Nanopharmaceutical Advanced Delivery Systems. Группа авторов
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3.3.4 Polymer-Based Nanoparticles
Polymeric nanoparticles are synthesized by the spontaneous aggregation of copolymers with unlikely hydrophobicity in the micelles forming core shell in the aqueous medium (Figure 3.6). They facilitate the encapsulation of lipophilic or hydrophilic drug molecules, nucleic acids, peptides, and smaller molecules to completely strengthen the drug protection in the systemic circulation. Usually they are biocompatible and systemic degradable particle of 10 to 1000 nm in size. They are used as carriers for sustained and controlled drug delivery by modifying the surface of the nanoparticle for passive and active target delivery [36].
3.3.5 Polymer-Based Micelles
Amphiphilic blockage of copolymers is structurally arranged in a nanosized core (Figure 3.7) ranging from 10 to 100 nm. They have a unique microscopic architecture enhancing their property such as increasing the solubility of poorly solubilizing agents, higher entrapment efficiency, nanosize, and biologically stable. They have the ability to tailor micelles for higher degree of desire drug compatibility for the delivery system [37].
Figure 3.5 Carbon nanotubes.
Figure 3.6 Polymer-based nanoparticles.
Figure 3.7 Polymer-based micelle formation.
3.3.6 Dendrimers
They are macromolecules that are naturally or synthetically branched compositions of amino acids, nucleotides, and saccharides (Figure 3.8). They are structured with an exterior outer surface, following the inner branched layers and centrally contain the core. They are synthesized by controlled polymerization to produce monodispersed highly branched polymer system. The cavities of the branched polymers in the core are loaded with small molecules by chemical bondage or hydrophobic linkage or by simple hydrogen bonding. They vary in size NMT 10 nm. They serve the positivity of their controlled delivery of biologically active agents targeting the macrophages and hepatic tissues [38].
Figure 3.8 Dendrimers.
3.3.7 Metallic Nanoparticles
Particles smaller than 100 nm using metals such as gold, silver, and iron oxides to formulate nanoparticles, nanocages, and nanoshells are utilized to enable and modify their advantages in therapy and diagnosis of diseases [39].
3.3.7.1 Gold Nanoparticles
Colloidal or suspension of gold in the nanometer scale offers different shapes and sides based on the optical property, chemical characteristics, surface modification, and biologically stable and compatible delivery of agents (Figure 3.9). They strongly process the optical properties like photo absorption, light scattering, modified SERS (Surface Enhanced Raman Scattering), and fluorescence because of their unparalleled free electron interaction in the nanoparticulate with light. Their investigation and estimations are used in determination of biomarkers in cancer and cardiac diseases; they also have several biomedical therapeutic applications. In a recent research, PEGylation of AuNPs that are conjugated with drugs helps to bypass the RES (reticular endothelial system) clearance. The antibodies can be conjugated to the surface of the gold nanocages and targeted to the cancerous cell receptors. FDA-approved drugs Verigene and Aurimmune in clinical trials (Phase II) are some of the AuNP for particular therapeutic areas. AuNP utilizes the principle of receptor site-specific targeted drug delivery strategy for the development and advances in the application of photothermal medical care, genomic regulations, and choice of drug for treatment for the disease. Hence, the solid spherical colloidal gold nanoparticles of 50 nm and above report of plasmonic photo thermal therapy (PPTT) due to its stronger NIR absorption (near-infrared). The Ab conjugated with AuNPs can be applicable for both PPTT and diagnosis [40].
Figure 3.9 PEG coated gold nanospheres.
3.3.7.2 Iron Oxide Nanoparticles
Ferric oxide is a paramagnetic inorganic compound. It is one of the three iron oxides. Fe2O3 NPs are magnetic nanosized particles present in reddish brown color. They are widely used in biological applications such as a resolution enhancer in the contrast therapeutic agents in MRI imaging, tracking of stem cells and cellular molecules, magnetic separation of biological molecules, hyperthermia, and gene therapy due to their inbuilt magnetic property, extremely fine structure, and biocompatibility [41].
3.3.8 Quantum Dots
Technically “small crystal sizing 2 to 10 nm—numbers of electrons variable occupying discrete amount, well defined state possessing electronic characteristics functionally intermediating between the bulk and discrete particulate.” They consist of a central core with semiconducting molecules encapsulated by cap shell enhancing their aqueous buffer solubility. They are used in multiple purposes like gene therapy, disease diagnosis, and drug delivery. The major limitations of quantum dot are the precipitation of nanotoxicity in biomedical applications [42].
3.3.9 Nanodiamonds
They show excellent optical and mechanical characters with larger surface area and modifiable surface morphology (Figure 3.10). Their uniqueness includes their nonhazardousness that is well suited for biomedical utilization and application. These tiny gems show a broad spectrum of potential in biological applications, drug delivery systems, tissue engineering, and bioimaging. It is also capable of mimicking the proteins and acts as a filler to fabricate the nanocomposition [65].
Figure 3.10 Nanodiamond particles with surface functional groups.
The characteristic properties of the above nanotools facilitate the advantages of decreasing the drug toxicity, minimize the drug resistance, improvise the eternal route of drug bioavailability, enhance the aqueous solubility by increasing its surface area and decreasing its particle size, and ultimately reduce the dose of drug required by increasing the ability to selectively target the specific site and enhance drug formulation stability. This uniqueness paves the way