A novel coating technology based upon polyatomic ions from plasma

Lead Research Organisation: Lancaster University
Department Name: Chemistry

Abstract

Plasma polymerisation is widely used in manufacturing and we would hope to extend the range of products that are plasma coated. We have focused on coatings in healthcare applications and in chemical sensing. We are all likely to be beneficiaries from the development of effective, safe and low-cost technologies that address the rise in antimicrobial resistance (AMR); microbes that develop resistance to antibiotics. As identified by Lord Jim O'Neil in his seminal report TACKLING DRUG-RESISTANT INFECTIONS GLOBALLY, 2016, AMR presents perhaps the greatest long-term threat to human health: it is estimated that up to 10 million people per year will die from AMR by 2050, without significant new interventions. The sensing application we have chosen is radioactive waste, where enhanced sensing increases safety and protects the environment and the public.
To achieve rapid impact, we will actively accelerate utilisation and translation of this plasma technology, by conducting in parallel to the main project, 3 demonstrator projects. These are designed to complete technology development up to TRL 4 and to introduce the technology to potential end users in the nuclear safety industry and the healthcare sector. The collaboration with Kratos Analytical will provide a platform for a much broader advertisement of the technology.
We will conduct a proof-of-concept demonstrator project, applying plasma amine (TREN) coatings to the surface of a quartz crystal microbalance in order to detect the pertechnetate anion (a fission product of 235U). Robust and reliable sensing in bore holes as well as in-line process monitoring will enhance the nuclear industry's ability to demonstrate compliance with statutory requirements and provide early warning of potential leak detection. We anticipate that based upon the novel monomers synthesised by Dr Nick Evans we can fabricate on-line sensors with greater specificity and sensitivity to currently employed methods. The plasma coatings could also be applied to magnetic beads which would offer a novel method for pertechnetate remediation from waste streams. Further spin-offs include applications in medical sensing, where amine surfaces are used to immobilise molecules on to surfaces.
In two further demonstrator projects, we will test novel plasma anti-microbial surfaces against pathogens that are most frequently associated with medical devices and wound colonisation. The PhD student will explore with Dr Achyat Guleri (a Consultant Microbiologist and Clinical Director at Blackpool Teaching Hospitals) a particularly interesting application in voice prosthesis, where the silicone is very readily colonised by Candida. We see a market for these surfaces (applied as dressings) in the treatment of wounds. Burn wounds, for example, are particularly prone to bacterial colonisation. (Dressings containing Ag have been used for about two decades, but recently questions about Ag toxicity to mammalian cells and overall benefit from the use of Ag have arisen.) In this context, nitric-oxide (NO) release surfaces could provide a less toxic and yet equally effective approach. Diabetic wounds (ca. 200-300,000 pa in the UK) provide an alternative target, where infection is a common reason for wounds failing to heal. A further target is hospital acquired infections which cost the NHS ca. £1Bn pa and approximately 24% of these are at the surgical site.

