Bacterial skin infections cause a variety of common skin diseases that require drugs that are safer than antibiotics and have fewer side effects. However, for evaluating skin disease drugs, human skin tissue in vitro constructed traditionally on Transwell has inefficient screening ability because of its fragile barrier function. With mechanical forces and dynamic flow, the organ-on-a-chip system became an innovative, automatic, and modular way to construct pathological models and analyze effective pharmaceutical ingredients in vitro. In this research, we integrated skin extracellular matrix and skin cells into a microfluidic chip to construct a biomimetic “interface-controlled-skin-on-chip” system (IC-SoC), which constructed a stable air–liquid interface (ALI) and necessary mechanical signals for the development of human skin equivalents. The results demonstrated that in the microfluidic system with a flowing microenvironment and ALI, the skin tissue formed in vitro could differentiate into more mature tissue morphological structures and improve barrier function. Then, following exposing the skin surface on the IC-SoC to the stimulation of Propionibacterium acnes (P.acnes) and SLS (sodium lauryl sulfate), the barrier function decreased, as well as inflammatory factors such as IL-1α, IL-8, and PEG2 increased in the medium channel of the IC-SoC. After this pathological skin model was treated with dexamethasone and polyphyllin H, the results showed that polyphyllin H had a significant repair effect on the skin barrier and a significant inhibition effect on the release of inflammation-related cytokines, and the effects were more prominent than dexamethasone. This automated microfluidic system delivers an efficient tissue model for toxicological applications and drug evaluation for bacterial-infected damaged skin instead of animals.

A magnetic-controlled flexible continuum robot (MFCR) is a kind of continuum robot with small-size and flexibility that deforms under controlled magnetic fields, which makes MFCRs easy to fit in special sizes and designs and provides them with the ability to feasibly arrive at the desired area through certain blood vessel bifurcation. The magnetic drive method is suitable for the miniaturization of soft continuum robots but shows limitations in realizing high flexibility. To achieve miniaturization and high flexibility, in this work, the deformation schemes of a magnetic-controlled flexible continuum robot (MFCR) are proposed, simulated, and experimentally validated. The proposed MFCR includes a soft steering part made of a silicone elastomer with uniformly dispersed NdFeB powder which has a specific magnetization direction. With the actuation of different magnetic fields, the proposed MFCR shows three different deformation modes (C-shape, J-shape, and S-shape) and high flexibility. By using the potential energy model combined with magnetic and elastic potential energy, the quasi-static deformation model of MFCR is built. Through various simulations and experiments, we analyzed and predicted different deformation modes. The results from the experiments demonstrate the accuracy of the deformation model. The results indicate that the MFCR has good control precision and deformation performance with potential applications in robot-assisted minimally invasive surgery.

Research on cells and organ‐like tissues is critical in the fields of molecular biology, genetic analysis, proteomics analysis, tissue engineering, and others. In recent years, advancements in precise cell manipulation technologies have made precise positioning and batch processing of cells feasible. Various methods are used for cell recognition, positioning, manipulation, and assembly, often introducing external fields such as electric, magnetic, acoustic, or optical fields into the liquid environment to interact with cells, applying forces to induce cell movement and rearrangement. Alternatively, three‐dimensional (3D) bioprinting technology is employed for precise cell positioning and assembly. This review will comprehensively assess the status, principles, advantages, disadvantages, and prospects of these precise cell manipulation technologies, covering single‐cell manipulation, multicellular assembly, and biological 3D printing techniques.

Circulating tumor cells (CTCs) break free from primary tumors and travel through the circulation system to seed metastatic tumors, which are the major cause of death from cancer. The identification of the major genetic factors that enhance production and persistence of CTCs in the bloodstream at a whole genome level would enable more comprehensive molecular mechanisms of metastasis to be elucidated and the identification of novel therapeutic targets, but this remains a challenging task due to the heterogeneity and extreme rarity of CTCs. Here, we describe an in vivo genome-wide CRISPR knockout screen using CTCs directly isolated from a mouse xenograft. This screen elucidated SLIT2 —a gene encoding a secreted protein acting as a cellular migration cue—as the most significantly represented gene knockout in the CTC population. SLIT2 knockout cells are highly metastatic with hypermigratory and mesenchymal phenotype, resulting in enhanced cancer progression in xenograft models.