O Q E Limpoma Supermolecular

Research in supramolecular engineering of functional biomaterials had sprouted from the need in (a) medicine for replacement materials and prosthetic devices with mechanical properties of soft and hard tissues such as skin, tendons, and bone, (b) agriculture and forestry for better crops and wood production, (c) food industries for improving production, quality, texture, processing, and manufacturing 1 , and (d) the biomedical and human health area where there is an...

Info

Source Adapted from Anderson, J.M., Gristina, A.G., Hanson, S.R., Harker, L.A., Johnson, R.J., Merritt, K., Naylor, P.T., and Schoen, F.J. in Biomaterials Science An Introduction to Materials in Medicine, B.D. Ratner, A.S. Hoffman, F.J. Schoen, and J.E. Lemons, Eds., Academic Press, New York, 1996, 165-214. Note In considering biomaterial-tissue interactions, it is important to know both the effect of the implant on the host and the effect of the host on the implant. The former can have local...

Introduction and Background

The current intense interest in the use of semiconductor nanocrystals or quantum dots as fluorophores in biological imaging and related applications can be traced to the 1998 publications by Bruchez et al. 1 and Chan and Nie 2 that demonstrated the possibility of using water-dispersible semiconductor nanoparticles as fluorescent probes in bioimaging. The advantages of such quantum dots over conventional organic fluorophores include high brightness, stability against photobleaching, narrow and...

References

Miller. 1965. Cation permeability of phospholipid model membranes Effect of narcotics. Nature 208 1295-1297. 2. Israelachvili, J.N. 1992. Intermolecular and surface forces With applications to colloidal and biological systems, 2nd ed. New York Academic Press. 3. Gelbart, W.M., and B.A. 1996. The new science of complex fluids. J Phys Chem 100 13169-13189. 4. Matsen, M.W., and F.S. Bates. 1996. Origins of complex self-assembly in block copolymers....

R857n34n36 2006

Visit the Taylor & Francis Web site at http www.taylorandfrancis.com and the CRC Press Web site at http www.crcpress.com Pioneers whose visions have Sailed to the outer edges of the universe, Pierced into the inner world of the atom, and Unlocked the mysteries of the human cell Nanotechnology in Biology and Medicine is intended to serve as an authoritative reference for a wide audience involved in research, teaching, learning, and practice of nanotechnology in life sciences. Nanotechnology,...

Template Synthesis

I Setup for applying a I transmembrane potential FIGURE 9.5 Illustration of a U-tube cell used for preparing and measuring the properties of nanotube membranes. Template synthesis is a powerful and elegant method capable of producing nanometer scale materials in a controlled fashion. Template synthesis involves the use of a template, or master, with nanometer scale features. Membranes, such as those described in the experimental section, have been our templates of choice because they are...

Structurally Inspired Biomaterial Virosomes

FIGURE 3.1 Structurally inspired biomaterials. Liposomes, virosomes, and polymersomes are examples of simple cell mimics without internal contents. They have been used for vaccines and targeted drug delivery systems. Peptide nucleic acids mimic both proteins and DNA, and peptoids are mimics of proteins. FIGURE 3.2 Functionally inspired biomaterials. Mussels and barnacles secrete proteinaceous bioglues for holdfasts on both organic and inorganic surfaces in aqueous environments....

Cellular and Intracellular Localization of MDR Proteins

Understanding the effect and localization of the MDR proteins would facilitate a more targeted strategy for chemotherapeutic agents or drugs that was developed for clinical application. The MDR activity has been thought to be mediated at the plasma membrane by several proteins. However, studies have shown that the intracellular localization of these proteins may also play a major role in the MDR activity. Therefore, for our localization studies, drug-sensitive CHO cells and drug-resistant...

Applications in Biology and Medicine 1051 Cellular Imaging and Tracking

The use of QDs for sensitive and multicolor cellular imaging has seen major recent advances, due to significant improvements in QD synthesis, surface chemistry, and conjugation. Wu et al. linked polymer-protected QDs to streptavidin and showed detailed cell skeleton structures using confocal microscopy 48 . The improved photostability of QDs allowed acquisition of many consecutive focal-plane images and their reconstruction into a high-resolution three dimensional projection. The high electron...

Nanowires as Electrochemical DNA Sensors

The construction of gold nanowires using templated metal deposition 23 (Figure 6.2) provides an easy route to a nanostructured material without the need for expensive or difficult nanofabrication. Both track-etched polycarbonate 23,24 and alumina membranes 24 can be used in conjunction with electroless or electrodeposition of gold and other metals, but most electrochemical studies have focused on the polycarbonate membranes with chemically plated gold, given that there are commercial sources...

Solution Phase Methods

Preparation of silicon nanoparticles by liquid-phase solution synthesis was first reported by Heath 37 , who reduced a mixture of chlorosilanes with sodium metal in organic solvents at high temperature ( 385 C) and pressure (> 100 bar). When a mixture of SiHCl3 and SiCl4 was reduced, the particle sizes ranged from 5 nm to 3 mm, but when octyltrichlorosilane was used instead of trichlorosilane, the particle size range was 2 to 9 nm. No PL was reported for these particles. Some of the particles...

Preparation of Bimetallic Nanoparticles

Metallic nanoparticles of definite size are easily synthesized via a bottom-up approach and can be surface modified with special functional groups. Nanocomposites, i.e., alloy and core-shell particles are an attractive subject mainly because of their composition-dependent optical, magnetic, and catalytic properties. In general, bimetallic nanoparticles can be prepared by simultaneous reduction or by successive reduction of two metal ions through a suitable stabilization strategy (capping or...

