Showing papers in "Nanotechnology, Science and Applications in 2008"

Applications of gold nanoparticles in cancer nanotechnology.

Abstract: It has been almost 4 decades since the “war on cancer” was declared. It is now generally believed that personalized medicine is the future for cancer patient management. Possessing unprecedented potential for early detection, accurate diagnosis, and personalized treatment of cancer, nanoparticles have been extensively studied over the last decade. In this review, we will summarize the current state-of-the-art of gold nanoparticles in biomedical applications targeting cancer. Gold nanospheres, nanorods, nanoshells, nanocages, and surface enhanced Raman scattering nanoparticles will be discussed in detail regarding their uses in in vitro assays, ex vivo and in vivo imaging, cancer therapy, and drug delivery. Multifunctionality is the key feature of nanoparticle-based agents. Targeting ligands, imaging labels, therapeutic drugs, and other functionalities can all be integrated to allow for targeted molecular imaging and molecular therapy of cancer. Big strides have been made and many proof-of-principle studies have been successfully performed. The future looks brighter than ever yet many hurdles remain to be conquered. A multifunctional platform based on gold nanoparticles, with multiple receptor targeting, multimodality imaging, and multiple therapeutic entities, holds the promise for a “magic gold bullet” against cancer.

Gold nanoparticles: From nanomedicine to nanosensing.

Abstract: Because of their photo-optical distinctiveness and biocompatibility, gold nanoparticles (AuNPs) have proven to be powerful tools in various nanomedicinal and nanomedical applications In this review article, we discuss recent advances in the application of AuNPs in diagnostic imaging, biosensing and binary cancer therapeutic techniques We also provide an eclectic collection of AuNPs delivery strategies, including assorted classes of delivery vehicles, which are showing great promise in specific targeting of AuNPs to diseased tissues However, successful clinical implementations of the promised applications of AuNPs are still hampered by many barriers In particular, more still needs to be done regarding our understanding of the pharmacokinetics and toxicological profiles of AuNPs and AuNPs-conjugates

Protein cages, rings and tubes: useful components of future nanodevices?

Abstract: There is a great deal of interest in the possibility that complex nanoscale devices can be designed and engineered. Such devices will lead to the development of new materials, electronics and smart drugs. Producing complex nanoscale devices, however will present many challenges and the components of such devices will require a number of special features. Devices will be engineered to incorporate desired functionalities but, because of the difficulties of controlling matter precisely at the nanoscale with current technology, the nanodevice components must self-assemble. In addition, nanocomponents that are to have wide applicability in various devices must have enough flexibility to integrate into a large number of potentially very different environments. These challenges are daunting and complex, and artificial nanodevices have not yet been constructed. However, the existence of nanomachines in nature in the form of proteins (eg, enzymes) suggests that they will be possible to produce. As the material from which nature’s nanomachines are made, proteins seem ideal to form the basis of engineered components of such nanodevices. Initially, engineering projects may focus on building blocks such as rings, cages and tubes, examples of which exist in nature and may act as a useful start point for modification and further development. This review focuses on the recent research and possible future development of such protein building blocks.

Distinct contributions of model MaSp1 and MaSp2 like peptides to the mechanical properties of synthetic major ampullate silk fibers as revealed in silico

Abstract: All characterized major ampullate silks from orb-web weaving spiders are composites of primarily two different proteins: MaSp1 and MaSp2. The conserved association of MaSp1 and MaSp2 in these spider species, the highly conserved amino acid motifs, and variable ratios of MaSp1 to MaSp2 demonstrate the importance of both MaSp1 and MaSp2 to the strength and elasticity of the fiber. Computer simulated mechanical tests predicted differing roles for MaSp1 and MaSp2 in the mechanical properties of the fibers. Recombinant MaSp1 and MaSp2 proteins were blended and spun into fibers mimicking the computer-simulated conditions. Mechanical testing verified the differing roles of MaSp1 and MaSp2.

Vibrio fischeri and Escherichia coli adhesion tendencies towards photolithographically modified nanosmooth poly (tert-butyl methacrylate) polymer surfaces.

Abstract: This study reports the adhesion behavior of two bacterial species, Vibrio fi scheri and Escherichia coli, to the photoresistant poly(tert-butyl methacrylate) (P(tBMA)) polymer surface. The data has demonstrated that ultraviolet irradiation of P(tBMA) was able to provide control over bacterial adhesion tendencies. Following photolithography, several of the surface characteristics of P(tBMA) were found to be altered. Atomic force microscopy analysis indi- cated that photolithographically modifi ed P(tBMA) (henceforth termed 'modifi ed polymer') appeared as a 'nanosmooth' surface with an average surface roughness of 1.6 nm. Although confocal laser scanning microscopy and scanning electron microscopy analysis clearly demon- strated that V. fi scheri and E. coli presented largely different patterns of attachment in order to adhere to the same surfaces, both species exhibited a greater adhesion propensity towards the 'nanosmooth' surface. The adhesion of both species to the modifi ed polymer surface appeared to be facilitated by an elevated production of extracellular polymeric substances when in contact with the substrate.

Self-assembled nanoscale architecture of TiO2 and application for dye-sensitized solar cells.

Abstract: A single-crystal-like titania nanowire network was successfully synthesized by a surfactant assisted "oriented attachment" mechanism. Highly crystallized titania nanorods have been synthesized by hydrothermal process using block-copolymer F127 with ethylenediamine. It was observed from high resolution TEM image that titanium atoms aligned perfectly in titania anatase structure with no defect. A high light-to-electricity conversion yield (9.3%) was attained by applying these titania nanoscale materials for making an electrode of dye-sensitized solar cells.