A motion-activated skeletal "Pacemaker" for systemic bone remodeling via oral piezoelectric microspheres

Area of Science:

• Biomaterials Science
• Nanotechnology
• Regenerative Medicine

Background:

• Loss of endogenous bioelectrical rhythms in bone contributes to osteoporosis.
• Restoring bone homeostasis requires synchronized bioelectrical rhythms and mechanical stimulation.

Purpose of the Study:

• To develop a motion-activated skeletal bioelectrical pacemaker for osteoporosis treatment.
• To enable noninvasive oral delivery and systemic skeletal enrichment of therapeutic nanoparticles.

Main Methods:

• Microfluidic encapsulation of alendronate-modified BaTiO3 piezoelectric nanoparticles (BTO@ALN) in chitosan/alginate hydrogel microspheres.
• Utilizing pH-responsive release and bone-targeting for systemic skeletal enrichment.
• Activating piezoelectric nanoparticles with physiological mechanical stimuli during daily motion.

Main Results:

• BTO@ALN showed 6.8-fold higher skeletal accumulation.
• Oral administration increased bone piezoelectric performance by 52% within 24 hours.
• Combined therapy with exercise amplified osteogenesis and suppressed bone resorption.

Conclusions:

• The developed strategy systematically re-establishes endogenous bone bioelectrical rhythms.
• This approach offers a novel electrophysiological regulation strategy for osteoporosis.
• The closed-loop system integrates oral delivery, bone targeting, and motion-synchronized electrical activation.