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Exosomes are extracellular vesicles that modulate essential physiological and pathological signals. Communication between cancer cells that express the von Hippel-Lindau (VHL) tumor suppressor gene and those that do not is instrumental to distant metastasis in renal cell carcinoma (RCC). In a novel metastasis model, VHL(−) cancer cells are the metastatic driver, while VHL(+) cells receive metastatic signals from VHL(−) cells and undergo aggressive transformation. This study investigates whether exosomes could be mediating metastatic crosstalk. Exosomes isolated from paired VHL(+) and VHL(−) cancer cell lines were assessed for physical, biochemical, and biological characteristics. Compared to the VHL(+) cells, VHL(−) cells produce significantly more exosomes that augment epithelial-to-mesenchymal transition (EMT) and migration of VHL(+) cells. Using a Cre-loxP exosome reporter system, the fluorescent color conversion and migration were correlated with dose-dependent delivery of VHL(−) exosomes. VHL(−) exosomes even induced a complete cascade of distant metastasis when added to VHL(+) tumor xenografts in a duck chorioallantoic membrane (dCAM) model, while VHL(+) exosomes did not. Therefore, this study supports that exosomes from VHL(−) cells could mediate critical cell-to-cell crosstalk to promote metastasis in RCC. [ABSTRACT FROM AUTHOR]

Serum alpha‐fetoprotein and radiologic imaging are the most commonly used tests for early diagnosis and dynamic monitoring of treatment response in hepatocellular carcinoma (HCC). However, the accuracy of these tests is limited, and they may not reflect the underlying biology of the tumor. Thus, developing highly accurate novel HCC biomarkers reflecting tumor biology is a clinically unmet need. Circulating tumor cells (CTCs) have long been proposed as a noninvasive biomarker in clinical oncology. Most CTC assays utilize immunoaffinity‐based, size‐based, and/or enrichment‐free mechanisms followed by immunocytochemical staining to characterize CTCs. The prognostic value of HCC CTC enumeration has been extensively validated. Subsets of CTCs expressing mesenchymal markers are also reported to have clinical significance. In addition, researchers have been devoting their efforts to molecular characterizations of CTCs (e.g. genetics and transcriptomics) as molecular profiling can offer a more accurate readout and provide biological insights. As new molecular profiling techniques, such as digital polymerase chain reaction, are developed to detect minimal amounts of DNA/RNA, several research groups have established HCC CTC digital scoring systems to quantify clinically relevant gene panels. Given the versatility of CTCs to provide intact molecular and functional data that reflects the underlying tumor, CTCs have great potential as a noninvasive biomarker in HCC. Large‐scale, prospective studies for HCC CTCs with a standardized protocol are necessary for successful clinical translation. [ABSTRACT FROM AUTHOR]

Background: Recent trends of hepatocellular carcinoma (HCC) mortality and outcome remain unknown in the United States. We investigated the recent trends of primary liver cancer (excluding intrahepatic cholangiocarcinoma) mortality and HCC stage, treatment, and overall survival (OS) in the United States.Methods: The National Center for Health Statistics Database was analyzed to investigate the trend of primary liver cancer mortality. We analyzed the Surveillance, Epidemiology, and End Results 18 Database to assess the temporal trend of tumor size, stage, treatment, and OS of HCC. We investigated the association between HCC diagnosis year and OS using Cox regression analysis. All statistical tests were 2-sided.Results: During 2000-2018, liver cancer mortality rates increased until 2013, plateaued during 2013-2016 (annual percent change = 0.1%/y, 95% confidence interval [CI] = -2.1%/y to 2.4%/y, P = .92), and started to decline during 2016-2018 (annual percent change = -1.5%/y, 95% CI = -3.2%/y to 0.2%/y, P = .08). However, mortality continues to increase in American Indian and Alaska Native, individuals aged 65 years or older, and in 33 states. There was a 0.61% (95% CI = 0.53% to 0.69%, P < .001) increase in localized stage HCC and a 0.86-mm (95% CI = -1.10 to -0.62 mm, P < .001) decrease in median tumor size per year. The 1-year OS rate increased from 36.3% (95% CI = 34.3% to 38.3%) to 58.1% (95% CI = 56.9% to 59.4%) during 2000-2015, and the 5-year OS rate almost doubled from 11.7% (95% CI = 10.4% to 13.1%) to 21.3% (95% CI = 20.2% to 22.4%) during 2000-2011. Diagnosis year (per year) (adjusted hazard ratio = 0.96, 95% CI = 0.96 to 0.97) was independently associated with OS in multivariable analysis.Conclusions: Primary liver cancer mortality rates have started to decline in the United States with demographic and state-level variation. With an increasing detection of localized HCC, the OS of HCC has improved over the past decades. [ABSTRACT FROM AUTHOR]

