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3 Nanoparticles
Published in Odireleng Martin Ntwaeaborwa, Luminescent Nanomaterials, 2022
S.J. Mofokeng, F.V. Molefe, L.L. Noto, M.S. Dhlamini
Luminescence is a phenomenon where light emission is produced from electron transitions when excited electrons de-excite to a ground state, radiatively [1]. There are various types of luminescence phenomena such as bioluminescence, phosphorescence, cathodoluminescence, and thermoluminescence, just to mention a few [2]. Bioluminescence is displayed by living organisms, like fireflies, glow-worms, and certain sea bacteria [3]. Phosphorescence and cathodoluminescence occur when a luminescent compound is irradiated with a photon and an electron beam (Fig. 9.1), respectively. Thermoluminescence occurs as a result of electron stimulation by thermal energy from electron trapping centres to a luminescent centre [1]. Figure 9.1 illustrates the luminescence phenomenon, where a luminescent compound is irradiated with an electron beam or a photon beam, which brings about electron excitation from the ground state to an excited state, from where they will de-excite radiatively back to the ground state.
Bioluminescence
Published in Margarida M. Barroso, Xavier Intes, In Vivo, 2020
Michael Conway, Tingting Xu, Amelia Brumbaugh, Anna Young, Dan Close, Steven Ripp
The following sections introduce how various bioluminescent technologies are leveraged in vivo for biological insight. Studying physiological and biochemical processes in vivo is essential for gaining a more complete understanding of animal development, cancer, and interventional medicine, among numerous other phenomena. BLI in vivo also presents challenges not typically found in two-dimensional, in vitro cell culture. The most consequential of which is the target’s depth within an animal. On one hand, bioluminescent technologies are well suited for deep tissue imaging because their emitted signal is initiated by a chemical substrate delivered via endogenous circulation and diffusion, whereas fluorescent markers require excitation light, which is not easily deliverable in this case. Furthermore, the surrounding tissues emit essentially no bioluminescence, unlike fluorescence, which produces high signal-to-noise ratios (SNR) for BLI (Figure 5.1). But on the other hand, the majority of bioluminescent modalities at present have weaker overall signals compared to fluorescence and have emission wavelengths readily absorbed by surrounding tissues. However, red-shifted bioluminescent technologies are reducing this problem. With these advantages and limitations in mind, the remainder of this chapter will introduce traditional and commonly utilized bioluminescent technologies for in vivo imaging, as well as introduce recent and innovative technologies that improve deep tissue imaging or facilitate the study of molecular interactions.
Phosphors in Role of Magnetic Resonance, Medical Imaging and Drug Delivery Applications: A Review
Published in Vikas Dubey, Sudipta Som, Vijay Kumar, Luminescent Materials in Display and Biomedical Applications, 2020
Neha Dubey, Vikas Dubey, Jagjeet Kaur, Dhananjay Kumar Deshmukh, K.V.R. Murthy
Bioluminescence imaging is a technology that allows for the non-invasive study of ongoing biological processes in small laboratory animals. Xing and co-workers (Yang et al. 2012) reported NIR light controlled uncaging of d-luciferin and bioluminescence imaging in vivo using NIR-to-UV UCNP probes. The core-shell NIR-to-UV UCNPs were coated with thiolated silane molecules and subsequently coupled to d-luciferin that was caged with a 1-(2-nitrophenyl) ethyl group. UV light emitted from UCNPs under NIR irradiation could activate caged d-luciferin to release d-luciferin molecules which was an active substrate of luciferase used in bioluminescence imaging. Cell viability assays showed no obvious cytotoxicity for C6 glioma cells treated with the d-luciferin/UCNP conjugate after two hours of irradiation with NIR light. In marked contrast, UV irradiation resulted in significant cellular damage after a short exposure time. Importantly, strong bioluminescence signals were detected in the mouse injected d-luciferin/UCNP conjugate after NIR-light induced photo uncaging. While under UV irradiation, no notable bioluminescence was detected in the mouse owing to the poor tissue penetration of UV light (Fig. 7.5).
Classification Framework for Clinical Datasets Using Synergistic Firefly Optimization
Published in IETE Journal of Research, 2021
V. R. Elgin Christo, H. Khanna Nehemiah, S. Keerthana Sankari, Shiney Jeyaraj, A. Kannan
Fireflies are best known for the biochemical light they emit. The process by which living organisms convert chemical energy into light is bioluminescence. Fireflies have an amazing flash communication system comprising precisely timed, rapid bursts of bioluminescence [31]. The two fundamental reasons for such flashes are to attract mating partners and to attract potential prey [32]. The basic Firefly algorithm was proposed based on a few of the bioluminescent characteristics of the firefly. The algorithm uses three idealized rules as presented below: All fireflies are regarded as unisexual. So, regardless of their sex, each firefly may be attracted to every other firefly.The brightness of the firefly or the bioluminescence in the firefly’s light organ determines its attractiveness. Thus, a less bright firefly will move towards a brighter firefly and if there is no brighter firefly than itself, the firefly moves randomly. Consequently, the attraction between two fireflies decreases as the distance between them increases.The objective function aims to maximize the brightness of the firefly based on its fitness.
