scholarly journals Simulation and Analysis of Highly Sensitive MEMS Cantilever Designs for “in vivo Label Free” Biosensing

2014 ◽  
Vol 14 ◽  
pp. 85-92 ◽  
Author(s):  
Deep Kishore Parsediya ◽  
Jawar Singh ◽  
Pavan Kumar Kankar
Keyword(s):  
2021 ◽  
Vol 6 (1) ◽  
pp. 20
Author(s):  
Trang-Anh Nguyen-Le ◽  
Diana Isabel Sandoval Bojorquez ◽  
Arnau Pérez Roig ◽  
Bergoi Ibarlucea ◽  
Gianaurelio Cuniberti ◽  
...  

Although showing impressive therapeutic potential, treatments of leukemias with T-cells expressing chimeric antigen receptors (CARs) is limited by their risk of several severe side effects. To overcome these problems, a switchable CAR platform has been developed termed UniCAR. Unlike conventional CAR, which is directed against tumor-associated antigens, UniCAR treatment involves an intermediate target module (TM), which can cross-link UniCAR T cells with tumor cells and lead to destruction. The development of these novel TMs against different tumor targets requires numerous repetitive tests on different synthesizing trials, which is usually limited in quantity and time-consuming. Meanwhile, nano-biosensors are lately known as analytical tools, which are highly sensitive, label-free, rapid and reagent-saving. Among them, silicon nanowire (SiNW) sensors have been extensively investigated by researchers over the past decades thanks to their compatibility with CMOS technology, enabling mass production. In this work, we demonstrated the application of a previously published SiNW biosensor on the detection of the binding of UniCAR and a part of different TMs. The results underline the advantages of the SiNW sensor over the ELISA method in terms of ease of preparation, speed and sensitivity. The method is able to evaluate the binding affinity of UniCAR to different TMs and open a potential to quantify the number of active UniCAR T-cells in an in vivo sample at a later stage. In the end, the application of a nanosensor may speed up the R&D process of the UniCAR concept and later play an important role in clinical monitoring of immunotherapy, especially in the era of precision medicine.


2002 ◽  
Vol 10 (5) ◽  
pp. 1451-1458 ◽  
Author(s):  
Sophie Martel ◽  
Jean-Louis Clément ◽  
Agnès Muller ◽  
Marcel Culcasi ◽  
Sylvia Pietri

Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 147
Author(s):  
Kristina A. Malsagova ◽  
Tatyana O. Pleshakova ◽  
Vladimir P. Popov ◽  
Igor N. Kupriyanov ◽  
Rafael A. Galiullin ◽  
...  

Gas-phase etching and optical lithography were employed for the fabrication of a silicon nanoribbon chip (Si-NR chip). The quality of the so-fabricated silicon nanoribbons (Si-NRs) was monitored by optical Raman scattering spectroscopy. It was demonstrated that the structures of the Si-NRs were virtually defect-free, meaning they could be used for highly sensitive detection of biological macromolecules. The Si-NR chips were then used for the highly sensitive nanoelectronics detection of DNA oligonucleotides (oDNAs), which represent synthetic analogs of 106a-5p microRNA (miR-106a-5p), associated with the development of autism spectrum disorders in children. The specificity of the analysis was attained by the sensitization of the Si-NR chip sur-face by covalent immobilization of oDNA probes, whose nucleotide sequence was complementary to the known sequence of miR-106a-5p. The use of the Si-NR chip was demonstrated to al-low for the rapid label-free real-time detection of oDNA at ultra-low (~10−17 M) concentrations.


2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Jun Zhu ◽  
Hercules Rezende Freitas ◽  
Izumi Maezawa ◽  
Lee-way Jin ◽  
Vivek J. Srinivasan

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.


2021 ◽  
pp. bjophthalmol-2020-318691
Author(s):  
Zhu Li Yap ◽  
Li-Fong Seet ◽  
Stephanie WL Chu ◽  
Li Zhen Toh ◽  
Farah Ilyana Ibrahim ◽  
...  

AbstractPurposeTo determine the effect of valproic acid (VPA) on bleb morphology and scar characteristics in a rabbit model of minimally invasive glaucoma surgery (MIGS).MethodsNine New Zealand white rabbits were subjected to MIGS with intraoperative implantation of the PreserFlo MicroShunt. Rabbits were then administered with subconjunctival injections of phosphate buffered saline (PBS) (n=4) or with VPA (n=5). Bleb morphology was examined by slit-lamp biomicroscopy and in vivo confocal microscopy. Postoperative day 28 tissues were examined by immunohistochemical evaluation and label-free multiphoton microscopy to visualise the collagen matrix, by terminal deoxynucleotidyl transferase dUTP nick-end labelling assay and immunofluorescent labelling for Ki67 expression to detect apoptosis and cell growth, and by real-time quantitative PCR to measure Col1a1, Fn, and Smad6 transcript expression.ResultsVPA-treated blebs were detectable on day 28, while the PBS-treated blebs were not detectable by day 14. VPA-treated blebs were diffuse, extended posteriorly with near normal conjunctival vascularity and featured a combination of reticular/blurred stromal pattern with evidence of relatively large stromal cysts. Instead of the deposition of thick, disorganised collagen fibres characteristic of the PBS bleb, the VPA bleb contained conspicuously thinner collagen fibres which were associated with similarly thinner fibronectin fibres. In corroboration, Col1a1 and Fn mRNA expression was reduced in the VPA blebs, while increased Smad6 expression implicated the disruption of the transforming growth factor beta pathway. Apoptosis and cell growth profiles appeared similar with both treatments.ConclusionsThe results support the application of VPA to enhance bleb morphology associated with good bleb function in MIGS with no apparent cytotoxicity.


Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 922
Author(s):  
William Querido ◽  
Shital Kandel ◽  
Nancy Pleshko

Advances in vibrational spectroscopy have propelled new insights into the molecular composition and structure of biological tissues. In this review, we discuss common modalities and techniques of vibrational spectroscopy, and present key examples to illustrate how they have been applied to enrich the assessment of connective tissues. In particular, we focus on applications of Fourier transform infrared (FTIR), near infrared (NIR) and Raman spectroscopy to assess cartilage and bone properties. We present strengths and limitations of each approach and discuss how the combination of spectrometers with microscopes (hyperspectral imaging) and fiber optic probes have greatly advanced their biomedical applications. We show how these modalities may be used to evaluate virtually any type of sample (ex vivo, in situ or in vivo) and how “spectral fingerprints” can be interpreted to quantify outcomes related to tissue composition and quality. We highlight the unparalleled advantage of vibrational spectroscopy as a label-free and often nondestructive approach to assess properties of the extracellular matrix (ECM) associated with normal, developing, aging, pathological and treated tissues. We believe this review will assist readers not only in better understanding applications of FTIR, NIR and Raman spectroscopy, but also in implementing these approaches for their own research projects.


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