scholarly journals Botulinum Neurotoxin-C Detection Using Nanostructured Porous Silicon Interferometer

Chemosensors ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 228
Author(s):  
Dashananda Nanda Kumar ◽  
Zina Baider ◽  
Daniel Elad ◽  
Shlomo E. Blum ◽  
Giorgi Shtenberg
Keyword(s):  
Porous Silicon ◽  
Optical Biosensor ◽  
Optical Signal ◽  
Practical Aspect ◽  
Farm Animals ◽  
Label Free ◽  
Life Threatening ◽  
Botulinum Neurotoxins ◽  
Evidence Based Therapy

Botulinum neurotoxins (BoNT) are the most potent toxins, which are produced by Clostridium bacteria and cause the life-threatening disease of botulism in all vertebrates. Specifically, animal botulism represents a serious environmental and economic concern in animal production due to the high mortality rates observed during outbreaks. Despite the availability of vaccines against BoNT, there are still many outbreaks of botulism worldwide. Alternative assays capable of replacing the conventional in vivo assay in terms of rapid and sensitive quantification, and the applicability for on-site analysis, have long been perused. Herein, we present a simple, highly sensitive and label-free optical biosensor for real-time detection of BoNT serotype C using a porous silicon Fabry–Pérot interferometer. A competitive immunoassay coupled to a biochemical cascade reaction was adapted for optical signal amplification. The resulting insoluble precipitates accumulated within the nanostructure changed the reflectivity spectra by alternating the averaged refractive index. The augmented optical performance allowed for a linear response within the range of 10 to 10,000 pg mL−1 while presenting a detection limit of 4.8 pg mL−1. The practical aspect of the developed assay was verified using field BoNT holotoxins to exemplify the potential use of the developed optical approach for rapid bio-diagnosis of BoNT. The specificity and selectivity of the assay were successfully validated using an adjacent holotoxin relevant for farm animals (BoNT serotype D). Overall, this work sets the foundation for implementing a miniaturized interferometer for routine on-site botulism diagnosis, thus significantly reducing the need for animal experimentation and shortening analysis turnaround for early evidence-based therapy.

scholarly journals Aptamer Functionalized Lipid Multilayer Gratings for Label-Free Analyte Detection

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2433
Author(s):  
Plengchart Prommapan ◽  
Nermina Brljak ◽  
Troy W. Lowry ◽  
David Van Winkle ◽  
Steven Lenhert
Keyword(s):  
Lipid Composition ◽  
Optical Biosensor ◽  
Optical Signal ◽  
Dna Aptamer ◽  
Critical Parameters ◽  
Label Free ◽  
Scale Thickness ◽  
Label Free Detection ◽  
Analyte Detection ◽  
Micrometer Scale

Lipid multilayer gratings are promising optical biosensor elements that are capable of transducing analyte binding events into changes in an optical signal. Unlike solid state transducers, reagents related to molecular recognition and signal amplification can be incorporated into the lipid grating ink volume prior to fabrication. Here we describe a strategy for functionalizing lipid multilayer gratings with a DNA aptamer for the protein thrombin that allows label-free analyte detection. A double cholesterol-tagged, double-stranded DNA linker was used to attach the aptamer to the lipid gratings. This approach was found to be sufficient for binding fluorescently labeled thrombin to lipid multilayers with micrometer-scale thickness. In order to achieve label-free detection with the sub-100 nm-thick lipid multilayer grating lines, the binding affinity was improved by varying the lipid composition. A colorimetric image analysis of the light diffracted from the gratings using a color camera was then used to identify the grating nanostructures that lead to an optimal signal. Lipid composition and multilayer thickness were found to be critical parameters for the signal transduction from the aptamer functionalized lipid multilayer gratings.

Label-free quantitative detection using porous silicon as optical biosensor

2012 ◽  
Vol 8 (4) ◽  
pp. 314-317
Author(s):  
Fu-ru Zhong ◽  
Xiao-lin Ma ◽  
Xiao-yi Lü ◽  
Zhen-hong Jia
Keyword(s):  
Porous Silicon ◽  
Optical Biosensor ◽  
Quantitative Detection ◽  
Label Free

In Silico Identification of a Potent Arsenic Based Approved Drug Darinaparsin against SARS-CoV-2: Inhibitor of RNA Dependent RNA polymerase (RdRp) and Essential Proteases

2020 ◽  
Vol 20 ◽  
Author(s):  
Trinath Chowdhury ◽  
Gourisankar Roymahapatra ◽  
Santi M. Mandal
Keyword(s):  
Rna Polymerase ◽  
Viral Entry ◽  
In Silico ◽  
Rna Dependent Rna Polymerase ◽  
Replication Complex ◽  
In Silico Study ◽  
Life Threatening ◽  
In Vivo Analysis ◽  
3Cl Protease

