo use of nanomaterials. Owing to their increasingly extensive use, their nanometer sizes and their physiological contact (more or less long), controlling the interaction of nanoparticles with biological systems became a fundamental challenge of nanomedicine [6]. Therefore the protein opsonization on the gold nanorods is a tremendous study and is accomplished via mass spectrometry analyses. [less ▲]

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See detailAnti-PSMA antibody-coupled gold nanorods detection by optical and electron microscopies
Schol, Daureen ULg; Fléron, Maximilien ULg; Greisch, Jean françois et al

in Micron (2013), (50), 68-74

While cancer is one of the greatest challenges to public health care, prostate cancer was chosen as cancer model to develop a more accurate imaging assessment than those currently available. Indeed, an ... [more ▼]

While cancer is one of the greatest challenges to public health care, prostate cancer was chosen as cancer model to develop a more accurate imaging assessment than those currently available. Indeed, an efficient imaging technique which considerably improves the sensitivity and specificity of the diagnostic and predicting the cancer behavior would be extremely valuable. The concept of optoacoustic imaging using home-made functionalized gold nanoparticles coupled to an antibody targeting PSMA (prostate specific membrane antigen) was evaluated on different cancer cell lines to demonstrate the specificity of the designed platform. [less ▲]

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See detailDesign of reversibly disulfide core cross-linked polymer micelles
Cajot, Sébastien ULg; Schol, Daureen ULg; Danhier, F. et al

Poster (2011, December 07)

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See detailDesign of reversibly disulfide core cross-linked polymer micelles
Cajot, Sébastien ULg; Schol, Daureen ULg; Danhier, F. et al

Poster (2011, November 21)

Over the last decade, polymer micelles attracted an increasing interest in drug pharmaceutical research because they could be used as efficient drug delivery systems. Micelles of amphiphilic block ... [more ▼]

Over the last decade, polymer micelles attracted an increasing interest in drug pharmaceutical research because they could be used as efficient drug delivery systems. Micelles of amphiphilic block copolymers are supramolecular core-shell type assemblies of tens of nanometers in diameter. An accumulation of polymer nanocarriers to solid tumours is possible due to the EPR effect. Even if micelles get a high stability in aqueous media, the dissociation of micelles is not always preserved when they are injected in the blood compartment. This work aims at reporting on the design of reversibly cross-linked micelles based on PEO-b-PCL copolymers by introducing disulfide bridges in the micelle core to provide higher stability. Different kinds of macromolecular architectures are employed to study their impact on the micelles and their biological behavior. These new functional copolymers were all successfully micellized, reversibly cross-linked and are stealthy, which show the efficiency of the developed cross-linking process and offer a set of nanocarriers to be tested further, as shown on the first biological tests. [less ▲]

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See detailDisulfide bridges, new prospect in drug delivery systems?
Cajot, Sébastien ULg; Danhier, F.; Schol, Daureen ULg et al

Poster (2011, September 03)

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See detailFunctionalized plasmonic gold nanoparticles for optoacoustic cancer detection
Schol, Daureen ULg; Fleron, Maximilien ULg; Greisch, Jean-François et al

Poster (2008, September 12)

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See detailOptoacoustic specific detection of prostate cancer using functionalized gold nanorods
Schol, Daureen ULg; Fleron, Maximilien ULg; Greisch, Jean-François et al

Poster (2008, March 12)

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See detailLNCaP prostate cancer imaging with biologically functionalized gold nanoparticles in 2D and 3D cell culture
Schol, Daureen ULg; Fleron, Maximilien ULg; Greisch, Jean - François et al

in Anticancer Research (2008), 28

One of the main objectives of this project is to realize and validate a versatile lab system composed of functionalized nanoparticles for diagnosis of different superficial and accessible cancers, e.g ... [more ▼]

One of the main objectives of this project is to realize and validate a versatile lab system composed of functionalized nanoparticles for diagnosis of different superficial and accessible cancers, e.g. prostate cancer. Gold nanorods have been synthesized and functionalized with antibodies targeting specific antigens on cancer cell lines. [less ▲]

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See detailOptoacoustic specific detection of prostate cancer using functionalized gold nanorods
Fleron, Maximilien ULg; Schol, Daureen ULg; Greisch, Jean-François et al

Poster (2007, November 16)

A major challenge in prostate cancer oncology is to develop more accurate imaging assessments than those currently available. Indeed, an efficient imaging technique which significantly improves the ... [more ▼]

