Permeability retrieval in InP-based waveguide optical device combined with metamaterial

An InP-based Mach-Zehnder interferometer combined with a metamaterial layer consisting of a split-ring resonator array was constructed to measure the complex permeability of the metamaterial. At a wavelength of 1.5 μm, the metamaterial showed non-unity relative permeability induced by magnetic interaction with propagating light in the device. This method of measurement would be useful to determine constitutive parameters in such waveguide-based photonic devices, allowing us to design photonic integrated circuits that make use of metamaterials.     

Suppressed Migration and Enhanced Cisplatin Chemosensitivity in Human Cancer Cell Lines by Tuning the Molecular Mobility of Supramolecular Biomaterials

Cancer cells recognize physical cues transmitted from the surrounding microenvironment, and accordingly alter the migration and chemosensitivity. Cell adhesive biomaterials with tunable physical properties can contribute to the understanding of cancer cell responses, and development of new cancer therapies. Previously, it was reported that polyrotaxane-based surfaces with molecular mobility effectively modulate cellular functions via the yes-associated protein (YAP)-related signaling pathway. In the present study, the impact of molecular mobility of polyrotaxane surfaces on the migration and chemosensitivity of lung (A549), pancreatic (BxPC-3), and breast cancer (MDA-MB-231) cell lines is investigated, and it is found that the cellular spreading of adherent A549 and BxPC-3 cells and nuclear YAP translocation are promoted on low-mobility surfaces, suggesting that cancer cells alter their subcellular YAP localization in response to molecular mobility. Furthermore, low-mobility surfaces suppress cellular migration more than high-mobility surfaces. Additionally, low-mobility surfaces promote the cisplatin chemosensitivity of each cancer cell line to a greater extent than high-mobility surfaces. These results suggest that the molecular mobility of polyrotaxane surfaces suppresses cellular migration and enhances chemosensitivity via the subcellular translocation of YAP in cancer cells. Biointerfaces based on polyrotaxanes can thus be a new platform for elucidating cancer cell migration and chemoresistance mechanisms.     

Thermally switchable polyrotaxane as a model of stimuli-responsive supramolecules for nano-scale devices

A polyrotaxane consisting of many β-cyclodextrins (β-CDs) and a triblock copolymer of poly(ethylene glycol) (PEG) and poly(propylene glycol) (PPG) capped with bulky end-groups was synthesized as a model of stimuli-responsive supramolecules for nanoscale devices. The polyrotaxane was reversibly soluble-insoluble in water in response to temperature. This was achieved through the assembled and dispersed states of β-CDs along the block copolymer. It is considered that intermolecular hydrogen bondings of β-CDs, as well as the PEG segment length of the copoloymer, are predominant factors for regulating such thermally switchable behavior of the polyrotaxane.     

Supramolecular network formation through inclusion complexation of an α‐cyclodextrin‐based molecular tube

The supramolecular network formation through inclusion complexation between α‐cyclodextrin‐based molecular tube (MT) and poly(ethylene oxide) monocetylether‐graft‐dextran (5C₁₆PEO‐g‐Dex40) was demonstrated. From isothermal titration calorimetric (ITC) measurement, it was confirmed that MT formed an inclusion complex with two C₁₆PEO side chains in 5C₁₆PEO‐g‐Dex40. From viscosity measurements, the specific viscosity of the solution containing MT and 5C₁₆PEO‐g‐Dex40 was much larger than that containing 5C₁₆PEO‐g‐Dex40. It is considered that MT participates in the supramolecular network formation of 5C₁₆PEO‐g‐Dex40 through inclusion complexation with two C₁₆PEOs grafted to independent Dex40s.