An innovative, preventive acting “bioinspired” antimicrobial surface based on peptides for space and Earth

Abstract

Antimicrobial surfaces are a well suited technology to prevent and reduce microbial loads in sensitive areas, where high humidity and temperature levels are causing increased microbial loads. These can endanger human health, health of organisms e.g. in bioregenerative life-support systems as well as technical equipment. Antimicrobial surfaces are preventively beneficial • in spaceflight – e.g. in confined environments in LEO and during exploration activities, to support breeding activities of e.g. algae in bioreactors and for biological experiments, and furthermore to meet the COSPAR planetary protection policy • as well as also on Earth - in hygiene areas during medical activities and food handling, in swimming baths, bathrooms, public transportation, submarines, greenhouses etc. For its dedicated use in space as well as on Earth, antimicrobial surfaces must be free of any toxic substance, otherwise higher non-target organisms would be affected. That means, that synthetic chemicals, silver, copper etc., as used until now, are not a suited solution - which in addition might lead to resistances of the bacteria to these toxic substances and are acting rather unspecific. A suited alternative to overcome these problems are bioinspired technologies as using antimicrobial peptides from nature (e.g. from frog skin etc.), immobilized on surfaces. High flexibility concerning the microbial target, acting specifically, low toxicity and an absence of resistances are the main advantages. As a logical step, the goal of the ESA-funded project BALS (Bioinspired antimicrobial lacquer for space) was the development of a new innovative antimicrobial acting lacquer based on peptides. Project partners were OHB System, Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM) (both Bremen, Germany) as well as the German Aerospace Center, Institute of Aerospace Medicine (Cologne, Germany). The developed antimicrobial lacquer with immobilized peptides showed an antimicrobial activity against S. cohnii and E. coli, compared to a reference lacquer without peptides. Its adhesion strength on space relevant substrates was demonstrated in a ECSS-Q-70-13A-test series, measuring the peel and pull-off strength using pressure-sensitive tapes. In addition, the absence of effects on higher organisms and the environment was shown in a laboratory aquatic biological multispecies test system (AquaHab®). With the successful demonstration of feasibility and use (TRL 4) of such a bioinspired antimicrobial lacquer and including these promising test results, all preconditions are now given for the further development and qualification until a full commercial exploitation, ready to be used in application fields in space and on Earth.