Poly(ethylene oxide) Concentration Gradient-Based Microfluidic Isolation of Circulating Tumor Cells.

Circulating tumor cells (CTCs) have emerged as promising circulating biomarkers for non-invasive cancer diagnosis and management. Isolation and detection of CTCs in clinical samples are challenging due to the extreme rarity and high heterogeneity of CTCs. Here, we describe a poly(ethylene oxide) (PEO) concentration gradient-based microfluidic method for rapid, label-free, highly efficient isolation of CTCs directly from whole blood samples. Stable concentration gradients of PEO were formed within the microchannel by co-injecting the side fluid (blood sample spiked with 0.025% PEO) and center fluid (0.075% PEO solution). The competition between the elastic lift force and the inertial lift force enabled size-based separation of large CTCs and small blood cells based on their distinct migration patterns. The microfluidic device could process 1 mL of blood sample in 30 min, with a separation efficiency of >90% and an enrichment ratio of >700 for tumor cells. The isolated CTCs from blood samples were enumerated by immunofluorescence staining, allowing for discrimination of breast cancer patients from healthy donors with an accuracy of 84.2%. The concentration gradient-based microfluidic separation provides a powerful tool for label-free isolation of CTCs for a wide range of clinical applications.

Thermophoretic Detection of Exosomal microRNAs by Nanoflares.

Exosomal microRNAs (miRNAs) are reliable and noninvasive biomarkers for the early diagnosis of cancer. Yet, accurate and feasible detection of exosomal miRNAs is often hampered by the low abundance of miRNAs in exosomes and the requirement for RNA extraction in large sample volumes. Here we show a thermophoretic sensor implemented with nanoflares for in situ detection of exosomal miRNAs, without resorting to either RNA extraction or target amplification. Thermophoretic accumulation of nanoflare-treated exosomes leads to an amplified fluorescence signal upon the binding of exosomal miRNAs to nanoflares, allowing for direct and quantitative measurement of exosomal miRNAs down to 0.36 fM in 0.5 µL serum samples. One of the best markers, exosomal miR-375, showed an accuracy of 85% for detection of estrogen receptor-positive breast cancer at early stages (stages I, II). This work provides a feasible tool to improve the diagnosis of cancer.

Low-cost thermophoretic profiling of extracellular-vesicle surface proteins for the early detection and classification of cancers.

Non-invasive assays for early cancer screening are hampered by challenges in the isolation and profiling of circulating biomarkers. Here, we show that surface proteins from serum extracellular vesicles labelled with a panel of seven fluorescent aptamers can be profiled, via thermophoretic enrichment and linear discriminant analysis, for cancer detection and classification. In a cohort of 102 patients, including 6 cancer types at stages I-IV, the assay detected stage I cancers with 95% sensitivity (95% confidence interval (CI): 74-100%) and 100% specificity (95% CI: 80-100%), and classified the cancer type with an overall accuracy of 68% (95% CI: 59-77%). For patients who underwent prostate biopsies, the assay was superior to the analysis of prostate-specific antigen levels (area under the curve: 0.94 versus 0.68; 33 patients) for the discrimination of prostate cancer and benign prostate enlargement, and also in the assessment of biochemical cancer recurrence after radical prostatectomy. The assay is inexpensive, fast, and requires small serum volumes (<1 µl), and if validated in larger cohorts may facilitate cancer screening, classification and monitoring.

λ-DNA- and Aptamer-Mediated Sorting and Analysis of Extracellular Vesicles.

Extracellular vesicles (EVs) are heavily implicated in diverse pathological processes. Due to their small size, distinct biogenesis, and heterogeneous marker expression, isolation and detection of single EV subpopulations are difficult. Here, we develop a λ-DNA- and aptamer-mediated approach allowing for simultaneous size-selective separation and surface protein analysis of individual EVs. Using a machine learning algorithm to EV signature based on their size and marker expression, we demonstrate that the isolated microvesicles are more efficient than exosomes and apoptotic bodies in discriminating breast cell lines and Stage II breast cancer patients with varied immunohistochemical expression of HER2. Our method provides an important tool to assess the EV heterogeneity at the single EV level with potential value in clinical diagnostics.

[The features and treatment of Xixia "May 17th" explosion accident].

