Protein covalently conjugated SU-8 surface for the enhancement of mesenchymal stem cell adhension and proliferation
Date of Issue2014
School of Chemical and Biomedical Engineering
Cell growing behavior is significantly dependent on the surface chemistry of materials. SU-8 is a high contrast, epoxy based negative photoresist. Its abilities of excellent thermal and mechanical stability make it popular to fabricate semi-conductor devices, microfluidics, microelectromechanical systems, as well as most biocompatible materials. But native SU-8 is also highly hydrophobic and has a low surface energy, which make it not favorable for cell culture, and cell attachment. Although physical adsorption of proteins could enhance the cell adhesion, the effect is not durable. In this work, SU-8 surface chemistry is modified by immobilizing fibronectin (FN) and collagen type I (COL I) covalently using (3-aminopropyl)triethoxy silane (APTES), and cross-linker glutaraldehyde (GA) to increase surface biofunctionality. The effectiveness of this surface treatment to improve the adhesion and viability of mesenchymal stem cells (MSCs) is investigated. It is found that the wettability of SU-8 surface can be significantly increased by this chemical modification. In addition, the spreading area of MSCs increases on the SU-8 surfaces with covalently conjugated matrix proteins, as compared to other unmodified SU-8 surface or those coated with proteins simply by physical adsorption. Furthermore, cell proliferation is dramatically enhanced on the SU-8 surfaces modified under the proposed scheme. Therefore, SU-8 surface modification with covalently bound matrix proteins assisted by APTES+GA provides a highly biocompatible interface for the enhanced adhesion, spreading and proliferation of MSCs.