Properties of gold nanoparticles can be varied by altering the size, shape, degree of aggregation, and local environment. They exhibit characteristic colors and unusual optical properties that strongly depend on their shape, size, and the dielectric constant of the surrounding medium . The characteristic wine-red color of spherical gold nanoparticles stems from a phenomenon termed surface plasmon resonance. The plasmonic effects include two main ingredients: the surface plasmon resonance that is the charge density wave propagation on the interface of metal and dielectric, and the localized surface plasmon resonance (LSPR) that is the non-propagating collective oscillation of electrons coupled to electromagnetic field. The early development of plasmonics in the last century is marked by several milestones including the description of free electron collective oscillation and the naming of ‘plasmon’ by D. Pines in 1956 .
Colloidal particulate carriers such as liposome or niosomes have been widely employed in drug delivery systems and producing them from proniosomes provides them a distinctive advantage. These carriers can act as drug reservoirs and the rate of drug release can be controlled by modification of their composition. These lipid vesicles can carry both hydrophilic drugs (by encapsulation) and hydrophobic drugs (in lipid domain). Due of their capability to carry a variety of drugs, these lipid vesicles have been extensively used in various drug delivery systems like drug targeting controlled release and permeation enhancement of drugs But there remains certain draw backs to be addressed and can be avoided if they are prepared in dry form. Proniosomes are dry formulation of water soluble carrier particles that are coated with surfactant.
Based on the weight gain of the substrate sample 8 possesses better deposition of nickel with addition of 0.1 g/ltr of SDS surfactant than other samples. Sample 6 having a weight gain of 0.12 g with 0.3 g/ltr of surfactant on Ni-P bath. Beyond this other samples possesses minor proportion of weight gain with their corresponding composition of nano Sic, SDS surfactant and temperature given in table. 4. Table.4.
Thus this formulation improved oral bioavailability by directly entering systemic circulation thereby reducing hepatic metabolism. Anil .B. Jindal et al prepared asymmetric lipomer using Gantrez AN 119 as the polymer and glyceryl monostearate as the lipid composition21. Due to its size and lipid composition lipomer can enter into the lymphatic circulation and treat many splenic diseases as well as cancers and enhance the delivery of si- rna molecules which otherwise becomes difficult to target at the site of action. LIPOSOMES: Liposomes are most widely used colloidal vesicular systems having many applications in the field of medicine.
These nanoscale particles have the high surface area to volume ratio, which creates a larger surface area and eventually increase the chemical reaction of the material. Figure 1 illustrates that nanoparticles stay on top of your skin and hard for the UV rays to pass through it (Threes, Stanislav, 2011, p.
Nanoparticles as photosensitizers must be in close proximity to the tumor cells that they are usually administered at the tumor site directly. Photodynamic therapy is desirable in that it is relatively non-invasive and low toxicity. The major technical barrier, however, of this therapy is its difficulty in systemic introduction of photosensitizer to the tumor site and local irradiation to activate them. Tumors that have disseminated throughout the whole body may not be adequate for this therapy since the current technology is not available to irradiate the whole body. In addition, UV light is the wavelength of choice for the most of traditional photosensitizers that cannot efficiently penetrate into deep
The method uses gold nanorods functionalized to attach to the type of protein generated by damaged kidneys. When protein accumulates on the nanorod the colour of the nanorod shifts. The test is designed to be done quickly and inexpensively for early detection of a problem. Nanotechnology in Medicine Application: AntiMicrobial Techniques Researchers at the University of Houston are developing a technique to kill bacteria using gold nanoparticles and infrared light. This method may lead to improved cleaning of instruments in hospital
1.5. QUANTITATIVE STRUCTURAL ACTIVITY RELATIONSHIP (QSAR) The QSAR is depends upon structure activity relation (SAR) approach. It uses physicochemical properties to indicate drug properties that can be theoretical to have a major influence on drug action. Some of the common pharmacophoric features include hydrophobic, aromatic, hydrogen bond acceptor, hydrogen bond donor, positive ionizable, and negative ionizable groups. PARAMETERS 1) Lipophilic parameters Two parameters are commonly used to relate drug absorption and distribution with biological activity, namely, the partition coefficient (P) and the lipophilic substituent Constant (p).
Enhancement in membrane rigidity is achieved by increasing the stress and decreasing the elongation. This must be due to the original property of inorganic materials and the re-enforcement effect of incorporated NPs in the membrane matrix (Ahsani and Yegani, 2015). The TGA analysis was carried out to further confirm the formation of PP composite membrane. Fig. 11 shows the weight loss curve obtained by TGA for the pure PP membrane and the modified membrane.
They include liposomes and niosomes, nanovesicles, nanoemulsions, nanocrystals, micelles , solid lipid nanoparticles, polymeric nanocapsules and nanostructured lipid carriers. ii) Non biodegradable nanomaterials which include insoluble particles or biopersistent particles like titanium dioxide (TiO2), zinc oxide, gold in nanoscale, fullerenes, quantum dots. The primary reason behind use of nanoparticles in cosmetics is i) enhanced permeation of ingredients like lipids, vitamins and anti oxidants ii)enhanced stability of unsaturated fatty acids, vitamins and antioxidants as they are protected when encapsulated within the nanoparticles, iii) increase the protection efficacy of UV filters, iv) better aesthetics especially in case of sunscreens in which the white cast on the skin is noticeably reduced v) use of lesser quantities ingredients in preparations with better effects like improving transparency and fluidity apart from and vi) ease of formulation and use. TYPES OF BIODEGRADABLE NANOMATERIALS USED IN COSMETICS 1. VESICULAR