Silkworm silk has outstanding mechanical properties despite being spun at room temperature and from aqueous solution. Although it has been proposed that fiber formation is mainly induced by shearing and extensional flow in the spinneret, the detailed structure and function of the spinning apparatus of Bombyx mori silkworms are still not fully elucidated. In this paper we describe three aspects of the functional microanatomy of the spinning apparatus: changes in the diameter of the silk gland duct with distance along the duct, how the birefringence of the fibroin changes as it flows down the duct, and the detailed three-dimensional structure of the silk press and related structures. The existence of a double escaped nematic liquid crystal texture in the fibroin in a region of the duct is described. After this region the birefringence suddenly disappeared until the start of an internal draw down taper which commenced just before the silk press. In the internal draw down taper the birefringence increased dramatically to an asymptotic value as a thread was drawn from the fibroin gel. The structure of the silk press suggests that it acts as a restriction die whose diameter can be regulated.

Polyion complexes (PICs) are attractive as ecofriendly materials, because they offer simple and fast preparation methods to exert various functionalities in aqueous medium. However, control of nanoarchitectures in PIC materials has not been fully realized, except for the case of micelles and unilamellar vesicles formed from block ionomers. Here, the procedure to control PIC nanoarchitectures with various morphologies was established for the first time by careful tuning in the composition of PICs made from PEGbased block-ionomers with a varying amount of homoionomers as additive to modulate the PEG weight fraction (f PEG ) in the obtained PICs. Accordingly, the variation in f PEG from 12.1% to 6.5% induced vigorous transition in the microphase separated structures of PICs basically from micelle to lamella via cylindrical network. Notably, uniformed lamella with alternative layers of PEG and PIC domains was found at elevated temperature (70 °C), which, by lowering temperature, reversibly transformed to cylindrical PIC network apparently with connected aqueous channel in mesoscopic scale.

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