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Phototherapy Using Nanomaterials
Published in D. Sakthi Kumar, Aswathy Ravindran Girija, Bionanotechnology in Cancer, 2023
A. N. Resmi, V. Nair Resmi, C. R. Rekha, V. Nair Lakshmi, Shaiju S. Nazeer, Ramapurath S. Jayasree
Scintillation nanoparticles, such as BaFBr: Eu2+, Mn2+, and LaF3:Tb3+, will emit luminescence for activating the photosensitizers following exposure to ionizing irradiation. This results in the production of 1O2 which enhances the destruction of cancer cells. The efficiency of LaF3:Tb3+-meso-tetra (4-carboxyphenyl) porphine (MTCP) nanoparticle conjugated as photodynamic agents following X-ray irradiation was investigated [211]. They described the effective energy transfer and 1O2 generation mechanism upon initiation by X-rays at low dose. These scintillation nanoparticles can be possibly utilized as a promising deep cancer treatment modality. Another study described SLPDT against ovarian cancer and they synthesized zinc oxide (ZnO) nanoparticles conjugated to porphyrin (ZnO-MTAP). The photoactivation of ZnO-MTAP conjugates led to ROS release, which could be effectively targeted to tumor cells [212]. In the case of persistent-luminescence nanoparticles, the luminescence continues even after the excitation source is ceased. This long decay lifetime will decrease the ionization dose and prolonged photosensitizer excitation required for cancer treatment. The application of these nanoparticles in biological systems needs to be further explored.
Alternative Tumor-Targeting Strategies
Published in David E. Thurston, Ilona Pysz, Chemistry and Pharmacology of Anticancer Drugs, 2021
The chemical structures of porfimer sodium and temoporfin are based on the porphyrin and closely related chlorin structures (Figure 10.28), a group of naturally occurring intensely colored compounds whose name originates in the Greek word for purple (i.e., porphura). Molecules of this type perform biologically important roles in plants, animals, and bacteria, including photosynthesis. The porphyrins are tetrapyrrolic molecules, with the overall heterocyclic macrocycle known as a porphine. The basic porphine frame consists of four pyrrolic subunits linked on opposing sides through four methine (CH) bridges known as the meso-carbon atoms/positions. The resulting conjugated planar macrocycle may be substituted at the meso- or other positions. The related chlorin structure consists of three pyrroles and one pyrroline coupled through four =CH- linkages. Unlike porphin, the central aromatic ring structure of the porphyrins, a chlorin is predominantly aromatic but not through the entire circumference of the macrocyclic ring. The chlorophyll macrocycles that provide the central photosensitive pigments in the chloroplasts of plants and bacteria are magnesium-containing chlorins. For porphyrin-based PDT agents such as porfimer sodium and temoporfin, the excited state of the porphyrin molecules after illumination with light of an appropriate wavelength and energy, and the subsequent electron spin transfer to molecular oxygen, generate singlet oxygen atoms (i.e., free radicals) which exert the cytotoxic effect.
Terpenes and Terpenoids
Published in William J. Rea, Kalpana D. Patel, Reversibility of Chronic Disease and Hypersensitivity, Volume 4, 2017
William J. Rea, Kalpana D. Patel
The terpenes are a class of natural products or hydrocarbons having structural relationship with isoprene or some of its multiple.1 Isoprene and porphin are building blocks of natural substances. Porphins are building blocks of natural substances such as heme, cytochrome, corroles, etc. Isoprene consists of five carbon atoms attached to eight hydrogen atoms (C5H8).2 It is 2-methyl-1,3-butadiene (CH2C(CH3)CH═CH2); terpenoids (HC═CH) are oxygenated derivatives of hydrocarbons or new compounds structurally related to isoprene. They are isolated from sources other than plants and are often included in the class of terpenes.1,2 More than 5000 structurally determined terpenes are known.1 Many of these have also been synthesized in the laboratory.1 Indoor air analysis of a house showed terpenes and acetic acid made by the chemical reaction of terpenes.
