Regulation of Mechanical Properties and Degradation Behavior of Poly(L-Lactide-Co-ε-Caprolactone) (PLCL) by Magnesium Oxide Nanoparticle

In tissue engineering and regenerative medicine, biodegradable PLCL polymers are highly valued. This is because their mechanical properties can be finely adjusted, and they are compatible with biological tissues. However, precise control over their degradation rate remains a challenge for biomedical applications. In this study, magnesium oxide (MgO) nanoparticles were incorporated into PLCL matrices to systematically modulate both mechanical properties and degradation behavior. To determine the microstructure and thermal robustness of the PLCL/MgO composites, a battery of tests was conducted. These tests included scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), rheometry, and thermogravimetric analysis (TGA). The results revealed that MgO nanoparticles significantly enhanced the ultimate tensile strength and modulus of elasticity of PLCL while simultaneously accelerating its hydrolytic degradation. This was attributed to MgO's dual role: (1) stabilizing the local pH by neutralizing acidic degradation byproducts, thereby mitigating autocatalytic degradation of the PLCL matrix, and (2) acting as an alkaline catalyst to facilitate ester bond hydrolysis. Notably, the degradation rate increased in a MgO concentration-dependent manner, with minimal impact on the polymer's biocompatibility. This study demonstrates that MgO can effectively modulate the degradation process, thereby enabling the creation of bioresorbable PLCL-based materials with tailored lifespans. This advancement holds great promise for advanced biomedical applications.