Piezoelectric scaffold based on polycaprolactone/thermoplastic polyurethane/barium titanate/cellulose nanocrystal for bone tissue engineering

This study presents the development of a novel piezoelectric scaffold for bone tissue engineering composed of poly(epsilon-caprolactone) (PCL), thermoplastic polyurethane (TPU), barium titanate (BT), and cellulose nanocrystals (CNC). PCL and TPU are considered advantageous materials because of their ease of processing, versatility in design, and ability to degrade over time; however, their inherent immiscibility poses challenges to achieving optimal porous structures. In this study, porous scaffolds were produced using gas foaming and salt leaching techniques, resulting in highly porous interconnected scaffolds exhibiting considerable elasticity that is suitable for dynamic cell culture while avoiding the use of toxic solvents. Given the piezoelectric nature of bone tissue, incorporating electric biosignals into scaffolds is essential to enhance bone regeneration. Therefore, BT was incorporated as a piezoelectric material. CNC, derived from cotton, assisted in BT distribution and acted as a reinforcing agent, imparting mechanoelectrical signaling properties to the scaffolds. The optimized scaffolds PCL/TPU (75/25) featuring 100 mu m pores were integrated with varying BT and CNC ratios and were subjected to multiple analyses. The results showed a measurable electrical output of 1.2 mV and enhanced cell adhesion, viability, and proliferation under dynamic culture conditions, underscoring their potential for bone tissue regeneration.