OBJECTIVE: To retrospectively analyze the injury characteristics of victims and treatment strategies in the explosion accident on the 17th May 2018 in Xixia county (Xixia "May 17th" explosion accident). METHODS: Completion the Level Three treatment on time, which was depended on the leading role played by the regional trauma centers was the main rescuing mode of the work in Xixia county, where the primary and secondary treatments were the key parts. The three-level treatment model includes: the local hospital acts as a level-one emergency medical institution, county hospitals function as secondary emergency medical institutions, and other higher medical institutions are the tertiary first aid medical institutions. The pre-hospital and in-hospital emergency procedures were initiated immediately after the large-scale explosive burn being identified, the key to the successfully rescue was to set up a comprehensive treatment team for burns and trauma. Rescue team should involve burn department and other related departments, including the departments of emergency, general surgery, orthopedic, thoracic surgery, neurosurgery, plastic surgery, intensive care unit, blood transfusion unit, anesthesiology, and interventional radiology, etc. All the thirteen burned patients were male, with inhalation injury, blast injury, hemopneumothorax, brain injury, bone fractures, and etc. Eight of them (61.54%) had multiple organ dysfunction syndrome (MODS). MODS mainly involved respiratory, circulatory, liver, gastrointestinal tract, kidney and coagulation function. With the multi-discipline treatment, the wound of 6 severely-burned patients started healing and can be discharged after keeping the patency of airway, applying resuscitation fluid and comprehensive treatments such as debridement and dressing change. Among 7 patients with extensive deep burns, one case with skull-based fracture, open craniocerebral, extensive intracranial hemorrhage and hemopneumothorax, died 9 hours later. Another case died within 24 hours after injury due to obvious exudation on the site of early incision and relaxation of wound. The escharotomy, micro-dermis and allograft skin transplantation were carried out for five cases with extensive deep burns from the 4th day after the recovery of shock. One week later, the second stage of microsphere skin transplantation was performed. But all died of sepsis or fungal infection. RESULTS: (1) A total of 113 elderly patients with sepsis were enrolled in the final analysis, including 67 patients in sepsis group and 46 patients in septic shock group. Thirty-two patients were enrolled as healthy controls and 31 elderly patients with CAP as elderly pneumonia group. The PCT, CRP, Lac, APACHE II and SOFA scores of the patients in the three groups were higher than those of the healthy control group, and they were gradually increased with the severity of infection. There was no significant difference in gender or age among the groups. Compared with the healthy control group, the other three groups had higher LL-37 level after admission, the LL-37 levels in the sepsis group and the septic shock group were decreased with the prolongation of the hospitalization time, and they were lower than the pneumonia group at 7 days after admission [LL-37 (µg/L): 1 403.9±501.9, 1 517.1±676.4 vs. 1 608.4±816.2, both P > 0.05]. It was shown by correlation analysis that the LL-37 level in peripheral blood of elderly patients with sepsis was significantly negatively correlated with APACHE II score (r = -0.329, P = 0.007) and SOFA score (r = -0.344, P = 0.005), but no significant correlation with Lac was found (r = -0.128, P = 0.311). (2) The 28-day survival analysis revealed that of the 113 elderly patients with sepsis, 54 (47.8%) survived at 28 days and 59 (52.2%) died. There was no significant difference in gender, age, PCT or CRP levels at 1 day after admission between the two groups. The 1-day Lac, APACHE II and SOFA scores of the patients in the non-survival group were significantly higher than those in the survival group, they were gradually increased with the prolongation of the hospitalization time, and they were significantly higher than those in the survival group at 7 days after admission [Lac (mmol/L): 2.4 (1.4, 4.4) vs. 1.0 (0.8, 1.7), APACHE II score: 21.77±5.85 vs. 13.74±4.99, SOFA score: 9.62±4.78 vs. 3.18±2.71, all P < 0.01]. With the prolongation of admission, there was no significant change in LL-37 level of peripheral blood in the survival group. The LL-37 level in the non-survival group showed a downward tendency, and it was significantly lower than that in the survival group at 7 days after admission (µg/L: 1 277.8±642.6 vs. 1 620.6±461.6, P < 0.05). It was shown by ROC curve analysis that the LL-37 in peripheral blood, Lac, APACHE II score and SOFA score at 7-day of admission of elderly patients with sepsis had predictive value for prognosis, and LL-37 had the best predicted effect for 28-day death, the area under the ROC curve (AUC) of LL-37 was 0.670, 95% confidence interval (95%CI) = 0.513-0.757, when the optimal cut-off value was 1 283.0 µg/L, the sensitivity was 75.7%, and the specificity was 61.5%. CONCLUSIONS: MODS and infection often occur during the course especially for patients with extensive and deep burns due to the great explosion in Xixia county, most of whom were accompanied with MODS and infection. Therefore, assembling multi-discipline team for treating the group of explosively-burned patients can increase the survival rate and reduce the possibility of disability.