Klaus Slenzka

Bio-inspired Polyphenolic Adhesives for Medical and Technical Applications

Nature has been developing adhesives for millions of years, mankind for just a few thousands of years. For this reason it is worth having a closer look at what nature does and how we can develop bio-inspired adhesives for technical and medical applications. Some examples of natural materials which have already been used for technical adhesives are casein, latex rubber, tree gum, and adhesives derived from natural sources used for the waterproofing of natural textiles, the production of paper, and the sealing of jars (Papov et al., 1995; Creton and Papon, 2003). Bio-inspired adhesives can be found in all areas of the natural world. Because of their origin, those adhesives are also called biological adhesives or bioadhesives and they fulfill several different functions (Smith and Callow, 2006; Carrington, 2008; Antonietti and Fratzl, 2010). Plants use adhesives, for example, for self-healing and for protecting themselves against wood defects, while animals use sticky materials for protecting themselves against predators and for hunting prey (Keckes et al., 2003; Schreiber et al., 2005; Flammang, 2006; Voigt and Gorb, 2008; Plaza et al., 2009). Microorganisms use adhesive material for settlement, surface attachment, and colonization (Melzer et al., 2008; Flammang et al., 2009; Santos et al., 2009; Scholz et al., 2009). Higher organisms, such as humans, rely on an inducible adhesive system: the wound healing promoter fibrinogen ((Berlind et al., 2010), which is discussed in detail in Chapter 15, p. 225 of this book).

Alternative concepts for microorganism induced hydrogen and oxygen release on outer space bodies - Bio-ISRU

2, 3 The limiting factor for the endurance of a long ter m spaceflight to reach outer space bodies is the fi nite energy supply to run devices and motors for spacecrafts as well as for local habitats. The fuel weight and volume makes embedding of local resources necessary to allow extension to long term missions. Some biological organisms demonstrate how to survive in extreme environments. The micro algae Chlamydomonas reinhardtii release elementary hydrogen from water by the use of the enzyme hydrogenase under special sulphur free nutrition and absence of oxygen. The same organism release oxygen under standard conditions, the counterpart of hydrogen to operate fuel cells. Planets of interests for exploration mission are co vered by potential toxic soil called “Regolith”. Lunar Regol ith is known to be extremely aggressive and might i nhibit cells growth not only due to its sharp edges. But f irst studies on lunar soil simulant tolerance of Chl. reinhardtii have shown promising results while photosynthesis rate was not negatively influenced. Single cells surround the substrate, without any negative influe nce, by extracting a 3-dimensional tissue like matr ix. This enables Chl. reinhardtii to become a first settler organism of the lunar su rface, maybe a first step of terraforming to allow the growth of higher organisms. To elucidate the terraforming aspect of microorganisms, additional experiments on Arabidopsis thaliana grown on Chl. reinhardtii and HS medium treated Lunar and Martian Soil were performed. These preliminary tests show shooting of the seeds follow ed by a reduced growth which might be influenced by the high salt concentration of the micro algae culture medium. Sterile water treated soil did not show the reduced growth effect in Martian Soil simulant and the shoo ts became small plants.