A major challenge in prostate cancer oncology is to develop more accurate imaging assessments than those currently available. Indeed, an efficient imaging technique which significantly improves the sensitivity and specificity of the diagnostic and predicting the cancer behaviour would be extremely valuable. This project intends to prove the concept of using optoacoustic imaging in combination with biologically functionalized nanoparticles as an integrated biosensor based system for the production of specific and sensitive data for accurate diagnosis of prostate cancer. This concept results on the use of contrast agents which transform an incident luminous energy into local heating inducing a pressure wave detectable by acoustic (echography). For the optoacoustic detection, the nanoparticles used must present a maximum of absorption in the optical transparency window of the human tissues in order to allow their and subsequently the tissue specific excitations while avoiding unwanted destructive energy transfers. According to these characteristics (energy transfer by thermoelastic reaction), rod-like gold nanoparticles (stick form) with a maximum of absorption towards 760 nm were produced by using a “bottom-up” approach with dynamic templates (surfactant). These nanoparticles are then coupled with an antibody directed against the cancerous cells to guarantee the specific detection of the particles. The development of the biosensor is firstly performed to target the Prostate Specific Membrane Antigen (PSMA), a transmembrane protein considered as a suitable biomarker for prostate cancer. Detection and localisation of PSMA on LNCaP fixed cell surface was performed by immunostainning on monolayer cell culture and on spheroid slices. Then, by backscattered electron (BSE) microscopy analysis and two-photon luminescence imaging, detection of nanoparticles on fixed and living cell surface shows the successful binding of the biosensor to the cells expressing PSMA. In prospect, the detection of the biosensor will be tested on spheroids, on human biopsies and finally on in vivo models (mouse xenograft models). [less ▲]

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See detailOptoacoustic specific detection of prostate cancer using functionalized gold nanorods
Fleron, Maximilien ULg; Schol, Daureen ULg; Greisch, Jean-François et al

Poster (2007, October 10)

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See detailDevelopment of a new integrated biosensor system for an accurate diagnosis of prostate cancer using optoacoustic detection
Fleron, Maximilien ULg; Schol, Daureen ULg; Greisch, Jean-François et al

Poster (2007, June 09)

The prostate cancer is the most common male-specific cancer observed in the European Union and is the second leading cause of cancer death in men in our industrialized countries. The choice of treatment ... [more ▼]

The prostate cancer is the most common male-specific cancer observed in the European Union and is the second leading cause of cancer death in men in our industrialized countries. The choice of treatment and its efficiency is largely dependent on the stage and on the degree of advancement of the cancer when it is diagnosed. Screening procedures like digital rectal examination (DRE) and free prostate specific antigen (PSA) level testing are well established but lack accuracy, yielding only 80% of prostate cancers diagnosed in an early stage. By providing a more accurate and precise tool for diagnosing prostate cancer in its early stages, the percentage of curable cancer patients would increase radically. Current imaging techniques have limited value, thus a major challenge in current prostate cancer oncology is to develop more accurate imaging assessments. An efficient imaging technique which significantly improves the sensitivity and specificity of diagnosing, staging and predicting the behaviour of prostate cancer would be extremely valuable. The ADONIS Project intends to prove the concept of using optoacoustic imaging in combination with biologically functionalized nanoparticles as an integrated biosensor based system for the production of specific and sensitive data for accurate diagnosis of prostate cancer. The achievement of this objective requires excellent know-how on a variety of scientific and technologic fields, brought by the partners of ADONIS, coming from five European countries, such as laser and ultrasound technologies and image reconstruction techniques, the bio-functionalization of nanoparticles, the system integration and, finally, experiments and competent evaluation of the results for their application potential. The development of the biosensor is firstly performed to target the Prostate Specific Membrane Antigen (PSMA), a transmembrane protein considered as a suitable biomarker for prostate cancer and which is under intense investigation for use as an imaging and therapeutic target. To allow the detection optimization of the biosensor, a 3D cellular culture technique (Rotating Cell Culture System) is developed with LNCaP cells (a human prostate carcinoma cell line reported to express PSMA) to be closest to the in vivo aspect for which a three-dimensional aspect of tumor for the biosensor detection is needed. Detection and localisation of PSMA on LNCaP cell surface was performed by immunostainning on monolayer culture and on spheroid slices. Then, by backscattered electron (BSE) microscopy analysis, detection of nanoparticles on cells surface shows the successful binding of the biosensor to the cells expressing PSMA. In prospect, the detection of the biosensor will be tested on large spheroids and finally tested on in vivo model. [less ▲]

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See detailOverview on the ADONIS Project: Accurate Diagnosis of prostate cancer using Optoacoustic detection of biologically functionalized gold Nanoparticles - A new Integrated Biosensor System
Fleron, Maximilien ULg; Schol, Daureen ULg; Greisch, Jean-François et al

Poster (2007, March 21)

Overview on the ADONIS Project: Accurate Diagnosis of prostate cancer using Optoacoustic detection of biologically functionalized gold Nanoparticles - A new Integrated Biosensor System

Detailed reference viewed: 13 (1 ULg)