Evaluation of the anti-oxidative and ROS scavenging properties of biomaterials coated with epigallocatechin gallate for tissue engineering

Abstract

In tissue engineering, excessively generated reactive oxygen species (ROS) during biomaterial implantation or cell transplantation is a one of major causes of diminishing therapeutic effects. In this study, we prepared biomaterial surfaces coated with antioxidant epigallocatechin gallate (EGCG) and metal ions, and evaluated their anti-oxidative and ROS scavenging properties. We revealed that EGCG-coating on polycaprolactone (PCL) film surface increased hydrophilicity and anti-oxidative properties as a function of total phenol content (TPC) potentially due to the increase in phenolic -OH and pi-electrons from structural maintenance and directly removed the hydrogen peroxide (H2O2) by resonance-stabilization. Furthermore, EGCG-coated PCL film increased attachment, spreading area, and viability of human adipose-derived stem cells (hADSCs) against H2O2 treatment while stimulated the cellular signaling to reduce apoptotic gene and enhance anti-oxidative enzyme expression. Further, we applied EGCG coating on the surface of poly-L-lactic acid (PLLA) fibers. Spheroids incorporating EGCG-coated PLLA fibers were able to maintain their shape and showed improved viability and anti-oxidative activities in response to H2O2-induced oxidative stress than control spheroids. Therefore, metal-phenolic network (MPN) coating of EGCG is a suitable method to impart the anti-oxidative properties to biomaterials by evaluating the structural properties and biological effects. Statement of Significance This manuscript describes an antioxidant coating for biomaterials to control reactive oxygen species (ROS). Antioxidant epigallocatechin gallate (EGCG) was coated on the PCL film surface via metal-phenolic network (MPN). We revealed that the phenolic functional groups of EGCG are structurally maintained as confirmed by quantitative reducing power, radical scavenging assays. EGCG coating not only removed ROS directly, but also is involved in cell signaling to enhance the anti-apoptotic gene, anti-oxidative enzyme expression. Furthermore, human adipose-derived stem cells (hADSCs) spheroid produced by self-assembly with EGCG-coated poly-L-lactic aicd (PLLA) fibers showed anti-oxidative properties from inside of spheroids. Thus, our evaluation of the anti-oxidative properties of EGCG coating can be applied to various tissue engineering applications.