Atmospheric Pressure Enhanced Self-Sealing Rotation-SlipChip with Programmable Concentration Gradient Generation for Microbiological Applications.

In microbiological research, traditional methods for bacterial screening and antibiotic susceptibility testing are resource-intensive. Microfluidics offers an efficient alternative with rapid results and minimal sample consumption, but the demand for cost-effective, user-friendly platforms persists in communities and hospitals. Inspired by the Magdeburg hemispheres, the strategy adapts to local conditions, leveraging omnipresent atmospheric pressure for self-sealing of Rotation-SlipChip (RSC) equipped with a 3D circular Christmas tree-like microfluidic concentration gradient generator. This innovative approach provides an accessible and adaptable platform for microbiological research and testing in diverse settings. The RSC can avoid leakage concerns during multiple concentration gradient generation, chip-rotating, and final long-term incubation reaction (≥24 h). Furtherly, RSC subtypes adapted to different reactions can be fabricated in less than 15 min with cost less than $1, the result can be read through designated observational windows by naked-eye. Moreover, the RSC demonstrates its capability for evaluating bacterial biomarker activity, enabling the rapid assessment of ß-galactosidase concentration and enzyme activity within 30 min, and the limit of detection can be reduced by 10-fold. It also rapidly determines the minimum antibiotic inhibitory concentration and antibiotic combined medications results within 4 h. Overall, these low-cost and user-friendly RSC make them invaluable tools in determinations at previously impractical environment.

High-throughput and proteome-wide discovery of endogenous biomolecular condensates.

Phase separation inside mammalian cells regulates the formation of the biomolecular condensates that are related to gene expression, signalling, development and disease. However, a large population of endogenous condensates and their candidate phase-separating proteins have yet to be discovered in a quantitative and high-throughput manner. Here we demonstrate that endogenously expressed biomolecular condensates can be identified across a cell's proteome by sorting proteins across varying oligomeric states. We employ volumetric compression to modulate the concentrations of intracellular proteins and the degree of crowdedness, which are physical regulators of cellular biomolecular condensates. The changes in degree of the partition of proteins into condensates or phase separation led to varying oligomeric states of the proteins, which can be detected by coupling density gradient ultracentrifugation and quantitative mass spectrometry. In total, we identified 1,518 endogenous condensate proteins, of which 538 have not been reported before. Furthermore, we demonstrate that our strategy can identify condensate proteins that respond to specific biological processes.

Rapid generation of hybrid biochemical/mechanical cues in heterogeneous droplets for high-throughput screening of cellular responses.

Cells in their native microenvironment are subjected to varying combinations of biochemical cues and mechanical cues in a wide range. Although many signaling pathways have been found to be responsive for extracellular cues, little is known about how biochemical cues crosstalk with mechanical cues in a complex microenvironment. Here, we introduced heterogeneous droplets on a microchip, which were rapidly assembled by combining wettability-patterned microchip and programmed droplet manipulations, for a high-throughput cell screening of the varying combinations of biochemical cues and mechanical cues. This platform constructed a heterogeneous droplet/microgel array with orthogonal gradual chemicals and materials, which was further applied to analyze the cellular Wnt/ß-catenin signaling in response to varying combinations of Wnt ligands and substrate stiffness. Thus, this device provides a powerful multiplexed bioassay platform for drug development, tissue engineering, and stem cell screening.

"All-in-One" Silver Nanoprism Platform for Targeted Tumor Theranostics.

Designing a multifunctional theranostic nanoplatform with optional therapeutic strategies is highly desirable to select the most suitable therapeutic manners for the patient's cancer treatment. Among all shapes of silver materials, a silver nanoprism was reported to have great potential in photothermal therapy (PTT) owing to its strong surface plasmon resonance band in the near-infrared region. However, its instability in physicochemical environments and its severe toxicity confined its further application. To overcome this, herein, we demonstrated a silver prism-polydopamine (PDA) hybrid nanoplatform for tumor treatment with three therapeutic strategies. Specifically, the PDA coating endows the silver prism with excellent stability, high photothermal conversion, long-term in vivo biocompatibility, ease of decorating targeting ligands, and drug delivery. Upon near-infrared laser irradiation (808 nm, 1 W/cm2), tumors can be eradicated by the as-prepared nanoparticle through monomodal PTT. Besides, when combined with a chemical drug, this nanoparticle is able to inhibit tumor growth via combined photochemotherapy under a lower laser treatment (0.7 W/cm2). Furthermore, by supplementing with an immune checkpoint blockade, the realized synergistic photochemoimmunotherapy exhibits high efficacy to inhibit tumor relapse and metastasis. Moreover, owing to the high photothermal conversion efficiency and great X-ray attenuation ability of the silver nanoprism, our designed nanoplatform can be used in photoacoustic, computed tomography, and infrared thermal multimodal imaging. Our study provides a multifunctional nanoparticle for tumor theranostics, and this therapeutic strategy-optional nanoplatform shows promise in future biomedicine.