ABSTRACT
Various types of circulating tumor cell (CTC) detection systems have recently been developed that show a high CTC detection rate. However, it is a big challenge to find a system that can provide better prognostic value than CellSearch in head-to-head comparison. We have developed a novel semi-automated CTC enumeration system (fluidic cell microarray chip system, FCMC) that captures CTC independently of tumor-specific markers or physical properties. Here, we compared the CTC detection sensitivity and the prognostic value of FCMC with CellSearch in breast cancer patients. FCMC was validated in preclinical studies using spike-in samples and in blood samples from 20 healthy donors and 22 breast cancer patients in this study. Using spike-in samples, a statistically higher detection rate (p=0.010) of MDA-MB-231 cells and an equivalent detection rate (p=0.497) of MCF-7 cells were obtained with FCMC in comparison with CellSearch. The number of CTC detected in samples from patients that was above a threshold value as determined from healthy donors was evaluated. The CTC number detected using FCMC was significantly higher than that using CellSearch (p=0.00037). CTC numbers obtained using either FCMC or CellSearch had prognostic value, as assessed by progression free survival. The hazard ratio between CTC+ and CTC- was 4.229 in CellSearch (95% CI, 1.31 to 13.66; p=0.01591); in contrast, it was 11.31 in FCMC (95% CI, 2.245 to 57.0; p=0.000244). CTC detected using FCMC, like the CTC detected using CellSearch, have the potential to be a strong prognostic factor for cancer patients.
Subject(s)
Breast Neoplasms/diagnosis , Breast Neoplasms/mortality , Microfluidic Analytical Techniques , Neoplastic Cells, Circulating/pathology , Adult , Aged , Aged, 80 and over , Breast Neoplasms/therapy , Case-Control Studies , Cell Count , Cell Line, Tumor , Disease Progression , Female , Humans , Microfluidic Analytical Techniques/instrumentation , Microfluidic Analytical Techniques/methods , Middle Aged , Neoplasm Staging , Prognosis , Treatment OutcomeABSTRACT
A microfluidic reflectometric interference spectroscopy (RIfS) system was adopted for the investigation of protein-protein interaction (PPI). The influence of reaction conditions (pH and temperature) on the antigen-antibody reaction of alpha-fetoprotein (AFP) and its monoclonal antibody (anti-AFP) as a model of PPI was investigated in real time with a label-free fusion, where anti-AFP was covalently immobilized on the carboxylated silicon nitride sensor chips via amide bonds. Optimal pH and temperature were rapidly found by successive and alternate injections of AFP and the regeneration solution (glycine-HCl, pH 1.5) onto the anti-AFP immobilized sensor chip. The resultant optimized reaction conditions (30°C, pH 5.0) gave a 10 times higher detection limit, compared with the response under the commonly employed conditions (25°C, pH 7.4). The proposed system was revealed to provide rapid tracking response against the change in temperature and pH. Consequently, the proposed RIfS system has a potential for the effective tool towards PPI analyses.
Subject(s)
Biosensing Techniques/instrumentation , Immunoassay/instrumentation , Microfluidic Analytical Techniques/instrumentation , Photometry/instrumentation , Protein Interaction Mapping/instrumentation , Refractometry/instrumentation , Spectrum Analysis/instrumentation , Equipment Design , Equipment Failure Analysis , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
Molecular self-assemblies exhibiting automatic motions have received much attention as potential artificial models of living organisms. We have developed a microfluidic picolitre nozzle-array device to form multilamellar lipid tubes (MLTs) under fluidic shear stress, which transformed into different two patterns (yarn-balls and double-helixes) and also exhibited unique self-actuation behaviors.