Effects of water produced by oil segment on aquatic organisms after treatment using advanced oxidative processes
Published in Journal of Toxicology and Environmental Health, Part A, 2021
T. S. Viana, T. C. R. Rialto, J. F. D. Brito, A. F. D. Micas, F. R. Abe, E. A. Savazzi, M.V.B. Boldrin Zanoni, D. P de Oliveira
Bioluminescence is an aerobic oxidation process that involves light production by luciferase enzyme. This enzyme catalyzes the oxidation of luciferin and this process is mediated by reduction of flavin coenzyme mononucletides. The interaction of toxic substances with the bioluminescent bacteria results in an inhibition of light production by these organisms (Girotti et al. 2008). Parvez, Venkataraman, and Mukherji (2006) reported that inhibition of luminescence in a bacterium served as an effective indicator of toxic effects for higher organisms, as re-affirmed by Manfra et al. (2010). When compared with other bacterial assays, the V. fischeri bioluminescence test is considered one of the most sensitive to a wide range of chemicals (Ferrer et al., 2001; Ferraz, Grando, and Oliveira 2011; Gatidou, Stasinakis, and Izatrou 2015; Heinlaan et al. 2008; Leme et al. 2015; Melo et al. 2019; Ranke et al. 2004; Rosado, Usero, and Morillo 2016; Ventura et al. 2014). As illustrated in Figure 2, luminescent light was increased until 25% dilution for the raw sample and until 45% after oxidative treatments, probably due to the salt content in the samples, considering that Vibrio fischeri is a marine organism. After exposure to more concentrated salt samples in conjunction with elevated quantities of toxic compounds (at highest doses), adverse responses were observed for both raw and PW treated with O3 (Figure 2(a,e)). Septer et al. (2015) postulated that metabolic changes affect availability of substrates for luciferase in Vibrio fischeri resulting in diminished luminescent. It is also possible that metabolic alterations trigger a regulatory response that leads to a change in expression of the lux operon, which is associated with the tricarboxylic acid (TCA) cycle leading to decreased luminescence (Septer et al. 2015).
Advances of engineered extracellular vesicles-based therapeutics strategy
Published in Science and Technology of Advanced Materials, 2022
Hiroaki Komuro, Shakhlo Aminova, Katherine Lauro, Masako Harada
Bioluminescence is a popular and widely used tool for both endogenous and exogenous labeling for EV imaging and tracking. Bioluminescence involves light emitted from the natural enzyme substrate reaction, unlike the excitation and emission required for fluorescence [155]. Reporters engineered to the EV surface that emit bioluminescence involve gaussian Luciferase (gLuc), NanoLuc, ThermoLuc, and Firefly [218]. Advantages to using this method include not having the problems of fluorescence in terms of autofluorescence, short shelf life, and high expense as seen in radiolabeling [249]. There are many types of luciferases, but they are not all equal, each coming with their own pros and cons. Gupta et al. tested out different reporters both in vitro and in vivo to see which gave the best brightness and stability in terms of half-life and pH sensitivity [218]. For in vitro experiments, nanoLuc performed better than the other reporters, but for in vivo, thermoLuc gave a high emission wavelength with no substrate toxicity [218]. A downside is that these bioluminescence reporter proteins require some genetic modifications to the EV or parent cell. One way to do this is to engineer the reporter to create fusion proteins with EV surface markers like lactadherin, which results in the presentation of the reporter protein on the surface of EVs, allowing for them to be visualized [216]. Bonsergent et al. used NanoLuc engineered EV markers in vitro that were presented both inside and outside of the EV, using Hsp70 and CD63 respectfully [250]. Additionally, Lai et al. created a metamodel imaging reporter for both fluorescent and bioluminescent in vivo imaging that was presented on the surface of EVs [248,251]. To control the expression of the fluorescent and bioluminescent, the researchers fused a biotin acceptor domain to gLuc. In the presence of biotin ligase, the bioluminescent signal was emitted, and with the addition of a biotin binding protein fused to a fluorescent label, fluorescence imaging could take place after injection [251]. Bioluminescence labeling has a multitude of options, each with scenarios where they best fit, that are widely used for in vivo imaging.