Lab on a Chip最新文献

The development of effective cancer therapies remains constrained by the complex and dynamic nature of the tumor microenvironment (TME), with tumor vasculature representing a critical barrier and modulator of treatment response. This review critically examines recent advances in the generation of vascularized tumor models using organ-on-a-chip (OoC) microfluidic technologies, emphasizing their capacity to recapitulate key interactions between tumor cells, stroma, and vasculature in vitro. We outline the mechanistic roles of tumor vasculature in therapy resistance, metastatic dissemination, and immune modulation, and highlight current strategies targeting vasculature for improved therapeutic outcomes. State-of-the-art biomaterials and engineering approaches, including template-based fabrication, self-organization, and the integration of patient-derived organoids, are discussed regarding their efficacy in constructing physiologically relevant vasculature. The review critically assesses findings from drug testing studies and discusses the translational potential of microfluidic platform capabilities, such as real-time monitoring, precise flow control, and functional assessment of vessel permeability and drug delivery, while identifying key limitations for clinical implementation. Challenges in standardization, scalability, and clinical translation are discussed, and recommendations are proposed to enhance the human-relevance and impact of vascularized OoC models in preclinical oncology research. These advanced platforms represent a transformative approach for bridging the translational gap between preclinical research and clinical oncology, offering opportunities to advance personalized cancer therapeutics and improve patient outcomes.

Microfluidic lab-on-a-chip technology has shown great potential in various fields such as bioscience, medical diagnostics, and environmental monitoring. However, its widespread adoption has been hindered by challenges in functional integration, operational autonomy, and manufacturing scalability. To address these limitations, we present a 3D-printed self-sensing magnetically actuated microfluidic (SMAM) chip designed for autonomous bioanalysis. This innovative device utilizes stereolithography apparatus (SLA) 3D printing to rapidly prototype and integrate microchannel networks alongside with a magnetically driven functional module. The chip employs magnetic actuation for precise, wireless manipulation of fluids within the microchannels, eliminating the need for bulky external pumps. Additionally, the system features an integrated self-sensing mechanism, enabling flow monitoring and on-chip analyte detection. The SMAM chip demonstrates exceptional dual-function performance, achieving a high pumping flow rate of up to 972 μL min⁻¹ and a good piezoresistive sensitivity of 43.1 MPa⁻¹. We first demonstrate its system-level utility by assembling the chip into a modular, wirelessly monitored microfluidic platform with an integrated flow rectifier. Furthermore, its potential for therapeutic interventions is validated through a proof-of-concept of an untethered device for magnetically guided, on-demand drug release. This work provides a novel approach for developing intelligent analytical devices, promising to enable new paradigms in automated biological research and diagnostics.

Three-dimensional (3D) printing has emerged as a promising method for fabricating microfluidic devices due to its rapid prototyping, adaptability, and cost-effectiveness. However, the intrinsic hydrophobicity of commercial photocurable resins limits their ability to generate stable oil-in-water (O/W) emulsion droplets. In this study, we addressed this limitation by introducing a simple yet effective surface modification technique, photochemical grafting, which covalently attaches hydrophilic methacrylic acid groups onto the surfaces of 3D-printed channels, enabling reliable monodisperse O/W droplet formation. Integrating two modules with contrasting wettabilities yields a modular platform for single-step production of double emulsions (W/O/W and O/W/O). The result is a versatile system with precise control over droplet formation and exceptional monodispersity with tunable shell-to-core ratios. The grafted surfaces retained wettability and droplet-generation performance after three months of storage and 25 hours of continuous shear. Collectively, this work presents a robust and scalable strategy to bridge rapid 3D printing with durable surface functionalization, expanding the potential of customizable emulsion generation in lab-on-a-chip applications.

Single-cell protein profiling furnishes exclusive insights into understanding and describing phenotypic heterogeneity in large populations, garnering significant attention from researchers. However, investigating protein information at single-cell resolution has presented significant challenges on account of the small size of cells, low abundance of proteins and scarcity of sensitive analytical methods. Microfluidics has emerged as a powerful platform for single-cell protein profiling because it enables efficient single-cell isolation, high-throughput processing of small-volume samples, and integrated microscale reactions in a user-friendly format. This review provides a broad perspective on the leading-edge microfluidic platforms for single-cell protein profiling. It showcases different microfluidic layouts for single-cell separation and explores how cutting-edge analysis techniques are integrated with these platforms for protein profiling. Furthermore, the potential challenges and future trends of microfluidics-based single-cell protein profiling are presented and evaluated.

