Effect of ethylene oxide and gamma sterilization on surface texture of films and electrospun poly(ε-caprolactone-co-p-dioxanone) (PCLDX) scaffolds

In the field of tissue engineering, synthetic and degradable polyesters like poly(ε-caprolactone) (PCL) and poly(ε-caprolactone-co-p-dioxanone) (PCLDX) are widely used as scaffolds. Our previous research revealed that thermal storage conditions could alter the surface texture of PCL and PCLDX scaffolds, which might influence cell-scaffold interactions in tissue engineering applications. These findings highlighted the importance of multi-scale characterization techniques to identify the scales most sensitive to external changes and the need for personalized surface texture analysis. Sterilization techniques, such as ethylene oxide and gamma radiation, are essential for ensuring the sterility of polymeric medical devices. However, these processes can significantly impact the bulk polymer properties and/or surface texture of the scaffolds, potentially affecting their biocompatibility, safety, and overall performance. Therefore, the influence of sterilization processes on the surface texture of PCLDX films and electrospun nanofibers and to correlate these findings with the thermal and physical properties of the polymer are essential and have been assessed. Our results demonstrated that ethylene oxide maintained the structural integrity and surface texture of PCLDX scaffolds, while gamma irradiation caused a significant reduction in molar mass and increased the number of hills (Shn) and dales (Sdn) on PCLDX samples. Despite these changes, both sterilization methods showed minimal effects on the thermal properties, such as melting temperature and degree of crystallinity, and surface wettability of the scaffolds. This comprehensive surface texture analysis highlights the importance of evaluating feature parameters such as Shn and Sdn for optimizing the performance and biocompatibility of polymeric scaffolds in tissue engineering.