Targeted drug delivery system, Nano particles (basic ideas)
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The document discusses nanoparticles, including their definition as particles between 1-100 nanometers in size, a brief history of their use dating back to ancient Rome and the Middle Ages, and their unique size-dependent properties. It also covers several common synthesis methods for nanoparticles, how they can be functionalized for different applications, some potential health and safety concerns, and examples of current applications in fields like medicine, optics, and electronics.
Targeted drug delivery system, Nano particles (basic ideas)
- 1. NANO PARTICLES • DEFINITION • HISTORY • PROPERTIES • SYNHESIS • FUNCTIONALISATION • HEALTH AND SAFETY • APPLICATIONS
- 2. NANO PARTICLES IUPAC definition Nanoparticles are particles between 1 and100 nanometres (nm) in size with a surrounding interfacial layer. The interfacial layer is an integral part of nanoscale matter, fundamentally affecting all of its properties. The interfacial layer typically consists of ions, inorganic and organic molecules. Organic molecules coating inorganic nanoparticles are known as stabilizers, capping and surface ligands, or passivating agents.
- 3. HISTORY Nanoparticles were used by artisans as far back as Rome in the fourth century in the famous Lycurgus cup made of dichroic glass as well as the ninth century in Mesopotamia for creating a glittering effect on the surface of pots In modern times, pottery from the Middle Ages and Renaissance often retains a distinct gold- or copper- colored metallic glitter. This luster is caused by a metallic film that was applied to the transparent surface of a glazing. The luster can still be visible if the film has resisted atmospheric oxidation and other weathering SILICON NANO PARTICLE Silicon nanopowder1 kg of particles of 1 mm3 has the same surface area as 1 mg of particles of 1 nm3
- 4. PROPERTIES • Nanoparticles are of great scientific interest as they are, in effect, a bridge between bulk materials and atomic or molecular structures. A bulk material should have constant physical properties regardless of its size, but at the nano-scale size-dependent properties are often observed. Thus, the properties of materials change as their size approaches the nanoscale and as the percentage of the surface in relation to the percentage of the volume of a material becomes significant. Semiconductor nanoparticle of lead sulfide with complete passivation by oleic acid, oleyl amine and hydroxyl ligands (size ~5nm) Semi-solid and soft nanoparticles have been manufactured. A prototype nanoparticle of
- 5. SYNTHESIS There are several methods for creating nanoparticles, including gas condensation, attrition, chemical precipitation, ion implantation, pyrolysis and hydrothermal synthesis. In attrition, macro- or micro-scale particles are ground in a ball mill, a planetary ball mill, or other size-reducing mechanism. Sol–gel The sol–gel process is a wet-chemical technique (also known as chemical solution deposition) widely used recently in the fields of materials science and ceramic engineering. Such methods are used primarily for the fabrication of materials (typically a metal oxide) starting from a chemical solution (sol, short for solution), which acts as the precursor for an integrated network (or gel) of either discrete particles or network polymers. Typical precursors are metal alkoxides and metal chlorides, which undergo hydrolysis and polycondensation reactions to form either a network "elastic solid" or a colloidal suspension (or dispersion) – a system composed of discrete (often amorphous) submicrometer particles dispersed to various degrees in a host fluid. Ion implantation Ion implantation may be used to treat the surfaces of dielectric materials such as sapphire and silica to make composites with near-surface dispersions of metal or oxide nanoparticles. See ion implantation#Ion implantation-induced nanoparticle formation
- 6. Functionalization is the introduction of organic molecules or polymers on the surface of the nanoparticle. The surface coating of nanoparticles determines many of their physical and chemical properties, notably stability, solubility, and targeting. A coating that is multivalent or polymeric confers high stability. Functionalized nanomaterial-based catalysts can be used for catalysis of many known organic reactions. Functionalization Surface coating for biological applications Main article: Nanoparticle–biomolecule conjugate For biological applications, the surface coating should be polar to give high aqueous solubility and prevent nanoparticle aggregation. In serum or on the cell surface, highly charged coatings promote non-specific binding, whereas polyethylene glycol linked to terminal hydroxyl or methoxy groups repel non-specific interactions. Common address tags are monoclonal antibodies, aptamers, streptavidin or peptides. These targeting agents should ideally be covalently linked to the nanoparticle and should be present in a controlled number per nanoparticle. Multivalent nanoparticles, bearing multiple targeting groups, can cluster receptors, which can activate cellular signaling pathways, and give stronger anchoring.
- 7. Health and safety Nanoparticles present possible dangers, both medically and environmentally. They are also able to pass through cell membranes in organisms, and their interactions with biological systems are relatively unknown.However, it is unlikely the particles would enter the cell nucleus, Golgi complex, endoplasmic reticulum or other internal cellular components due to the particle size and intercellular agglomeration.A recent study looking at the effects of ZnO nanoparticles on human immune cells has found varying levels of susceptibility to cytotoxicity. Carbon Nanotubes: Carbon materials have a wide range of uses, ranging from composites for use in vehicles and sports equipment to integrated circuits for electronic components. The interactions between nanomaterials such as carbon nanotubes and natural organic matter strongly influence both their aggregation and deposition, which strongly affects their transport, transformation, and exposure in aquatic environments Cerium oxide: Nanoscale cerium oxide is used in electronics, biomedical supplies, energy, and fuel additives. Titanium dioxide: Nano titanium dioxide is currently used in many products. Depending on the type of particle, it may be found in sunscreens, cosmetics, and paints and coatings Nano Silver: Nano silver is being incorporated into textiles, clothing, food packaging, and other materials to eliminate bacteria. EPA are studying certain products to see whether they transfer nano-size silver particles in real-world.
- 8. Applications Scientific research on nanoparticles is intense as they have many potential applications in medicine, physics,optics, and electronics.The U.S. National Nanotechnology Initiative offers government funding focused on nanoparticle research. The use of nanoparticles in laser dye-doped poly(methyl methacrylate) (PMMA) laser gain media was demonstrated in 2003 and it has been shown to improve conversion efficiencies and to decrease laser beam divergence.Researchers attribute the reduction in beam divergence to improved dn/dT characteristics of the organic- inorganic dye-doped nanocomposite. Nanoparticles are being investigated as potential drug delivery system. nanoparticle-assisted delivery allows for spatial and temporal controls of the loaded drugs to achieve the most desirable biological outcome. Nanoparticles are also studied for possible applications as dietary supplements for delivery of biologically active substances, for example mineral elements