High-toughness silk produced by a transgenic silkworm expressing spider (Araneus ventricosus) dragline silk protein.

Spider dragline silk is a natural fiber that has excellent tensile properties; however, it is difficult to produce artificially as a long, strong fiber. Here, the spider (Araneus ventricosus) dragline protein gene was cloned and a transgenic silkworm was generated, that expressed the fusion protein of the fibroin heavy chain and spider dragline protein in cocoon silk. The spider silk protein content ranged from 0.37 to 0.61% w/w (1.4-2.4 mol%) native silkworm fibroin. Using a good silk-producing strain, C515, as the transgenic silkworm can make the raw silk from its cocoons for the first time. The tensile characteristics (toughness) of the raw silk improved by 53% after the introduction of spider dragline silk protein; the improvement depended on the quantity of the expressed spider dragline protein. To demonstrate the commercial feasibility for machine reeling, weaving, and sewing, we used the transgenic spider silk to weave a vest and scarf; this was the first application of spider silk fibers from transgenic silkworms.

[Hygienic assessment of children's clothes made using new-generation textile auxiliaries].

The paper presents the results of sanitary-and-chemical studies of samples of tissues treated with new-generation textile auxiliaries (TAs). The application of new-generation TAs containing the lower levels of formaldehyde (FA) is shown not to eliminate the problem of their safe use in making children's clothes. The safe values for exposure to FA have been estimated in relation to the real load of a garment. The toxic action of cutaneous versus intragastric FA has been evaluated in immature rats. The clothes FA level of 20 microg/g has been found to produce no toxic effect on a living organism.