Jeonbuk National University (JBNU) doctoral candidate Chae-hwa Kim (Department of Bionanosystem Engineering, affiliated with the Korea Institute of Industrial Technology) has developed an integrated cell culture system that uses carbon nanotubes (CNTs) to generate mechanoelectric energy for electrical stimulation. The paper reporting this research was published in the online latest issue of the world-renowned scientific journal Advanced Functional Materials (2022 Impact Factor: 19.407). 

When mechanical force is applied to carbon nanotubes (CNTs), triboelectricity is generated. The experimental results of this study confirmed that stimulating chondrocytes with the produced mechanoelectric energy promoted cell proliferation and differentiation.

Research aimed at promoting chondrocyte differentiation is active, and many studies have reported that electrical stimulation enhances cell differentiation. However, most approaches supply energy via external power supplies or function generators. These methods increase system complexity and size, making integration with incubators for cell culture experimentally challenging.

To address these challenges, the doctoral candidate fabricated, for the first time worldwide, coil-shaped carbon nanotubes (CNTs) that can generate electrical energy inside an incubator solely through simple mechanical motion without external power. She coated the coils with polydopamine (PDA) to improve biocompatibility.

She also developed a conductive support using the conductive polymer poly(3,4-ethylenedioxythiophene) (PEDOT/CNT) so that the mechanoelectric energy could be effectively transferred to the cell culture medium. The conductive support lowered impedance (resistance) to ensure the generated energy was efficiently delivered to the cell scaffold.

Using the developed mechanoelectric integrated electrical stimulation cell culture system, the research team identified optimal conditions that promote proliferation and differentiation of chondrocytes, which had previously been difficult to achieve. 

This research was conducted jointly by the research teams of Dr. Si-hyung Kim and Dr. Tae-hee Kim at the Korea Institute of Industrial Technology and Jeonbuk National University (JBNU). The cell culture system is expected to be applicable not only to chondrocytes but also to neuromodulation and wound healing, arrhythmia management, muscle stimulation and rehabilitation, and tissue engineering.

Doctoral candidate Chae-hwa Kim stated, 'We plan to conduct various cell culture studies related to mechanoelectric energy stimulation based on this system. We will continue technical improvements so that the technology can progress from basic research toward commercialization.'