ALVO introduces patent-pending copper-based antibacterial coatings to hospitals with the use of innovative thermal spraying technology

Introduction

The outbreak of novel human coronavirus, SARS-CoV-2, has raised an alert in the global healthcare environment about the persistence of bacteria and viruses, especially coronaviruses that cause severe respiratory tract infections in humans. Human-to-human transmissions are reported with incubation times between 2-10 days, facilitating its spread via droplets, contaminated hands or surfaces. Following the demand for hygienic surfaces to minimize Hospital Acquired Infections (HAI) related with multi-resistant strains of bacteria and dangerous viruses, ALVO Medical is introducing new copper-based coatings with the addition of metals such as Ti, Sn, Al, Ni and composite coatings with additives of titanium oxides, including those with a nanometric structure. Innovative antibacterial coatings based on thermal spraying techniques provide evidence-based hygienic features and can be widely used in public facilities, including healthcare facilities. The technology is patent-pending.

Insight

According to the European Center for Disease Prevention and Control (ECDC), 3 million hospital infections lead to approximately 50,000 deaths annually. About 80% of infectious diseases are transmitted directly by contact. Not all infections acquired in hospitals are avoidable, but research has confirmed that their number can be reduced by at least 15-30%. As stated by the World Health Organization (WHO):

• 20%-40% of Hospital Associated Infections (HAI) are caused by cross-contamination (pathogens are transmitted via hands)
• 1 in 10 patients gets an infection while receiving care
• More than 50% of surgical site infections can be antibiotic-resistant

In recent years microbes, in particular, bacteria, have become increasingly resistant to various antimicrobials, antibiotics. The World Health Assembly’s endorsement of the Global Action Plan on Antimicrobial Resistance (AMR) [1] in May 2015, and the Political Declaration of the High-Level Meeting of the General Assembly on AMR in September 2017, both recognize AMR as a global threat to public health.
Antimicrobial surface coatings developed within the project are compliant with preventive measures to reduce nosocomial infections, in particular those associated with dangerous strains of bacteria such as Staphylococcus aureus, Escherichia coli, or Pseudomonas aeruginosa. The technology is also submissive to the European Joint Program Initiative on Antimicrobial Resistance (JPIAMR) aimed at reducing the problem of antibiotic resistance.

Antimicrobial performance

Against: Escherichia coli ATCC 25922

Against: Pseudomonas aeruginosa ATCC 9027

Thermal spraying technology enables the wide application of the developed solutions in public buildings and medical facilities. Antimicrobial properties of the copper-based sprayed coatings are compared to those offered by antimicrobial copper, while, what’s quite important, they offer higher aesthetic value (no copper oxidation effect).

Copper-based sprayed coatings can be easily applied to different fields of application, for instance, catering facilities, public transport, nursing homes, kindergartens, and schools. In addition, the composite with antibacterial and fungicidal properties developed in the project can expand the field of application of the materials being developed by air conditioning, water supply solutions, etc.

Surgical table with copper-based antimicrobial coating on side rails, for mounting surgical accessories.

Method

The company tested the persistence of common dangerous bacteria and viruses on inanimate surfaces as well as inactivation strategies resulting from incorporating new functional alloy and composite coatings based on copper with antibacterial properties, produced by thermal spraying techniques.

Copper is present in two oxidation states: Cu2 + and Cu1 +. The structure of the external electron shell of a copper atom is the cause of many properties useful in practice, including thermal and electrical conductivity, as well as special electrochemical properties. Copper shows a high ability to give away or accepting electrons. This enables its free ion to interact with bacterial proteins, which results in their inhibition. The aim of the project was to develop alloying and composite materials in place of pure copper. The insight comes from the demand for new materials with both high mechanical durability, proven hygienic features and high aesthetics, which is of growing importance in public places and ‘sensitive areas’ eg. hospitals and surgery rooms.

The innovation includes developing a copper-based composite with TiO2, and one with a nanocrystalline structure. This is because TiO2 shows strong catalytic properties of this compound. The TiO2 compound causes a photocatalytic reaction, which is why it has proven to be effective in the aspect of the application for antibacterial, antifungal, or self-cleaning coatings. The addition of TiO2 to copper not only improved the antibacterial effect but also increased the anti-fungal effect of copper. The patent applicants propose the production of Cu / TiO2 powder composite by powder metallurgy techniques. This composite will then be used to create layers by APS and HVOF spraying (enabling the production of layers with a different microstructure, which seems to be important in terms of the main properties of the layers produced, i.e. antimicrobial properties). This is a different technological approach from the one for producing Cu / TiO2 layers using the HiPIMS technique. The method proposed by the Consortium enables the production of layers with a greater thickness of 100 mm, thus potentially more durable coatings. Due to the technology used, the solution will also be more economically advantageous.

Conclusions

Tests have shown that coating the surfaces of hospital accessories with copper or copper-based alloys significantly reduced the number of pathogenic microorganisms on frequently touched hospital surfaces, such as doors, furniture, bedside handrails, IV stands, nurse call buttons, taps, light switches. On surfaces of copper-containing hospital equipment elements, there were 90-100% fewer bacterial infections than on objects made of conventional materials. Copper-based surfaces have also been proven to exhibit significantly less microbial contamination between periods of routine cleaning and disinfection operations. Their use is, therefore, an additional useful way to improve hygiene.

New functional alloy and composite copper-based coatings with antibacterial properties produced by thermal spraying techniques was already tested and is being introduced on sensitive surfaces of furniture elements and accessories used in medical facilities such as operating tables, tables for sterile materials and surgical instruments, dressing tables, IV stands, cabinets and trolleys.

Cooper-based alloys coatings on stainless steel are bringing the essential mixture of antimicrobial properties with high mechanical durability unavailable for pure coper-based selection of materials.

[1] Resolution WHA 68-7. Global action plan on antimicrobial resistance. In: Sixty-eighth World Health Assembly, Geneva, 26 May 2015. Annex 3. Geneva: World Health Organization; 2015.