Degradation Kinetics, Mechanisms, and Antioxidant Activity of PCL-Based Scaffolds with In Situ Grown Nanohydroxyapatite on Graphene Oxide Nanoscrolls

Abstract

Polycaprolactone (PCL) degradation is critical in bone tissue engineering, where scaffold degradation must align with tissue regeneration to ensure stability and integration. This study explores the effects of nanofillers, hydroxyapatite (nHA), and graphene oxide nanoscrolls (GONS) on PCL-based scaffold degradation kinetics. Both PHAP (nHA-PCL) and PGAP (nHA-GONS-PCL) scaffolds exhibited changes to relaxation-driven degradation, as indicated by adherence to the Korsmeyer–Peppas model (R2 = 1.00). PHAP scaffolds showed lower activation energies (5.02–5.54 kJ/mol), promoting faster chain relaxation and degradation in amorphous regions. PGAP scaffolds, with higher activation energies (12.88–12.90 kJ/mol), displayed greater resistance to chain relaxation and slower degradation. Differential scanning calorimetry (DSC) revealed that both nanofillers disrupted the crystalline regions, shifting degradation behavior from diffusion-based to relaxation-driven mechanisms in the amorphous zones, which was also reflected by changes in crystallization temperature (Tc) and melting temperature (Tm). Additionally, PGAP scaffolds demonstrated antioxidant potential, which decreased over time as degradation progressed. These results provide a mechanistic understanding of how nanofiller-modulated degradation dynamics can be strategically leveraged to optimize scaffold performance, facilitating precise control over degradation rates and bioactivity.