A biodegradable piezoelectric scaffold promotes spinal cord injury nerve regeneration

Neural repair and regeneration remain one of the greatest challenges in regenerative medicine. The incorporation of intelligent scaffolds with noninvasive in vivo electrical stimulation illustrates considerable potential for tissue repair and regeneration. Nevertheless, the development of biomaterials that possess both biodegradable tissue scaffolds and electrical stimulation capabilities at a high level remains a significant obstacle. In this study, we effectively integrated the organic piezoelectric material poly-L-lactic acid (PLLA) with inorganic piezoelectric nanowires (potassium sodium niobate coated with polydopamine, KNN@PDA) to fabricate PLLA/KNN@PDA piezoelectric composite fibers. These fibers exhibit in-situ electrical stimulation capabilities, rendering them suitable for direct application in living tissues. The PLLA/KNN@PDA piezoelectric composite fibers not only function as biodegradable scaffolds for regenerative tissue engineering and platforms for in-situ electrical stimulation to enhance dorsal root ganglion axon growth, proliferation, and neuronal differentiation but also serve as versatile scaffolds for broader tissue engineering applications. In the complete spinal cord transection rat model, the piezoelectric scaffold enabled the recovery of rat motor function, indicating its significant ability to promote tissue formation and regeneration. Therefore, combining biodegradable piezoelectric tissue scaffolds with in situ electrical stimulation has significant therapeutic advantages for spinal cord injury repair and may be extended to other damaged tissues regeneration.