Effect of Elastic Modulus Gradient on Osteoclastic Metabolic Behavior on Bioabsorbable Substrates Prepared by Welding PLA and PCL

Abstract

This study aimed to evaluate the effect of the elastic modulus gradient on the osteoclastic metabolic behavior on the functional gradient substrates prepared by welding PLA and PCL. First, the elastic modulus distribution of the substrates with the elastic modulus gradient in the depth-direction were directly evaluated and verified by the tensile and indentation tests. Then, the osteoclasts were cultured on the PLA-side surface of the PCL/PLA functional gradient substrates. The osteoclastic metabolic behavior was evaluated by the ATR method using a FT-IR. As a result, it was confirmed that the elastic modulus of the PCL/PLA functional gradient substrates decreased from the PLA side to the PCL side. This indicates that the functional gradient substrates have the elastic modulus gradient successfully. The FT-IR measurement revealed that the osteoclastic dissolution rate of the substrates increased with the increase of the culture period until 4 weeks, and then decreased at the 5th week. This indicates that the elastic modulus gradient in the depth direction could control the osteoclastic metabolic behavior.