Composite additive manufacturing for suspended microelectrode arrays: Advancing oriented myocardial tissue culturing and electrophysiological sensing.

Microelectrode arrays (MEAs) have ushered in a new era of in vitro drug screening and cardiotoxicity evaluation. However, the morphological constraints of two-dimensional (2D) planar culture and the mechanical rigidity of conventional electrodes hinder the formation of myocardial tissues that closely resemble native physiological conditions and limit the accuracy of drug efficacy analysis based on electrophysiological signals. Here, we present a flexible MEA platform enabled by a composite additive manufacturing approach, with key steps including melt electrowriting of microfibers, electrostatic spraying of insulation layer, and electrospinning of nanofiber scaffolds.

Flexible beam-based microelectrode arrays integrated with oriented nanofiber scaffolds for electrophysiological monitoring of cardiac tissue.

In vitro culture and electrophysiological monitoring of engineered cardiac tissue (ECT) are crucial for the screening and evaluation of cardiotoxic drugs. Microelectrode arrays (MEAs) offer significant advantages in non-invasive, high-throughput detection. However, existing MEAs face challenges in replicating the natural growth environment of cardiomyocytes, which hinders the morphology and functional maturation of cells.

Rapid Video Analysis for Contraction Synchrony of Human Induced Pluripotent Stem Cells-Derived Cardiac Tissues.

Background: The contraction behaviors of cardiomyocytes (CMs), especially contraction synchrony, are crucial factors reflecting their maturity and response to drugs. A wider field of view helps to observe more pronounced synchrony differences, but the accompanied greater computational load, requiring more computing power or longer computational time.

Methods: We proposed a method that directly correlates variations in optical field brightness with cardiac tissue contraction status (CVB method), based on principles from physics and photometry, for rapid video analysis in wide field of view to obtain contraction parameters, such as period and contraction propagation direction and speed.

3D Nanofiber-Assisted Embedded Extrusion Bioprinting for Oriented Cardiac Tissue Fabrication.

Three-dimensional (3D) bioprinting technology stands out as a promising tissue manufacturing process to control the geometry precisely with cell-loaded bioinks. However, the isotropic culture environment within the bioink and the lack of topographical cues impede the formation of oriented cardiac tissue. To overcome this limitation, we present a novel method named 3D nanofiber-assisted embedded bioprinting (3D-NFEP) to fabricate cardiac tissue with an oriented morphology.

Reinforced Magnetic-Responsive Electro-Ionic Artificial Muscles by 3D Laser-Induced Graphene Nano-Heterostructures.

Efficient ion transport and enriched responsive modals via modulating electrochemical properties of conductivity and capacitance are essential for soft electro-ionic actuators. However, cost-effective and straightforward approaches to achieve expedited fabrication of active electrode materials capable of multimodal-responsiveness remain limited. Herein, this work reports the one-step ultrafast laser direct patterning method, to readily synthesize electro- and magneto-active electrode material, derived from the unique cobalt-phosphorus co-doped core-shell heterostructures within 3D graphene frameworks, for fulfilling the dual-mode responsive electro-ionic actuators.

Real-Time Wireless Sensing of Cardiomyocyte Contractility by Integrating Magnetic Microbeam and Oriented Nanofibers.

In vitro cardiomyocyte mechano-sensing platform is crucial for evaluating the mechanical performance of cardiac tissues and will be an indispensable tool for application in drug discovery and disease mechanism study. Magnetic sensing offers significant advantages in real-time, in situ wireless monitoring and resistance to ion interference. However, due to the mismatch between the stiffness of traditional rigid magnetic material and myocardial tissue, sensitivity is insufficient and it is difficult to achieve cell structure induction and three-dimensional cultivation.

3D Aligned Nanofiber Scaffold Fabrication with Trench-Guided Electrospinning for Cardiac Tissue Engineering.

Constructing three-dimensional (3D) aligned nanofiber scaffolds is significant for the development of cardiac tissue engineering, which is promising in the field of drug discovery and disease mechanism study. However, the current nanofiber scaffold preparation strategy, which mainly includes manual assembly and hybrid 3D printing, faces the challenge of integrated fabrication of morphology-controllable nanofibers due to its cross-scale structural feature. In this research, a trench-guided electrospinning (ES) strategy was proposed to directly fabricate 3D aligned nanofiber scaffolds with alternative ES and a direct ink writing (DIW) process.