Tuning riboflavin derivatives for photodynamic inactivation of pathogens.

The development of effective pathogen reduction strategies is required due to the rise in antibiotic-resistant bacteria and zoonotic viral pandemics. Photodynamic inactivation (PDI) of bacteria and viruses is a potent reduction strategy that bypasses typical resistance mechanisms. Naturally occurring riboflavin has been widely used in PDI applications due to efficient light-induced reactive oxygen species (ROS) release. By rational design of its core structure to alter (photo)physical properties, we obtained derivatives capable of outperforming riboflavin's visible light-induced PDI against E. coli and a SARS-CoV-2 surrogate, revealing functional group dependency for each pathogen. Bacterial PDI was influenced mainly by guanidino substitution, whereas viral PDI increased through bromination of the flavin. These observations were related to enhanced uptake and ROS-specific nucleic acid cleavage mechanisms. Trends in the derivatives' toxicity towards human fibroblast cells were also investigated to assess viable therapeutic derivatives and help guide further design of PDI agents to combat pathogenic organisms

Security governance : making the concept fit for the analysis of a multipolar, global and regionalized world

Recently introduced in the academic and political debate, the concept of “security governance” still needs to be clarified. In particular, to make the concept more useful for an assessment of current security dynamics, four main shortcomings need to be overcome: in the first place, attention has been devoted more to “governance” than to “security”, while greater attention should be paid to how security is understood and perceived by the actors involved in the governance system. Second, the literature is divided in two main branches, one looking at security governance predominantly by/through governmental organizations and one dealing with non-state actors: attempts should be made to give sense of coordination efforts (or lack thereof) among different actors and layers of governance, even when focussing attention predominantly on one type of actor (e.g. regional state powers). Third, the literature (with notable exceptions though) has predominantly focused on Europe and the transatlantic area: an effort should be made to look at extra-European dynamics, also with an aim to evaluate the relationship between political/security culture and security governance, as well as between political/economic development and security governance. Finally, the literature on security governance has been too often detached from reflections over regionalism, while it would be useful to explore further the relationship between cognitive definitions of regional and security dynamics. This is all the more important when considering the progressive emergence of non-European regional powers, possibly interpreting security challenges in different terms and displaying different likelihoods and modalities to arrange coordination patterns and solve security problems