In situ assembly of an injectable cardiac stimulator

Area of Science:

• Biomedical Engineering
• Materials Science
• Cardiology

Background:

• Cardiac arrhythmias present a significant fatality risk.
• Current interventions like defibrillators or implanted devices are often impractical or invasive.
• There is a need for minimally invasive, readily deployable cardiac stimulation solutions.

Purpose of the Study:

• To develop and evaluate an injectable cardiac stimulator for treating arrhythmias.
• To create a minimally invasive alternative to traditional cardiac stimulation methods.
• To assess the biocompatibility, conductivity, and efficacy of the injectable stimulator.

Main Methods:

• An injectable solution of conductive polymer and monomer nanoparticles was formulated.
• The solution was injected, forming an in vivo conductive structure around the heart.
• The material's mechanical properties (Young's modulus) and electrical conductivity were measured.
• In vivo electrocardiogram measurements, heartbeat regulation, and arrhythmia rectification were performed.
• Biocompatibility and toxicity were assessed at organism, organ, and cellular levels.

Main Results:

• The injectable solution formed a conductive electrode adhering to the beating heart in vivo.
• The material exhibited a tissue-compatible Young's modulus of 21 kPa and high conductivity of 55 S/cm.
• The device successfully facilitated electrocardiogram measurements, regulated heartbeat, and rectified arrhythmia in vivo.
• Conductive functionality persisted for five days.
• No organism, organ, or cellular toxicity was observed.

Conclusions:

• The electrofunctionalized injectable cardiac stimulator offers a promising, minimally invasive approach for arrhythmia treatment.
• This technology eliminates the need for surgical extraction of implanted devices.
• The injectable stimulator demonstrates excellent biocompatibility, electrical properties, and therapeutic efficacy.