Context: Crosstalk through receptor ligand interactions at the maternal-fetal interface is impacted by fetal sex. This affects placentation in the first trimester and differences in outcomes. Sexually dimorphic signaling at early stages of placentation are not defined.Objective: Investigate the impact of fetal sex on maternal-fetal crosstalk.Design: Receptors/ligands at the maternal-fetal surface were identified from sexually dimorphic genes between fetal sexes in the first trimester placenta and defined in each cell type using single-cell RNA-Sequencing (scRNA-Seq).Setting: Academic institution.Samples: Late first trimester (~10-13 weeks) placenta (fetal) and decidua (maternal) from uncomplicated ongoing pregnancies.Main Outcome Measures: Transcriptomic profiling at tissue and single-cell level; immunohistochemistry of select proteins.Results: We identified 91 sexually dimorphic receptor-ligand pairs across the maternal-fetal interface. We examined fetal sex differences in 5 major cell types (trophoblasts, stromal cells, Hofbauer cells, antigen-presenting cells, and endothelial cells). Ligands from the CC family chemokine ligand (CCL) family were most highly representative in females, with their receptors present on the maternal surface. Sexually dimorphic trophoblast transcripts, Mucin-15 (MUC15) and notum, palmitoleoyl-protein carboxylesterase (NOTUM) were also most highly expressed in syncytiotrophoblasts and extra-villous trophoblasts respectively. Gene Ontology (GO) analysis using sexually dimorphic genes in individual cell types identified cytokine mediated signaling pathways to be most representative in female trophoblasts. Upstream analysis demonstrated TGFB1 and estradiol to affect all cell types, but dihydrotestosterone, produced by the male fetus, was an upstream regulator most significant for the trophoblast population.Conclusions: Maternal-fetal crosstalk exhibits sexual dimorphism during placentation early in gestation. [ABSTRACT FROM AUTHOR]

