Laboratoire des Interactions Moléculaires et Réactivité Chimique et Photochimique
UMR 5623

Clémence Nadal, PhD student at IMRCP, has defended her thesis on a biomaterial by colloidal self-assembly

Clémence carried out her research in the P3R team at the IMRCP laboratory, in collaboration with the laboratory CIRIMAT.

On 16th December, she defended her thesis entitled: "Elaboration of a biomaterial by colloidal self-assembly: Surface modification of hydrogel-based nanoparticles with a thermoresponsive block copolymer"

Progress in regenerative medicine is closely related to the elaboration of new biomaterials tailored to meet certain specifications. Biomaterials are expected to maintain and/or restore the healthy tissu’s function and be easily implanted into patients. In this context, thermosensitive nanoparticle-based biomaterials are promising as they can be injected and, in response to a stimulus such as body temperature, they undergo in situ self-assembly.

We propose an innovative strategy aiming at the design of a biomaterial by colloidal self-assembly based on the surface modification of hydrogel-based nanoparticles with a thermoresponsive copolymer. The objective of this work is to answer the following question: does surface modification of nanoparticles with a thermoresponsive copolymer bring thermosensitive properties to these particles?

First, pH- and thermoresponsive PVAm-b-PNIPAM copolymer was synthetized and characterized to study its physico-chemical properties in aqueous medium, including its critical temperature and self-assembly properties.
Hydrogel-based core/shell particles with diameter of around 500 nm were obtained by layer-by-layer assembly of two natural polyelectrolytes, chitosan and alginate, coated onto a silica core. Surface modification was characterized, 1H NMR and XPS confirmed the presence of copolymer onto the particles surface, and a quantification was carried out by spectrofluorimetry.
Finally, thermosensible properties of the modified nanoparticles suspension was investigated and showed that a rise of temperature above the critical temperature of the copolymer induced the destabilization of the suspension. This result answered positively to our question and confirmed the interest of such system for biomedical applications.

Highlight of the thesis:

  • in 2019, Clémence attended the Bayreuth International Summer School which focused on current trends in biomaterials research and biofabrication;
  • she presented her research at C'Nano, an international meeting in nanoscience, on November 2021.

Congratulations to Clémence for the quality of her work!

 

2022 IMRCP