advanced-compositional-analysis-nanoparticle-polymer-composites-using

Advanced Compositional Analysis of Nanoparticle-polymer Composites Using Direct Fluorescence Imaging

The fabrication of polymer-nanoparticle composites is extremely important in the development of many functional materials. Identifying the precise ...

University College London

In this critical review the biocidal efficacies of a variety of antimicrobial coatings currently in use for catheter surfaces are discussed to formulate the best strategy for decreasing the risk of catheter-associated infections. The development of new coatings containing antimicrobial chemicals and light-activated antimicrobial agents, and their applicability for use in catheters are summarised (132 references).

The role of surfaces in catheter-associated infections.

This review focuses on the development of light activated antimicrobial surfaces. These surfaces kill microbes by the action of light and have potential applications in domestic and healthcare settings. The inspiration for the new self-cleaning surfaces originates from photodynamic therapy where light is used to locate and destroy tumours. The first generation photosensitiser molecules, based on a porphyrin ring structure, could be considered as bioinspired and chemically related to chlorophyll. The review looks at developments of both soft polymeric surfaces with either surface bound or impregnated photosensitiser molecules; and hard inorganic surfaces such as modified titanium dioxide. The bacterial kill mechanisms are looked into with both surface types showing primary microbial kill through a radical induced pathway. The hard inorganic surfaces also show low bacterial adherence by means of a light activated photo-wetting of the surfaces meaning that they are "Easy Clean" and wash off microbes uniformly.

Shining light on materials--a self-sterilising revolution.

We report the preparation, characterisation and antimicrobial functional testing of various titanium dioxide and gold modified titanium dioxide nanoparticles embedded into a polysiloxane polymer by a swell dip-coating procedure. We show that the surfaces are effective in killing both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria under different lighting conditions. The presence of the nanoparticles was of critical importance in improving the functional properties of the surface. These materials have the potential to reduce hospital-acquired infection, by killing bacteria on the polymer surface.

Functionalised gold and titania nanoparticles and surfaces for use as antimicrobial coatings.

A simple, easily up-scalable swell-encapsulation-shrink technique was used to incorporate small 2.5 nm copper nanoparticles (CuNPs) into two widely used medical grade polymers, polyurethane, and silicone, with no significant impact on polymer coloration. Both medical grade polymers with incorporated CuNPs demonstrated potent antimicrobial activity against the clinically relevant bacteria, methicillin-resistant Staphylococcus aureus and Escherichia coli. CuNP-incorporated silicone samples displayed potent antibacterial activity against both bacteria within 6 h. CuNP-incorporated polyurethane exhibited more efficacious antimicrobial activity, resulting in a 99.9% reduction in the numbers of both bacteria within just 2 h. With the high prevalence of hospital-acquired infections, the use of antimicrobial materials such as these CuNP-incorporated polymers could contribute to reducing microbial contamination associated with frequently touched surfaces in and around hospital wards (e.g., bed rails, overbed tables, push plates, etc.).

Article	Year
The role of surfaces in catheter-associated infections. Chemical Society reviews\| PubMed ID: 20449061	2009
Shining light on materials--a self-sterilising revolution. Advanced drug delivery reviews\| PubMed ID: 22819684	2013
Functionalised gold and titania nanoparticles and surfaces for use as antimicrobial coatings. Faraday discussions\| PubMed ID: 25370309	2014
Potent Antibacterial Activity of Copper Embedded into Silicone and Polyurethane. ACS applied materials & interfaces\| PubMed ID: 26418101	2015

Sacha Noimark

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