Séminaire de Etienne Piantanida (Institut de Science et d’Ingénierie Supramoléculaires UMR7006 Université de Strasbourg, France.) sur le thème « Nanocomposite hydrogel for biomedical applications ».
Hydrogels are materials that can entrap a high amount of water (up to 98%) and, thanks to their porous structure that allows oxygen and nutrients permeation , they are suitable for the development of biomedical materials. Poly(amidoamine) (paam) hydrogel are a class of materials of particular interest because the cross-linking occurs in water, at room temperature and without the need of an external initiator; they are formed through aza-Michael condensation of N,N’-methylene-bis-acrylamide (MBA) with cross-linking agents based on amine functionalities. The introduction of different pending groups and cross-linkers allows to tune the mechanical properties of the material and to introduce other feature such as conductivity or tissue adhesiveness. Hydrogels based on poly(amidoamines) have already been successfully employed, in our group, as platform for cell growth and proliferation . The properties of the hydrogel can be further tuned with the introduction of nanoparticles able to improve the mechanical properties, to act as drug delivery systems or eventually to impart anisotropy to the material.
Herein we present the design and the application of injectable hydrogels in tumor resection and in hernia reduction in pig models. To prove the use of paam hydrogel for biomedical applications we used the soft structure as cushion to aid the resection of tissue, mimicking a tumor, during the endoscopic submucosal dissection (ESD) procedure. The material resulted to be easily injectable and able, one injected in vivo, to promptly form a gel that facilitates the surgical procedure in comparison with the existing techniques . The combination of paam with alginate in the hydrogel formulation allowed to obtain an injectable high viscous pre-hydrogel. We proved the use of this material for the reduction of direct hernia. The hydrogel can be placed via percutaneous injection and it is a promising alternative to mesh implantation .
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