Hepatocellular carcinoma (HCC) is a leading cause of mortality. Checkpoint inhibitors of programmed cell death protein‐1 (PD‐1) and programmed death‐ligand 1 (PD‐L1) have shown great efficacy, but lack biomarkers that predict response. Circulating tumor cells (CTCs) have promise as a liquid‐biopsy biomarker; however, data on HCC CTCs expressing PD‐L1 have not been reported. We sought to detect PD‐L1‐expressing HCC‐CTCs and investigated their role as a prognostic and predictive biomarker. Using an antibody‐based platform, CTCs were enumerated/phenotyped from a prospective cohort of 87 patients with HCC (49 early‐stage, 22 locally advanced, and 16 metastatic), 7 patients with cirrhosis, and 8 healthy controls. Immunocytochemistry identified total HCC CTCs (4′,6‐diamidino‐2‐phenylindole–positive [DAPI+]/cytokeratin‐positive [CK+]/clusters of differentiation 45–negative [CD45−]) and a subpopulation expressing PD‐L1 (DAPI+/CK+/PD‐L1+/CD45−). PD‐L1+ CTCs were identified in 4 of 49 (8.2%) early‐stage patients, but 12 of 22 (54.5%) locally advanced and 15 of 16 (93.8%) metastatic patients, accurately discriminating early from locally advanced/metastatic HCC (sensitivity = 71.1%, specificity = 91.8%, area under the receiver operating characteristic curve = 0.807; P < 0.001). Compared to patients without PD‐L1+ CTCs, patients with PD‐L1+ CTCs had significantly inferior overall survival (OS) (median OS = 14.0 months vs. not reached, hazard ratio [HR] = 4.0, P = 0.001). PD‐L1+ CTCs remained an independent predictor of OS (HR = 3.22, P = 0.010) even after controlling for Model for End‐Stage Liver Disease score (HR = 1.14, P < 0.001), alpha‐fetoprotein (HR = 1.55, P < 0.001), and overall stage/tumor burden (beyond University of California, San Francisco, HR = 7.19, P < 0.001). In the subset of 10 patients with HCC receiving PD‐1 blockade, all 5 responders demonstrated PD‐L1+ CTCs at baseline, compared with only 1 of 5 nonresponders, all of whom progressed within 4 months of starting treatment. Conclusion: We report a CTC assay for the phenotypic profiling of HCC CTCs expressing PD‐L1. PD‐L1+ CTCs are predominantly found in advanced‐stage HCC, and independently prognosticate OS after controlling for Model for End‐Stage Liver Disease, alpha‐fetoprotein, and tumor stage. In patients with HCC receiving anti‐PD‐1 therapy, there was a strong association with the presence of PD‐L1+ CTCs and favorable treatment response. Prospective validation in a larger cohort will better define the utility of PD‐L1+ CTCs as a prognostic and predictive biomarker in HCC. [ABSTRACT FROM AUTHOR]

Determining the status of epidermal growth factor receptor (EGFR) T790M mutation is crucial for guiding further treatment intervention in advanced non-small cell lung cancer (NSCLC) patients who develop acquired resistance to initial EGFR tyrosine kinase inhibitor (TKI) treatment. Circulating tumor cells (CTCs) which contain plentiful copies of well-preserved RNA offer an ideal source for noninvasive detection of T790M mutation in NSCLC. We developed a CTC-based digital assay which synergistically integrates NanoVelcro Chips for enriching NSCLC CTCs and reverse-transcription droplet digital PCR (RT-ddPCR) for quantifying T790M transcripts in the enriched CTCs. We collected 46 peripheral arterial and venous blood samples from 27 advanced NSCLC patients for testing this CTC-based digital assay. The results showed that the T790M mutational status observed by the CTC-based digital assay matched with those observed by tissue-based diagnostic methods. Furthermore, higher copy numbers of T790M transcripts were observed in peripheral arterial blood than those detected in the matched peripheral venous blood. In short, our results demonstrated the potential of the NanoVelcro CTC-digital assay for noninvasive detection of the T790M mutation in NSCLC, and suggested that peripheral arterial blood sampling may offer a more abundant CTC source than peripheral venous blood in advanced NSCLC patients. [ABSTRACT FROM AUTHOR]

Somatic copy number alterations (SCNAs) are important genetic drivers of many cancers. We investigated the feasibility of obtaining SCNA profiles from circulating tumor cells (CTCs) as a molecular liquid biopsy for hepatocellular carcinoma (HCC). CTCs from ten HCC patients underwent SCNA profiling. The Cancer Genome Atlas (TCGA) SCNA data were used to develop a cancer origin classification model, which was then evaluated for classifying 44 CTCs from multiple cancer types. Sequencing of 18 CTC samples (median: 4 CTCs/sample) from 10 HCC patients using a low-resolution whole-genome sequencing strategy (median: 0.88 million reads/sample) revealed frequent SCNAs in previously reported HCC regions such as 8q amplifications and 17p deletions. SCNA profiling revealed that CTCs share a median of 80% concordance with the primary tumor. CTCs had SCNAs not seen in the primary tumor, some with prognostic implications. Using a SCNA profiling model, the tissue of origin was correctly identified for 32/44 (73%) CTCs from 12/16 (75%) patients with different cancer types. [ABSTRACT FROM AUTHOR]

