Predictive Analysis in Oral Cancer Immunotherapy: Profiling Dual PD-L1-Positive Extracellular Vesicle Subtypes with Step-Wedge Microfluidic Chips

PD-L1-positive extracellular vesicles (PD-L1+ EVs) play a pivotal role as predictive biomarkers in cancer immunotherapy. These vesicles, originating from immune cells (I-PD-L1+ EVs) and tumor cells (T-PD-L1+ EVs), hold distinct clinical predictive values, emphasizing the importance of deeply differentiating the PD-L1+ EV subtypes for effective liquid biopsy analyses. However, current methods such as ELISA lack the ability to differentiate their cellular sources. In this study, a novel step-wedge microfluidic chip that combines magnetic microsphere separation with single-layer fluorescence counting is developed. This chip integrates magnetic microspheres modified with anti-PD-L1 antibodies and fluorescent nanoparticles targeting EpCAM (tumor cell marker) or CD45 (immunocyte marker), enabling simultaneous quantification and sensitive analysis of PD-L1+ EV subpopulations in oral squamous cell carcinoma (OSCC) patients' saliva without background interference. Analysis results indicate reduced levels of I-PD-L1+ EVs in OSCC patients compared to those in healthy individuals, with varying levels of heterogeneous PD-L1+ EVs observed among different patient groups. During immunotherapy, responders exhibit decreased levels of total PD-L1+ EVs and T-PD-L1+ EVs, accompanied by reduced levels of I-PD-L1+ EVs. Conversely, nonresponders show increased levels of I-PD-L1+ EVs. Utilizing the step-wedge microfluidic chip allows for simultaneous detection of PD-L1+ EV subtypes, facilitating the precise prediction of oral cancer immunotherapy outcomes.

Circulating tumor cells in gastric cancer: developments and clinical applications

Circulating tumor cells (CTCs), which are shed from primary tumor or metastatic sites into the bloodstream and subsequently seed into distant tissues, are considered as the precursors of metastases. Gastric cancer (GC) is a highly heterogeneous malignant tumor. With regard to the diagnosis of GC, secondary pathological biopsy is difficult, while invasive examination is harmful to patients. In recent years, CTCs have made great progress in tumor diagnosis, prognosis prediction, efficacy detection and treatment guidance, but the research on the role of CTCs in GC remains limited. The following sections review the landmark studies demonstrating the technical approaches of CTCs monitoring in the field of GC. Moreover, we highlight the clinical application of CTCs numbers and phenotypes in monitoring the therapeutic efficacy and judging patient prognosis by sequential blood analyses.

Clinical diagnostic biomarker "circulating tumor cells" in breast cancer - a meta-analysis

Objective

Using meta-analysis, we evaluate circulating tumor cells(CTCs) as a potential diagnostic tool for breast cancer.

Methods

A document search was conducted using publicly available databases up to May 2021. Specific inclusion and exclusion criteria were formulated and summarize relevant data through literature types, research types, case populations, samples, etc. Subgroup analysis of documents based on regions, enrichment methods, and detection methods. The included research projects were evaluated using DeeKs' bias, and evaluation indicators such as specificity (SPE), sensitivity (SEN), diagnosis odds ratio (DOR) were used as evaluation indicators.

Results

16 studies on the use of circulating tumor cells to diagnose breast cancer were included in our meta-analysis. Overall sensitivity value was 0.50 (95%CI:0.48-0.52), specificity value was 0.93 (95%CI:0.92- 0.95), DOR value was 33.41 (95%CI:12.47-89.51), and AUC value was 0.8129.

Conclusion

In meta-regressions and subgroup analysis, potential heterogeneity factors were analyzed, but the source of heterogeneity is still unclear. CTCs, as a novel tumor marker, have a good diagnostic value, but its enrichment and detection methods still need to continue to be developed to improve detection accuracy. Therefore, CTCs can be used as an auxiliary means of early detection, which is helpful to the diagnosis and screening of breast cancer.

Process simplification and structure design of parallelized microslit isolator for physical property-based capture of tumor cells

A facile, scalable, and highly efficient approach to physically capturing CTCs from blood samples has been developed using a microfluidic isolator with parallelized microslit channels.

