Controllable Histotomy Based on Hierarchical Magnetic Microneedle Array Robots

Abstract

Investigation of patient-derived primary tissues is of great importance in the biomedical field, but recent tissue slicing and cultivation techniques still have difficulties in satisfying clinical requirements. Here, we propose a controllable histotomy strategy that utilizes hierarchical magnetic microneedle array robots to tailor primary tissues and establish the desired high-throughput tissue-on-a-chip. This histotomy is performed using a three-dimensional printed, mortise-tenon-structured slicing device coupled with a magnetic-particle-loaded and pagoda-shaped microneedle array scaffold. Due to the multilayered structure of these microneedles, tissue specimens can be fixed onto the microneedle scaffold via mechanical interlocking, thereby effectively avoiding tissue slipping during the slicing process. Owing to the encapsulation of magnetic microneedle fragments, these tissue pieces can act as magnetically responsive biohybrid microrobots and can be easily manipulated by magnetic fields, facilitating their separation, transportation, and dynamic culture. Using this strategy, we demonstrate that primary pancreatic cancer tissues can be tailored into tiny pieces and cultured in multilayered microfluidic chips for efficient high-throughput drug screening, indicating the promising future of this technique’s application in clinical settings.