A system for uniform cell spheroid preparation based on inkjet printing

The three-dimensional cell spheroids hold great potential for accurately simulating the microenvironment of cells or tissues within living organisms, making them indispensable in various fields including drug screening and tissue engineering. However, traditional methods employed to generate three-dimensional cell spheroids suffer from limitations such as slow production speed, high operational complexity, and inadequate uniformity. In light of these challenges, we have developed an intelligent system designed to address these issues and facilitate the efficient fabrication of three-dimensional cell spheroids. This innovative system facilitates precise control over the movement of the printing head through the utilization of a development board and software. Moreover, the printing chip, manufactured using CMOS-MEMS technology, enables the placement of a 3×3 grid of cell spheroids within each well of a 96-well plate lid. Remarkably, the production of 864 cell spheroids across the entire lid of the 96-well plate requires only 54 minutes, thus effectively achieving high-throughput production of three-dimensional cell spheroids. Furthermore, the coefficient of variation (CV) pertaining to the diameter of the printed cell spheroids can be remarkably reduced to 4.97%. To enhance the uniformity and size precision of the cell spheroids, we propose two optimization techniques: extending the settling time for the cells and incorporating the use of an ultrasonic cleaner. Application of these methods individually resulted in reductions of 4.7% and 1.77%, respectively, in the diameter of the cell spheroids. This integrated system not only exhibits promising implications for advancing the preparation of proteins and organ-like structures but also opens new avenues for further exploration in these areas.