Exploring new frontiers in drug delivery with minimally invasive microneedles: fabrication techniques, biomedical applications, and regulatory aspects
Published in Expert Opinion on Drug Delivery, 2023
Niha Sultana, Ayesha Waheed, Asad Ali, Samreen Jahan, Mohd Aqil, Yasmin Sultana, Mohd. Mujeeb
The first research work on drug delivery was published in 1988 by Henry et al. on MN-assisted transdermal drug delivery. The study demonstrated the poke and patch approach using solid MN for the delivery of calcein. Since then, there is extensive use of this approach [79]. Similarly, Stahl et al. have shown the permeation enhancement of the NSAIDs such as diclofenac, ibuprofen, ketoprofen, and paracetamol through transdermal delivery by pretreating with an MN roller device [80]. In another study, McAllister et al. used metal MN to deliver various molecules, including macromolecules such as BSA and insulin [36]. Mikolejewska et al. have reported that MN arrays can successfully enhance the intradermal delivery of preformed photosensitizer Meso-tetra ((N-methyl-4-pyridyl) porphine tetra tosylate [81]. Martanto et al. observed the potential of solid metal MNs to facilitate transdermal delivery of insulin and lower the blood sugar level of rats by 80% [82]. Badran et al. have shown the skin permeation enhancement of MN device, i.e. derma roller of varying needle sizes for the drug delivery. MN with medium and short length were found to be promising for the purpose of drug delivery [83].
Targeting therapy effects of composite hyaluronic acid/chitosan nanosystems containing inclusion complexes
Published in Drug Delivery, 2022
Tetrakis (4-carboxyphenyl) porphine was encapsulated into the composite nanosystems as a fluorescent probe. A mouse wound infection model was established to test the targeting delivery performance of the composite nanosystems. Briefly, the nude mice were anesthetized with ether cotton balls and the epidermis was cut on the right hindlimb by surgical scissors to form a 5 mm diameter wound. Subsequently, S. aureus was injected into the wound (107 CFU/mL, 100 μL). After infection for 24 h, the same amount of free fluorescent probe and composite nanosystems loaded fluorescent probe were injected intravenously (n = 3). After medication, the fluorescence intensity at the infection site was observed at a given time (6, 12, 24, and 48 h) by the IVIS Spectrum small animal in vivo imaging system (PerkinElmer, USA). At the end of the experiment, the fluorescence of the viscera was measured after the mice was slaughtered.
Mechanistic studies on the drug metabolism and toxicity originating from cytochromes P450
Published in Drug Metabolism Reviews, 2020
Chaitanya K. Jaladanki, Anuj Gahlawat, Gajanan Rathod, Hardeep Sandhu, Kousar Jahan, Prasad V. Bharatam
QC methods have a limitation in terms of the size of the system, which can be studied. The time required to solve the elecronic structure of a given system exponentially depends on the number of electrons present in it. The Cpd I model (Figure 4) used for a majority of studies is the iron (IV)-oxo -porphine with SH¯ as the axial ligand (Wallar and Lipscomb 1996; Himo and Siegbahn 2003; Shaik et al. 2005; Shaik et al. 2010; Taxak et al. 2011; Boulenc et al. 2012; Taxak et al. 2012; Hirao et al. 2013; Taxak, Kalra, et al. 2013; Taxak, Patel, et al. 2013; Taxak, Prasad, et al. 2013; Arfeen et al. 2014), as it has been proved to be sufficient in obtaining reliable results for the reactions catalyzed by CYP450 enzymes. Commonly, the hybrid B3LYP functional is being employed for geometry optimizations for Cpd I in these metabolic studies, where the Los Alamos effective core potential coupled with the double-ζ LACVP (or LanL2DZ) basis set is chosen for heme iron (Hay and Wadt 1985; Wallar and Lipscomb 1996) and 6-31 + G(d) basis set for the remaining atoms. Single point energy calculations are thereafter, carried out employing triple-ζ potential on iron and 6-311++G (d, p) basis set on other atoms. The solvation effects are also considered for the enzymatic reactions, which occur in aqueous solution. Several scientific groups have employed chlorobenzene (ε = 5.7) as the implicit solvent using Integral Equation Formalism variant of Polarizable Continuum Model (IEFPCM) to account for bulk polarity effects of the protein environment in the active site of CYP 450s.