Project: Antimicrobial coating for peripheral venous catheters

BACKGROUND_x000D__x000D_Many polymer products (made in e.g. silicone or polyurethane) used in the medical field today are exposed to microorganisms – typically bacteria, fungi and in particular bacteria and fungi in symbiosis in so-called biofilms. Several products, including catheters, feed tubes, voice prostheses and implants, are subject to biofilm formation. The biofilm formed on such products increases the risk for infections of the patients significantly. _x000D__x000D_Biofilm formation on an implanted medical device is initiated by adhesion of proteins from the patient, which rapidly adsorb onto the surface of an implanted device and form a good substrate for planktonic, free-swimming bacteria and fungi to adhere to. The biofilm usually anchors to polymeric materials by means of in-growth of the fungi into irregularities and pores of the material. The biofilm serves as host for various bacteria and it has also been shown that the bacteria, hosted in biofilm, is more difficult to treat with antibiotics. Products intended for a prolonged use inside the human body, such as CVC’s, implants and feed tubes are often completely or partially deteriorated by these fungal attacks. Prevention methods today are based on controversial constant exposure to antimicrobial agents such as silver ions or antibiotics or slow release of such agents. Slow release over prolonged durations has not yet been achieved to a satisfactory degree._x000D__x000D_By applying a surface coating, which significantly prohibits biofilm formation, and particularly in-growth of fungi, on polymeric products, all kinds of biofilm related infections can be controlled. This includes also so-called hospital acquired infections. Deterioration of long-term implanted products, due to in-growth or fungi, can also significantly be suppressed._x000D__x000D_MARKET_x000D__x000D_ANTIFUNGAL COATING SYSTEM_x000D__x000D_The antifungal coating system to be evaluated in this project represents a new way of thinking when dealing with infection control by preventing in-growth of fungi hyphae into a protected product, thus also preventing biofilm formation. This is assumed to result in fewer infections and also in an increased sustainability of the products._x000D__x000D_The system consists of two polymeric layers in which:_x000D_1. an innermost barrier layer comprises up to 5 wt-% of immobilized silver (or copper) nanoparticles, a well-known antimicrobial agent, and _x000D_2. an outermost protective layer solely made from a polymer. The outermost protective layer is designed to effectively prevent leakage of silver from the innermost layer to the surrounding, eliminating silver exposure to both patients and environment. _x000D__x000D_Both layers can suitably be applied to the product to be protected by sequential dip coating techniques._x000D__x000D_When biofilm starts to form on a coated polymeric product, hyphae (usually from fungi of the genus Candida) penetrate the material of the product. The fungi hyphae will be hindered from further in-growth when reaching the innermost layer by the presence of silver nanoparticles. The investigation of this effect represents one part of the present project and the hypothesis is that the coating will work by the above-described mechanism. The antifungal coating does not leak silver particles or ions to the surrounding since the outer layer seals the barrier layer. _x000D__x000D_PROJECT_x000D__x000D_The project aims to investigate the antimicrobial effect of the novel coating system on peripheral venous catheters from BD (Becton Dickinson and Company) and to introduce the antifungal coating system into the production of peripheral venous catheters at BD. _x000D__x000D_Biological systems like biofilms formed on catheters are almost impossible to accurately investigate in vitro and animal testing will be used to examine the effectiveness of the coating. The project can be summarized in the following bullet points:_x000D__x000D_1. Coating peripheral venous catheters from BD with the antimicrobial coating system from Nanexa_x000D_2. Mechanical and toxicological tests of coating_x000D_3. Planning of animal tests_x000D_4. Animal tests_x000D_5. Optimization of coating_x000D_6. Adapting coating system to fit into existing production line_x000D__x000D_CONSORTIUM_x000D_Nanexa AB - A Swedish nanotech company, which specializes in surface coatings. Nanexa is also CO applicant, leads the project and provides the material expertise._x000D__x000D_BD - is a leading global medical technology company that develops, manufactures and sells medical devices, instrument systems and reagents._x000D__x000D_Karolinska Institutet is one of the leading medical universities in Europe. Through research and education, Karolinska Institutet contributes to improving human health. _x000D__x000D_University of Copenhagen - Faculty of Life Sciences, at University of Copenhagen, is one of Europe's leading university environments in the areas of veterinary science, food and natural resources. Within the field of biomedicine, researchers at LIFE develop animal models (in particular pigs) that can give us insight into and tools to improve the health of both humans and animals._x000D__x000D__x000D__x000D_

Acronym	AMC (Reference Number: 6963)
Duration	01/03/2012 - 31/08/2013
Project Topic	The project aims at developing an antifungal coating system on peripheral venous catheters .The coating system has a barrier layer that is assumed to have an anti- microbial effect by preventing in-growth of Candida into the coated device, which reduces infection risks by hindering biofilm formation
Project Results (after finalisation)	.1 The first objective was to develop a coating process for catheters and other products with an antifungal coating from Nanexa. That was achieved with good results and Nanexa learned a lot about this system. _x000D_A second objective of the project was to show that the antifungal coating decreased biofilm adherance in peripheral venous catheters. The coating of the cathteters was not optimal for this purpose and could not be evaluated in this system._x000D_ An in vitro model has been established for investigating if fungal in-growth can be inhibit due to the effects of the antifungal coating. From the knowledge we gained in the animal tests, we found that in order to achieve in-growth and not only achive biofilms we need another system than vascular catehters .
Network	Eurostars
Call	Eurostars Cut-Off 7

Project partner

Number	Name	Role	Country
4	Becton Dickinson Infusion Therapy AB	Partner	Sweden
4	Karolinska Institutet	Partner	Sweden
4	Nanexa AB	Coordinator	Sweden
4	University of Copenhagen	Partner	Denmark