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Functional nanostructured chitosan coatings for medical instruments and devices

a technology of chitosan and nanostructure, applied in the field of surface of medical instruments and devices, can solve the problems of lack of uniform coating, limited limited conventional coating techniques in terms of morphology or nanostructure of the resulting chitosan, so as to facilitate the function of the surface being coated, facilitate the application of the article being coated, and high uniform

Inactive Publication Date: 2013-08-08
NANO & ADVANCED MATERIALS INST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The present invention provides a novel method for coating biopolymers onto surfaces with functional additives. The method results in a highly uniform coating that can be customized for different surfaces. The method involves dissolving the biopolymer in a non-aqueous solvent system and adjusting the electrolyte to an acidic pH. The negative counter electrode, reference electrode and positive working electrode are used to apply an electric field to the solution, causing the biopolymer to deposit onto the positive working electrode and form a coating. The present method also allows for the biopolymer coating to be modified with different functional additives to customize its properties.

Problems solved by technology

However, many of the conventional biopolymer coating techniques, such as spincasting, electrospinning and spraying, result in coatings lacking uniformity, especially on irregular shapes which are very often present in medical instruments.
Furthermore, the conventional coating techniques are very limited in terms of morphology or nanostructure of the resulting chitosan.
Morphology of the resulting chitosan coating prepared by conventional methods is typically limited to a single form.
That is, the morphology cannot be tuned and customized for the specific functions of the particular medical instruments coated therewith.

Method used

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  • Functional nanostructured chitosan coatings for medical instruments and devices
  • Functional nanostructured chitosan coatings for medical instruments and devices
  • Functional nanostructured chitosan coatings for medical instruments and devices

Examples

Experimental program
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example 1

Electrodepositing A Chitosan Coating Containing 5-Florouracil Onto A Stainless Steel Surface

[0023]To demonstrate electrodeposition of chitosan coatings incorporating 5-florouracil (5-FU) onto a stainless steel surface according to the present invention, the chitosan and 5-florouracil containing electrolyte is prepared by dissolving 8 mg of chitosan in 45 ml PC:EG (1:4 v / v). An appropriate amount of H2SO4 is added to adjust pH of the electrolyte to pH 4-4.5. The electrolyte is then subject to ultrasonication for 2 hours for proper dissolution. Supporting electrolyte LiClO4 at 5.5 mM or 55 mM, respectively along with 65 mg 5-florouracil are added to the acidic electrolyte. In this example, the ratio of chitosan to 5-FU is 1:8. Stainless steel surface to be coated with the chitosan and 5-FU and the prepared acidic electrolyte are set up according to FIG. 1 and undergo electrochemical deposition at −5V for 40 mins.

[0024]FIGS. 2A-D show that a 3-dimensional flower-like morphology and an ...

example 2

Electrodepositing A Chitosan Coat With Calcium Carbonate (CaCO3) Onto Titanium Surface

[0026]The same conditions and procedures as illustrated in Example 1 are applied to electrodeposit chitosan coatings with CaCO3 onto a titanium surface. Instead of florouracil, 40 mg of CaCO3 and 55 mM LiClO4 are added to the electrolyte solution. The ratio of chitosan to CaCO3 is 1:5. The morphology of chitosan coating having CaCO3 incorporated therein prepared according to the present method is observed and MC3T3-E1 cell viability on bare titanium versus coated titanium is tested. The results show that not only does the addition of CaCO3 to the chitosan can significantly promote cell adhesion and proliferation as compared to bare titanium surface and the chitosan coating alone (FIG. 4B), the CaCO3 incorporated chitosan coating is also observed to form a nanoflake morphology on the titanium surface under the SEM (FIG. 4A). The results in this Example further demonstrate that the present method of ...

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Abstract

Disclosed herein is an approach for coating a biocompatible material, in particular chitosan, onto a surface in need thereof. This approach results in a coating that is highly uniform, even on irregular surfaces, and enables ready adjustment of the morphology of the coated material. A convenient means to add a functional property to the biocompatible material by incorporation of functional additives is also provided.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]The present application claims priority of U.S. provisional application No. 61 / 633,141 filed on Feb. 6, 2012, the disclosure of which is herein incorporated by reference.FIELD OF THE INVENTION[0002]The present invention relates to methods of coating biopolymer with at least one functional additive onto surfaces in need thereof and more particularly to surfaces of medical instruments and devices. The present invention also relates to medical devices coated by the present methods and uses thereof.BACKGROUND[0003]Medical instruments and devices, such as medical implants, are very often coated with one or more coatings to impart biocompatibility, enable drug delivery, provide lubricity and so on. Various research groups focus on development of different nanostructure coatings for medical implants. For instance, Seoul National University discloses inorganic nanostructured coatings on titanium for preosteoblastic cell growth (Journal of Biomedi...

Claims

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Application Information

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IPC IPC(8): C25D9/02
CPCC09D5/4419C25D9/02
Inventor WONG, KA WAICHAN, MUI KIMMYLAM, CHING YEE NOVEM
Owner NANO & ADVANCED MATERIALS INST