Showing papers on "Nanobiotechnology published in 2005"

Peptide-Based Nanotubes and Their Applications in Bionanotechnology.

Abstract: In nature, biological nanomaterials are synthesized under ambient conditions in a natural microscopic-sized laboratory, such as a cell. Biological molecules, such as peptides and proteins, undergo self-assembly processes in vivo and in vitro, and these monomers are assembled into various nanometer-scale structures at room temperature and atmospheric pressure. The self-assembled peptide nanostructures can be further organized to form nanowires, nanotubes, and nanoparticles via their molecular-recognition functions. The application of molecular self-assemblies of synthetic peptides as nanometer-scale building blocks in devices is robust, practical, and affordable due to their advantages of reproducibility, large-scale production ability, monodispersity, and simpler experimental methods. It is also beneficial that smart functionalities can be added at desired positions in peptide nanotubes through well-established chemical and peptide syntheses. These features of peptide-based nanotubes are the driving force for investigating and developing peptide nanotube assemblies for biological and non-biological applications.

Nanobiotechnology :concepts, applications and perspectives

Abstract: Nanobiotechnology :concepts, applications and perspectives , Nanobiotechnology :concepts, applications and perspectives , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

The Impact of Nanobiotechnology on the Development of New Drug Delivery Systems

Abstract: Nanotechnology, or systems/devices manufactured at the molecular level, is a multidisciplinary scientific field undergoing explosive development. A part of this field is the development of nanoscaled drug delivery devices. Nanoparticles have been developed as an important strategy to deliver conventional drugs, recombinant proteins, vaccines and more recently nucleotides. Nanoparticles and other colloidal drug delivery systems modify the kinetics, body distribution and drug release of an associated drug. Other effects are tissue or cell specific targeting of drugs and the reduction of unwanted side effects by a controlled release. Therefore nanoparticles in the pharmaceutical biotechnology sector improve the therapeutic index and provide solutions for future delivery problems for new classes of so called biotech drugs including recombinant proteins and oligonucleotides. This review discusses nanoparticular drug carrier systems with the exception of liposomes used today, and what the potential and limitations of nanoparticles in the field of pharmaceutical biotechnology are.

Nanomedicine : nanotechnology, biology and medicine.

Abstract: ING AND INDEXING

Functionalized Gold Nanoparticles for Applications in Bionanotechnology

Abstract: Gold nanoparticles have unique optical and chemical properties that make them ideally suited for a number of applications in bionanotechnology, including optical probes, targeted drug delivery, and programmed materials synthesis. The recurring theme is the versatility of gold nanoparticles and how this versatility can be exploited to adapt gold nanoparticles to fit into different chemical environments—from aqueous suspensions to the hostile conditions of a cell culture or the human bloodstream. Herein, the optical and chemical properties of gold nanoparticles are described, and a number of specific applications within bionanotechnology are reviewed.

S-layers as patterning elements for application in nanobiotechnology.

Abstract: Two-dimensional bacterial cell surface layer protein crystals (S-layers) are the most commonly observed cell surface structure in bacteria and archaea. Isolated S-layer proteins have the intrinsic tendency to self-assemble into crystalline arrays in suspension and on various interfaces. Basic research on the structure, genetics, chemistry, morphogenesis and function of S-layers has led to a broad spectrum of applications in nanotechnology and biomimetics. The possibility to change the properties of S-layer proteins by genetic engineering opens new ways for tuning their functional and structural features. Functionalized S-layer proteins that maintain their ability to self-assemble have led to new affinity matrices, diagnostic tools, vaccines or biocompatible surfaces, as well as to biological templating or specific biomineralisation strategies at surfaces.

Functional Hydrogel Surfaces: Binding Kinesin-Based Molecular Motor Proteins to Selected Patterned Sites†

Abstract: Hydrogel microstructures with micrometer-scale topography and controllable functionality have great potential for numerous nanobiotechnology applications including, for example, three-dimensional structures that exhibit controlled interactions with proteins and cells Taking advantage of the strong affinity of histidine (His) residues for metal-ion-nitrilotriacetic acid (NTA) complexes, we have chemically modified hydrogels to enable protein immobilization with retention of activity by incorporating 2-methacrylamidobutyl nitrilotriacetic acid, an NTA-containing monomer that can be copolymerized with a series of monomers to form NTA-containing hydrogels By varying the NTA-monomer composition in the hydrogels, it is possible to control the amount of protein bound to the hydrogel surface The retention of biological activity was demonstrated by microtubule gliding assays Normally, hydrogels are resistant to protein binding, but we have selected these materials because of their porous nature Bringing together hydrogel functionalization and soft-lithography patterning techniques, it was possible to create a hybrid hydrogel superstructure that possesses binding specificity to His-tagged protein in selected sites This type of surface and microstructure is not only advantageous for motor protein integration, but it can also be generally applied to the formation of His-tagged molecules for sensors and biochip applications

