Substrate protein-coated

The presence of these spontaneously adsorbed (i.e. adsorbed during minimum exposure times), thin films on polymeric substrates such as polystyrene culture dishes and glass plates usually cannot be demonstrated by other spectroscopic methods. For example, the modified internal reflection spectroscopic technique, in which an auxiliary salt prism (usually the malleable salt KRS-5) is pressed against the demonstrably (by other techniques) protein-coated substrates, always fails this technique is not sensitive enough for the near monolayer ranges required for this demonstration. The required sensitivity is achieved only when adsorption occurs directly on the face of a clean, or thin film-coated, internal reflection element. 

All of the DCDR spectra shown in this work were acquired with a home-built confocal Raman system equipped with a 632.8 nm, 45 mW, HeNe excitation laser [5]. A lOOx objective (NA 0.95, Olympus) was used to both focus the laser to a spot size of approximately 1 pm at the protein-coated substrate surface (with about 10 mW of laser power at the sample) and to collect the back-scattered Raman light. 

FIG. 23 Schematic drawing of using microcontact printing for obtaining hydrophobic areas on a gold-coated substrate. After pattern transfer (a and b), incubation with an S-layer protein solution (c) leads to the formation of a protein monolayer on the hydrophobic areas only. 

While the composition and sequence of the amino acids have been known since 1983 (2,3), methods for increased-scale extraction were not developed until 1985. This scaled production has allowed for the development of single-part adhesive systems (Cell-Tak adhesive) for the immobilization of biologically active moieties to inert substrates. It has also permitted research on two-part adhesive formulations for the bonding of tissues. This paper specifically addresses the biocompatibility issue with descriptions of the immobilization of cells to Cell-Tak protein-coated plasticware, methods for wound closure, and preliminary toxicology data. 

In order to functionalize the metal-coated substrates with MPA, they were immersed in an ethanolic solution of 0.02 M MPA. The MPA layer was activated using a solution of 0.002 M ethyl dimethylaminopropyl carbodiimide (EDC) and 0.005 M n-hydroxy succinimide (NHS) in 2-(Ai-morpholino) ethanesulfonic acid (MES) buffer solution (20 mM MBS, 0.1 M NaCl, pH5). The carboxylate groups of the MPA react with NHS in the presence of EDC to form NHS-esters which can then react with amine groups of proteins. After 15 min of activation, the metalized... 

The highly complex and variable composition of natural cell membranes makes them a difficult subject for experimental studies. Artificial lipid membranes have consequently been prepared and studied for many years as models of cell membranes [1,3-7], A diverse array of geometries has been developed, including small and large unilamellar vesicles, giant lipid vesicles, lipid membranes supported on solid and polymer-coated substrates, and BLMs. These have been used to study the physical and chemical properties of lipids and lipid mixtures as well as membrane-associated proteins, including reconstituted transmembrane receptors. 

The work to be discussed here deals with platelet adhesion to protein coated surfaces. The protein coating, the cells on the surface and the moving fluid adjacent to the surface may be viewed as a system of interacting components. Flow is an important feature of this system since it brings new protein and cells to the system, augments the transport of cells to the surface and can cause the detachment of adherent cells. Each component of the system may influence the conditions of the other components. The variation of the surface concentrations of proteins on a solid substrate continues to be studied and remains a key area of interest. However, the action of immobilized cells on the substrate needs to be examined more carefully as well as their contribution of secreted substances to the fluid phase adjacent to the substrate and to the substrate protein itself Red cells, platelets and white cells may also adhere and detach from the substrate changing its make-up by yet another mechanism. 

Bionanotechnology can also be used to form semiconductor circuits that assemble themselves (Fairley, 2003). One means to do this is to use a virus as a carrier of spedflc materials. The virus must first be able to stick to a substrate (for example, zinc sulfide). Various proteins on the surfaces of viruses have a range of affinities for the substrate material. A selection process is used whereby viruses are exposed to the substrate material and then washed with a dilute acid. Those viruses whose protein coats have a natural affinity for the substrate remain and the others are gone. The viruses that remain are isolated and allowed to multiply by infecting bacteria. The process is repeated however, a stronger acid solution is used for each cycle. In this way, only the viruses that stick most strongly to the substrate remain after several cycles. 

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