Surface silanols as key descriptor of the silica hazard – Experimental validation
The variability of quartz hazard stands as one of the most puzzling issues in particle toxicology. However, a few gaps are still present in the physico-chemical determinants and cellular pathways involved in the mechanisms of silica pathogenicity (Donaldson & Borm, 1998; Pavan & Fubini, 2017). In our recent investigations, we produced quartz crystals of respirable size, exposing intact crystal faces, which did not show a biological reactivity in a series of toxicologically relevant tests (Pastero et al., 2016; Turci et al., 2016). Mechanical grinding of these unique crystal samples largely increased their activity. By combining the knowledge acquired with these synthetic quartz crystals and with a large set of silica samples (both amorphous and crystalline) from previous studies (Pavan et al., 2013; Pavan et al., 2014; Pavan et al., 2017), we newly propose silica surfaces characterized by heterogeneous and disorganized silanol patterns available for H-bonding with external molecules, such as after fracturing, as the peculiar surfaces that can promote membrane damage and inflammation, a process at the origin of silica-related diseases. We hypothesize that characterizing these specific silanols through physico-chemical and in vitro analyses will allow identifying the pathogenic activity of silica materials. In this sense, the project aims to develop a set of assays to identify and predict the respiratory hazard of quartz particles based on the analysis of silanol distribution and to validate this approach in vivo.
On Sep. 27-28th we organized the Workshop "Silica: Are We Bridging the Gaps between Surface States and Toxicity?". The Workshop gathered in Torino a multidisciplinar yet highly focused group of European researchers active in fields fundamental for silica toxicology. For two days, we openly shared knowledges and ideas to pave the road to a novel understanding of the key molecular events involved in the various steps of crystalline silica interaction with cell and tissue in the human body.
You can download the Book of Abstract and the Speakers' presentations here:
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Our bibliography on the subject:
Pavan et al., 2013 (DOI: 10.1021/tx400105f)
Pavan et al., 2014 (DOI: 10.1186/s12989-014-0076-y)
Pastero et al., 2016 (DOI: 10.1021/acs.cgd.6b00183)
Pavan et al., 2016 (DOI: 10.1093/toxsci/kfw101)
Turci et al., 2016 (DOI: 10.1186/s12989-016-0136-6)
Pavan & Fubini, 2017 (DOI: 10.1021/acs.chemrestox.6b00409)
Pavan et al., 2017 (DOI: 10.1016/j.colsurfb.2017.06.012)