Tumor stem cells (TSCs) play a pivotal role in the development of tumor organoids. Consequently, the development of effective methods for the isolation and differential induction of TSCs is essential for the establishment of tumor organoids. In this study, we demonstrate a microfluidic single-cell culture technique that facilitates the selective expansion of TSCs and the subsequent generation of tumor organoids. Our findings demonstrate that microfluidic single-cell culture enables the generation of single-cell-derived tumorspheres (SDTs) across a variety of tumor cell lines of various tissue origins. The SDT cells exhibited definitive stem cell characteristics, as confirmed by the expression of stemness markers and functional cellular assays. Furthermore, the differential induction of individual TSCs resulted in the formation of single-cell-derived tumor organoids (STOs). The suitability of a microfluidic single-cell culture approach for patient-derived tumor specimens was also evaluated. Specifically, TSCs were successfully expanded from 16/26 primary colorectal cancer specimens, with SDT formation rates ranging from 0.02% to 17.77%. Differential induction culture of individual TSCs yielded enhanced STO formation efficiencies (25.02% to 65.30%). Collectively, these results establish microfluidic single-cell culture as a robust and adaptable methodology for TSC expansion and tumor organoid generation, offering a valuable platform to advance the field of tumor organoid engineering.

Emerging therapies in sickle cell disease (SCD) aim to restore healthy red blood cell (RBC) function, but they often yield heterogeneous cellular responses. There are no proven techniques to evaluate restored rheological functionality and heterogeneity in these RBCs. We present a biomimetic microcapillary network, high-speed imaging, and computational algorithms to analyze RBC capillary velocity profiles of the entire sample population at single-cell resolution. Using peripheral RBCs from SCD patients and healthy donors, we showed that RBC capillary transit velocity correlated with cell shape, hydrodynamic adaptability, and elongation index. Healthy RBCs exhibited a velocity distribution skewed toward higher values, whereas RBCs from individuals with SCD showed a shift toward lower velocities. SCD samples had a greater fraction of slow RBCs than healthy controls (42.1% ± 12.0% vs. 19.0% ± 4.9%, p < 0.0001). We tested mixtures of healthy and SCD RBCs to simulate heterogeneous therapeutic effects and demonstrated that the assay was sensitive to small fractions of abnormal RBCs. The slow RBC fraction emerged as a potential biomarker associated with SCD disease severity. This fraction significantly increased under hypoxia showing sensitivity to hypoxia-induced sickling. Finally, we assessed in vitro-derived RBCs and observed distinct velocity profiles for nucleated and enucleated cells. Processing methods to enrich enucleated RBCs improved the velocity profile, producing a distribution that was more comparable to that of peripheral RBCs. This platform's ability to assess individual RBCs and generate a velocity profile from a small number of cells makes it well suited for evaluating the rheological properties of in vitro-derived RBCs.

Extracellular vesicles (EVs), especially the exosome-sized subset are increasingly exploited as minimally invasive cancer biomarkers. These small vesicles are abundant in biofluids and play crucial roles in intercellular communication and disease progression by transporting bioactive molecules. Exosomes offer distinct diagnostic and prognostic advantages over traditional cancer biomarkers, but purifying and extracting exosomes from blood remains challenging. There is a need to simply and cost-effectively isolate exosomes from milliliter quantities of whole blood for transcriptional and other omics-based research. Addressing this gap, we propose a microfluidic cartridge, the EV-Blade, for size and affinity-based purification of exosomes on a centrifugal microfluidic platform. We demonstrate a method to automate exosome purification from whole blood samples on a single microfluidic cartridge. The EV-Blade system combines blood centrifugation, plasma filtration for EV size selection and immunomagnetic capture using functionalized superparamagnetic nanoparticles targeting CD9, CD63, and CD81 exosomal surface proteins. We report on the device performance, purity of exosome recovery and the quality of RNA collected following on-chip EV lysis. We use this automated method to detect relevant long coding and non-coding RNA transcripts in circulating blood exosomes, showcasing the EV-Blade for use in cancer patient risk stratification. The system presented herein represents a significant advancement in exosome purification, offering a robust and automated platform for liquid biopsy-based cancer research and clinical applications. This innovation holds promise for cancer diagnosis, prognosis, and monitoring through non-invasive biomarkers.

Microfluidic probes (MFPs) are an emerging class of open microfluidic devices that use hydrodynamic flow confinement (HFC) to enable precise, contact-free delivery, and removal of fluids on biological surfaces. Unlike closed-channel microfluidics, MFPs operate in open environments, allowing localized chemical and biological interactions with high spatial and temporal resolution. Since their introduction in 2005, MFPs have advanced through major innovations, including multipolar flow designs, vertical configurations, 3D printing, and structural enhancements such as herringbone micromixers. This review presents a comprehensive overview of MFP technologies, covering core physical principles, flow dynamics, operating modes, and the influence of geometric and hydrodynamic design. We examine fabrication techniques such as photolithography, soft lithography, and 3D printing, highlighting their trade-offs in precision, scalability, and cost. We also explore biological applications of MFPs, including tissue assays, cellular manipulation, molecular patterning, and single-cell biopsy. Emerging integrations with heating, dielectrophoresis, and real-time feedback are expanding the utility of MFPs for adaptive high-throughput workflows. By tracing two decades of development, this review positions MFPs as transformative tools in open-space microfluidics and outlines opportunities for future progress.