PEG/clay nanocomposite hydrogel: a mechanically robust tissue engineering scaffold

Nanocomposite hydrogels with enhanced mechanical properties could have tremendous biomedical applications. Here we describe synthesis and characterizations of biocompatible poly(ethylene glycol) diacrylate (PEGDA)/Laponite nanocomposite (NC) hydrogels that can support both two-and three-dimensional (2D and 3D) cell cultures. The PEGDA/Laponite NC hydrogels with enhanced mechanical properties were developed by harnessing the ability of PEGDA oligomers to simultaneously form chemically crosslinked networks while interacting with Laponite nanoparticles through secondary interactions. Incorporation of Laponite nanoparticles significantly enhanced both the compressive and tensile properties of PEGDA hydrogels, which were dependent on both the molecular weight of PEG, and concentrations of Laponite nanoparticles. Unlike PEGDA hydrogels, PEGDA-NC hydrogels supported cell adhesion and their subsequent spreading in a 2D culture. In addition to supporting the 2D cell growth, the PEGDA NC hydrogels supported 3D cell encapsulation similar to that of widely used PEGDA hydrogel systems. Such nanocomposite hydrogels with enhanced mechanical properties could have potential applications as 3D scaffolds for tissue engineering. Additionally, the ability of PEGDA NC hydrogels to support 3D culture of encapsulated cells makes them an ideal injectable system with minimally invasive strategies for in vivo applications.