China
Africa
Explore chapters and articles related to this topic
Current in vivo Models for Brain Disorders
Published in Carla Vitorino, Andreia Jorge, Alberto Pais, Nanoparticles for Brain Drug Delivery, 2021
Marta Guerra-Rebollo, Cristina Garrido
In the specific case of brain tumours, one of the most utilised techniques to visualise drug delivery into the tumour is using BLI. The firefly luciferase (FLuc) can be used as a reporter gene and d-luciferin as a substrate. FLuc catalyses d-luciferin oxidation in the presence of adenosine triphosphate (ATP) and coenzyme A (CoA) producing O2 and photons which can be detected in vivo. Recording of the emitted light by photodetectors, capable of linear response allows for real-time measurements [57, 58]. This technique is based on the stable expression of luciferase by the brain tumour cell line selected for the experiment. Once the cells are implanted into the mouse brain, d-luciferin could be injected intraperitoneally into the host mice, where it is distributed throughout the mouse body and crosses the BBB. The intensity of the emitted light correlates to the size of the tumour and allows comparisons of tumours size across different animals but also within the same animal in different time points (Fig. 13.1) [59].
Lab-on-a-Chip-Based Devices for Rapid and Accurate Measurement of Nanomaterial Toxicity
Published in Suresh C. Pillai, Yvonne Lang, Toxicity of Nanomaterials, 2019
Mehenur Sarwar, Amirali Nilchian, Chen-zhong Li
Bioluminescence and chemiluminescence represent similar phenomena. Because of a series of chemical reactions, reactive compounds give rise to a molecule which is in an electronically excited state. Ultimately, the excited molecule returns to its ground states (lower energy level) and emits characteristic photons of light. In fact, bioluminescence is a subcategory of chemiluminescence, where the source of emission is a bio-molecule. For example, a class of different bio-compounds called Luciferin are the source of bioluminescence in several living organisms. Light-emitting Luciferin molecules reach their excited state as a result of oxidative-chemical reactions. Typically, an enzyme from a class of oxidative-enzymes called Luciferase couples with the corresponding Luciferin molecule to catalyse the reaction. In summary, chemiluminescence is the emission of light due to chemical reactions while bioluminescence is the emission of light from living organisms (Mirasoli et al. 2014; Roggo and van der Meer 2017).
Optical-CT Imaging
Published in George C. Kagadis, Nancy L. Ford, Dimitrios N. Karnabatidis, George K. Loudos, Handbook of Small Animal Imaging, 2018
Xueli Chen, Dongmei Chen, Fenglin Liu, Wenxiang Cong, Ge Wang, Jimin Liang
Bioluminescent light is produced from the expression of luciferase enzymes, such as firefly luciferase, Renilla luciferase, and jellyfish luciferase. Cells encoded with the luciferase enzymes can serve as bioluminescent probes, which allow bioluminescent light emission. The BLT technique uses the luciferase enzyme gene as a reporter (Contag and Bachmann 2002). Oxidation of luciferin, which is injected into the animal, leads to the emission of bioluminescent light and occurs only in cells in which the luciferase enzyme is expressed by the reporter gene. The major attraction of this approach is that although absolute light levels are low, signal is produced only where luciferase is present, leading to extremely low background signals (Troy et al. 2004). BLT was first proposed by Wang’s group in 2003 (Wang et al. 2003). In mathematics, it is an inverse source problem. Based on an accurate light transport model, BLT aims to reconstruct the 3D spatial distribution and concentration of the bioluminescent probes inside a small living animal.
Advances in luminescence-based technologies for drug discovery
Published in Expert Opinion on Drug Discovery, 2023
Bolormaa Baljinnyam, Michael Ronzetti, Anton Simeonov
Other bioluminescence-based enzyme assays exploit the unique structure of luciferin and how it cannot be metabolized by many mammalian and prokaryotic enzymes. For such assays, a pro-luciferin molecule which cannot enable luminescence directly is used. It must first be converted into luciferin by another enzyme before it can be used as a substrate for a luciferase. For example, DEVD-6′-aminoluciferin is a specific substrate for protease cleavage by caspase-3 or caspase-7. The cleavage by caspase-3 and −7 liberates aminoluciferin which becomes available for the luciferase, generating a luminescence signal that is directly proportional to the caspase enzyme activity. Since the substrate is specific for caspase-3 and −7, this assay can be used in both biochemical and cell-based assays and has seen widespread adoption as a method with which to measure the population of apoptotic cells [27]. Based on the same principle, a new ultra-sensitive assay to monitor monoacylglycerol lipase activity, a promising therapeutic target involved in endocannabinoid system modulation, was recently reported [28].
In vivo generated human CAR T cells eradicate tumor cells
Published in OncoImmunology, 2019
Shiwani Agarwal, Tatjana Weidner, Frederic B. Thalheimer, Christian J. Buchholz
NSG mice (NOD.Cg.PrkdcscidIL2rgtmWjl/SzJ, Jackson Laboratory) were intravenously (i.v.) injected with 1 × 105 Nalm-6-luc cells, which stably express firefly luciferase.12 Two days prior to vector application, in vivo imaging (IVIS Spectrum, Perkin Elmer) was performed to arrange animals in two different groups based on luciferase signal intensities for unbiased outcomes. A day later 5 × 106 activated human PBMC from two donors were i.v. injected (mice 1–4 and 9–12 received PBMC from donor 1; the other eight mice received PBMC from donor 2). On the next day, 2.5 × 1011 particles of CD8-LV encoding CD19-CAR or PBS as control were i.v. administered. PBS was chosen as control to exclude any influence on tumor growth by the transplanted donor lymphocytes. To follow up tumor progression, IVIS imaging was performed on days 4, 7, 12, 14 and 17 post-vector application. For this purpose, mice were intraperitoneally injected with D-luciferin (Perkin Elmer) at 150 µg/g body weight. Imaging data were obtained 10 min after luciferin injection. Mice were regularly checked for their health status and tumor load by IVIS. They were sacrificed when termination criteria had been reached.
In vitro intestinal toxicity of copper oxide nanoparticles in rat and human cell models
Published in Nanotoxicology, 2019
Taylor E. Henson, Jana Navratilova, Alan H. Tennant, Karen D. Bradham, Kim R. Rogers, Michael F. Hughes
IEC-6 cells were plated (60,000 cells/well) and the following day treated with CuO NPs (0.1–100 µg/mL; 0.08–80 µg Cu/mL) or CuSO4 (80 µg Cu/mL) for 4 h. GSH concentration in the cells was measured using the GSH-Glo™ Glutathione Assay kit from Promega Corp. In this assay, the cells are lysed and a derivatized luciferin substrate is added to the lysate. The luciferin substrate is converted to luciferin in the presence of GSH. GSH-S-transferase, which is supplied in the assay kit, catalyzes the reaction. Luciferin is detected in a coupled reaction with a recombinant luciferase enzyme, generating a luminescent signal that is proportional to GSH concentration. GSH (2.5 µM) in media was added to one column of wells without cells as a positive control. The SpectraMax i3 plate reader with a luminescence cartridge was used to measure the luminescent signal.