The homology‐independent targeted integration (HITI) strategy enables effective CRISPR/Cas9‐mediated knockin of therapeutic genes in nondividing cells in vivo, promising general therapeutic solutions for treating genetic diseases like X‐linked juvenile retinoschisis. Herein, supramolecular nanoparticle (SMNP) vectors are used for codelivery of two DNA plasmids—CRISPR‐Cas9 genome‐editing system and a therapeutic gene, Retinoschisin 1 (RS1)—enabling clustered regularly interspaced short palindromic repeats (CRISPR)‐associated protein 9 (CRISPR/Cas9) knockin of the RS1 gene with HITI. Through small‐scale combinatorial screenings, two SMNP vectors, with Cas9 and single guide RNA (sgRNA)‐plasmid in one and Donor‐RS1 and green fluorescent protein (GFP)‐plasmid in the other, with optimal delivery performances are identified. These SMNP vectors are then employed for CRISPR/Cas9 knockin of RS1/GFP genes into the mouse Rosa26 safe‐harbor site in vitro and in vivo. The in vivo study involves intravitreally injecting the two SMNP vectors into the mouse eyes, followed by repeated ocular imaging by fundus camera and optical coherence tomography, and pathological and molecular analyses of the harvested retina tissues. Mice ocular organs retain their anatomical integrity, a single‐copy 3.0‐kb RS1/GFP gene is precisely integrated into the Rosa26 site in the retinas, and the integrated RS1/GFP gene is expressed in the retinas, demonstrating CRISPR/Cas9 knockin of RS1/GFP gene. [ABSTRACT FROM AUTHOR]

Background: The strong invasive and metastatic nature of non-small cell lung cancer (NSCLC) leads to poor prognosis. Collagen triple helix repeat containing 1 (CTHRC1) is involved in cell migration, motility and invasion. The object of this study is to investigate the involvement of CTHRC1 in NSCLC invasion and metastasis.Methods: A proteomic analysis was performed to identify the different expression proteins between NSCLC and normal tissues. Cell lines stably express CTHRC1, MMP7, MMP9 were established. Invasion and migration were determined by scratch and transwell assays respectively. Clinical correlations of CTHRC1 in a cohort of 230 NSCLC patients were analysed.Results: CTHRC1 is overexpressed in NSCLC as measured by proteomic analysis. Additionally, CTHRC1 increases tumour cell migration and invasion in vitro. Furthermore, CTHRC1 expression is significantly correlated with matrix metalloproteinase (MMP)7 and MMP9 expression in sera and tumour tissues from NSCLC. The invasion ability mediated by CTHRC1 were mainly MMP7- and MMP9-dependent. MMP7 or MMP9 depletion significantly eradicated the pro-invasive effects mediated by CTHRC1 on NSCLC cells. Clinically, patients with high CTHRC1 expression had poor survival.Conclusions: CTHRC1 serves as a pro-metastatic gene that contributes to NSCLC invasion and metastasis, which are mediated by upregulated MMP7 and MMP9 expression. Targeting CTHRC1 may be beneficial for inhibiting NSCLC metastasis. [ABSTRACT FROM AUTHOR]

