Abstract
This chapter focuses on the influence of biomaterial hydrophilicity/hydrophobicity, stiffness, and protein adsorption ability on the behaviors of stem cells. Biomaterials are usually designed with a combination of suitable biological and mechanical properties such as biocompatibility, high porosity, and suitable mechanical strength to mimic the natural extracellular matrix and nature microenvironment. Human mesenchymal stem cells were the first stem cells used to present the effect of matrix stiffness on stem cell differentiation. Protein adsorption on the biomaterial surface is believed to be the initial event when a material comes into contact with a biological environment. The stiffness of polyethylene glycol (PEG) hydrogels can be tuned with the PEG length and their antifouling property will prevent unspecific protein adsorption. Understanding the influence of different biomaterial properties on stem cell behaviors and the possible underlying mechanisms is essential in engineering biomaterials for further clinical applications.