scholarly journals Carbon-based Fluorescent Antibody Nanoprobes as Brain Tumour Glioblastoma Diagnostics.

2021 ◽  
Author(s):  
Mattia Ghirardello ◽  
Radhe Shyam ◽  
Xia Liu ◽  
Teodoro Garcia Millan ◽  
Imke Sittel ◽  
...  

The development of efficient and sensitive tools for the detection of brain cancer in patients is of the utmost importance particularly because many of these tumours go undiagnosed until the disease has advanced and when treatment is less effective. Current strategies employ antibodies (Abs) to detect Glial Fibrillary Acid Protein (GFAP) in tissue samples, since GFAP is unique to the brain and not present in normal peripheral blood and rely on fluorescent reporters. Herein we describe a low cost, practical and general method for the labelling of proteins and antibodies with fluorescent carbon dots (CD) to generate diagnostic probes that are robust, photostable and applicable to the clinical setting. The two-step protocol relies on the conjugation of a dibenzocyclooctyne (DBCO)-functionalised CD with azide functionalised proteins by combining amide conjugation and strain promoted alkyne-azide cycloaddition (SPAAC) ligation chemistry. The new class of Abs-CD conjugates developed using this strategy were used for the immunohistochemical staining of human brain tissues of patients with glioblastoma (GBM) to validate the approach. Overall, these novel fluorescent probes offer a promising and versatile strategy in terms of costs, photostability and applicability which can be extended to other Abs and protein systems.

2019 ◽  
Vol 39 (4) ◽  
pp. 179-197 ◽  
Author(s):  
Samira Bagheri ◽  
Amin TermehYousefi ◽  
Javad Mehrmashhadi

AbstractFluorescent carbon dots (CDs) are a new class of carbon nanomaterials and have demonstrated excellent optical properties, good biocompatibility, great aqueous solubility, low cost, and simple synthesis. Since their discovery, various synthesis methods using different precursors were developed, which were mainly classified as top-down and bottom-up approaches. CDs have presented many applications, and this review article mainly focuses on the development of CD-based fluorescent sensors. The sensing mechanisms, sensor design, and sensing properties to various targets are summarized. Broad ranges of detection, including temperature, pH, DNA, antibiotics, cations, cancer cells, and antibiotics, have been discussed. In addition, the challenges and future directions for CDs as sensing materials are also presented.


Author(s):  
Fatma Söylemez ◽  
Çağatay Han Türkseven

Aptamers are a new class of recognizing agents which are defined as short biomolecules like oligonucleotides and peptides that are used in diagnostics and therapeutics. They can bind to specific targets with extremely high affinity based on their structural conformations. It is believed that in the near future, aptamers could replace monoclonal antibody. The biggest advantage of using aptamers is that the process is in vitro in nature and does not require the use of animals and they also have unique properties, such as thermal stability, low cost, and unlimited applications. Aptamers have been studied as a biomaterial in numerous investigations concerning their use as a diagnostic and therapeutic tool and biosensing probe. DNA aptamers were also used for the diagnosis and treatment of neurodegeneration and neurodegenerative diseases. For example, functional nucleic acid aptamers have been developed to detect Aβ fragments in Alzheimer’s brain hippocampus tissue samples. Aptamers are promising materials for diverse areas, not just as alternatives to antibodies but as the core components of medical equipment. Although they are in the preliminary stages of development, results are quite encouraging, and it seems that aptamer research has a very bright future in neuroscience.


Nanomaterials ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 76
Author(s):  
Thanh-Lieu Thi Le ◽  
Lam Tan Nguyen ◽  
Hoai-Hue Nguyen ◽  
Nguyen Van Nghia ◽  
Nguyen Minh Vuong ◽  
...  

Nanostructures of titanium nitride (TiN) have recently been considered as a new class of plasmonic materials that have been utilized in many solar energy applications. This work presents the synthesis of a novel nanostructure of TiN that has a nanodonut shape from natural ilmenite ore using a low-cost and bulk method. The TiN nanodonuts exhibit strong and spectrally broad localized surface plasmon resonance absorption in the visible region centered at 560 nm, which is well suited for thermoplasmonic applications as a nanoscale heat source. The heat generation is investigated by water evaporation experiments under simulated solar light, demonstrating excellent solar light harvesting performance of the nanodonut structure.


2021 ◽  
Author(s):  
Song-Jeng Isaac Huang ◽  
Adil Muneeb ◽  
Sabhapathy Palani ◽  
Anjaiah Sheelam ◽  
Bayikadi Khasimsaheb ◽  
...  

Developing a non-precious metal electrocatalyst for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is desirable for low-cost energy conversion devices. Herein, we designed and developed a new class...


