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Logic-gate operations displaying macroscopic outputs are promising systems for the development of intelligent soft materials that can perform effective functions in response to various input patterns. A supramolecular hydrogel comprising the phosphate-type hydrogelator 1 exhibits macroscopic gel-sol behavior in response to four distinct input stimuli: temperature, pH, Ca(2+), and light. We characterized this performance through microscopic, spectroscopic, and rheological measurements. On the basis of its multiple-stimulus responsiveness, we constructed gel-based supramolecular logic gates from hydrogelator 1 that demonstrated AND, OR, NAND, and NOR types of stimulus-responsive gel-sol behavior in the presence of various combinations of the four stimuli. Implementation of such logic-gate functions into semiwet soft materials (e.g., supramolecular hydrogels) is an important step toward the design of controlled drug delivery and release systems. Indeed, we demonstrate herein that one of our gel-based supramolecular logic gates is capable of holding and releasing bioactive substances in response to logic triggers. Furthermore, combining our supramolecular gel-based AND logic gate with a photoresponsive supramolecular gel could temporarily modulate the release rate of the bioactive substance.

Tutorial review: to achieve molecule-based spintronic devices, an organic conducting magnet that exhibits both conductivity and magnetism in a cooperative manner must be constructed. As a building block for such new materials, a spin-polarized donor radical, which serves as a molecular "spin-filter" in its singly oxidized state, was designed and synthesized. The resistivity of ion radical salts of selenium-substituted, tetrathiafulvalene-based spin-polarized donor radicals decreased substantially in the presence of a magnetic field, thus indicating cooperative conductivity and magnetism.

In a focused library of glycolipid-based hydrogelators bearing fumaric amide as a trans-cis photoswitching module, several new photoresponsive supramolecular hydrogelators were discovered, the gel-sol/sol-gel transition of which was pseudo-reversibly induced by light. Studying the optimal hydrogel by NMR spectroscopy and various microscopy techniques showed that the trans-cis photoisomerization of the double bond of the fumaric amide unit effectively caused assembly or disassembly of the self-assembled supramolecular fibers to yield the macroscopic hydrogel or the corresponding sol, respectively. The entanglement of the supramolecular fibers produced nanomeshes, the void space of which was roughly evaluated to be 250 nm based on confocal laser scanning microscopy observations of the size-dependent Brownian motion of nanobeads embedded in the supramolecular hydrogel. It was clearly shown that such nanomeshes become a physical obstacle that captures submicro- to micrometer-sized substrates such as beads or bacteria. By exploiting the photoresponsive property of the supramolecular nanomeshes, we succeeded in off/on switching of bacterial movement and rotary motion of bead-tethered F(1)-ATPase, a biomolecular motor protein, in the supramolecular hydrogel. Furthermore, by using the photolithographic technique, gel-sol photopatterning was successfully conducted to produce sol spots within the gel matrix. The fabricated gel-sol pattern not only allowed regulation of bacterial motility in a limited area, but also off/on switching of F1-ATPase rotary motion at the single-molecule level. These results demonstrated that the photoresponsive supramolecular hydrogel and the resulting nanomeshes may provide unique biomaterials for the spatiotemporal manipulation of various biomolecules and live bacteria.

Fluorescent sensor materials for rapidly and conveniently detecting polyamines in biological fluids are highly desirable for cancer diagnosis. We herein describe the hybridization of a supramolecular hydrogel with a layered inorganic host adsorbing a fluorescent dye which produces a fluorocolorimetric sensor for spermine and spermidine, important biomarkers for cancers, in artificial urine.

1. Sato's definition of hyperfunctions. The hyperfunctions are a class of generalized functions introduced by M. Sato [34], [35], [36] in 1958-60, only ten years later than Schwartz' distributions [40]. As we will see, hyperfunctions are natural and useful, but unfortunately they are not so commonly used as distributions. One reason seems to be that the mere definition of hyperfunctions needs a lot of preparations. In the one-dimensional case his definition is elementary. Let Ω be an open set in R. Then the space B(Ω) of hyperfunctions on Ω is defined to be the quotient space (1.1) B(Ω) = O(V \Ω)/O(V) , where V is an open set in C containing Ω as a closed set, and O(V \Ω) (resp. O(V)) is the space of all holomorphic functions on V \Ω (resp. V). The hyper-function f (x) represented by F (z) ∈ O(V \Ω) is written (1.2) f (x) = F (x + i0) − F (x − i0) and has the intuitive meaning of the difference of the "boundary values"of F (z) on Ω from above and below. V Ω Fig. 1 [233]

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