Pump-Free Glass-Based Capillary Microfluidic Immuno-Assay Chip for Electrochemical Detection of Prostate-Specific Antigen.

Immuno-assay is one of diagnostic methods that usually measures biomarkers associated with cancers. However, this method is complex and take a long time to analyze. To overcome these disadvantages, many immuno-sensing chips have been designed and developed. However, these devices still require an external pump or electrical source. In this study, our group fabricated a capillary microfluidic device using glass and adhesive polyethylene terephthalate (PET) film, which were designed by simply patterning and cutting to make the microfluidic capillary channels. Using capillary force alone, glass microfluidic chip can control the speed of fluid-flow and the flow sequence by adjusting the width of the channel and design. In addition, each flow can push out other flow without mixing. The glass-based capillary microfluidic chip (GCMC) can automatically perform immunoassay in regular order without external devices and it provide an electrochemical signal analysis in an average of 2 min. The concentration of the prostate-specific antigen (PSA), a biomarker of prostate cancer, was measured by cyclic voltammetry (CV). In conclusion, GCMC can detect between a range of 100 pg/ml to 1 µg/ml of PSA and provide high selectivity to PSA.

Both sitagliptin analogue & pioglitazone preserve the beta-cell proportion in the islets with different mechanism in non-obese and obese diabetic mice.

In this study, the effects of sitagliptin analogue (SITA) or pioglitazone (PIO) treatment on glucose homeostasis and Β-cell dynamics in animal models of type 2 diabetes--Akita and db/db mice were evaluated. After 4-6 weeks of treatment, both SITA and PIO were shown to lower non-fasting glucose levels and reduced glycemic excursion in the intraperitoneal glucose tolerance test. In addition, both drugs preserved normal islet structure and the proportion of Β-cells in the islets. Compared to the controls, SITA treatment induced a higher Β-cell proliferation rate in Akita mice and a lower rate of apoptosis in db/db mice, whereas PIO treatment induced a lower rate of apoptosis in db/db mice and reduced proliferation rates in Akita mice. In conclusion, both SITA and PIO appear to exert some beneficial effects on the islet structure in addition to glycemic control via different mechanisms that involve Β-cell dynamics in Akita and db/db mice. [BMB reports 2011; 44(11): 713-718].