Hemolysin Structure and Biology

A-Hemolysin is a 33.2 kDa protein toxin secreted by Staphylococcus aureus. It forms a multisubunit ring (four to eight identical subunits) on the surface of a cell or artificial bilayer and then inserts a beta-barrel channel across the target membrane.45,46 The x-ray crystal structure of the pore-forming heptamer was described in 1996 by Song and colleagues47 (Figure 11.3). The heptamer is about 10 nm long, and FIGURE 11.1 Schematic of nucleic acid detection using a nanoscale pore. One end of a...

Application of Bimetallics

The alteration in collective electronic, optical, and magnetic properties of organized nanoensembles for bimetallics over their monometallic counterpart is increasingly the subject of investigation 98 leaving catalytic applications aside 3,98-100 . It has the potential to be used as a nonlinear optical material. Possible future applications include the areas of ultrafast data communication and optical data storage 3-4,101 . Such materials would be useful in developing nanodevices (e.g.,...

Fabrication Methods and Nanopore Structures

Materials used in fabrication methods to produce single solid-state nanoscale pores include silicon nitride,24,26 silicon oxide,29 and polyethylene terephthalate (PET).30 Variations in structure include material thickness and shape of opening. The ability of a synthetic nanopore to conduct ionic current has been used as a measure of robustness. The Harvard Nanopore Laboratory has applied an ion beam-etching method to sculpt a nanoscale pore in silicon nitride.24,25 By manipulating the sample...

Vapor Phase Methods

Silicon nanoparticles can be prepared in the vapor phase by decomposition of silicon-containing gases or vapors such as silane, disilane, and chlorosilanes, or by thermal, plasma, or laser-driven vaporization (evaporation) of solid silicon followed by nucleation of silicon particles and rapid quenching to prevent their growth and agglomeration. Unwanted silicon particle formation is a common by-product of silicon film deposition by thermal or plasma chemical vapor deposition in the...

Nanostructured Titanium Implants In Parkridge Illinois Dentist

FIGURE 2.8 Time course of osteoblast (OB) differentiation and synthesis of extracellular matrix (ECM) proteins on newly implanted biomaterials. Three distinct stages are observed (a) cell proliferation and ECM synthesis, (b) ECM development and maturation, and (c) ECM mineralization. The proteins synthesized at each stage are shown in the respective columns. (Adapted from Webster, T.J. in Advances in Chemical Engineering. Nanostructured Materials, J.Y. Ying, Ed., Academic Press, San Diego,...

Double Effective Medium Model for the Optical Properties

Various groups have tried, with mixed success, to explain the optical properties of thin films formed from organically cross-linked gold nanoparticles (mainly for LBL films).20,28 The optical properties of the films can be described with a two-step EMA.33,39 Two steps are needed because three phases are present in the film the gold particles, the molecules, and voids, and because of the way they are distributed. The presence of the voids could be vaguely seen in previous SEM, scanning tunneling...

Ab Initio and Semiempirical Quantum Chemistry

In order to eliminate any fundamental dependence on the assumed potential model, one must resort to the more complicated and time-consuming methods of quantum chemistry. Whereas clearly these techniques in theory provide the correct treatment of molecular and atomic systems, incomplete basis sets and limitations due to electron correlation or exchange for the methods capable of treating reasonably sized molecules can present considerable complications. In the present case, we are primarily...

Structure of PPVBased Systems

Based on molecular mechanics energy minimization in a vacuum, a single MEH-PPV or CN-PPV molecule containing tetrahedral defects has a lower total potential energy when folded into cofacial-stacked chain segments see Figure 14.5 than in an extended chain configuration on the order of tens of kcal mol determined from the MM3 model for the all trans-anti-configuration. For MEH-PPV, an all trans-syn-configuration lies at 3 kcal mol higher in potential energy than the anti'-configuration due to...

Hydrosilylation Reactions

Mechanism Hydrosilylation Surface

Hydrosilylation reactions are probably the best-developed solution-phase method for attaching organic molecules to silicon. In this reaction, a silicon-hydrogen bond on a silicon surface reacts with a double or triple bond in an alkene or alkyne to form a direct silicon-carbon bond. Hydrosilylation reactions for attachment of alkenes to a silicon surface was first demonstrated by Linford and coworkers 87,88 . Analogous reactions involving organosilanes in solution are well known. The first...

Effect of MDR Expression on Drug Accumulation

Overexpression of MDR proteins is associated with the decreased intracellular accumulation and increased efflux of various chemotherapeutic drugs. Consequently, it is necessary for researchers to study and understand how the activity and distribution of the MDR proteins affects the accumulation and localization of therapeutic drugs. In our study, confocal microscopy and NSOM were used to monitor the effect of MDR protein, Pgp on the intracellular accumulation of MDR substrates, and...

Mussel Adhesive Proteins

The harsh living conditions of the seashore, the impact of strong waves, and the buoyant force of water turn out to be selective forces in evolution. Only organisms that developed strategies for holding tightly to surfaces survived. The science of the mussel's strong adhesion was the subject of famous work done by Brown in 1952 90 , and later, Waite and Tanzer made a major breakthrough 91 . In their study, they found that MAPs in threads and plaques have extensive amount of posttranslationally...