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Accueil du site > LPCNO > Séminaires > 2017 > Adhesion of Hydrogels to Liver Effect of hydration and interfacial nanoparticles

Adhesion of Hydrogels to Liver Effect of hydration and interfacial nanoparticles

Date : 07/12/2017 à 14:00

Titre : Adhesion of Hydrogels to Liver Effect of hydration and interfacial nanoparticles

Intervenant : Raphaël Michel

Provenance : Laboratoire Matière Molle et Chimie, CNRS UMR 7167 ; ESPCI-Paris ; Paris, France.

Salle : Salle de séminaire - LPCNO

Abstract : Attaching hydrogel membranes to the soft hydrated tissues of internal organs is of major interest for wound dressing and hemostatic purposes, drug and cell delivery and sensor applications. Accordingly, new adhesive strategies have recently been developed such as bio-inspired adhesives (1), polymer glues with specific fonctionalisation (2, 3), mechanical interlocking (4), or coating with nanoparticles (5, 6). These new concepts are often evaluated ex vivo on relatively dried tissues without monitoring liquid exchanges, although it is known that wet conditions can dramatically alter the adhesive power of hydrogels (7). This raises the question of the validity of the so-recorded performances and their transferability to clinics.
Accordingly, the present work aims at understanding the influence of liquid distribution at the hydrogel/tissue interface on the adhesive properties. Herein, we address this question using a model system of polyethylene glycol (PEG) hydrogel and porcine liver tissues. Using an optimized peeling experiment, we could measure the adhesion created between hydrogels and tissues and evaluate the influence of interfacial fluid transport on adhesive properties. We could distinguish between two regimes : a “lubricated” regime where the interfacial liquid prevents adhesion and an “adhesive” regime in which strong adhesion induces a visible deformation of tissues during the peeling (8). A simple model describing the dehydration of the superficial tissue layer predicts the transition between these regimes and suggests that adhesion occurs upon local tissue dehydration. In this dehydrated state, the addition of nanoparticles at the interface - after the method proposed by Leibler and co-workers (5, 6) - leads to enhanced adhesion energies of interest for surgical practice. Overall, this work shed a new light on recent advances in the field of bioadhesives while offering valuable guidelines for the design and evaluation of adhesive hydrogels.
1. J. Shin et al., Advanced Functional Materials 25, 3814 (2015).
2. J. Li et al., Science 357, 378 (2017).
3. C. K. Roy et al., Adv. Mater. 27, 7344 (2015).
4. S. Y. Yang et al., Nat. Commun. 4, 1702 (2013).
5. A. Meddahi-Pelle et al., Angew. Chem.-Int. Edit. 53, 6369 (Jun, 2014).
6. S. Rose et al., Nature 505, 382 (Jan, 2014).
7. N. Annabi et al., Nano Today 9, 574 (Oct, 2014).
8. R. Michel, L. Corté, to be submitted, (2017).