Slide-Ring Structured Stress-Electric Coupling Hydrogel Microspheres for Low-Loss Transduction Between Tissues

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• High transductive loss at tissue injury sites hinders natural repair processes.
• Piezoelectric biomaterials face challenges due to high energy dissipation during electromechanical conversion.

Purpose of the Study:

• To develop novel low-dissipation, stress-electric coupling hydrogel microspheres for enhanced tissue repair.
• To investigate the mechanism of reduced energy loss in engineered hydrogel microspheres.

Main Methods:

• Utilized supramolecular engineering and microfluidic technology to create hydrogel microspheres incorporating slide-ring polyrotaxane and conductive polypyrrole.
• Incorporated piezoelectric barium titanate for stress-electricity conversion and a conductive network for improved electron transfer.
• Evaluated microsphere performance through stress-electric coupling efficiency, energy dissipation measurements, cellular assays, and in vivo osteoarthritis models in rats.

Main Results:

• The developed microspheres demonstrated a 2.3-fold increase in stress-electric coupling efficiency and a 43% decrease in energy dissipation compared to traditional piezoelectric hydrogels.
• Generated electrical signals promoted stem cell chondrogenic differentiation via Ca2+ influx and cAMP pathways.
• Enhanced electrical signals induced M2 macrophage polarization, modulating inflammation and promoting tissue repair.
• In vivo studies showed restored low-loss transduction, alleviated cartilage damage, and improved outcomes in a rat osteoarthritis model.

Conclusions:

• This study presents a new strategy for restoring low-loss transduction in mechanically sensitive tissues.
• The developed low-dissipation hydrogel microspheres offer a promising approach for regenerative medicine and treating conditions like osteoarthritis.