Planned Impact

This project will furnish new insights into the plasma polymerisation process and provide coatings that can be applied in a wide range of different applications. Fragmentation of the starting compound (in the plasma) has limited our ability to fabricate coatings from "fragile" molecules. New knowledge would provide a boost to the capability of the plasma community and we would anticipate that our peers would be keen to explore the principles we establish to a much broader range of compounds for host of applications we cannot even begin to predict.
Plasma polymerisation is widely used in manufacturing and we would hope to extend the range of products that are plasma coated. We have focused on coatings in healthcare applications and in chemical sensing. We are all likely to be beneficiaries from the development of effective, safe and low-cost technologies that address the rise in antimicrobial resistance (AMR), which are microbes that develop resistance to antibiotics. As identified by Lord Jim O'Neil in his seminal report TACKLING DRUG-RESISTANT INFECTIONS GLOBALLY, 2016, AMR presents perhaps the greatest long- term threat to human health: it is estimated that up to 10 million people per year will die from AMR by 2050, without significant new interventions. The sensing application we have chosen is radioactive waste, where enhanced sensing increases safety and protects the environment and the public.
To achieve rapid impact, we will actively accelerate utilisation and translation of this plasma technology, by conducting in parallel to the main project, 3 demonstrator projects. These are designed to complete technology development up to TRL 4 and to introduce the technology to potential end users in the nuclear safety industry and the healthcare sector. The collaboration with Kratos Analytical will provide a platform for a much broader advertisement of the technology.
We will conduct a proof-of-concept demonstrator project, applying plasma amine (TREN) coatings to the surface of a quartz crystal microbalance in order to detect the pertechnetate anion (a fission product of 235U). Robust and reliable sensing in bore holes as well as in-line process monitoring will enhance the nuclear industry's ability to demonstrate compliance with statutory requirements and provide early warning of potential leak detection. We anticipate that based upon the novel monomers synthesised by Dr Nick Evans (Co-I) we can fabricate on-line sensors with greater specificity and sensitivity to currently employed methods. The plasma coatings could also be applied to magnetic beads which would offer a novel method for pertechnetate remediation from waste streams. Further spin-offs include applications in medical sensing, where amine surfaces are used to immobilise molecules on to surfaces.
In two further demonstrator projects, we will test novel plasma anti-microbial surfaces against pathogens that are most frequently associated with medical devices and wound colonisation. The PhD student will explore with Dr Achyat Guleri (a Consultant Microbiologist and Clinical Director at Blackpool Teaching Hospitals) a particularly interesting application in voice prosthesis, where the silicone is very readily colonised by Candida. We see a market for these surfaces (applied as dressings) in the treatment of wounds. Burn wounds, for example, are particularly prone to bacterial colonisation. (Dressings containing Ag have been used for about two decades, but recently questions about Ag toxicity to mammalian cells and overall benefit from the use of Ag have arisen.) In this context, nitric-oxide (NO) release surfaces could provide a less toxic and yet equally effective approach. Diabetic wounds (ca. 200-300,000 pa in the UK) provide an alternative target, where infection is a common reason for wounds failing to heal. A further target is hospital acquired infections which cost the NHS ca. £1Bn pa and approximately 24% of these are at the surgical site.
 
Description We have already shown we can deposit polymeric thin films from plasma (pure TEMPO monomer precursor) from largely the arrival of intact molecular ions of the monomer species. Normally plasma deposition creates many dissociated species and scrambled chemistries.

We have used a method of RF sheath biasing to lower the positive acceleration and hence ion energy to the growing film allowing more soft landing of ions and less scrambling of the resultant film chemistry. We are working towards a publication to show this.

We have shown that the initial stages of plasma deposition are highly dependent on the material onto which the coatings is being deposited. As the plasma polymer films grow, the coating becomes independent of the substrate influence. This happens by a thickness of ca. 30 nm. This finding may have significant implications on the amount of material used in depositing functional plasma coatings, reducing the amount used and consequently the environmental impact. A manuscript is being prepared and an abstract has been submitted to a leading plasma conference.

During the height of the pandemic, we explored with Dr Munir Muhammad (Virologist, Lancaster University) and his team the anti-viral properties of plasma coatings. We have identified a plasma polymer bilayer combination that is splash-proof and exhibits significant anti-viral properties against COVID SARS-2. Furthermore, this coating works well at reduced temperature (4oC) and is an ideal for coating surfaces used in cooling and refrigeration. We are currently understanding how this coating works, using scanning probe microscopy in liquids in collaboration with Dr Sam Jarvis (Physics, Lancaster University). Lancaster University is reviewing a manuscript for patentable material.
Exploitation Route As originally set out in the proposal, we have focused on developing coatings that can be used in the production of antimicrobial bandages and wound dressings. Plasma deposited TEMPO coatings are still being evaluated for their potential to prevent microbial attachment in collaboration with Prof Gordon Ramage at Glasgow University. The potential of amine surfaces is being evaluated at Lancaster by Dr. Tim Douglas and Prof Roger Pickup.

The inclusion of the study of anti-viral properties is a new feature of this stud. This may well the most readily exploited by others. An initial review suggests that the coating may be patentable.
Sectors Healthcare

 
Description A manuscript is being reviewed for patentable material for new surfaces for anti-viral application. These specific data remain unpublished as we complete final studies.
First Year Of Impact 2023
Sector Manufacturing, including Industrial Biotechology
Impact Types Economic