China
Africa
Explore chapters and articles related to this topic
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
Advances in nanotechnology allow researchers to develop nanoparticle-based MRI contract agents with higher magnetization and the required surface characteristics to satisfy the specific requirements for effective biodistribution [184]. There are two types of iron oxide that were specifically investigated for use in magnetic NP formulation: maghemite (α-Fe2O3) and magnetite (Fe3O4), both biocompatible, while the most promising candidate is magnetite. Typically, they are coated with dextran, phospholipids, or other compounds to inhibit aggregation and improve stability [185]. A nanocarrier made up of polymeric diacyl phospholipid– PEG micelles co-loaded with the photosensitizer 2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-a (HPPH) and magnetic Fe3O4 nanoparticles showed excellent stability and effective uptake by HeLa cells. The magnetic response of nanocarriers was demonstrated by their targeted delivery to tumor cells in vitro when exposed to an external magnetic field. The magnetophoretic regulation of the cellular uptake improved imaging and phototoxicity [186]. The magnetic core containing chitosan nanoparticles and photosensitizer carriers encapsulating photosensitizer 2,7,12,18-tetramethyl-3,8-di(1-propoxyethyl)-13,17-bis(3-hydroxypropyl) porphyrin (PHPP) was found to have excellent targeting and imaging ability. With these nanoparticles at the level of 0–100 mM, non-toxicity and high photodynamic efficacy on SW480 carcinoma cells were achieved, both in vitro and in vivo [187].
Designing Smart Nanotherapeutics
Published in Suresh C. Pillai, Yvonne Lang, Toxicity of Nanomaterials, 2019
A. Joseph Nathanael, Tae Hwan Oh, Vignesh Kumaravel
MNPs (e.g., iron oxide) have been widely employed for different bio-medical applications (such as drug delivery, medical imaging, and biosensor) under the guidance of an external magnetic field. The US Food and Drug Administration has accepted iron oxide nanoparticles (e.g., Fe3O4) for its clinical use as a magnetic resonance contrast agent (Kim et al. 2011). The magnetism and functionality of the nanoparticles are influenced by their shape, size, particle size distribution, and surface characteristics (Lee et al. 2015). Hydrothermal (Chen et al. 2008), precipitation (Rajamohan et al. 2017, Vignesh et al. 2014), thermal decomposition (Unni et al. 2017), and electro-chemical (Starowicz et al. 2011) methods are commonly used to synthesize MNPs. The biocompatibility and colloidal stability of MNPs are significantly determined by the nature of surface ligands. The surface of Fe3O4 is generally decorated by a polymer with required surface ligands for drug delivery. The surface modification is performed using ligand exchange (e.g., sulfonates, phosphonates, thiols, catechol, and carboxylic acids) and encapsulation (e.g., polymers, silica, DNA, and inorganic metal/metal oxide) techniques. Stimuli-responsive (internal and external) ligands have received much attention in recent years to improve the drug delivery of MNPs (Kang et al. 2017). The interaction of stimuli-responsive MNPs with internal/external factors results in a wide range of structural changes as shown in Figure 6.3a (Kang et al. 2017).
Imaging of Cell Trafficking and Cell Tissue Homing
Published in George C. Kagadis, Nancy L. Ford, Dimitrios N. Karnabatidis, George K. Loudos, Handbook of Small Animal Imaging, 2018
Iron oxide nanoparticles for magnetic resonance imaging contain iron and, although it is a natural and essential mineral, an overdose can be toxic to cells (Soenen et al. 2011). Moreover, aggregation of these nanoparticles in the presence of a magnetic field can lead to embolization (Gupta et al. 2007). Several studies have looked into the adverse effects of iron oxide particles on cells, but the reports have been contradictory. Importantly, however, the variety of the applied methods and model systems to assess cytotoxicity plays a critical role and can contribute significantly to these contradictory findings (Soenen and De Cuyper 2010). As a result, many highlighted the need for a more standardized procedure for the assessment of nanoparticle cytotoxicity. In general, the toxicity associated with iron oxide nanoparticles, or their coatings, appears to be closely related to the release of ions and the generation of free radicals following passage through the cell’s lysosomes (Soenen and De Cuyper 2010; Taylor et al. 2012). On the positive side, the uptake and toxicity of these nanoparticles can be manipulated by modifications in the surface chemistry and selecting the right size and biocompatible coating of the nanomaterial (Alkilany and Murphy 2010).
