Recent Advances in Electrophysiological Recording Platforms for Brain and Heart Organoids

Abstract

Organoids refer to 3D stem cells that have been developed to model neurological disorders in vitro. Typically, brain and heart organoids have gained interest for their potential to truly mimic the functional ability of real organs. Morphological analysis methods using immunostaining and slicing of the organoids are explored extensively over the past decade to evaluate the structures and functions of organoids. However, the destructiveness of these methods limits real‐time monitoring of the dynamic responses of the organoids. Therefore, electrophysiological functional analysis of organoids with minimally invasive forms can be a key solution to an improved understanding of the nature of complex organoids. Herein, the latest advances in the recording platforms are reviewed and a comprehensive study of considerations regarding electrophysiological factors is provided. Furthermore, current challenges are discussed along with prospects for next‐generation electrophysiological analysis of brain and heart organoids.

Electrical stimulation for therapeutic approach

“…Therefore, the electrical stimulation triggers action potentials of the neurons and facilitates electrical stimulation to the target tissues. In the following section, we review two mechanisms of charge transfer in the electrode‐electrolyte interface to understand how electric charges are transmitted from the electrode to the tissue: Faradaic charge transfer and capacitive charge transfer 35–38 …”

“…In the following section, we review two mechanisms of charge transfer in the electrode-electrolyte interface to understand how electric charges are transmitted from the electrode to the tissue: Faradaic charge transfer and capacitive charge transfer. [35][36][37][38] Figure 1B describes the mechanism of Faradaic charge transfer caused by the direct movements of electrons across the electrode-electrolyte interface. There are various cations and anions in the electrolyte, and they are involved in charge redistribution by participating in the oxidationreduction reaction.…”

Materials and Structural Designs for Neural Interfaces

“…First, graphene is an attractive material for neural interfaces due to its excellent conductivity, flexibility, transparency, and biocompatibility. − Lu et al, developed a porous graphene-based flexible neural 16-electrode array for cortical recording and stimulation . The electrode was fabricated by laser pyrolysis for direct growing.…”

Neuromodulation of the peripheral nervous system: Bioelectronic technology and prospective developments

“…[190][191][192] For instance, gallium-based LMs, such as Galinstan or eutectic gallium indium alloy (EGaIn), have not only a low modulus (204 kPa) but also excellent electrical conductivity (3.4 MS m −1 ), making them ideal candidates for neuromodulation applications. [193][194][195][196][197][198][199][200][201][202][203] One of the key advantages of utilizing LM in bioelectronics applications pertains to its facile patterning method. The inherent softness of LM enables the creation of intricate 2D or 3D patterns even on flexible and curved surfaces such as human skin (Figure 7a).…”