Approach on environmental risk assessment of nanosilver released from textiles.

Based on the increased utilization of nanosilver (silver nanomaterials=AgNM) as antibacterial agent, there is the strong need to assess the potential environmental implication associated with its new application areas. In this study an exemplary environmental risk assessment (ERA) of AgNM applied in textiles was performed. Environmental exposure scenarios (via municipal sewage treatment plant (STP)) with wastewater supply from domestic homes) were developed for three different types of textiles equipped with AgNM. Based on these scenarios predicted environmental concentrations (PECs) were deduced for STPs and for the environmental compartments surface water, sediment as well as soil. These PECs were related to PNECs (predicted no effect concentrations). PNECs were deduced from results of ecotoxicity tests of a selected AgNM (NM-300K). Data on ecotoxicology were derived from various tests with activated sludge, cyanobacteria, algae, daphnids, fish, duckweed, macrophytes, chironomids, earthworms, terrestrial plants as well as soil microorganisms. Emission data for the AgNM NM-300K from textiles were derived from washing experiments. The performed ERA was based on the specifications defined in the ECHA Guidances on information requirements and chemical safety assessment. Based on the chosen scenarios and preconditions, no environmental risk of the AgNM NM-300K released from textiles was detected. Under conservative assumptions a risk quotient for surface water close to 1 indicated that the aquatic compartment may be affected by an increased emission of AgNM to the environment due to the high sensitivity of aquatic organisms to silver. Based on the successful retention of AgNM in the sewage sludge and the still ongoing continual application of sewage sludge on farmland it is recommended to introduce a threshold for total silver content in sewage sludge into the respective regulations. Regarding potential risk mitigation measures, it is emphasized to preferably directly introduce AgNM into the textile fiber since this will strongly minimize the release of AgNM during washing. If this is not possible due to technical limitations or other reasons, the introduction of a threshold level controlling the release of AgNM from textiles is suggested. It has to be noted that this study is a case study which is only valid for the investigated NM-300K and its potential application in textiles.

Screening for nutritive peptides that modify cholesterol 7alpha-hydroxylase expression.

Bioactive peptides with a variety of effects have been described from several nutritive proteins. They exhibit antimicrobial, blood-pressure lowering, antithrombotic, immunomodulatory, and cholesterol-modulating effects. In this study, we have examined whether peptides derived from food proteins might influence bile acid synthesis. A reporter gene cell line that carries a cholesterol 7alpha-hydroxylase promoter fragment fused to firefly luciferase ( cyp7a-luc) was used to screen for nutritive peptides affecting cyp7a expression, the enzyme catalyzing the rate-limiting step in bile acid synthesis. Proteolytic hydrolysates were prepared from soy protein and bovine casein with pepsin, trypsin, chymotrypsin, and elastase and size fractionated using ultrafiltration. Several bioactive hydrolysates could be identified that inhibited luciferase expression. Also, an activation of kinase (AKT, ERK, p38-MAPK) signaling could be observed. Selected hydrolysates were further fractionated by reversed-phase HPLC. Bioactive HPLC-fractions were obtained from casein but not from soy hydrolysates; however, activity could not be recovered in single peak fractions. Peptides in such fractions were identified by mass spectrometry. Five selected peptides from alpha S1-casein present in active fractions were synthesized, but none of these showed activity in the cyp7a-luc screening system. However, two of them activated MAP-kinase signaling similar to the hydrolysates, which suggests, that these peptides are involved in cyp7a regulation by the casein hydrolysates.

Stable transgenic expression of IL-2 and HSV1-tk by single and fusion tumor cell lines bearing EWS/FLI-1 chimeric genes.

In augmenting systemic anti-tumor immune response, the authors evaluated the genetic modification of Ewing family tumor (EFT) cell lines for use as allogeneic vaccines. EFT cell lines A673 and RD-ES were transfected with cDNAs for human interleukin (IL)-2 and/or HSV1 thymidine kinase (HSV1-tk), respectively. Clones with high and stable secretion of IL-2 alone or with coexpression of functional HSV1-tk were obtained and their features were analyzed. IL-2 expressing clones derived from the A673 cell line demonstrated decreased expression of HLA class I molecules compared with the parental cell line and corresponding clones derived from RD-ES. However, IFN-gamma could upregulate the expression of HLA class I antigens by IL-2 transfected A673 cells. Ganciclovir induced apoptosis in double-transfected cell clones. IL-2/HSV1-tk cells continued to produce and release IL-2 after initial ganciclovir treatment. After gamma-irradiation, transfected clones released bioactive IL-2 in a quantity sufficient to activate T and natural killer cells in culture. A polyvalent allogeneic vaccine was also obtained using fusion of two different transgenic cell lines. The resulting hybrids inherited antigenic and transgenic characteristics of both parental cell lines. It is presumed that the cell lines generated here could be used as allogeneic vaccines for treatment of patients with EFTs.