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Radiolabeled Nanoparticles as Diagnostic and Therapeutic Agents of Cancer
Published in Costas Demetzos, Stergios Pispas, Natassa Pippa, Drug Delivery Nanosystems, 2019
Charalampos Tsoukalas, Maria-Argyro Karageorgou, Penelope Bouziotis
Dendrimers are nanostructures synthesized from branched monomer units, which can easily be functionalized with a wide variety of groups on their surface. Their monodisperse nature and structural/chemical uniformity make them excellent candidates for drug delivery applications. Zhang et al. functionalized polyamidoamine (PAMAM) dendrimers with FA and consequently radiolabeled them with 99mTc via 1B4M-DTPA, which acts as the chelating agent [22]. Biodistribution and micro-SPECT imaging studies showed definitive accumulation in nude mice bearing folate receptor–positive KB tumors. Because of the significant kidney uptake of the FA dendrimer derivative, the group next reported on the synthesis of a dendrimer-avidin conjugate, which could be easily radiolabeled with 99mTc and showed excellent in vitro/in vivo stability, rapid blood clearance, and very low kidney uptake [23].
Superparamagnetic Iron Oxide Nanoparticles for Magnetic Hyperthermia Applications
Published in Bhupinder Singh, Rodney J. Y. Ho, Jagat R. Kanwar, NanoBioMaterials, 2018
Yogita Patil-Sen, Vikesh Chhabria
The size and size distribution are the significant parameters which affect the residual time of SPIONs in blood and thus their uptake by cells and elimination from the body (Chouly et al., 1996). Nanoparticles greater than 200 nm are captured by the spleen and liver, whereas those which are less than 10 nm in diameter are selectively removed from the body by the renal system (Gupta and Gupta, 2005; Thorek et al., 2006). Moreover, magnetic properties of SPIONs are strongly influenced by their size (Mahmoudi et al., 2009a). SPIONs exhibit excellent superparamagnetic properties (see Section 2.2.4), though these particles tend to aggregate. Therefore, particles in the size range of 10–100 nm are preferred, as these are comparable to viruses (20–450 nm), proteins (5–50 nm) and genes (2–100 nm). Moreover, such small-sized particles can penetrate through small capillaries, can easily escape through immune system, and have longer circulation time which is essential for the bioapplications of SPIONs (Gupta and Wells, 2004). Although it is desirable to produce monodisperse particles, control over the size is a major challenge. All SPION synthesis methods tend to generate particles of varying size showing polydispersity which poses an important concern for their biodistribution and bioelimination (Andrade et al., 2011).
Colloidal Systems
Published in K.S. Birdi, Surface Chemistry and Geochemistry of Hydraulic Fracturing, 2016
Another very important physical parameter one must consider is the size (and shape) distribution of the colloids. A system consisting of particles of the same size is called monodisperse. A system with different sizes is called polydisperse. It is also obvious that systems with monodisperse will exhibit different properties than those with polydisperse. In many industrial applications (such as coating on tapes used for recording music, coatings on CDs or DVDs), mono disperse coatings are most preferred. The method used to prepare monodisperse colloids is to achieve a large number of critical nuclei in a short interval of time. This induces all equally sized nuclei to grow simultaneously and thus produce a monodisperse colloidal product.
Preparation of α-Tocopherol based nanoemulsion for efficacious delivery of Methotrexate
Published in Journal of Dispersion Science and Technology, 2023
Jyoti Rathee, Rohini Kanwar, Laxmi Kumari, Sandip V. Pawar, Deepak B. Salunke, Surinder Kumar Mehta
In recent times, monodisperse systems like nanoemulsion (NEm) have come forth as a respite that offered improved therapeutic effect, good tolerability, higher bioavailability, and enhanced targeting of drugs. NEm is a kinetically stable mixture of two immiscible liquids having a droplet size of 100 nm that offers numerous advantages like increased rate of adsorption, protection from the environment, and enhanced lipophilic drug delivery after solubilization over other dosages. It is a non-equilibrium system that requires some input of energy in the form of agitation to assist the emulsification process by reducing the interfacial tension and droplet size. Several techniques such as high-speed homogenization and high energy agitations are preferred for NEm preparation. However, utilization of these techniques requires high energy and does not regulate the size and stability of NEm. While, the method of ultra-sonication is found to be an efficient technique for NEm preparation being simple, eco-friendly, and capable of regulating the size and stability of the NEm.[3] There are several reports[4] wherein, ultrasound-assisted preparation of NEm has proven to be a better candidate for the encapsulation and delivery of bioactive agents. In some recent reports[5,6] such formulation has been used in the delivery of several anticancer drugs like doxorubicin and paclitaxel.