1. What Is Oxytech Antimicrobial glove?
Oxytech are the world’s first non-leaching antimicrobial gloves, designed to kill microorganisms on the external side of the glove quickly upon contact
2. What Is the purpose of the Oxytech antimicrobial glove?
Though conventional gloves provide a barrier between a healthcare worker and patient, it does not tackle the problem of transient transmission, where microbes get transmitted from one surface to another. The Oxytech glove is designed to help reduce the spread of HAI’s as it is proven to kill up to 99.999% of selected microbes.
3. Why do Oxytech gloves provide Active Protection Against HAI’s?
The use of medical gloves is intended to prevent cross contamination between the patient, the user and its environment.
However, conventional gloves can only provide passive protection as contaminated gloves caused by inappropriate storage, inappropriate use and techniques for donning and removing, may in turn become a vehicle for transmission of microbes.
Conversely, Oxytech gloves provide an active approach in HAI prevention as the gloves can continuously and effectively reduce or inhibit microbial colonisation on the glove surface within a short amount of time, thus further reducing the risk of cross contamination.
4. Do Oxytech antimicrobial gloves replace the need for hand hygiene?
Although the Oxytech glove has been found effective against a wide range of microbes, it does not replace the need for hand hygiene. Oxytech serves as an extra precaution or tool to help mitigate the spread of HAI’s. Protocols for hand sanitising or hand washing should still be performed before donning and after removing the gloves.
5. What does it mean by non-leaching? Is it safe?
We designed the antimicrobial gloves to be non-leaching to ensure the active ingredient does not transfer to the patient. To further ensure the safety of the active ingredient, the gloves were tested for bio-compatibility. The tests carried out are described below:
- Tested at Intertek UK, the gloves were extracted using water, artificial saliva, artificial sweat and alcohol at room and body temperature. The extracts were analysed by validated analytical techniques to detect the active. No active could be found extracted from the gloves inner or outer surface.
- ISO 10993 biocompatibility testing has been conducted on the inside and external surface of the gloves. Results confirm that the gloves are non-sensitising, non-irritating, non-toxic (oral) and non-cytotoxic.
- The Modified Draize-95 test was also conducted where both the inner and outer surfaces of the gloves were tested on human skin. The gloves provided no clinical evidence of inducing allergic reactions. With this test result, USFDA allows a “Low Dermatitis Potential” claim for the gloves.
6. What materials are in contact with my skin when using Oxytech antimicrobial gloves?
Oxytech’s technology is introduced on the external side of the glove. The glove user is exposed to the donning side of the glove, which is similar to a standard examination glove. The skin of the glove user is not exposed to this technology.
7. How does singlet oxygen work?
In this technology a special dye is used. The dye absorbs visible light. The dye is thus raised from a ground state to an excited quantum state, in which an elevation in energy takes place. The energy then transfers to a proximal oxygen molecule found in the air, causing the oxygen molecule to also rise to an excited quantum state. The ground state of oxygen present in air, is a triplet electronic configuration, written as 3O2. Upon sensitisation by the dye molecule, the electronic configuration changes and enters the singlet state, 1O2.
This singlet oxygen state is reactive and more oxidative compared to ground state oxygen and is therefore able to kill microbes such as bacteria by oxidising the cells protein and lipid. Using the dye as a catalyst, singlet oxygen can be generated continuously as it absorbs light and air.
8. What are the advantages of using the singlet oxygen antimicrobial system?
Singlet oxygen is a non-selective system that can react rapidly against many microbial components. There is not one single protection mechanism that bacteria can protect itself from singlet oxygen. This contrasts with antibiotics, which need very specific mechanisms to treat a patient. As singlet oxygen is transient, it does not lead to the release of persistent biocides into the environment.
Oxytech will as such transform the standard examination glove from a passive medical device to a medical device with active protection which will actively reduce or inhibit microbial colonisation.
9. Has singlet oxygen technology been used before commercially?
In humans, singlet oxygen generating dyes are used for cancer treatment, known as photodynamic therapy, PDT.
