Procedia Technology最新文献

Introduction

Protein nanocages (PNCs) have been recognized as a promising platform for nanomedicine innovation. Real-time in vivo tracking of PNCs can provide critically important information for the development of PNC-based diagnostics and therapeutics. Here we demonstrate a strategy for monitoring the behaviors of PNCs in vivo by encapsulating a Ag₂S quantum dot (QD) with fluorescence in the second near-infrared window (NIR-II, 1000-1700 nm) inside the PNC, using a simian virus 40 (SV40) PNC (PNC_SV40) as a model.

Methods

The Ag₂S QD was encapsulated into the PNC_SV40 through controllable molecular self-assembly. The dynamic migration of Ag₂S@PNC_SV40 in living mouse was tracked in real time under an InGaAs-based shortwave infrared imaging system and was further corroborated by ex vivo imaging, inductively coupled plasma mass spectrometry analysis, and macrophage endocytosis assay.

Results

Benefitting from the high spatiotemporal resolution and deep tissue penetration of NIR-II fluorescence imaging, the dynamic distribution of the PNC_SV40 in living mice was tracked in real time with high fidelity, revealing rapid clearance from bloodstream within 5 min post-intravenous injection and selective accumulation in liver, spleen and bone marrow. Furthermore, adopting the PEGylation strategy, PEGylated PNC_SV40 presents remarkably different behaviors in vivo with significantly prolonged blood circulation and much less uptake in the reticuloendothelial system (RES), leading to desirable pharmacokinetics and pharmacodynamics of PNC-based nanomedicines.

Discussion

This study represents the first evidence of real-time tracking of the intrinsic behaviors of PNCs in vivo without interference in PNC-host interactions by encapsulating nanoprobes inside, instead of conjugating nanoprobes onto the outer surface of PNCs. The as-described imaging strategy will facilitate the study of interactions between exogenously introduced PNCs and host body, prompting the development of future protein-based drugs, high-efficacy targeted delivery system, sensors, etc.

Antibiotic resistance threatens global public health. Clinical methods that simplify and accelerate resistance diagnosis are urgently needed. Here we describe a function-based antibiotic resistance detection and classification strategy to improve diagnosis. The method identifies resistance enzymes by directly measuring the thermal signal generated when an antibiotic i enzymatically degraded. A substrate specificity profile is created by analyzing a panel of antibiotics. Here we show proof of principle by differentiating two antibiotic resistance enzymes based on their substrate specificities profiles. The method provides a fast, simple, cost effective alternative for diagnosing and classifying antibiotic resistance.

Already mass-produced stainless-steel pins offer the possibility of developing low-cost electroanalytical devices with a versatile disposition of the electrodes. Here we use these prefabricated pins as electrodes for enzymatic amperometric sensing. A conventional three-electrode configuration device is designed using two bare pins as reference and counter electrodes, and a carbon-coated pin as working electrode. Using a transparency sheet and standard connections as interface to conventional instrumentation, a pin-based sensor for glucose determination is developed. Finally, a multiplexed device with four pins acting as working electrodes, which can be useful for multiplexed immunosensing purposes, is designed.

Analytical Chemistry is nowadays one of the branches of Chemistry that has changed enormously due to the advances in technology and the trends it follows. Currently, the development of low-cost devices that are, at the same time, easy-to use and dispose, and produce fast and reliable responses is of eminent significance. Electrochemical biosensors fit perfectly with these requirements, as do paper-based devices. Here we present an enzymatic biosensor using a simple single-use paper-based device in which carbon ink is deposited in a hydrophilic area delimited by wax printing for acting as working electrode. Low-cost gold-plated connector headers are employed as reference and auxiliary electrodes as well as connections to the potentiostat. Glucose oxidase (GOx), horseradish peroxidase (HRP) and potassium ferrocyanide used as mediator of the electron transfer are adsorbed in the ink.

Innovations in ultra low-light CMOS bio-optical sensor design, combined with microfluidics technology can enable a new generation of low cost, portable molecular diagnostics platforms. This combination of technologies have been applied successfully in a miniaturized qPCR system, and a chemiluminescence microfluidic immunoassay platform to detect a variety of infectious pathogens. Cost reduction and miniaturization of molecular test enabled by this technology will have positive impact on global battle against infectious diseases.

The innovative photoelectrochemical properties of multifunctional nanomaterials are here investigated for the development of biosensing platforms for rapid and sensitive detection of a class of cancer biomarker candidates, known as microRNAs. Many different transducers have been proposed, so far, for microRNA detection. Recently, with the emergence of novel photoelectrochemically active species and new detection schemes, photoelectrochemistry has received increasing attention. Gold nanostructures have been, here, used to modify TiO₂ electrodes. The surface of the nanostructured platform has been modified by nucleic acid capture probes (CPs). Biotinylated target miRNAs have been recognized by the specific CPs. The biosensing platform has been incubated with streptavidin alkaline phosphatase and exposed to a proper substrate. The product of the enzymatic reaction has been photoelectrochemically monitored. A compact and hand-held analytical device has been developed in order to have a final prototype in line with the concept of point of care testing.