Nanotechnology is now touching every aspects of day to day life. So there is always evolution in the field of nanotechnology to produce the required size, shape and type of nanothings. Rising demand made chemical and physical methodologies to be used extensively which ultimately created hurdles for the use of nanomaterials in the biomedical applications and caused environmental damage because of the extensive use of ecological hazardous non-polar solvents and costly techniques. Therefore serious efforts should be made to create alternate, eco-friendly, greener technology for the synthesis of nanoparticles.
Hence attempts of finding newer biological materials for the synthesis of silver nanoparticles and their effects to pathogenic microorganism as well as to mammalian cells has been made and presented.
9.2. Competent components of the thesis
The major focus of the work presented in this thesis is on the development of the greener and faster rout of biological synthesis of silver nanoparticles and their cytotoxicity measurements. The possible different biological ways to produce silver nanoparticles have been described in different chapters and summarized in this chapter.
For the first microorganism is used for the synthesis of silver nanoparticles. Rhodococcus NCIM 2891, an actinobacteria, has been demonstrated for the intra- and extracellular synthesis of silver nanoparticles. Initially by varying the pH, growth phase, temperature, precursor concentration, nitrate source, carbon source, it is predicted that for synthesis of nearly monodispersed synthesis of silver nanoparticles using Rhodococcus sp, 2mM AgNO3, Log phase culture of microorganism, slight alkaline pH sodium acetate as carbon source, and 30-35 οC temperature is...
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... leaf extract mediated silver nanoparticles are less cytotoxic than microbial one.
9.4. Future scope of the thesis
Different biological methods to synthesize AgNPs have described in this thesis. As-prepared AgNPs showed good antimicrobial activity against pathogenic microorganisms. Different silver salts other tan AgNO3 must be used to study the variations with respect to size and shapes. The polymer entrapped AgNPs can be further tested for the wound healing property in both ways in-vivo and in-vitro. Also showed that the concentration of AgNPs required to kill pathogenic microorganisms is far minimum than that required to be toxic to mammalian cells. But in depth study of the cytotoxicity is required to be done to use biological synthesized nanoparticles in medicine as nanomedicine. Antiviral studies of biological synthesized AgNPs must be studied extensively.
Antimicrobial encapsulated into polymeric nanoparticles is a suggested novel drug delivery system to treat CRS. Nanoparticles are categorized into nanospheres (matrix-like structure) and nanocapsules (vesicular systems). Nanospheres are a type of nanoparticles that allows drug encapsulation surrounded by a polymer matrix (Pinto Reis C. et al., 2006). Literature suggests Poly Lactic-co-Glycolic Acid (PLGA) is an attractive polymer to coat the nanospheres due to their biodegradable and biocompatible properties (Makadia HK. & Siegel SJ., 2011). The nanoprecipitation solvent-diffusion method was chosen for encapsulation of the poorly water-soluble drug MUP. Initially, an oil-in-water emulsion is formed. PLGA and MUP in a 1:1...
Native Silver, or more commonly know as just “silver,” is a mineral that is created from the element silver (also called Argentum; abbreviated on the periodic table as Ag). It is seldom found as a native element mineral. Instead, it has tendencies to mix together with other minerals such as quartz, gold, and copper.1 11 Silver is actually not really reactive. It is even considered one of the “noblest” of the transition metals, noblest meaning “least chemically reactive.”5 In fact, it is used in many dishes as a fancy garnish that is able (and sometimes meant) to be eaten. Native silver also has one of the highest conductivity rates, both electrical and thermal, of metals. Because of this property, it is used in many electronic circuits as a thin coating.5 Due to its shiny, lustrous quality, native silver is also used for jewelry, decorations, and ornaments.
They have a larger surface area in proportion to their volume. This enables them to interact with different types of biological systems and provides a wide variety of possibilities (Nuruzatulifah, Nizam, & Ain, 2015). The nanoparticles can be seen by transmission electron microscopy (TEM). When there is one nanoparticle, it is called a primary particle. When there is more than one, it is called a secondary particle. In order to measure these particles, they need to be suspended in a solution (Pruneanu, Coros & Pogacean, 2015). Dyed nanoparticles or internally fluorescent nanoparticles barely interact with cellular proteins which is what the study requires. They are also quite easy to manipulate. They can be easily internalized into cells and can be programmed to go to specific sites (Wolbeis,
[27] Jatariu A, Peptu C, Popa M, Indrei A. Micro− and nanoparticles−medical applications. Rev Med Chir Soc Med Nat Iasi. 2009; 113:1160−1169.
I have used the work that Jana et al. conducted regarding a batch process synthesis of silver nanowires as a basis for generation of our silver nanowires. I will use a solution based process that is cost effective, quick, and easy to control for the uniform synthesis of silver nanowires and other silver nanoparticles. Microreactor-assisted nanomaterial de...
