Arti Vashist

Nano-biosensors to detect beta-amyloid for Alzheimer's disease management

Beta-amyloid (β-A) peptides are potential biomarkers to monitor Alzheimers diseases (AD) for diagnostic purposes. Increased β-A level is neurotoxic and induces oxidative stress in brain resulting in neurodegeneration and causes dementia. As of now, no sensitive and inexpensive method is available for β-A detection under physiological and pathological conditions. Although, available methods such as neuroimaging, enzyme-linked immunosorbent assay (ELISA), and polymerase chain reaction (PCR) detect β-A, but they are not yet extended at point-of-care (POC) due to sophisticated equipments, need of high expertize, complicated operations, and challenge of low detection limit. Recently, β-A antibody based electrochemical immuno-sensing approach has been explored to detect β-A at pM levels within 30-40 min compared to 6-8h of ELISA test. The introduction of nano-enabling electrochemical sensing technology could enable rapid detection of β-A at POC and may facilitate fast personalized health care delivery. This review explores recent advancements in nano-enabling electrochemical β-A sensing technologies towards POC application to AD management. These analytical tools can serve as an analytical tool for AD management program to obtain bio-informatics needed to optimize therapeutics for neurodegenerative diseases diagnosis management.

Electrochemical Biosensors for Early Stage Zika Diagnostics

Health agencies have declared the recent Zika virus (ZIKV) infection an epidemic and a public health emergency of global concern due to its association with microcephaly and serious neurological disorders. The unavailability of effective drugs, vaccines, and diagnostic tools increases the demand for efficient analytical devices to detect ZIKV infection. However, high costs, longer diagnostic times, and stringent expertise requirements limit the utility of reverse transcriptase-PCR methods for rapid diagnostics. Therefore, developing portable, sensitive, selective, and cost-effective sensing systems to detect ZIKV at picomolar concentrations in biofluids would be a breakthrough in diagnostics and therapeutics. This paper highlights the advancements in developing smart sensing strategies to monitor ZIKV progression, with rapid point-of-care diagnostics as the ultimate aim.

Recent trends on hydrogel based drug delivery systems for infectious diseases

Since centuries, the rapid spread and cure of infectious diseases have been a major concern to the progress and survival of humans. These diseases are a global burden and the prominent cause for worldwide deaths and disabilities. Nanomedicine has emerged as the most excellent tool to eradicate and halt their spread. Various nanoformulations (NFs) using advanced nanotechnology are in demand. Recently, hydrogel and nanogel based drug delivery devices have posed new prospects to simulate the natural intelligence of various biological systems. Owing to their unique porous interpenetrating network design, hydrophobic drug incorporation and stimulus sensitivity hydrogels owe excellent potential as targeted drug delivery systems. The present review is an attempt to highlight the recent trends of hydrogel based drug delivery systems for the delivery of therapeutic agents and diagnostics for major infectious diseases including acquired immune deficiency syndrome (AIDS), malaria, tuberculosis, influenza and ebola. Future prospects and challenges are also described.

Electrochemical monitoring-on-chip (E-MoC) of HIV-infection in presence of cocaine and therapeutics

Electrochemical monitoring-on-chip (E-MoC)-based approach for rapid assessment of human immunodeficiency virus (HIV)-infection in the presence of cocaine (Coc) and specific drugs namely i.e., tenofovir (Tef), rimcazole (RA) is demonstrated here, for the first time, using electrochemical impedance spectroscopy (EIS). An in-vitro primary human astrocytes (HA) model was developed using a cultureware chip (CC, used for E-MoC) for HIV-infection, Coc exposure and treatment with anti-HIV drug i.e., Tef, and Coc antagonist i.e., RA. The charge transfer resistance (Rct) value of each CC well varies with respect to infection and treatment demonstrated highly responsive sensitivity of developed chip. The results of E-MoC, a proof-of-the concept, suggested that HIV-infection progression due to Coc ingestion and therapeutic effects of highly specific drugs are measurable on the basis of cell electrophysiology. Though, this work needs various molecular biology-based optimizations to promote this technology as an analytical tool for the rapid assessment of HIV-infection in a patient to manage HIV diseases for timely diagnosis. The presented study is based on using CNS cells and efforts are being made to perform this method using peripheral cells such as monocytes derived dendritic cells.