Self-assembly of functionalized spherical nanoparticles on chemically patterned microstructures

Abstract: The production of hierarchical nanopatterns (using a top-down microfabrication approach combined with a subsequent bottom-up self-assembly process) will be an important tool in many research areas. We report the fabrication of silica nanoparticle arrays on lithographically pre-patterned substrates suitable for applications in the field of nanobiotechnology. Two different approaches to reach this goal are presented and discussed: in the first approach, we use capillary forces to self-assemble silica nanoparticles on a wettability contrast pattern by controlled drying and evaporation. This allows the efficient patterning of a variety of nanoparticle systems and—under certain conditions—leads to the formation of novel branched structures of colloidal lines, that might help to elucidate the formation process of these nanoparticle arrays. The second approach uses a recently developed chemical patterning method that allows for the selective immobilization of functionalized sub-100 nm particles at distinct locations on the surface. In addition, it is shown how these nanocolloidal micro-arrays offer the potential to increase the sensitivity of existing biosensing devices. The well-defined surface chemistry (of particle and substrate) and the increased surface area at the microspots, where the nanoparticles self-assemble, make this patterning method an interesting candidate for micro-array biosensing.

Sensing DNA - DNA as nanosensor: a perspective towards nanobiotechnology

Abstract: (Dated: 2nd February 2008)Based on modern single molecule techniques, we devise a number of possible experimental setupsto probe local properties of DNA such as the presence of DNA-knots, loops or folds, or to obtaininformation on the DNA-sequence. Similarly, DNA may be used as a local sensor. Employingsingle molecule fluorescence methods, we propose to make use of the physics of DNA denaturationnanoregions to find out about the solvent conditions such as ionic strength, presence of bindingproteins, etc. By measuring dynamical quantities in particular, rather sensitive nanoprobes may beconstructed with contemporary instruments.Key words: DNA, DNA breathing, single molecule spectroscopy, nanosensors, fluorescence correla-tion spectroscopy, fluorescent resonance energy transfer

Sensing DNA - DNA as nanosensor: a perspective towards nanobiotechnology

Abstract: Based on modern single molecule techniques, we devise a number of possible experimental setups to probe local properties of DNA such as the presence of DNA-knots, loops or folds, or to obtain information on the DNA-sequence. Similarly, DNA may be used as a local sensor. Employing single molecule fluorescence methods, we propose to make use of the physics of DNA denaturation nanoregions to find out about the solvent conditions such as ionic strength, presence of binding proteins, etc. By measuring dynamical quantities in particular, rather sensitive nanoprobes may be constructed with contemporary instruments.

Nanopatterned structures for biomolecular analysis toward genomic and proteomic applications

Abstract: We report our fabrication of nanoscale devices using electron beam and nanoimprint lithography (NIL). We focus our study in the emerging fields of NIL, nanophotonics and nanobiotechnology and give a few examples as to how these nanodevices may be applied toward genomic and proteomic applications for molecular analysis. The examples include reverse NIL-fabricated nanofluidic channels for DNA stretching, nanoscale molecular traps constructed from dielectric constrictions for DNA or protein focusing by dielectrophoresis, multi-layer nanoburger and nanoburger multiplets for optimized surface-plasma enhanced Raman scattering for protein detection, and biomolecular motor-based nanosystems. The development of advanced nanopatterning techniques promises reliable and high-throughput manufacturing of nanodevices which could impact significantly on the areas of genomics, proteomics, drug discovery and molecular clinical diagnostics.

The synthesis of nanoparticles and nanowires by bio-template platform, cage-shaped protein supramolecules

Abstract: The nanotechnology is one of the hottest research areas and nano particle (NP) and nanowire (NW) are the fundamental components. We synthesize the nano-particles by the protein cage, apoferritin and Listeria ferritin. Bio-template methods for synthesis of nano-particles and nano-wire are most popular in bionanotechnology field. We can synthesize metal oxide nano-particles (Co, Ni, Cr nano-particles) and semiconductor nano-particles (CdSe, ZnSe) by using apoferritin with 7 nm diameter inner cavity. The synthesized nano-particles have the high quality and low dispersion. We will apply the synthesized nanoparticles to the nanoelectronics devices, for example, a floating gate memory. There are a lot of kinds protein cages to use as bio-template in nature world. Many researchers have been searched new bio-templates which has inner cavity and the special character. They also have been synthesized nano-particles in the many bio-template and studied the mechanism of the biomineralization. We would like to review the recent works relating the synthesis of NPs and NWs by supramoleculer protein cages and we also describe recent our work about the synthesis of nano-particles by bio-template. We will focus on the fusion of biotechnology and nano-technology in this manuscript.