Am. Chem. Soc. 2012, 134, 13212−13215). First, 20 mL nanopure water (18.2 MΩ) was boiled with a constant stirring in a 25 mL RB flask fitted with condenser. 778 µL of 3.8 mM H2PtCl4.6H2O (chloroplatinic acid) was added to the boiling water. After 1 minute, 244 µL of solution containing 38 mM trisodium citrate and 2.6 mM citric acid was injected at once into the solution. Without further waiting, 122 µL of 21 mM sodium borohydride solution was mixed into the boiling solution. Within 10-60 s colorless solution turned into blackish solution showing the evidence of formation of citrate capped ~4 nm size platinum seed particles. This method is a standard protocol to prepare seed platinum nanoparticles, therefore, these NPs were used without
Nanoparticles present a high surface area to volume ratio with decrease in the size of the particles. Specific surface area is relevant to catalytic activity and other related properties such as the antimicrobial activity (Bae et al., 2010). As the specific surface area of nanoparticles is increased, their biological effectiveness will also increase on the count of a rise in surface area (Mukunthan et al., 2011). Nanoparticles of noble metals, such as silver, gold and platinum are widely applied in products that directly come in contact with human body, such as shampoos, soaps, detergents, shoes, cosmetic products and toothpaste, besides medical and pharmaceutical applications (Mukunthan et al., 2011).
Gold NPs are one of the most popular NP that have been widely used in researches for their inertness, biocompatibility, easy synthesis in different sizes and shapes. Due to their small size, gold NPs are absorbed in blood circulation and they have good permeation in tumor tissue. This is called enhanced permeation and retention effect (EPR). Due to their unique optical properties and high z (z= 79), AuNPs are ideal for hyperthermia and radiation sensitization, respectively.
In case of nobel metal nanoparticles (NPs) tipped semiconductor quantum rods; Liang et al.1 represents a facile method for synthesis of Au-AgCdSe hybrid nanorods (NRs) through the deposition of silver (Ag) tips at the ends of Au NRs as a seed solution, followed by selenization of the silver (Ag) tips, and overgrowth of CdSe on these sites.1 This is method has been carried out by controlling the pH value.1 Das et al.2 demonstrate a method to fabricate Au decorated CdSe nanowires (NWs) based on the wet chemical method 3-5 to be employed as surface enhanced Raman spectroscopy (SERS) substrates.2 In this synthetic route, the Au NPs prefer to nucleate on lattice defects at the lateral facets of the CdSe NWs, which have a great effect to obtain a homogeneous distribution of Au NPs on the nanowire.2,5 Bala et al.6 demonstrated an effective procedure based on phase transfer between the aqueous and organic media in order to form Au tips on cadmium chalcogenide NPs and NRs. This phase transfer process can be achieved in presence of organic ligand which act as phase transfer and reducing agent for Au3+ ions.6 Salant et al.7 modified a hybrid metal-tipped semiconductor nanorods system known as nano-dumbbells, and used the gold tips as an anchor points for self-assembly using simple thiol molecules.7 I...
[7] Chen, Xiaobo and Samuel S. Mao. “Titanium Dioxide Nanomaterials: Synthesis, Properties, Modifications, and Applications." Chemical Reviews 107.7 (2007): 2891-959. ACS Publications. Web. 10 July 2010.
The main purpose of green nanotechnology has been to develop clean technologies that would minimize potential human and environmental health risk. Also, to encourage replacement of existing products with the clean technologies that is more environmentally friendly. There are many benefits of using green nanotechnologies as the new solution for energy in both their current availability and their current development. Over the new few decades, the highest growth opportunities will come from application of nanomaterials for making better use of existing resources. Nanotechnologies will help reduce weight of carbon emission in transportation utilizing nanocomposite materials that quickly diffuses across the automotive and aerospace industries. Applications of nanotechnologies will result in a global annual savings of 8000 tons of carbon dioxide, which will rise even further to over millions tons by 2020. But, let’s focus on the positive effects of Green Nanotechnology in Solar.
These also find its application in electroplating. Articles are electroplated with the complexes of gold and silver [Ag(CN)2]–and [Au(CN)2].
Nanoscience has developed a lot in modern technologies. A number of nano materials have been synthesized that are being used in different fields in different ways. In biological sciences product of nanobiotechnology has been used as:
Our body is in need for many nutrients in order to maintain a good health and a healthy immune system; some of these nutrients are introduced in food via nanotechnology. There are nano-sized capsules designed to carry omega-3 fatty acids, antioxidants, enzymes, and providing the solubility of some vitamins that are being used in food ...