News Column

Patent Application Titled "Analytical Aids with Hydrophilic Coating Containing Nanoparticles with Silica Structure and Methods of Producing and Using...

February 6, 2014



Patent Application Titled "Analytical Aids with Hydrophilic Coating Containing Nanoparticles with Silica Structure and Methods of Producing and Using the Same" Published Online

By a News Reporter-Staff News Editor at Politics & Government Week -- According to news reporting originating from Washington, D.C., by VerticalNews journalists, a patent application by the inventors Babic, Branislav (Mannheim, DE); Greiwe, Peter (Heidelberg, DE), filed on September 16, 2013, was made available online on January 23, 2014.

The assignee for this patent application is Roche Diagnostics Operations, Inc.

Reporters obtained the following quote from the background information supplied by the inventors: "A great many analytical aids are known for rapid and quantitative analytical determination of constituents of liquid samples. The analytical aids can be in the form of individual test elements such as test strips or strip-shaped test materials, as well as in integrated systems in which the testing element is a part of a sampling device. For reasons of simplified and more economical production and component stability, such analytical aids typically are made of plastic or metal and generally have a comparatively hydrophobic surface, which is a disadvantage for rapid and uniform wetting of the analytical aid with liquid samples.

"Intl Patent Application Publication No. WO 2007/045412 describes sampling devices for collecting body fluids that have a needle element and that are equipped with a testing element, with which at least one analyte in the body fluid can be detected qualitatively or quantitatively. In this case, the body fluid sample is transported along the needle element to the testing element. Because the site of insertion of the needle element into the skin is disposed at some distance from the testing element, the body fluid sample must travel a few millimeters (mm) along the capillary to reach the testing element. The needle elements are made of steel and therefore have a relatively hydrophobic steel surface and thus are not very suitable for transporting the body fluid sample.

"For the purpose of increasing the flow rate of the body fluid sample along the needle element, EP Patent Application Publication No. 2025287 describes modifying the surface of the needle element with a hydrophilic coating. Non-ionic surfactants, such as polysorbate, are mentioned for use as the hydrophilic coatings.

"Similarly, EP Patent Application Publication No. 2014727 describes hydrophilizing metal-oxide coatings such as, for example, AlOOH, TiO.sub.X, SiO.sub.2 or the like. The metal-oxide coatings can be applied and fixed in the form of discrete particles in suspensions. The use of organic polymer compounds such as, for example, PVP-PEG, and of water-soluble organic poly-acids and/or salts thereof such as, for example, PAA or heparin salts, as the hydrophilic coating, also is known.

"For forming a hydrophilic surface of the needle element, hydrophilization by physicochemical means also is possible. For example, etching of a steel surface or a plasma or corona treatment can be used to create active metal surfaces. Unfortunately, these effects are temporary, and therefore only are auxiliary measures for preparing the needle element surface for subsequent coating.

"Likewise, a capillary-active surface structure can be provided to improve the transport of the body fluid sample along the needle element, where a hydrophilic coating of the capillary surface structure can be especially advantageous for speed of transport of the body fluid along the needle element.

"In this manner, EP Patent Application Publication No. 1887355 describes a needle element designed as a microfluidic system for capillary transport of a body fluid sample and a method of applying a hydrophilic surface coating on the needle element. Polyacrylic acid, polyacrylate, dextran sulphate and/or chondroitin sulphate are mentioned for use as the hydrophilic surface coating materials. To ensure rapid and reliable transport of the body fluid sample along the needle element, a surface structure is further described that can be formed as a microchannel on the needle element with the hydrophilic surface coating.

"However, the known coating materials demonstrate inadequate stability, in particular, they have inadequate long-term stability. One reason for the inadequate stability includes insufficient bonding of the coating to the surface of the substrate, which may result in detachment of the coating during the coating process, during storage or during use of the substrate such as, for example, when a needle element coated in this way is inserted into the skin. Another reason is that the hydrophilic coating may not even be resistant to longer storage at room temperature or to temperature fluctuations. Moreover, some compounds display low stability when exposed to sterilization conditions and/or low resistance to gas evolution from packaging.

"In particular, instability with respect to packaging materials often means that in the case of substrates packaged in plastic materials, the hydrophilicity of the coated surfaces decreases markedly during storage and sufficient hydrophilicity of the substrates after storage is no longer guaranteed. This loss of hydrophilicity can be explained by adsorption of volatile, nonpolar constituents of the packaging materials.

"To prevent such loss of hydrophilicity, Intl Patent Application Publication No. WO 2008/015227 describes using specific packaging that contains a loose covering for the hydrophilic coating and/or the addition of adsorbents in the packaging to prevent absorption of volatile constituents by the hydrophilic coating. Unfortunately, the packaging is complicated, expensive and, in particular, is disadvantageous for measuring equipment with automatic operation, which also must provide reliable unpacking of the substrate from the packaging.

"US Patent Application Publication No. 2007/0179373 describes apparatuses and methods for collecting a body fluid sample. It discloses inter alia an integrated collection device having an analyte detector and a gradient means to drive the transport of the body fluid from a point of contact to a point of detection. The integrated collection device has a layered structure that includes multiple layers and features a first layer and a second layer that forms a surface layer. A hydrophilic surface is generated by powder coating the surface layer with fumed silica nanoparticles.

"For the foregoing reasons, there is a need for analytical aids with hydrophilic coatings that have sufficient stability, in particular, sufficient stability even in the presence of volatile, nonpolar constituents of packaging materials."

