Adsorption de protéines sur des colloïdes et agrégation induite

Abstract : Colloids are used in many applications such as contrast agents in MRI or magnetic immuno-agglutination in diagnosis. To improve their performance, the interaction between particles and biological media - in particular proteins - has been studied for more than 150 years; nevertheless this phenomenon is still not well described. The first part of this thesis is dedicated to an application of colloids: detection of target proteins. Based on orientation of anisotropic magnetic aggregates, a new method has been developed, which generates a signal of aggregation, directly proportional to the amount of protein in the sample: lowering the detection limit. This technique has been validated on a real system: C-reactive protein. The second part is dedicated to protein adsorption on colloids. The first objective was the development of a protocol to obtain reliable measurements; adsorption could then be characterized in a model system: bovine serum albumin and silica. Results obtained were thus able to dismiss certain paradoxes and to propose a new model. Ultimately the studies reveal how proteins, by adsorbing between two particles, aggregate colloids. In sufficient quantities, they can also protect against aggregation, enabling a new method of particle stabilization.
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Contributor : Donatien Ramiandrisoa <>
Submitted on : Wednesday, May 28, 2014 - 10:50:48 AM
Last modification on : Thursday, July 4, 2019 - 11:00:05 AM
Long-term archiving on : Thursday, August 28, 2014 - 11:56:19 AM

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Donatien Ramiandrisoa. Adsorption de protéines sur des colloïdes et agrégation induite. Chimie-Physique [physics.chem-ph]. Université Pierre et Marie Curie - Paris VI, 2014. Français. ⟨pastel-00997448⟩

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