Background: Occult metastatic tumors, below imaging thresholds, are a limitation of staging systems that rely on cross-sectional imaging alone and are a cause of the routine understaging of pancreatic ductal adenocarcinomas (PDACs). We investigated circulating tumor cells (CTCs) as a preoperative predictor of occult metastatic disease and as a prognostic biomarker for PDAC patients.Experimental Design: A total of 126 patients (100 with cancer, 26 with benign disease) were enrolled in our study and CTCs were identified and enumerated from 4 mL of venous blood using the microfluidic NanoVelcro assay. CTC enumeration was correlated with clinicopathologic variables and outcomes following both surgical and systemic therapies.Results: CTCs were identified in 78% of PDAC patients and CTC counts correlated with increasing stage (ρ = 0.42, p < 0.001). Of the 53 patients taken for potentially curative surgery, 13 (24.5%) had occult metastatic disease intraoperatively. Patients with occult disease had significantly more CTCs than patients with local disease only (median 7 vs. 1 CTC, p < 0.0001). At a cut-off of three or more CTCs/4 mL, CTCs correctly identified patients with occult metastatic disease preoperatively (area under the receiver operating characteristic curve 0.82, 95% confidence interval (CI) 0.76-0.98, p < 0.0001). CTCs were a univariate predictor of recurrence-free survival following surgery [hazard ratio (HR) 2.36, 95% CI 1.17-4.78, p = 0.017], as well as an independent predictor of overall survival on multivariate analysis (HR 1.38, 95% CI 1.01-1.88, p = 0.040).Conclusions: CTCs show promise as a prognostic biomarker for PDAC patients at all stages of disease being treated both medically and surgically. Furthermore, CTCs demonstrate potential as a preoperative biomarker for identifying patients at high risk of occult metastatic disease. [ABSTRACT FROM AUTHOR]

Background: Sequencing analysis of circulating tumor cells (CTCs) enables "liquid biopsy" to guide precision oncology strategies. However, this requires low-template whole genome amplification (WGA) that is prone to errors and biases from uneven amplifications. Currently, quality control (QC) methods for WGA products, as well as the number of CTCs needed for reliable downstream sequencing, remain poorly defined. We sought to define strategies for selecting and generating optimal WGA products from low-template input as it relates to their potential applications in precision oncology strategies.Methods: Single pancreatic cancer cells (HPAF-II) were isolated using laser microdissection. WGA was performed using multiple displacement amplification (MDA), multiple annealing and looping based amplification (MALBAC) and PicoPLEX. Quality of amplified DNA products were assessed using a multiplex/RT-qPCR based method that evaluates for 8-cancer related genes and QC-scores were assigned. We utilized this scoring system to assess the impact of de novo modifications to the WGA protocol. WGA products were subjected to Sanger sequencing, array comparative genomic hybridization (aCGH) and next generation sequencing (NGS) to evaluate their performances in respective downstream analyses providing validation of the QC-score.Results: Single-cell WGA products exhibited a significant sample-to-sample variability in amplified DNA quality as assessed by our 8-gene QC assay. Single-cell WGA products that passed the pre-analysis QC had lower amplification bias and improved aCGH/NGS performance metrics when compared to single-cell WGA products that failed the QC. Increasing the number of cellular input resulted in improved QC-scores overall, but a resultant WGA product that consistently passed the QC step required a starting cellular input of at least 20-cells. Our modified-WGA protocol effectively reduced this number, achieving reproducible high-quality WGA products from ≥5-cells as a starting template. A starting cellular input of 5 to 10-cells amplified using the modified-WGA achieved aCGH and NGS results that closely matched that of unamplified, batch genomic DNA.Conclusion: The modified-WGA protocol coupled with the 8-gene QC serve as an effective strategy to enhance the quality of low-template WGA reactions. Furthermore, a threshold number of 5-10 cells are likely needed for a reliable WGA reaction and product with high fidelity to the original starting template. [ABSTRACT FROM AUTHOR]

