Update on the spaceflight experiment “BIOFILMS”: Testing laser-structured antimicrobial surfaces under space conditions

Kurzfassung

A major concern during human space missions is microbial contamination. Biofilms are of particular importance as a potential hazard because they damage equipment and pose a health risk to astronauts. Biofilm formation can be inhibited by using antimicrobial active metals such as copper for contact surfaces. Previous studies have shown that the efficacy of copper surfaces can be increased by additional surface functionalization using ultrashort pulsed direct laser interference patterning (USP-DLIP). The antimicrobial efficacy of these surfaces under altered gravity conditions is investigated in the spaceflight experiment “BIOFILMS” onboard the International Space Station (ISS). Using the KUBIK facility in the Columbus laboratory on board the ISS, the antimicrobial efficacy of Cu/ CuZn37 surfaces with different surface topographies is tested under three different gravity levels (µg, 0.4 x g, 1 x g) and compared to inert stainless steel. Staphylococcus capitis, Cupriavidus metallidurans and Acinetobacter radioresistens were selected as bacterial model organisms that are incubated during the experiment in a specialized hardware that allows biofilm formation to occur under controlled conditions. BIOFILMS experiments will be conducted during three flights on board the ISS to accommodate the complete set of sample configurations. The first launch of BIOFILMS was in August 2021 with SpX-23, the second in June 2022 with SpX-25 and the last flight is planned for 2023 with SpX-27. The preliminary data gathered suggest that the functionalized copper surfaces are effective as antimicrobial surfaces under altered gravity conditions for the organisms tested. Here we present preliminary results from the first flight with the caveat that a complete interpretation and evaluation of the data can only be made after the completion of all three flights and post flight investigations. The results of BIOFILMS will help to make space travel safer and more sustainable by providing new insights and design capabilities in contamination control.