Controlled release from a mechanically-stimulated thermosensitive self-heating composite hydrogel

Abstract

a b s t r a c tTemperature has been extensively explored as a trigger to control the delivery of a payload from environment-sensitive polymers. The need for an external heat source only allows limited spatiotemporal control over the delivery process. We propose a new approach by using the dissipative properties of a hydrogel matrix as an internal heat source when the material is mechanically loaded. The system is comprised of a highly dissipative hydrogel matrix and thermo-sensitive nanoparticles that shrink upon an increase in temperature. Exposing the hydrogel to a cyclic mechanical loading for a period of 5 min leads to an increase of temperature of the nanoparticles. The concomitant decrease in the volume of the nanoparticles increases the permeability of the hydrogel network facilitating the release of its payload. As a proof-of-concept, we showed that the payload of the hydrogel is released after 5e8 min following the initiation of the mechanical loading. This delivery method would be particularly suited for the release of growth factor as it has been shown that cell receptor to growth factor is activated 5e20 min following a mechanical loading.

Improving hydrogels׳ toughness by increasing the dissipative properties of their network

“…Among different hydrogel systems being covalently crosslinked, Poly(2-hydroxyethyl methacrylate) (PHEMA) has received considerable attention as a biocompatible hydrogel with tunable mechanical properties (Voldrich et al, 1975;Lou et al, 2004;Young et al, 1998;Traian, 2001;Moghadam et al, 2014). HEMA monomers have a hydrophilic nature.…”

Biodegradable HEMA‐based hydrogels with enhanced mechanical properties

“…Longterm degradation mirrors the rate of tissue development in load-bearing tissues like cartilage and nucleus pulposus where the healing process is slow. [37][38][39] In parallel, the high damping properties observed in the develop hydrogels provided load and crack resistance under the loading conditions of such tissues. 12,18 It has been already shown that HEMA-based hydrogels can partially degrade when they are cross-linked to some natural polysaccharides molecules such as chitosan, 22 dextran-based molecules, 7,40 hyaluronic acid and poly(lactic acid) PLA.…”

Strategies for Improving the Repair of Focal Cartilage Defects

“…Review Abdel-Sayed & Pioletti delivery with cell receptors activation, which is essential for an enhancement of the tissue regeneration [88]. Indeed, mechanical loading has been shown to activate cell receptors to growth factors involved in the regeneration of cartilage [89][90][91], therefore a temporally adapted delivery induces maximum potency of the drug.…”