Applications of precision oncology strategies rely on accurate tumor genotyping from clinically available specimens. Fine needle aspirations (FNA) are frequently obtained in cancer management and often represent the only source of tumor tissues for patients with metastatic or locally advanced diseases. However, FNAs obtained from pancreas ductal adenocarcinoma (PDAC) are often limited in cellularity and/or tumor cell purity, precluding accurate tumor genotyping in many cases. Digital PCR (dPCR) is a technology with exceptional sensitivity and low DNA template requirement, characteristics that are necessary for analyzing PDAC FNA samples. In the current study, we sought to evaluate dPCR as a mutation analysis tool for pancreas FNA specimens. To this end, we analyzed alterations in the KRAS gene in pancreas FNAs using dPCR. The sensitivity of dPCR mutation analysis was first determined using serial dilution cell spiking studies. Single-cell laser-microdissection (LMD) was then utilized to identify the minimal number of tumor cells needed for mutation detection. Lastly, dPCR mutation analysis was performed on 44 pancreas FNAs (34 formalin-fixed paraffin-embedded (FFPE) and 10 fresh (non-fixed)), including samples highly limited in cellularity (100 cells) and tumor cell purity (1%). We found dPCR to detect mutations with allele frequencies as low as 0.17%. Additionally, a single tumor cell could be detected within an abundance of normal cells. Using clinical FNA samples, dPCR mutation analysis was successful in all preoperative FNA biopsies tested, and its accuracy was confirmed via comparison with resected tumor specimens. Moreover, dPCR revealed additional KRAS mutations representing minor subclones within a tumor that were not detected by the current clinical gold standard method of Sanger sequencing. In conclusion, dPCR performs sensitive and accurate mutation analysis in pancreas FNAs, detecting not only the dominant mutation subtype, but also the additional rare mutation subtypes representing tumor heterogeneity. [ABSTRACT FROM AUTHOR]

Simultaneous delivery of multiple genes and proteins (e.g., transcription factors; TFs) is an emerging issue surrounding therapeutic research due to their ability to regulate cellular circuitry. Current gene and protein delivery strategies, however, are based on slow batch synthesis, which is ineffective, poorly controlled, and incapable of simultaneous delivery of both genes and proteins with synergistic functions. Consequently, advances in this field have been limited to in vitro studies. Here, by integrating microfluidic technologies with a supramolecular synthetic strategy, we present a high-throughput approach for formulating and screening multifunctional supramolecular nanoparticles (MFSNPs) self-assembled from a collection of functional modules to achieve simultaneous delivery of one gene and TF with unprecedented efficiency both in vitro and in vivo. We envision that this new approach could open a new avenue for immunotherapy, stem cell reprogramming, and other therapeutic applications. [ABSTRACT FROM AUTHOR]

Simultaneous delivery of multiple genes and proteins (e.g., transcription factors; TFs) is an emerging issue surrounding therapeutic research due to their ability to regulate cellular circuitry. Current gene and protein delivery strategies, however, are based on slow batch synthesis, which is ineffective, poorly controlled, and incapable of simultaneous delivery of both genes and proteins with synergistic functions. Consequently, advances in this field have been limited to in vitro studies. Here, by integrating microfluidic technologies with a supramolecular synthetic strategy, we present a high-throughput approach for formulating and screening multifunctional supramolecular nanoparticles (MFSNPs) self-assembled from a collection of functional modules to achieve simultaneous delivery of one gene and TF with unprecedented efficiency both in vitro and in vivo. We envision that this new approach could open a new avenue for immunotherapy, stem cell reprogramming, and other therapeutic applications. [ABSTRACT FROM AUTHOR]

Pancreatic cancer (PC) is the fourth most common cause of cancer-related death in the USA, primarily due to late presentation coupled with an aggressive biology. The lack of adequate biomarkers for diagnosis and staging confound clinical decision-making and delay potentially effective therapies. Circulating tumor cells (CTCs) are a promising new biomarker in PC. Preliminary studies have demonstrated their potential clinical utility, and newer CTC isolation platforms have the potential to provide clinicians access to tumor tissue in a reliable, real-time manner. Such a ‘liquid biopsy’ has been demonstrated in several cancers, and small studies have demonstrated its potential applications in PC. This article reviews the available literature on CTCs as a biomarker in PC and presents the latest innovations in CTC research as well as their potential applications in PC. [ABSTRACT FROM PUBLISHER]

