No abstract

Imaging systems using closed bipolar electrode (cBPE) arrays and electrochemiluminescence (ECL) have attracted great attention in recent years as a 2D imaging platform with high spatiotemporal resolution. However, the fabrication techniques for cBPE arrays involve complicated procedures. Therefore, a new fabrication scheme enabling the mass production of cBPE arrays with high precision, reproducibility, and yield, is desired. Here, the use of a versatile and scalable thermal drawing process as a novel fabrication method for fiber‐based cBPEs with feature sizes down to micro‐/nanoscales is proposed. First, a single‐electrode fiber consisting of a carbon‐based composite as the electrode material is produced by thermal drawing. The fundamental electrical properties of the single‐electrode fiber are characterized, and its applicability to the cBPE‐ECL system is demonstrated. A multielectrode fiber is fabricated by subjecting a bundle of 104 single‐electrode fibers to thermal drawing. Its usability as a cBPE array for ECL imaging is confirmed with a functional rate of 99%. Further the multielectrode fiber, utilizing the principle of thermal drawing, for magnified electrochemical imaging is tapered. This work establishes a novel mass‐production method for cBPE arrays, as well as a proof of concept for magnified electrochemical imaging using a thermally‐drawn electrode array fiber.

Preparing drug-eluting beads (DEBs) from radiopaque materials such as titania (TiO 2 ) can meet clinical need for directly visualizing DEBs during drug-eluting bead transcatheter arterial chemoembolization (DEB-TACE). Porous anatase-type TiO 2 microspheres with mean volume diameters of approximately 30 µm were obtained when silica nanoparticles (SiNPs) were introduced into the TiO 2 matrix by a sol-gel process involving a water-in-oil emulsion, and the SiNPs were then dissolved by subsequent treatment with NaOH solution. Of special note, microspheres prepared using SiNPs of approximately 20 -25 nm in diameter had a high specific surface area of~120 m 2 •g −1 and a high doxorubicin (DOX)-adsorption capacity of 150 mg•mL −1 , and they gradually released~10% of the adsorbed DOX within 5 days. The DOX-loaded microspheres were non-cytotoxic, moreover, and exerted anticancer effects on HeLa cells. We propose that the present TiO 2 microspheres are potentially useful as novel radiopaque embolic materials for DEB-TACE.