Irradiation effects on antibody performance in the frame of biochip-based instruments development for space exploration

Abstract

International audienceSeveral instruments based on immunoassay techniques have been proposed for life-detection experiments in the framework of planetary exploration but few experiments have been conducted so far to test the resistance of antibodies against cosmic ray particles. We present several irradiation experiments carried out on both grafted and free antibodies for different types of incident particles (protons, neutrons, electrons and 12C) at different energies (between 9 MeV and 50 MeV) and different fluences. No loss of antibodies activity was detected for the whole set of experiments except when considering protons with energy between 20 and 30 MeV (on free and grafted antibodies) and fluences much greater than expected for a typical planetary mission to Mars for instance. Our results on grafted antibodies suggest that biochip-based instruments must be carefully designed according to the expected radiation environment for a given mission. In particular, a surface density of antibodies much larger than the expected proton fluence would prevent significant loss of antibodies activity and thus assuring a successful detection

Biochip-based instruments development for space exploration: influence of the antibody immobilization process on the biochip resistance to freeze-drying, temperature shifts and cosmic radiations

“…To improve the understanding of Ab surfaces resistance to space hazards in real-space constraints with cumulative effects, full-length Ab-NHS surfaces were chosen to be exposed outside the International Space Station on the EXPOSE-R2 platform (Vigier et al 2013;Cottin et al 2014). In recent results (Baqué et al 2015), our group demonstrated that Ab surfaces should have a higher density than the fluence of incident particles in order to minimize the radiation effects on Ab performances. Since DGL(G3/ G4) surfaces help to increase the number of immobilized Abs, the Ab-DGL(G3/G4) surfaces could be proposed in future exobiology experiments.…”

“…For protons, five different energies (14.4, 20.9, 25.9, 29.4 and 50.5 MeV) and two fluences (3 × 10 11 and 3 × 10 12 protons cm −2 ) were used. All the parameters are described in detail in Baqué et al (2015).…”

“…The electron irradiation is described in Baqué et al . (2015). It was performed at the Institut Bergonié (Bordeaux, France).…”

“…Recently, studies have demonstrated that cryoprotectants or thermal protectants help in stabilizing Ab chips for long-time storage, temperature shifts or freezedrying (Wang et al 2007;Baqué et al 2011;de Diego-Castilla et al 2011). Regarding the resistance to cosmic rays, the type of particles that a biochip can face in space has been defined (Le Postollec et al 2009a) and the influence of several particles on Ab has been studied (Le Postollec et al 2009b;Baqué et al 2011Baqué et al , 2015de Diego-Castilla et al 2011). These previous results suggest that the close environment (ions, storage additives) of Abs greatly influences its resistance to space constraints.…”

“…Regarding the resistance to cosmic rays, the type of particles that a biochip can face in space has been defined (Le Postollec et al . 2009a) and the influence of several particles on Ab has been studied (Le Postollec et al 2009b; Baqué et al 2011, 2015; de Diego-Castilla et al 2011). These previous results suggest that the close environment (ions, storage additives) of Abs greatly influences its resistance to space constraints.…”