Quantum dots in nanobiotechnology

Abstract: Research on semiconductor nanocristals (also known as quantum dots of QD) in the field of nanobiotechnology is rapidly evolving thanks to progresses in their synthesis and their surface chemistry. Two types of materials, water soluble and biocompatible single QD and beads containing QDs, are becoming available and exciting applications based on these new materials are developed. We will present the recent progress in the synthesis of these materials and their applications. We will discuss the problems that remain to be solved and the perspectives.

Afm: a powerful tool for nanobiotechnology

Abstract: In the past 15 years, atomic force microscopy (AFM) has emerged as a powerful tool for exploring biological systems at the nanoscale and has opened exciting perspectives in biomedicine and nanobiotechnology. While AFM imaging makes it possible to visualize surface structure under physiological conditions and at high resolution, force spectroscopy provides information on biomolecular interactions and physical properties [1,2]. In this contribution, I will discuss some of these capabilities using recent examples from my group, going from single biomolecules to lipid membranes and living cells.

BioMEMS and bionanotechnology and applications to biological sensing

Abstract: Biomedical or Biological Micro-Electro-Mechanical-Systems (BioMEMS) and Bionanotechnology has found widespread use in a wide variety of applications in diagnostics, sensing, and characterization of biological entities. This paper reviews some of the interdisciplinary work performed in our group in the recent years to develop micro-integrated devices to characterize biological entities. We have used electrical based phenomena to perform characterization and various functions needed for integrated biochips. One sub-system takes advantage of the dielectrophoretic effect to sort and concentrate bacterial cells and viruses within a micro-fluidic biochip. Another sub-system measures impedance changes produced by the metabolic activity of bacterial cells to determine their viability. The last sub-system described has been used to detect the charge on DNA molecules as it translocates through nanopore channels. These devices with an electronic or mechanical signal output can be very useful in producing practical systems for rapid detection and characterization of cells for a wide variety of applications in the food safety and health diagnostics industries. INTRODUCTION BioMEMS and microfluidics are at present a heavily researched area with a wide variety of important biomedical applications. The ability to fabricate micro and nano-structures with scales and dimensions similar to biological entities has paved the way to new concepts and systems for a variety of cellular, diagnostic and therapeutic applications, such as intelligent biochips and biosensors. In recent years, we have devoted our efforts to develop bioMEMs devices and demonstrate their applications in sorting and concentrating bacterial cells using dielectrophoresis technique, measuring the metabolic activity of bacterial cells using impedance measurement, and detecting DNA molecules in nanopore channels by electrical signal. DIELECTROPHORESIS AND ANTIBODY MEDIATED SELECTIVE CAPTURE OF LISTERIA CELLS ON A MICRO-FLUIDIC CHIP The technique of dielectrophoresis (DEP) and manipulation of biological particles by electrical forces provide unique means to control the separation dynamics of biological agents as most biological cells or bacteria behave as dielectric particles in external electric field. We have demonstrated that dielectrophoresis is capable of separating live and heat-killed Listeria bacteria on microfabricated interdigitated electrodes in a static solution, as well as different biological particles in a micro-fluidic device in the dynamic flow by considering the differences in their sizes and dielectric properties. However, in many cases, the dielectric properties and the sizes of the different particle types are not significantly different, as a result, the differential driving force acting to the particles will not be sufficient to separate different types of particle. The challenge therefore exists to develop micro-systems which are capable of separating biological cells with similar size and dielectric properties. We proposed to combine the advantages of DEP concentration and antibody selective capture, which demonstrated selective capture of target cells from a mixture of cells with similar dielectric properties in a microfluidic biochip. The micro-fluidic biochip used in the DEP mediated selective capture was fabricated as our previous report. Monoclonal anti-Listeria antibody C11E9 was immobilized onto the surface of DEP chamber through biotin-streptavidin chemistry. Listeria monocytogenes V7 cells and Escherichia coli K12 cells were used to demonstrate the function of the biochip. Fig. 1 shows the images of L. E. coli K12 E. coli K12 L. monocytogenes L. monocytogenes 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

Multivalent Circular Aptamers: Versatile Nanostructures for Biomedical Applications

Abstract: Nucleic acid aptamers are moving towards genuine competitiveness in therapeutic, diagnostic and biomaterials applications. We have introduced a major new aptamer class multivalent circular aptamers or ‘captamers’ that combines aptameric recognition with multitasking nucleic acid functions through the use of modular engineering principles derived from DNA nanotechnology. DNA captamers have been demonstrated in 2-, 3and 4-headed versions, focussing upon the pleiotropic activity that can be obtained by combining different functions together. Several multitasking applications are described here. Development of captamer therapeutic candidates is moving towards a practical implementation of autonomous biomolecular computing that offers the potential to create a powerful class of smart nucleic acid drugs.