2003 ◽  
Vol 40 (1) ◽  
pp. 97-102 ◽  
Author(s):  
B. Porter ◽  
A. DeLahunta ◽  
B. Summers

Gliomatosis cerebri is a well-recognized entity in human medicine characterized by unusually widespread infiltration of the neuraxis by neoplastic glial cells with relative preservation of brain architecture. This report describes the pathologic features of the disease in six dogs. The dogs ranged from 3 to 9 years of age (mean 6.1 years) without evidence of breed predilection; five of the six dogs were neutered or intact males. The clinical findings were mixed (including depression, circling, cranial nerve deficits), reflecting the diffuse nature of the disease. Histologically, there was remarkably diffuse infiltration of the white and gray matter of the brain by small numbers of elongated neoplastic cells. Areas of greater cellularity formed grossly visible lesions in four cases. Anisocytosis and pleomorphism were greater in areas of higher cellularity. Other features of tumor growth included subpial accumulation, neuronal satellitosis, perivascular cuffing, and tropism for cranial nerve and brain stem nuclei. Neoplastic cells were negative on immunohistochemical stains for glial fibrillary acid protein (GFAP) and leukocyte markers, reflecting the uncertain histogenesis of these unusual neoplasms.


2011 ◽  
Vol 94 (6) ◽  
pp. 1896-1905 ◽  
Author(s):  
James D Crutchfield ◽  
John H Grove

Abstract A reusable catalytic reductor consisting of 96 copperized-cadmium pins attached to a microplate lid was developed to simultaneously reduce nitrate (NO3–) to nitrite (NO2–) in all wells of a standard microplate. The resulting NO2– is analyzed colorimetrically by the Griess reaction using a microplate reader. Nitrate data from groundwater samples analyzed using the new device correlated well with data obtained by ion chromatography (r2 = 0.9959). Soil and plant tissue samples previously analyzed for NO3– in an interlaboratory validation study sponsored by the Soil Science Society of America were also analyzed using the new technique. For the soil sample set, the data are shown to correlate well with the other methods used (r2 = 0.9976). Plant data correlated less well, especially for samples containing low concentrations of NO3–. Reasons for these discrepancies are discussed, and new techniques to increase the accuracy of the analysis are explored. In addition, a method is presented for analyzing NO3– in physiological fluids (blood serum and urine) after matrix modification with Somogyi's reagent. A protocol for statistical validation of data when analyzing samples with complex matrixes is also established. The simplicity, adaptability, and low cost of the device indicate its potential for widespread application.


Author(s):  
Simon Perreault ◽  
Philippe Cardou ◽  
Cle´ment Gosselin

We propose a new class of pantographs, i.e., of mechanisms that allow the reproduction of the displacements of an input link, the master, with an output link, the slave. The application we envision for these devices is the telemanipulation of objects from small distances, at low cost, where magnetic fields or other design constraints prohibit the use of electromechanical systems. Despite the long history of pantographs, which were invented in the 17th century, the class of pantographs proposed here is new, as it relies on parallel cable-driven mechanisms to transmit the motion. This allows the reproduction of rigid-body displacements, while previous pantographs were limited to point displacements. This important characteristic and others are described in the paper. One important challenge in the design of the proposed systems is that the cables must remain taut at all time. We address this issue by introducing nonlinear springs that passively maintain a minimum tension in the cables, while approximating static balancing of the mechanism over its workspace. Approximating static balancing allows the forces applied at the slave to reflect more accurately at the master, and vice versa. As a preliminary validation, a two-degree-of-freedom parallel cable-driven pantograph is designed. A prototype of this apparatus that does not include approximate static balancing is built, which demonstrates the working principle of these mechanisms.


1996 ◽  
Vol 39 ◽  
pp. 207-207
Author(s):  
Paul G Ekert ◽  
Neil MacLusky ◽  
Larry Becker ◽  
Martin Post ◽  
A. Keith Tanswell

2021 ◽  
Author(s):  
Sierra A. Codeluppi ◽  
Dipashree Chatterjee ◽  
Thomas D. Prevot ◽  
Keith A. Misquitta ◽  
Etienne Sibille ◽  
...  

AbstractBackgroundNeuromorphological changes are consistently reported in the prefrontal cortex (PFC) of patients with stress-related disorders and in rodent stress models, but the effects of stress on astrocyte morphology and potential link to behavioral deficits are relatively unknown.MethodsTo answer these questions, transgenic mice expressing green fluorescent protein (GFP) under the glial fibrillary acid protein (GFAP) promotor were subjected to 7, 21 or 35 days of chronic restraint stress (CRS). CRS behavioral effects on anhedonia- and anxiety-like behaviours were measured using the sucrose intake and the PhenoTyper tests, respectively. PFC GFP+ or GFAP+ cells morphology was assessed using Sholl analysis and associations with behavior were determined using correlation analysis.ResultsCRS-exposed mice displayed anxiety-like behavior at 7, 21 and 35 days and anhedonia-like behavior at 35 days. Analysis of GFAP+ cell morphology revealed significant atrophy of distal processes following 21 and 35 days of CRS. CRS induced similar decreases in intersections at distal radii for GFP+ cells, accompanied by increased proximal processes. Additionally, the number of intersections at the most distal radius step significantly correlated with time spent in the shelter zone in the PhenoTyper test (r=-0.581, p<0.01) for GFP+ cells and with behavioural emotionality calculated by z-scoring all behavioral measured deficits, for both GFAP+ and GFP+ cells (r=-0.400, p<0.05; r=-0.399, p<0.05).ConclusionChronic stress exposure induces a progressive atrophy of cortical astroglial cells, potentially contributing to maladaptive neuroplastic changes associated with stress-related disorders.


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