In addition to obtaining background information on this patent application, VerticalNews editors also obtained the inventors' summary information for this patent application: "The present disclosure is concerned with the problems noted above by providing analytical aids with a hydrophilic coating, which has advantageous wetting properties and is characterized by a high stability.

"Surprisingly, it was found that the problems can be solved when nanoparticles with silica structure and an average particle size in the range from about 1 nm to about 500 nm are used for coating analytical aids. The coated analytical aids are characterized by advantageous hydrophilicity and wettability. Moreover, high stability of the coated analytical aids is provided.

"Accordingly, and in one aspect, analytical aids are disclosed that include a surface coated at least partially with a hydrophilic coating, where the hydrophilic coating contains nanoparticles with silica structure and an average particle size, determined according to DIN ISO 22412:2008 (dynamic light scattering), in the range from about 1 nm to about 500 nm, where the nanoparticles include groups of structure (I) and/or structure (II):

"##STR00001##

"where in each of the groups of structure (I), independently of one another, R is selected from H, a metal-containing ion,

"##STR00002##

"where R.sup.w, R.sup.x, R.sup.y and R.sup.z, independently of one another, are selected from H and alkyl, where R.sup.a, R.sup.b and R.sup.c, independently of one another, are optionally substituted residues, selected from H, alkyl, aryl, heteroaryl, cycloalkyl, cycloheteroalkyl, alkenyl and alkoxyalkyl, where n, m and p, independently of one another, are 0 or 1, and where M.sup.+ is a metal ion and A.sup.- is a physiologically compatible anion.

"In contrast to the above, US Patent Application Publication No. 2007/0179373 discloses only a hydrophilic surface coating with fumed silica nanoparticles. The nanoparticles as described herein thus comprise groups of structure (I) and/or (II).

"In another aspect, methods are disclosed for producing an analytical aid as described herein, where the method includes, but is not limited to, steps such as: a step of providing the analytical aid; a step of coating the analytical aid by bringing the analytical aid into contact with a mixture G of at least one dispersant and nanoparticles with silica structure, where the nanoparticles have an average particle size, determined according to DIN ISO 22412:2008, in the range from about 1 nm to about 500 nm, where the nanoparticles include groups of structure (I) and/or (II):

"##STR00003##

"where in each of the groups of structure (I), independently of one another, R is selected from H, a metal-containing ion,

"##STR00004##

"where R.sup.w, R.sup.x, R.sup.y and R.sup.z, independently of one another, are selected from H and alkyl, where R.sup.a, R.sup.b and R.sup.c, independently of one another, are optionally substituted residues, selected from H, alkyl, aryl, heteroaryl, cycloalkyl, cycloheteroalkyl, alkenyl and alkoxyalkyl, where n, m and p, independently of one another, are 0 or 1, and where M.sup.+ is a metal ion and A.sup.- is a physiologically compatible anion; a step of drying the analytical aid obtained in the previous step; and an optional step of sterilizing the analytical aid obtained in the previous step.

"In one embodiment, the coating/contacting step includes dip coating and/or spray coating and/or contact coating, where the analytical aid and/or the surface of the analytical aid includes at least partially of a metal and/or a metal alloy and/or a metal oxide and/or a mixed metal oxide and/or a mixed metal oxide.

"In another aspect, compositions including the nanoparticles described herein are disclosed.

"In another aspect, uses of nanoparticles described herein are disclosed such as, for example, as a hydrophilic coating for a needle element or a testing element of a sampling device for collecting a body fluid, where the nanoparticles includes groups of structure (I) and/or structure (II):

"##STR00005##

"where in each of the groups of structure (I), independently of one another, R is selected from H, a metal-containing ion,

"##STR00006##

"where R.sup.w, R.sup.x, R.sup.y and R.sup.z, independently of one another, are selected from H and alkyl, where R.sup.a, R.sup.b and R.sup.c, independently of one another, are optionally substituted residues, selected from H, alkyl, aryl, heteroaryl, cycloalkyl, cycloheteroalkyl, alkenyl and alkoxyalkyl, where n, m and p, independently of one another, are 0 or 1, and where M.sup.+ is a metal ion and A.sup.- is a physiologically compatible anion.

"These and other advantages, effects, features and objects of the invention will become better understood from the description that follows. In the description, reference is made to the accompanying drawings, which form a part hereof and in which there is shown by way of illustration, not limitation, embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

"The advantages, effects, features and objects other than those set forth above will become more readily apparent when consideration is given to the detailed description below. Such detailed description makes reference to the following drawings, wherein:

"FIG. 1 shows an exemplary sampling device.

"While the present invention is susceptible to various modifications and alternative forms, exemplary embodiments thereof are shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description of exemplary embodiments that follows is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all advantages, effects, features and objects falling within the spirit and scope of the invention as defined by the embodiments above and the claims below. Reference should therefore be made to the embodiments above and claims below for interpreting the scope of the invention. As such, it should be noted that the embodiments described herein may have advantages, effects, features and objects useful in solving other problems."

For more information, see this patent application: Babic, Branislav; Greiwe, Peter. Analytical Aids with Hydrophilic Coating Containing Nanoparticles with Silica Structure and Methods of Producing and Using the Same. Filed September 16, 2013 and posted January 23, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=3024&p=61&f=G&l=50&d=PG01&S1=20140116.PD.&OS=PD/20140116&RS=PD/20140116

Keywords for this news article include: Patents, Nanoparticle, Nanotechnology, Silicon Nanocrystals, Emerging Technologies, Roche Diagnostics Operations Inc..

Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC


For more stories covering the world of technology, please see HispanicBusiness' Tech Channel



Source: Politics & Government Week


Story Tools