Anisotropic Bone Surface Topography Mimicked Chitosan/Graphene Oxide Membranes

Synergy between biomaterial surfaces and cells is known to be important due to the direct and inevitable interactions that mediate cell behavior. Thus, the design of biomimetic surfaces with proper topography and chemistry is crucial for optimization of cellular responses. Herein, we report surface topography mimicking ability of chitosan (CH) biopolymer and its promising application as a platform for osteoblast cell culture. CH is frequently used in bone tissue engineering applications. For this reason, anisotropic bone surface was chosen to demonstrate its surface mimicking skill. Initially, bone surface topography is replicated by using soft lithography and polydimethylsiloxane (PDMS) molds. Subsequently, solvent casting by CH is performed on the replicated molds, and then polymer membranes with bone surface topography are obtained. To prepare nanocomposite, graphene oxide (GO) is blended into CH membranes to enhance biocompatibility. It is observed that CH and CH/GO nanocomposite membranes are both eligible to mimic anisotropic bone surface. Considering the surface of bone tissue, hydroxyapatite (HA) modification is also conducted using ultraviolet/ozone method. Following that, human osteoblasts are chosen to evaluate the cell responses on mimicked surfaces. The results indicate that surface mimicking has a positive impact on osteoblast viability and morphology.