Interaction of Human Mesenchymal Stem Cells with Soft Nanocomposite Hydrogels Based on Polyethylene Glycol and Dendritic Polyglycerol

Abstract

Keeping the stemness of human mesenchymal stem cells (hMSCs) and their adipocyte differentiation potential is critical for clinical use. However, these features are lost on traditional substrates. hMSCs have often been studied on stiff materials whereas culturing hMSCs in their native niche increases their potential. Herein, a patterned hydrogel nanocomposite with the stiffness of liver tissues is obtained without any molding process. To investigate hMSCs' mechanoresponse to the material, the RGD spacing units and the stiffness of the hydrogels are dually tuned via the linker length. This work suggests that hMSCs' locomotion is influenced by the nature of the hydrogel layer (bulk or thin film). Contrary to on bulk surfaces, cell traction occurs during cell spreading on thin films. In addition, hMSCs' spreading behavior varies from shorter to longer linker-based hydrogels, where on both surfaces hMSCs maintains their stemness as well as their adipogenic differentiation potential with a higher number of adipocytes for nanocomposites with a longer polymer linker. Overall, this work addresses the need for a new alternative for hMSCs culture allowing the cells to differentiate exclusively into adipocytes. This material represents a cell-responsive platform with a tissue-mimicking architecture given by the mechanical and morphological properties of the hydrogel.