Advanced Devices for Tumor Diagnosis and Therapy

At present, tumor diagnosis is performed using common procedures, which are slow, costly, and still presenting difficulties in diagnosing tumors at their early stage. Tumor therapeutic methods also mainly rely on large-scale equipment or non-intelligent treatment approaches. Thus, an early and accurate tumor diagnosis and personalized treatment may represent the best treatment option for a successful result, and the efforts in finding them are still in progress and mainly focusing on non-destructive, integrated, and multiple technologies. These objectives can be achieved with the development of advanced devices and smart technology that represent the topic of the current investigations. Therefore, this review summarizes the progress in tumor diagnosis and therapy and briefly explains the advantages and disadvantages of the described microdevices, finally proposing advanced micro smart devices as the future development trend for tumor diagnosis and therapy.

Detection and isolation of free cancer cells from ascites and peritoneal lavages using optically induced electrokinetics (OEK)

Detection of free gastric cancer cells in peritoneal lavages and ascites plays a vital role in gastric cancer. However, due to the low content of cancer cells in patients' peritoneal lavages, traditional detection methods lack sensitivity and cannot satisfy clinical demand. In this study, we used an optically induced electrokinetics (OEK) microfluidic method for label-free separation and characterization of patient gastric cancer cells. This method showed high effectiveness and sensitivity. We successfully separated cancer cells from a simulated peritoneal lavage mixture of gastric cancer cell lines and peritoneal lavage cells in a ratio of 1:1000. We further separated gastric cancer cells from six patients' ascites with purity up to 71%. In addition, we measured the cell membrane capacitances, which may be used as a biomarker for gastric cancer cells. Thus, our method can be used to effectively and rapidly detect peritoneal metastasis and to acquire cellular electrical information.

Negative depletion mediated brightfield circulating tumour cell identification strategy on microparticle-based microfluidic chip

Background

The most convenient circulating tumor cells (CTCs) identification method is direct analysis of cells under bright field microscopy by which CTCs can be comprehensive studied based on morphology, phenotype or even cellular function. However, universal cell markers and a standard tumour cell map do not exist, thus limiting the clinical application of CTCs.

Results

This paper focuses on an automatic and convenient negative depletion strategy for circulating tumour cell identification under bright field microscopy. In this strategy, immune microparticles (IMPs) are applied to negatively label white blood cells rather than the tumour cells, such that tumour cells can be directly distinguished under brightfield of the microscopy. In this way, all of the heterogeneous tumour cells and their phenotype properties can be retained for further cancer-related studies. In addition, a wedge-shaped microfluidic chip is constructed for heterogeneous CTC pre-purification and enrichment by size, thus significantly decreasing the interference of haematological cells. Additionally, all cell treatments are processed automatically, and the tumour cells can be rapidly counted and distinguished via customized cell analytical software, showing high detection efficiency and automation. This IMPs based negative cell labelling strategy can also be combined with other classic cell identification methods, thus demonstrating its excellent compatibility.

Conclusion

This identification strategy features simple and harmless for tumour cells, as well as excellent accuracy and efficiency. And the low equipment demand and high automation level make it promise for extensive application in basic medical institutions.

Simultaneous and automated detection of influenza A virus hemagglutinin H7 and H9 based on magnetism and size mediated microfluidic chip

Influenza viruses with multiple subtypes have highly virulent in humans, of which influenza hemagglutinin (HA) is the major viral surface antigen. Simultaneous and automated detection of multiple influenza HA are of great importance for early-stage diagnosis and operator protection. Herein, a magnetism and size mediated microfluidic platform was developed for point-of-care detection of multiple influenza HA. With multiplex microvalves and computer program control, the detection process showed high automation which had a great potential for avoiding the high-risk virus exposure to the operator. Taking advantage of magnetism and size mediated multiple physical fields, multiple influenza HA could be simultaneous separation and detection depended on different-size magnetic beads. Using high-luminance quantum dots as reporter, this assay achieved high sensitivity with a detection limit of 3.4 ng/mL for H7N9 HA and 4.5 ng/mL for H9N2 HA, and showed excellent specificity, anti-interference ability and good reproducibility. These results indicate that this method may propose new avenues for early detection of multiple influenza subtypes.