Phytochemical Mediated Synthesis of Goldnanoparticles …
This review is concerned with the synthesis of metallic nanoparticles using plant extracts
Plant-mediated synthesis of silver and gold nanoparticles …
Some well-known examples of microbial systems synthesizing inorganic materials include magnetotactic bacteria for magnetite nanoparticles (, ), S-layer bacteria for gypsum and calcium carbonate layers () and silver mine- inhabiting Pseudomonas sp. that reduces silver ions to form silver nanoparticles (). Nanocrystals of gold, silver and their alloys have been synthesized within the cells of lactic acid bacteria (). Fungus and actinomycete species were reported to synthesize silver or gold nanoparticles of different shapes and sizes (, ), but use of green plants for similar nanoparticle biosynthesis methodologies is an exciting possibility that is largely unexplored.
Biosafety is the primary concern in clinical translation of nanomedicine. As an intrinsic ingredient of human blood without immunogenicity and encouraged by its successful clinical application in Abraxane, albumin has been regarded as a promising material to produce nanoparticles for bioimaging and drug delivery. The strategies for synthesizing albumin-based nanoparticles could be generally categorized into five classes: template, nanocarrier, scaffold, stabilizer and albumin-polymer conjugate. This review introduces approaches utilizing albumin in the preparation of nanoparticles and thereby provides scientists with knowledge of goal-driven design on albumin-based nanomedicine.
Synthesis of plant-mediated gold nanoparticles and catalytic …
Highly monodisperse sodium citrate-coated spherical silver nanoparticles (Ag NPs) with controlled sizes ranging from 10 to 200 nm have been synthesized by following a kinetically controlled seeded-growth approach via the reduction of silver nitrate by the combination of two chemical reducing agents: sodium citrate and tannic acid. The use of traces of tannic acid is fundamental in the synthesis of silver seeds, with an unprecedented (nanometric resolution) narrow size distribution that becomes even narrower, by size focusing, during the growth process. The homogeneous growth of Ag seeds is kinetically controlled by adjusting reaction parameters: concentrations of reducing agents, temperature, silver precursor to seed ratio, and pH. This method produces long-term stable aqueous colloidal dispersions of Ag NPs with narrow size distributions, relatively high concentrations (up to 6 × 1012 NPs/mL), and, more important, readily accessible surfaces. This was proved by studying the catalytic properties of as-synthesized Ag NPs using the reduction of Rhodamine B (RhB) by sodium borohydride as a model reaction system. As a result, we show the ability of citrate-stabilized Ag NPs to act as very efficient catalysts for the degradation of RhB while the coating with a polyvinylpyrrolidone (PVP) layer dramatically decreased the reaction rate.
On the basis of the high biocompatibility and long blood circulation half-life of albumin, many studies have been devoted to the development of albumin-stabilized nanoparticles for biomedical applications [-]. Albumin could be introduced during nanoparticle synthesis or stabilizer replacement [-].
Plant Mediated Green Synthesis of Silver Nanoparticles …
Gold nanorods of controllable aspect ratio were synthesized by a seed-mediated, surfactant-assisted, three-step protocol, in which the size and nature of the seeds were varied.
In conclusion, this study demonstrates an interesting case of plant-mediated gold nanoparticle synthesis, and in situ catalytic functions of the nanoparticle-rich biomatrix. The reduction of metal ions occurs in the root cells resulting in the formation of nanoparticles that are transported symplastically to the aerial parts or shoots. The biomatrix nanomaterial exhibited fairly well-defined dimensions and monodispersity. This is a novel introduction of a cell-immobilized stable catalyst which may find applications in future.
agents for the synthesis of silver nanoparticles ..
Methanobactin-Mediated One-Step Synthesis of Gold Nanoparticles
Synthesis of plant-mediated gold nanoparticles and catalytic role of biomatrix-embedded nanomaterials.
Seed-Mediated Synthesis of Gold Nanorods: Role of …
Plant Mediated Green Synthesis of Silver Nanoparticles Using Tecomella undulata Leaf Extract and Their Characterization
Strategies for Preparing Albumin-based Nanoparticles …
The current approach suggested that rapid synthesis of gold nanoparticles would be ..
Surface modification, functionalization and …
It is important to understand the biosynthetic pathway involved in the fabrication of metal nanomaterial mediated by a biological system to gain a better control on the process and products. Little is known so far about the interaction of biomolecules and gold nanoparticles. Shankar et al. () believed that the reduction of tetrachloroaurate ions was caused by the reducing sugar present in the lemongrass extract, while the growth of gold nanotriangle crystal was the result of an interaction between de novo gold nanoparticles and aldehydes/ketones present in the extract. The reduction of the metal ions and stabilization of the gold/silver nanoparticles was believed to occur by the various terpenoids or alkaloids present in the geranium extract (). Similarly, S. drummondii, used in this study, has been reported for its contents of alkaloids or other secondary metabolites () that might function as a reducing agent for the reduction of gold ions and stabilization of nanoparticles in cells. Identification and isolation of the biomolecules responsible for the fabrication of observed monodisperse nanoparticles is currently in progress.
Journal of Nanoscience and Nanotechnology
The active uptake of heavy metals has been reported in few wild plants (). In Sesbania drummondii, it has been earlier reported that this plant accumulates lead (Pb) by symplastic mode of transport (, ). The occurrence of gold nanoparticle, arranged in a definite order, exclusively in the cytoplasm under TEM examination of several root cells () is indicative of the symplastic transport of gold in this study. We hypothesize that the roots of this plant traps gold from solution as a result of the affinity between carboxylic acid moieties present in the cell wall and Au(III) as reported in other living systems (). Once gold enters root cells, it is transported symplastically to the conducting tissues and aerial parts of the plants in the manner similar to Pb. With regard to the precise location where synthesis of nanoparticles could occur, the cell wall (external boundary) or cytoplasmic membrane (inner boundary) was demonstrated as the possible site in Verticillium sp. (), whereas periplasmic space was the site for silver nanoparticles assembly in silver-resistant bacteria (). Sesbania thus presents a unique feature of intracellular formation of nanomaterials. The cellular microenvironment is characteristic of a living organism and may impose conditions suitable for uncommon functions such as accumulation and biotransformation of unique elements. The monodispersity, size distribution or the uniformly spherical shape of gold nanoparticles formed inside Sesbania cells may be one of such functions.
Journal of Biomedical Nanotechnology
122. Zhou HF, Yu WT, Guo X, Liu XD, Li N, Zhang Y, Ma XJ. Synthesis and characterization of amphiphilic glycidol-chitosan-deoxycholic acid nanoparticles as a drug carrier for doxorubicin. 2010;12(11):3480-3486
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