It is also used in dental disinfection prior to procedures like root canal treatments, in which the dye is rinsed into the patient’s mouths, a light applied, and disinfection occurs safely and rapidly.
However, probably the most ubiquitous use is in laundry powders, where a singlet oxygen generating dye is washed onto clothing, and subsequently acts as a photobleach. Many readers of this will therefore be unwitting users of singlet oxygen and wearing some singlet oxygen generating dye.
10. Is there literature to show the potential of bacterial resistance using the singlet oxygen antimicrobial system?
Experimental studies have been done and reported in the literature about singlet oxygen efficacy and resistance18,19. In these, bacteria were killed to a high extent with singlet oxygen, typically 99.9% or 99.99%, leaving only the most robust bacteria. These were then re-cultivated and re-exposed to singlet oxygen. This cycle is repeated 10 or 20 times, and the efficacy of killing is measured. In all cases, it was found that there is no decrease in efficacy and no development in resistance.
Many of the mechanisms used by bacteria to confer resistance involve processes internal to the cell. However, in the Oxytech system, the singlet oxygen is generated purely exogenously to the cell – the dye is separated from the bacteria, it does not leach, and it cannot enter the cells. Other authors in the literature have noted that this makes development of resistance especially difficult, because singlet oxygen is short lived and with a short length of diffusion – nothing the bacterial cell does internally will affect the process of oxidation by singlet oxygen.
Furthermore, a review of the potential for resistance to biocidal materials was done by the EU expert scientific committee. The report puts biocidal materials into three categories: low risk of resistance developing, medium risk and high risk. These authors put oxidative systems as low risk, some traditional biocide materials such as chlorhexidine and PHMB as medium risk, and silver as high risk.
11. What is the amount of light needed to activate the Oxytech antimicrobial glove?
Testing of the Oxytech glove has been conducted at general lighting condition at hospitals of 1000 lux and 500 lux. Results show that there was no significant difference in bactericidal efficacy. Further testing at lower light levels is currently underway.
12. Would difference in lighting type affect the efficacy of Oxytech Antimicrobial gloves (for example – LED, fluorescent, incandescent light bulb?)
No. The Oxytech is activated by any white light source. It is specifically activated by light in the 600 – 700 nm region but all white light sources contain this, otherwise they would be coloured.
13. Will the dye be depleted if the Oxytech Antimicrobial gloves are continually exposed to light?
No. So long as there is light and oxygen, the gloves are active. Heat aged Oxytech gloves (accelerated aging equivalent to 3 years of shelf life) did not show significant difference in bactericidal efficacy compared to fresh Oxytech gloves.
Oxytech gloves were also exposed to ‘light’ (equivalent to 30 days in an open box environment). Again, there was no significant difference in bactericidal efficacy compared to fresh Oxytech gloves.
14. What are the different classifications of bacteria?
Bacteria are classified into gram-positive or gram-negative. This classification came from a staining property observed by Hans Gram in 1884. It was observed that some bacteria could be stained with a dye and others could not. It was later found that bacteria have a different cell wall structure. Gram-positive bacteria allow substances to cross the cell wall more easily. The cell wall of gram-negative bacteria is multi-layered and so it is harder for substances to cross the cell wall.
15. What are some examples of gram-negative bacteria?
Gram-negative bacteria include Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Acinetobacter baumannii among others.
16. What are some examples of gram-positive bacteria?
Gram-positive bacteria include MRSA, Staphylococcus aureus, Enterococcus faecium and Streptococcus pyogenes, Enterococcus faecalis (VRE) amongst others.
17. What type of bacteria survive longer on surfaces, which allow the possibility of infection transfer?
Based on a study conducted by Hirai which measures the survival of different types of bacteria on cotton lint, the results showed that gram-positive bacteria have longer lifetimes on surfaces, which may have implications that these bacteria are available for transfer to cause HAI’s. Gram-negative bacteria are known to die more quickly on surfaces, especially if the surface is dry.
