A three-dimensional hybrid pacemaker electrode seamlessly integrates into engineered, functional human cardiac tissue...

Area of Science:

• Biomaterials Engineering
• Cardiovascular Device Technology
• Tissue Engineering

Background:

• Pacemaker electrodes face immune encapsulation, reducing efficiency and requiring higher excitation thresholds.
• Current planar electrodes have limitations in tissue integration due to implant properties like size and flexibility.
• Developing advanced electrode materials is crucial for improving pacemaker performance and longevity.

Purpose of the Study:

• To fabricate and evaluate a novel three-dimensional (3D), tissue-like electrode scaffold as an alternative to conventional 2D electrodes.
• To compare the electrical and immunological properties of the 3D fiber scaffold with traditional 2D titanium nitride (TiN) electrodes.
• To assess the biocompatibility and integration of the 3D electrode with cardiac tissue for a seamless electronic-tissue interface.

Main Methods:

• Fabrication of a conductive, porous 3D fiber scaffold using a modified electrospinning process and high-temperature treatment.
• Comparative analysis of electrical performance and immunological response between 3D fiber and 2D TiN electrodes.
• In vivo subcutaneous implantation for early and late host response evaluation, and in vitro generation of a tissue-electrode hybrid with human cardiomyocytes.

Main Results:

• The 3D fiber electrode demonstrated enhanced electrical performance due to its increased surface area compared to 2D electrodes.
• Cell migration into the 3D construct was observed, alongside a reduced inflammatory and foreign body response.
• A fused hybrid of the 3D fiber scaffold and a cardiac patch resulted in a mechanically stable, electrically excitable unit, proving a seamless electronic-tissue interface.

Conclusions:

• The 3D fiber scaffold electrode offers superior electrical and immunological properties compared to conventional 2D electrodes.
• The developed scaffold exhibits excellent biocompatibility, with no adverse foreign body response observed in vivo.
• The successful creation of a seamless electronic-tissue interface using a tissue-electrode hybrid demonstrates significant potential for advanced pacemaker systems.