Development of Injectable Thermosensitive Chitosan-Based Hydrogels for Cell Encapsulation

Featured Application: The developed thermoresponsive injectable hydrogels might be used as cell-delivery systems, 3D matrices for cell culture study, drug screening platforms, and for regenerative medicine applications. The three-dimensional complexity of the native extracellular matrix (ECM) suggests switching from 2D to 3D culture systems for providing the cells with an architecture more similar to the physiological environment. Reproducing the three-dimensionality in vitro can guarantee beneficial eects in terms of cell growth, adhesion, proliferation, and/or their dierentiation. Hydrogels have the same tailorable physico-chemical and biological characteristics as ECM materials. In this study, we propose a thermoresponsive chitosan-based hydrogel that gels thanks to the addition of organic and inorganic salt solutions (beta-glycerolphosphate and sodium hydrogen carbonate) and is suitable for cell encapsulation allowing obtaining 3D culture systems. Physico-chemical analyses showed that the hydrogel formulations jellify at physiological conditions (37 C, pH 7.4), are stable in vitro up to three weeks, have high swelling ratios and mechanical stiness suitable for cellular encapsulation. Moreover, preliminary biological tests underlined the pronounced biocompatibility of the system. Therefore, these chitosan-based hydrogels are proposed as valid biomaterials for cell encapsulation.