Background: COVID-19 is a life threatening novel corona viral infection to our civilization and spreading rapidly. Terrific efforts are generous by the researchers to search for a drug to control SARS-CoV-2. Methods: Here, a series of arsenical derivatives were optimized and analyzed with in silico study to search the inhibitor of RNA dependent RNA polymerase (RdRp), the major replication factor of SARS-CoV-2. All the optimized derivatives were blindly docked with RdRp of SARS-CoV-2 using iGEMDOCK v2.1. Results: Based on the lower idock score in the catalytic pocket of RdRp, darinaparsin (-82.52 kcal/mol) revealed most effective among them. Darinaparsin strongly binds with both Nsp9 replicase protein (-8.77 kcal/mol) and Nsp15 endoribonuclease (-8.3 kcal/mol) of SARS-CoV-2 as confirmed from the AutoDock analysis. During infection, the ssRNA of SARS-CoV2 is translated into large polyproteins forming viral replication complex by specific proteases like 3CL protease and papain protease. This is also another target to control the virus infection where darinaparsin also perform the inhibitory role to proteases of 3CL protease (-7.69 kcal/mol) and papain protease (-8.43 kcal/mol). Conclusion: In host cell, the furin protease serves as a gateway to the viral entry and darinaparsin docked with furin protease which revealed a strong binding affinity. Thus, screening of potential arsenic drugs would help in providing the fast invitro to in-vivo analysis towards development of therapeutics against SARS-CoV-2.

scholarly journals Fibrosis after Myocardial Infarction: An Overview on Cellular Processes, Molecular Pathways, Clinical Evaluation and Prognostic Value

2021 ◽  
Vol 9 (1) ◽  
pp. 16
Author(s):  
Renato Francesco Maria Scalise ◽  
Rosalba De Sarro ◽  
Alessandro Caracciolo ◽  
Rita Lauro ◽  
Francesco Squadrito ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Signaling Pathways ◽  
Ventricular Dysfunction ◽  
Healing Process ◽  
Molecular Signaling ◽  
Cellular Processes ◽  
Molecular Signaling Pathways ◽  
Fibrotic Scar ◽  
Life Threatening

The ischemic injury caused by myocardial infarction activates a complex healing process wherein a powerful inflammatory response and a reparative phase follow and balance each other. An intricate network of mediators finely orchestrate a large variety of cellular subtypes throughout molecular signaling pathways that determine the intensity and duration of each phase. At the end of this process, the necrotic tissue is replaced with a fibrotic scar whose quality strictly depends on the delicate balance resulting from the interaction between multiple actors involved in fibrogenesis. An inflammatory or reparative dysregulation, both in term of excess and deficiency, may cause ventricular dysfunction and life-threatening arrhythmias that heavily affect clinical outcome. This review discusses cellular process and molecular signaling pathways that determine fibrosis and the imaging technique that can characterize the clinical impact of this process in-vivo.

scholarly journals Mammary gland 3D cell culture systems in farm animals

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Laurence Finot ◽  
Eric Chanat ◽  
Frederic Dessauge
Keyword(s):  
Cell Culture ◽  
Mammary Gland ◽  
Bacterial Infections ◽  
Three Dimensional ◽  
3D Cell Culture ◽  
Farm Animals ◽  
Culture Systems ◽  
Cell Culture Systems

AbstractIn vivo study of tissue or organ biology in mammals is very complex and progress is slowed by poor accessibility of samples and ethical concerns. Fortunately, however, advances in stem cell identification and culture have made it possible to derive in vitro 3D “tissues” called organoids, these three-dimensional structures partly or fully mimicking the in vivo functioning of organs. The mammary gland produces milk, the source of nutrition for newborn mammals. Milk is synthesized and secreted by the differentiated polarized mammary epithelial cells of the gland. Reconstructing in vitro a mammary-like structure mimicking the functional tissue represents a major challenge in mammary gland biology, especially for farm animals for which specific agronomic questions arise. This would greatly facilitate the study of mammary gland development, milk secretion processes and pathological effects of viral or bacterial infections at the cellular level, all with the objective of improving milk production at the animal level. With this aim, various 3D cell culture models have been developed such as mammospheres and, more recently, efforts to develop organoids in vitro have been considerable. Researchers are now starting to draw inspiration from other fields, such as bioengineering, to generate organoids that would be more physiologically relevant. In this chapter, we will discuss 3D cell culture systems as organoids and their relevance for agronomic research.

scholarly journals 1700 nm optical coherence microscopy enables minimally invasive, label-free, in vivo optical biopsy deep in the mouse brain

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Jun Zhu ◽  
Hercules Rezende Freitas ◽  
Izumi Maezawa ◽  
Lee-way Jin ◽  
Vivek J. Srinivasan
Keyword(s):  
Minimally Invasive ◽  
Mouse Brain ◽  
Numerical Aperture ◽  
Optical Biopsy ◽  
Optical Coherence ◽  
Label Free ◽  
Optical Coherence Microscopy ◽  
Minimal Invasiveness ◽  
Cortical Regions

AbstractIn vivo, minimally invasive microscopy in deep cortical and sub-cortical regions of the mouse brain has been challenging. To address this challenge, we present an in vivo high numerical aperture optical coherence microscopy (OCM) approach that fully utilizes the water absorption window around 1700 nm, where ballistic attenuation in the brain is minimized. Key issues, including detector noise, excess light source noise, chromatic dispersion, and the resolution-speckle tradeoff, are analyzed and optimized. Imaging through a thinned-skull preparation that preserves intracranial space, we present volumetric imaging of cytoarchitecture and myeloarchitecture across the entire depth of the mouse neocortex, and some sub-cortical regions. In an Alzheimer’s disease model, we report that findings in superficial and deep cortical layers diverge, highlighting the importance of deep optical biopsy. Compared to other microscopic techniques, our 1700 nm OCM approach achieves a unique combination of intrinsic contrast, minimal invasiveness, and high resolution for deep brain imaging.

Sign in / Sign up

Export Citation Format

Share Document