Antimicrobial Surfaces for Applications on Confined Inhabited Space Stations

Abstract

An overview of the current surface treatments/coatings that introduce antimicrobial properties to the exposed surfaces in confined space stations is provided. General aspects, such as biofilm formation and the specific requirements associated with this application, are discussed. Antimicrobial coatings used on the International Space Station (ISS) are reviewed. A selection of commercial and developed coatings targeting space applications is presented. Also, some developments that can be used in the space industry are highlighted.

Mitigation and use of biofilms in space for the benefit of human space exploration

“…This includes understanding how microorganisms become deposited on surfaces, which is likely through means of direct contact and air circulation since aerosol settling is not a factor in microgravity [ 38 ]. There are also questions regarding the importance of the surface material in the development and morphology of the dry biofilm [ 11 ]; UC Boulder Space Biofilms, 2019; [ 39 ]. Once deposited, it needs to be assessed how the ‘sticky’ matrix can hold the microorganisms in place.…”

“…Furthermore, evaluation of how the biofilms can collect organic and other materials as well as nutrients is important [ 11 ]. Possible detrimental impacts of biofilm growth have been identified, including (1) microbially induced corrosion (MIC) or blockage of mechanical components, (2) detriment to human health through infection or allergy response, (3) potential to harbor pathogens to both humans and plants, and (4) the development of antimicrobial resistance [ [39] , [40] , [41] ].…”

“…Given that wipes are frequently employed on the ISS, it is presumed that this provides mechanical removal of the dried biofilm, and thus is beneficial in achieving both aims. Finally, precaution must always be taken to consider the toxicity of the compounds used for cleaning, especially when cleaning with volatiles within a closed system like the ISS [ 39 ].…”

“…While antimicrobial surfaces have been extensively explored as an approach to control microbial contamination on hard, non-porous, and high-touch surfaces in a hospital environment, the use of antimicrobial surfaces has not yet been implemented on the ISS [ 39 , 45 ]. However, studies by the European Space Agency (ESA) and Boeing are ongoing aboard the ISS to assess the antimicrobial nature of materials for use in future applications [ 46 , 47 ].…”

Antimicrobial and Aging Properties of Ag-, Ag/Cu-, and Ag Cluster-Doped Amorphous Carbon Coatings Produced by Magnetron Sputtering for Space Applications

“…To combat the threats from overgrown microorganisms, the employment of chemicals and disinfectants 3 has been proposed and studied; however, the use of antimicrobial coatings to control microbiological growth in a space station has emerged as a more effective and sustainable solution. Very recently, Wang et al published a thorough and detailed review 4 on the topic of antimicrobial surfaces for applications on confined inhabited space stations, in which a selection of commercial and developed coatings targeting space applications was summarized. It was concluded that although the approach of organic biocompatible coatings presents fewer health issues, the durability of such coatings under operational conditions is a formidable challenge to be tackled.…”