A reusable PMMA/paper hybrid plug-and-play microfluidic device for an ultrasensitive immunoassay with a wide dynamic range
MICROSYSTEMS & NANOENGINEERING
Authors: Sanjay, Sharma T.; Li, Meihan; Zhou, Wan; Li, Xiaochun; Li, XiuJun
Abstract
Conventional colorimetric enzyme-linked immunosorbent assay (ELISA) is a time-consuming laboratory assay that is not very sensitive and consumes a large amount of samples. Herein, the development of a reusable, cost-effective, and eco-friendly poly(methyl methacrylate) (PMMA)/paper hybrid plug-and-play (PnP) device for high-sensitivity immunoassay by analyte enrichment and efficient passing-through washing has been reported. The PMMA device has multiple slots where a pre-patterned paper substrate can be inserted. The sample flows back-and-forth through a low-cost, 3D paper substrate within the PMMA channels, thereby enhancing the amount of analyte adsorbed and dramatically increasing the sensitivity while decreasing the assay time. After the enrichment assay, the paper substrate can simply be pulled out of the device, and the results can be qualitatively viewed with the naked eye or scanned through a simple desktop scanner for quantitative analysis. The paper substrate can be replaced with a new substrate so that the device can be reused. The limits of detection (LODs) of 200pg/mL for immunoglobulin G (IgG) and 270pg/mL for hepatitis B surface antigen (HBsAg) were obtained. This IgG assay is at least 10 times more sensitive than commercial ELISA kits. In addition, the PnP ELISA exhibited a significant increase in the linear dynamic range from 3 orders of magnitude in a common paper-based device to a wide range of six orders of magnitude in the PnP hybrid device. This reusable PnP device has great potential for the low-cost yet high-sensitivity detection of infectious diseases, cancers, and other important biomolecules. Bioanalysis: Simple, eco-friendly, portable PnP device for ultrasensitive immunoassaysA reusable, cost-effective, and environment-friendly PnP device has been developed for high-sensitivity immunoassays (biochemical tests that measure proteins or other substances through their properties as antigens or antibodies). Immunoassays are widely used in the diagnosis, screening, and monitoring of diseases. However, such techniques as enzyme-linked immunosorbent assay (ELISA), which are extensively applied in developed countries, are not widely available in developing nations owing to limited funding and lack of skilled manpower. They are also time consuming and lacking in sensitivity. A team headed by XiuJun Li at the University of Texas at El Paso produced a low-cost device using poly(methyl methacrylate) (PMMA or Perspex) that is 10 times more sensitive than commercial ELISA kits. The authors believe that their PMMA device offers considerable potential for application in detecting infectious diseases and cancers in resource-poor settings.
Disease burden of chronic hepatitis B and complications in China from 2006 to 2050: an individual-based modeling study
VIROLOGY JOURNAL
Authors: Zheng, Yang; Wu, Jie; Ding, Cheng; Xu, Kaijin; Yang, Shigui; Li, Lanjuan
Abstract
Background Chronic hepatitis B has become a major public health problem in China. An accurate depiction of the disease burden has not yet been thoroughly conducted. We aimed to project the disease burden of chronic hepatitis B virus (HBV) infection and related complications by modeling various scenarios. Method An individual-based Markov model was used to predict disease burden from 2006 through 2050. We simulated 5 scenarios with different annual incidences, diagnoses and nucleotide analog (NA) treatment rates as well as treatment eligibility, which included a natural history without diagnosis or NA therapy, a base case, a World Health Organization (WHO)-proposed target case and two ideal cases. Result The natural history scenario is projected to have the fewest HBsAg losses (27.59 million) and highest number of HBV-related deaths (27.19 million). With improved diagnosis and treatment rates of NA therapy, ideal cases have fewer HBV-related deaths (14.46-14.77 million) than do WHO-proposed cases (15.13 million) and base cases (16.89 million), but the proportion of HBsAg loss is similar among them. With a reduction in new infections, the prevalence of chronic HBV in 2050 is expected to be a minimum of 27.03-27.49 million under WHO and ideal cases. Conclusion Ideal scenarios 1 and 2 contribute to the lowest disease burden of HBV and its complications in the future, in which new infection control is more effective than increasing diagnosis, treatment rate and treatment eligibility. However, considering the large existing chronic HBV infected population and the low HBsAg loss rate of NA therapy, it is still difficult to avert the increasing trend of cumulative cirrhosis, DC, HCC, LT, and HBV-related death in all scenarios. If new high-potency drugs are not developed, the disease burden of chronic HBV will remain high in the future.