Periodic Mesoporous Organosilica-Based Nanocomposite Hydrogels as Three-Dimensional Scaffolds

摘要

Hydrogels, which are three-dimensional (3D) polymeric networks, are widely used not only as separation membranes, but also as biosensors, tissue engineering scaffolds, and drug delivery vehicles, or for stem cell cultures, owing to their stimuli responsive, hydrophilic, and biocompatible properties. However, their mechanically fragile nature limits their specific uses, especially in hard-tissue-engineering applications. The generation of nanocomposite (NC) hydrogels alters this situation. NC hydrogels are organic-inorganic nanocomposites that are produced by chemical or physical cross-linking of organic polymers in water by nanometer-scale objects, such as clays, silica nanoparticles, magnetic nano-particles, or carbon nanotubes. Owing to the reinforcement of the polymer matrix with nanoparticles, NC hydrogels show extraordinary mechanical strength and swelling/deswelling properties. Additionally, current traditional tissue engineering scaffold approaches based on the control of cell behaviors and artificial tissue formation by suitable surface functional-ization that closely mimics the natural extracellular matrix (ECM). Therefore NC hydrogels are excellent candidates for 3D scaffolds for use in tissue engineering. Some research groups have reported the use of NC hydrogels in pharmaceutical and medical fields, such as wound dressing, cell cultivation, and bone remediation. For example, recently Yang et al. described a new NC hydrogel from polyethylene glycol diacrylate and hydroxy mesoporous silica nanoparticles (MSNs-OH), which showed enhanced mechanical properties and promoted cellular affinity at the hydrogel surface. However, these studies are limited with respect to the inorganic material used in the NC hydrogel composition and the investigation of the obtained NC hydrogels for biochemical applications, because most of these studies represent the 2D cell growth on NC hydrogel surface and very few studies describe 3D cell encapsulation or cell growth in NC hydrogel scaffold.