A label-free electrochemical immunosensor for beta-amyloid detection

A label-free detection of beta-amyloid (βA) protein using an electrochemical immunosensor fabricated via immobilizing specific anti-beta-amyloid antibodies (An-βA-Abs) onto an interdigitated electrode of gold (IDE-Au) modified using a self-assembled monolayer (SAM) of dithiobis(succinimidyl propionate) [DTSP] is presented here. The βA has been investigated as a potential biomarker for monitoring Alzheimers disease (AD), permanent irreversible and progressive brain damage. Thus βA detection at the pM level is of high significance for AD diagnostics. The IDE-Au modification and covalent immobilization of An-βA-Abs onto electrodes were characterized by differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) as a function of electrical response variation in each step involved in sensor fabrication. The EIS studies confirmed that the developed βA immunosensor is selective and exhibits a detection limit of 10 pM, its detection range varies from 10 pM to 100 nM, and it has a high sensitivity of 11 kΩ M−1 with a regression coefficient of 0.99. Thus, the developed sensitive and selective immunosensor with the features of the IDE-Au can be integrated with a miniaturized potentiostat (M-P) to develop a sensing system to detect βA for point-of-care (POC) applications for the assessment and management of AD. The bio-informatics gathered from such a system could be useful to make timely therapeutic decisions.

Nanogels as potential drug nanocarriers for CNS drug delivery

Hydrogel-based drug delivery systems (DDSs) have versatile applications such, as tissue engineering, scaffolds, drug delivery, and regenerative medicines. The drawback of higher size and poor stability in such DDSs are being addressed by developing nano-sized hydrogel particles, known as nanogels, to achieve the desired biocompatibility and encapsulation efficiency for better efficacy than conventional bulk hydrogels. In this review, we describe advances in the development of nanogels and their promotion as nanocarriers to deliver therapeutic agents to the central nervous system (CNS). We also discuss the challenges, possible solutions, and future prospects for the use of nanogel-based DDSs for CNS therapies.

Advances in Carbon Nanotubes–Hydrogel Hybrids in Nanomedicine for Therapeutics

In spite of significant advancement in hydrogel technology, low mechanical strength and lack of electrical conductivity have limited their next-level biomedical applications for skeletal muscles, cardiac and neural cells. Host-guest chemistry based hybrid nanocomposites systems have gained attention as they completely overcome these pitfalls and generate bioscaffolds with tunable electrical and mechanical characteristics. In recent years, carbon nanotube (CNT)-based hybrid hydrogels have emerged as innovative candidates with diverse applications in regenerative medicines, tissue engineering, drug delivery devices, implantable devices, biosensing, and biorobotics. This article is an attempt to recapitulate the advancement in synthesis and characterization of hybrid hydrogels and provide deep insights toward their functioning and success as biomedical devices. The improved comparative performance and biocompatibility of CNT-hydrogels hybrids systems developed for targeted biomedical applications are addressed here. Recent updates toward diverse applications and limitations of CNT hybrid hydrogels is the strength of the review. This will provide a holistic approach toward understanding of CNT-based hydrogels and their applications in nanotheranostics.

Hydrogels: Smart Nanomaterials for Biomedical Applications

Abstract Hydrogels have emerged as smart nanomaterials and have shown great potential in biomedical applications. They have gained recent attention because of their three-dimensional network and their features which are responsive to various external stimuli. These smart materials are being significantly explored for their advanced application in bone and knee replacement technology, dental applications, and, most importantly, sensing and diagnostics management. This chapter highlights recent advancements in hydrogels as nanomaterials and their application in sensing and diagnostics.

Nanotechnology for Therapeutics

Tremendous growth in the field of pharmacology and therapeutics has been observed due to revolutionised development of novel drug delivery systems predominantly based on “Nanotechnology”. Treatment of wide varieties of diseases is made possible by miniaturisation of drug delivery systems. Nanotechnology delivers a unique approach, which promises higher drug efficacy, targeted drug delivery, on demand delivery, biocompatibility, etc. The importance of nanotechnology can be visualised by its ability of addressing several problems in central areas of biomedical, chemical, mechanical and electronics. Here, we discuss how nano-therapeutics can be fruitful for the treatment of brain diseases such as human immunodeficiency virus (HIV), Parkinson’s, cancer, Alzheimer and their drug delivery mechanism. In this regard, the challenges involved and required future developments in drug delivery systems becomes few important topics to be worked on for expanding the utilization of nano-therapeutics.

Hydrogels: Stimuli Responsive to on-Demand Drug Delivery Systems

Hydrogels are the three dimensional crosslinked network of polymeric materials, which have the ability to respond and adapt to the surrounding environment inside the human body. Hydrogels are the upcoming class of biomaterials, which act as excellent drug delivery systems. These materials have important characteristic feature that they respond to various external stimuli like pH, light, temperature, magnetic field, electric field and pressure. Present chapter gives a broad overview of the recent hydrogels used for drug delivery using various external stimuli. Concluding remarks and viewpoints for the future development of stimuli responsive hydrogels are addressed.