Exploring the impact of microfluidic chip structure on the efficacy of three-dimensional tumor microspheres cultivation.

Three-dimensional (3D) tumor microspheres can simulate the interaction and growth dynamics of tumor cells, and have been used as a new in vitro model for drug screening and tumor biology related research. The scaffold-free culture of 3D tumor microspheres on microfluidic chips has many advantages, including low cost, high throughput, convenience and flexibility. However, it is still unclear how various factors, such as chip structure, influence the culture effect of tumor microspheres. The lack of standardized evaluation and characterization of the culture effect hinders the further optimization and development of chip function. This study presents numerical simulations of multiple parts or processes of the proposed 3D culture chips with two different structural parameters based on computational fluid dynamics (CFD) methods. An evaluation system for tumor microspheres was established. The prediction of the CFD simulation was consistent with the culture results of the chips, reflecting the important role of the structural parameters of the microtrap in the formation of uniform tumor microspheres. Furthermore, the velocity of cell suspension also had a significant impact on the retention of tumor cells. Additionally, the drug screening results of tumor microspheres indicated that tumor microspheres exhibit greater drug resistance, which may be attributed to their size. These results offer valuable insights into the factors that influence the characteristics of tumor microspheres. This research provides a reference and direction for the optimal design and functional evaluation of scaffold-free 3D culture chips, and holds promise for promoting the development of novel drug research platforms.