BACKGROUND Although enumeration of circulating tumor cells (CTCs) has shown some clinical value, the pool of CTCs contains a mixture of cells that contains additional information that can be extracted. The authors subclassified CTCs by shape features focusing on nuclear size and related this with clinical information. METHODS A total of 148 blood samples were obtained from 57 patients with prostate cancer across the spectrum of metastatic states: no metastasis, nonvisceral metastasis, and visceral metastasis. CTCs captured and enumerated on NanoVelcro Chips (CytoLumina, Los Angeles, Calif) were subjected to pathologic review including nuclear size. The distribution of nuclear size was analyzed using a Gaussian mixture model. Correlations were made between CTC subpopulations and metastatic status. RESULTS Statistical modeling of nuclear size distribution revealed 3 distinct subpopulations: large nuclear CTCs, small nuclear CTCs, and very small nuclear CTCs (vsnCTCs). Small nuclear CTCs and vsnCTC identified those patients with metastatic disease. However, vsnCTC counts alone were found to be elevated in patients with visceral metastases when compared with those without (0.36 ± 0.69 vs 1.95 ± 3.77 cells/mL blood; P<.001). Serial enumeration studies suggested the emergence of vsnCTCs occurred before the detection of visceral metastases. CONCLUSIONS There are morphologic subsets of CTCs that can be identified by fundamental pathologic approaches, such as nuclear size measurement. The results of this observational study strongly suggest that CTCs contain relevant information regarding disease status. In particular, the detection of vsnCTCs was found to be correlated with the presence of visceral metastases and should be formally explored as a putative blood-borne biomarker to identify patients at risk of developing this clinical evolution of prostate cancer. Cancer 2015;121:3240-3251. © 2015 American Cancer Society. [ABSTRACT FROM AUTHOR]

Confined to one cell: A method to detect and isolate single circulating melanoma cells (CMCs; see figure) has been produced by integrating a polymer‐nanofiber‐embedded nanovelcro cell‐affinity assay with a laser microdissection (LMD) technique. This method is able to separate CMCs from normal white blood cells (WBCs) and sequence individual cells for a specific mutation related to cancer progression, allowing for more personalized cancer therapy. [ABSTRACT FROM AUTHOR]

Eine Methode zur Detektion und Isolierung einzelner zirkulierender Melanomzellen (CMCs; siehe Bild) beruht auf der Kombination eines in eine Polymer ‐ Nanofaser eingebetteten „Nanoklettband“ ‐ Zellaffinitätsassays mit Laser ‐ Mikrodissektion (LMD). Für eine personalisiertere Krebstherapie lassen sich so CMCs von normalen weißen Blutzellen (WBCs) abtrennen und einzelne Zellen hinsichtlich einer bestimmten, mit dem Fortschreiten der Krankheit assoziierten Mutation sequenzieren. [ABSTRACT FROM AUTHOR]

Using liquid slugs as microreactors and microvessels enable precise control over the conditions of their contents on short-time scales for a wide variety of applications. Particularly for screening applications, there is a need for control of slug parameters such as size and composition. We describe a new microfluidic approach for creating slugs in air, each comprising a size and composition that can be selected individually for each slug. Two-component slugs are formed by first metering the desired volume of each reagent, merging the two volumes into an end-to-end slug, and propelling the slug to induce mixing. Volume control is achieved by a novel mechanism: two closed chambers on the chip are initially filled with air, and a valve in each is briefly opened to admit one of the reagents. The pressure of each reagent can be individually selected and determines the amount of air compression, and thus the amount of liquid that is admitted into each chamber. We describe the theory of operation, characterize the slug generation chip, and demonstrate the creation of slugs of different compositions. The use of microvalves in this approach enables robust operation with different liquids, and also enables one to work with extremely small samples, even down to a few slug volumes. The latter is important for applications involving precious reagents such as optimizing the reaction conditions for radiolabeling biological molecules as tracers for positron emission tomography. [ABSTRACT FROM AUTHOR]