Paper-based loop-mediated isothermal amplification and CRISPR integrated platform for on-site nucleic acid testing of pathogens.

We report the development and initial validation of a paper-based nucleic acid testing platform that integrates Loop-mediated isothermal amplification (LAMP) with clustered regularly interspaced short palindromic repeats (CRISPR) technology, referred to as PLACID (Paper-based LAMP-CRISPR Integrated Diagnostics). LAMP eliminates the need for thermal cycling, resulting in simplified instrumentation, and the CRISPR-associated protein (Cas 12a) system eliminates false positive signals from LAMP products, resulting in highly selective and sensitive assays. We optimized the assay to perform both amplification and detection entirely on paper, eliminating the need for complex fluid handling steps and lateral flow assay transfers.

High-Resolution Single Particle Zeta Potential Characterisation of Biological Nanoparticles using Tunable Resistive Pulse Sensing.

Physicochemical properties of nanoparticles, such as size, shape, surface charge, density, and porosity play a central role in biological interactions and hence accurate determination of these characteristics is of utmost importance. Here we propose tunable resistive pulse sensing for simultaneous size and surface charge measurements on a particle-by-particle basis, enabling the analysis of a wide spectrum of nanoparticles and their mixtures. Existing methodologies for measuring zeta potential of nanoparticles using resistive pulse sensing are significantly improved by including convection into the theoretical model.

A standardized method to determine the concentration of extracellular vesicles using tunable resistive pulse sensing.

Background: Understanding the pathogenic role of extracellular vesicles (EVs) in disease and their potential diagnostic and therapeutic utility is extremely reliant on in-depth quantification, measurement and identification of EV sub-populations. Quantification of EVs has presented several challenges, predominantly due to the small size of vesicles such as exosomes and the availability of various technologies to measure nanosized particles, each technology having its own limitations.

Materials And Methods: A standardized methodology to measure the concentration of extracellular vesicles (EVs) has been developed and tested.

High resolution particle characterization to expedite development and regulatory acceptance of nanomedicines.

The pharmaceutical industry as well as European and US governing agencies have indicated the need for more accurate, high resolution, characterization of complex drug materials, nanomedicines, to facilitate their development and eventual approval. In particular, accurately measuring the size, zeta-potential, and concentration of nanomedicines is desired. Herein we demonstrate the comprehensive and high resolution analysis capabilities of tunable resistive pulse sensing (TRPS) on the most widely approved nanomedicines to-date, liposomal particles.

Monitoring aptamer-protein interactions using tunable resistive pulse sensing.

Aptamers are short single-stranded pieces of DNA or RNA capable of binding to analytes with specificity and high affinity. Due to their comparable selectivity, stability, and cost, over the last two decades, aptamers have started to challenge antibodies in their use on many technology platforms. The binding event often leads to changes in the aptamer's secondary and tertiary structure; monitoring such changes has led to the creation of many new analytical sensors.

Characterization of a nanoparticulate drug delivery system using scanning ion occlusion sensing.

Purpose: To explore the application of scanning ion occlusion sensing (SIOS) as a novel technology for characterization of nanoparticles.

Methods: Liposomes were employed as model nanoparticles. The size distribution of the liposomes was measured by both SIOS and dynamic light scattering (DLS).