Role of nanotechnology in the prolonged release of drugs by the subcutaneous route
Published in Expert Opinion on Drug Delivery, 2023
Inorganic-based nanosystems are made of several materials, including calcium, gold, iron, and silica. They have unique electrical, magnetic, physical, and optical properties. Calcium phosphate and mesoporous silica nanosystems have been used mainly in genetic delivery [53]. Gold-based nanosystems, nanospheres, nanorods, nanostars, nanoshells, and nanocages [61], have free electrons on their surface, giving them photothermal properties that are beneficial for cancer therapy [62]. Iron oxide is present in most inorganic nanomedicines approved by the FDA. An inorganic nanosystem loaded with Au-Fe3O4 and small interfering RNA (siRNA) nanoparticles through hydrophobic and electrostatic interactions, respectively, is shown in Figure 2c. Magnetite and maghemite are magnetic iron oxides commonly used in nanosystem-based formulations due to their photothermal and superparamagnetic properties. They can also be used as contrast agents or drug-delivery vehicles [63]. However, their utilization may be compromised by their low solubility and toxicity properties, particularly in formulations with heavy metals [6].
Metal Nanoparticles in Infection and Immunity
Published in Immunological Investigations, 2020
Other metals which have been investigated as nanoparticles, include those composed of copper, iron, and zinc. In addition, semi-metals such as gallium and bismuth have been incorporated into nanoparticles as well (Hernandez-Delgadillo et al. 2013; Vega-Jimenez et al. 2017). Iron and zinc may decompose into the ionic forms of those elements in acidic cellular compartments, and therefore might be considered partially biodegradable. In addition to pure metal, metal oxides feature prominently in the field of nanoparticles, such as iron oxide NPs, zinc oxide (ZnO) NPs, titanium oxide (TiO2) NPs, and others. Iron oxide can be in the form of Fe2O3 (ferric iron, Fe III) or Fe3O4 (Fe II/III). The latter is magnetic, which means it can be used to separate a target from background in vitro or in vivo. Fe3O4 nanoparticles can also be injected into a target tissue (such as cancerous tumor) and then heated by application of a high frequency alternating magnetic field, known as magnetic hyperthermia.
Current trends in chemical modifications of magnetic nanoparticles for targeted drug delivery in cancer chemotherapy
Published in Drug Metabolism Reviews, 2020
Ahmad Gholami, Seyyed Mojtaba Mousavi, Seyyed Alireza Hashemi, Younes Ghasemi, Wei-Hung Chiang, Najmeh Parvin
In another research, magnetite nanoparticles like iron oxide with core/shell structure are primarily used as sources of magnetic materials (Drbohlavova et al. 2009; Ebrahimi et al. 2016). Iron oxide has several crystalline polymorphs called Fe2O3 hematite, Fe2O3 maghemite, Fe3O4 magnetite, and a few other forms (high-pressure forms and amorphous) (Zboril et al. 2002). Nevertheless, only maghemite and magnetite are found to be the most significant interest in bioapplications. Until now, widely MNPs synthesis methods have been investigated. There are many favorable methods to get MNPs by high stability, monodisperse nanoparticles, and shape-controlling (Chen et al. 2018). There are used several methods in the synthesis of MNPs such as coprecipitation (Hashemi et al. 2019), thermal decomposition, microemulsion, sol–gel, and additional chemical processes that are shown in Figure 1 (Avval et al. 2019).