The ability to predict the skin sensitization potential of small organic molecules is of high importance to the development and safe application of cosmetics, drugs and pesticides. One of the most widely accepted methods for predicting this hazard is the rodent local lymph node assay (LLNA). The goal of this work was to develop in silico models for the prediction of the skin sensitization potential of small molecules that go beyond the state of the art, with larger LLNA data sets and, most importantly, a robust and intuitive definition of the applicability domain, paired with additional indicators of the reliability of predictions. We explored a large variety of molecular descriptors and fingerprints in combination with random forest and support vector machine classifiers. The most suitable models were tested on holdout data, on which they yielded competitive performance (Matthews correlation coefficients up to 0.52; accuracies up to 0.76; areas under the receiver operating characteristic curves up to 0.83). The most favorable models are available via a public web service at https://nerdd.zbh.uni-hamburg.de/skinDoctor/ that, in addition to predictions, provides assessments of the applicability domain and indicators of the reliability of the individual predictions.

Blood-derived products (BP) like citrate-platelet-rich plasma (CPRP) or hyperacute serum (HAS) are known to contain many growth factors. Combined mitogenic and DNA damaging stimuli might lead to increased senescent cell burden and altered senescence-associated secretory pheno-type (SASP). Therefore, the senescent state was extensively tested by γH2AX staining, p21 Q-PCR and western blot, growth curves and senescence associated ß-galactosidase staining. Two main treatments with BP were performed early (immediately after etoposide) and late (after addition-al 11days). Effects of the BP treatment was evaluated by IL-6 and IL-8 measurement as well as collagen (COL1) and p21 mRNA expression. Additionally, XTT assays, cell size measurements, viability assays, and cell number calculations were performed. HAS treated cells in early treat-ment had the lowest observed IL-6 and IL-8. In contrast, there was a clear inflammatory response for IL-8 on HAS and CPRP treated cells in late treatment. For COL1 expression an upregulation in early treatment could be shown, meanwhile cells in the late treatment group remained unaf-fected. In CPRP treated cells, the COL1 expression decreased. All in all, BP treatment seems to have slightly positive effects regarding skin rejuvenation.