18. How about in a clinical environment? Is there a survival difference between gram-positive and gram-negative bacteria?
The pattern of lower survival of gram-negative bacteria is also seen in the clinical environment. In Wilson et al study, gram-positive bacteria such as Staph a. were found in numerous locations in the hospital environment, but gram-negative bacteria such as E.Coli were not found on any surfaces sampled, despite having a number of patients in the ward with E.Coli infections.
19. Do biocides kill gram-positive or gram-negative bacteria easily?
All bacteria respond to biocides differently, requiring different contact times and concentrations for inactivation. In general, gram-negative bacteria are harder to kill with biocides.
20. How is the bactericidal efficacy of Oxytech Antimicrobial gloves measured?
Oxytech Antimicrobial gloves will start generating singlet oxygen and start killing bacteria immediately upon exposure to light and oxygen. Based on the requirements of ASTM D7907-14, the contact time in which the bacteria have been exposed to the external surface of the glove containing antimicrobial agent needs to be measured at intervals of 5 mins, 10 mins, 20 mins and 30 mins.
At the end of each contact time, the gloves is transferred into a validated neutraliser to stop the bactericidal activity. This will stop the singlet oxygen killing activity on the microbes, which will in turn allow the calculation of bacteria kill.
Additional testing has been conduced at shorter contact times of 1 min and 2 mins on Staphylococcus aureus with bacteria kill rates of 99.898% and 99.998% respectively.
21. Do Oxytech gloves have any efficacy on viruses?
We believe that Oxytech can kill viruses as well as bacteria. This is the reason we have chosen to name it Antimicrobial instead of the more limited Antibacterial. However, all our tests are based on ASTM D7907 Standard Test Methods for Determination of Bactericidal Efficacy on the Surface of Medical Examination Gloves. This test method specified the glove to be tested against four specific bacteria. As Oxytech is a new invention, there is no other standard that we can use to test for viral efficacy. Nevertheless, we are working on adapting D7907 to test for viruses. This work will take a longer time to complete. One of the challenges is that viruses only replicate inside living cells; once exposed to the environment they are destroyed quickly; therefore, making it difficult for us to test.
22. What is the medical device classification for Oxytech Antimicrobial gloves in MDD93/42/EEC?
European Union MDD93/42/EEC Annex IX:
Class I (Rule 5) includes “All invasive devices with respect to body orifices, other than surgically invasive devices and which are not intended for connection to an active medical device…”.
As such, the Oxytech Antimicrobial Nitrile Powder Free Examination Gloves are an invasive device intended for short transient use (I. Definitions, 1.1) for examinations on intact skin and also involve body orifices (I. Definitions, 1.2). All other parts of rule 5 do not apply.
Based on rule 5 (iii. Classification, section 2, 2.1), the Antimicrobial Nitrile Powder Free Examination Gloves are classified as a medical device Class 1.
23. What is the intended use and indication for Oxytech Antimicrobial gloves in the technical file?
The Antimicrobial Nitrile Powder Free Examination Gloves are intended to be used in the framework of medical examination and diagnostic and therapeutic procedures conducted under non-sterile conditions. Further, the use of the device is intended to help prevent cross contamination.
Its indication is stated as “Any medical condition requiring an examination, a diagnostic or therapeutic procedure on the intact skin or mucosa under non-sterile conditions”.
24. Do Oxytech Antimicrobial gloves require registration under the EU Biocidal Regulations?
The Biocides Regulation (EU) No. 528/2012 are not applicable for medical devices unless they are intended to be used for other purposes not covered by the medical device directive, in which case the Biocides Regulation shall also apply to that product insofar as those purposes are not addressed by those instruments. In our understanding, this would mean that the biocides regulation is only applicable if the gloves are intended for other non-medical purposes or if the antimicrobial feature would not be within the original purpose of the medical device. As the gloves medical purpose is to prevent infection of the patient and the antimicrobial feature supports this purpose, we believe that the biocides regulation is not applicable.
