Biodegradable Self-Enhancing Piezoelectric Scaffold for Synchronized Tendon-to-Bone Regeneration

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Tissue Engineering

Background:

• Achieving coordinated regeneration of tendon, fibrocartilage, and bone at the tendon-bone interface (TBI) is crucial for rotator cuff repair.
• Current scaffolds struggle to replicate the complex mechanical and biochemical gradients of the native TBI microenvironment.
• This limits the synchronous differentiation of stem cells required for functional tissue integration.

Purpose of the Study:

• To develop an innovative scaffold system that integrates mechanical, electrical, and biochemical cues for TBI structural reconstruction and functional restoration.
• To enhance stem cell differentiation for multi-tissue regeneration within the rotator cuff tear (RCT) microenvironment.
• To address the limitations of existing scaffolds in mimicking the TBI's intricate spatial organization.

Main Methods:

• Constructed a gradient scaffold using piezoelectric degradable materials and electrospun fibers for topological guidance.
• Integrated biomimetic mineralization and in situ electrical stimulation to create a coupled cue system.
• Investigated the scaffold's piezoelectric enhancement effect (3x greater than traditional PLLA scaffolds) and its impact on the PI3K/AKT signaling pathway in mesenchymal stem cells.
• Evaluated the scaffold's efficacy in a rat rotator cuff tear (RCT) model.

Main Results:

• The gradient scaffold successfully generated precise electrical stimulation and mechanical microenvironment gradients.
• Dynamically controlled electrical signals activated the PI3K/AKT pathway, modulating stem cell differentiation towards tenogenic, chondrogenic, and osteogenic lineages.
• In the rat RCT model, the scaffold combined with electrical stimulation therapy achieved coordinated multi-tissue regeneration at the TBI.

Conclusions:

• The developed "mechanical-electrical-biochemical cue" coupled system effectively reconstructs the TBI microenvironment.
• This innovative approach facilitates synchronized regeneration of functionally graded tendon, fibrocartilage, and bone tissues.
• The study presents a promising strategy for advancing rotator cuff repair and functional restoration.