Teaching Responsible Research and Innovation: A Phronetic Perspective.

Across the European research area and beyond, efforts are being mobilized to align research and innovation processes and products with societal values and needs, and to create mechanisms for inclusive priority setting and knowledge production. A central concern is how to foster a culture of "Responsible Research and Innovation" (RRI) among scientists and engineers. This paper focuses on RRI teaching at higher education institutions. On the basis of interviews and reviews of academic and policy documents, it highlights the generic aspects of teaching aimed at invoking a sense of care and societal obligation, and provides a set of exemplary cases of RRI-related teaching. It argues that the Aristotelian concept of phronesis can capture core properties of the objectives of RRI-related teaching activities. Teaching should nurture the students' capacity in terms of practical wisdom, practical ethics, or administrative ability in order to enable them to act virtuously and responsibly in contexts which are often characterized by uncertainty, contention, and controversy.

Fluorophore labeling of a cell-penetrating peptide significantly alters the mode and degree of biomembrane interaction.

The demand for highly efficient macromolecular drugs, used in the treatment of many severe diseases, is continuously increasing. However, the hydrophilic character and large molecular size of these drugs significantly limit their ability to permeate across cellular membranes and thus impede the drugs in reaching their target sites in the body. Cell-penetrating peptides (CPP) have gained attention as promising drug excipients, since they can facilitate drug permeation across cell membranes constituting a major biological barrier. Fluorophores are frequently covalently conjugated to CPPs to improve detection, however, the ensuing change in physico-chemical properties of the CPPs may alter their biological properties. With complementary biophysical techniques, we show that the mode of biomembrane interaction may change considerably upon labeling of the CPP penetratin (PEN) with a fluorophore. Fluorophore-PEN conjugates display altered modes of membrane interaction with increased insertion into the core of model cell membranes thereby exerting membrane-thinning effects. This is in contrast to PEN, which localizes along the head groups of the lipid bilayer, without affecting the thickness of the lipid tails. Particularly high membrane disturbance is observed for the two most hydrophobic PEN conjugates; rhodamine B or 1-pyrene butyric acid, as compared to the four other tested fluorophore-PEN conjugates.

Cellular Effects and Delivery Propensity of Penetratin Is Influenced by Conjugation to Parathyroid Hormone Fragment 1-34 in Synergy with pH.

The cell-penetrating peptide (CPP) penetratin has demonstrated potential as a carrier for transepithelial delivery of cargo peptides, such as the therapeutically relevant part of parathyroid hormone, i.e., PTH(1-34). The purpose of the present study was to elucidate the relevance of pH for PTH(1-34)-penetratin conjugates and coadministered penetratin with PTH(1-34) regarding transepithelial permeation of PTH(1-34) and cellular effects. Transepithelial permeation was assessed using monolayers of the Caco-2 cell culture model, and effects on Caco-2 cellular viability kinetics were evaluated by using the Real-Time-GLO assay as well as by microscopy following Tryphan blue staining. Morphological Caco-2 cell changes were studied exploiting the impedance-based xCELLigence system as well as optically using the oCelloscope setup. Finally, the effect of pH on the folding propensity of the PTH(1-34)-penetratin conjugate and its ability to disrupt lipid membranes were assessed by circular dichroism (CD) spectroscopy and the calcein release assay, respectively. The transepithelial PTH(1-34) permeation was not pH-dependent when applying the coadministration approach. However, by applying the conjugation approach, the PTH(1-34) permeation was significantly enhanced by lowering the pH from 7.4 to 5 but also associated with a compromised barrier and a lowering of the cellular viability. The negative effects on the cellular viability following cellular incubation with the PTH(1-34)-penetratin conjugate were moreover confirmed during real-time monitoring of the Caco-2 cell viability as well as by enhanced Tryphan blue uptake. In addition, morphological changes were primarily observed for cells incubated with the PTH(1-34)-penetratin conjugate at pH 5, which was moreover demonstrated to have an enhanced membrane permeating effect following lowering of the pH from 7.4 to 5. The latter observation was, however, not a result of better secondary folding propensity at pH 5 when compared to pH 7.4.

Fluorophore labeling of a cell-penetrating peptide induces differential effects on its cellular distribution and affects cell viability.

Cell-penetrating peptides constitute efficient delivery vectors, and studies of their uptake and mechanism of translocation typically involve fluorophore-labeled conjugates. In the present study, the influence of a number of specific fluorophores on the physico-chemical properties and uptake-related characteristics of penetratin were studied. An array of seven fluorophores belonging to distinct structural classes was examined, and the impact of fluorophore labeling on intracellular distribution and cytotoxicity was correlated to the physico-chemical properties of the conjugates. Exposure of several mammalian cell types to fluorophore-penetratin conjugates revealed a strong structure-dependent reduction in viability (1.5- to 20-fold lower IC50 values as compared to those of non-labeled penetratin). Also, the degree of less severe effects on membrane integrity, as well as intracellular distribution patterns differed among the conjugates. Overall, neutral hydrophobic fluorophores or negatively charged fluorophores conferred less cytotoxicity as compared to the effect exerted by positively charged, hydrophobic fluorophores. The latter conjugates, however, exhibited less membrane association and more clearly defined intracellular distribution patterns. Thus, selection of the appropriate flurophore is critical.

Human urinary excretion and metabolism of (82)Se-enriched selenite and selenate determined by LC-ICP-MS.

Urinary excretion of selenium after ingestion of isotope labeled selenite and selenate was studied in seven healthy volunteers, 4 men and 3 women (age 28-50 years). An aqueous solution containing 330 µL (82)Se-selenate (corresponding to 74.3 µg (82)Se) was given orally and urine samples were subsequently collected during the following 24 hours. The scheme was repeated four weeks later with a 280 µL (82)Se-selenite solution (corresponding to 74.4 µg (82)Se). The amount of total Se in the urine samples was determined by inductively coupled mass spectrometry. The mean total urinary excretion of (82)Se following (82)Se-selenate administration was 33.7% (range 15.6-42.5%) while the mean total excretion of (82)Se after (82)Se-selenite administration was 3.2% (range 2.8-3.9%) of the ingested amount. LC-ICPMS analysis of the urine samples showed that the majority of the selenium excreted after selenate ingestion was unchanged selenate for 6 of the individuals while one individual had metabolized a fraction (approx. 20%) of the selenate to selenosugar. Ingestion of 10 times larger doses of selenite in two individuals resulted in 13-23% excretion primarily excreted as selenosugar. These results show that the human metabolic pathways of selenite and selenate are different and indicate that not all selenate, although well absorbed, may be available for the beneficial health effects.