Fluorinated Ferrocene Moieties as a Platform for Redox-Responsive Polymer 19F MRI Theranostics

Long-term in vivo dissolution of thermo- and pH-responsive, 19F magnetic resonance-traceable and injectable polymer implants

19F magnetic resonance (19F MR) tracers stand out for their wide range of applications in experimental and clinical medicine, as they can be precisely located in living tissues with negligible fluorine background. This contribution demonstrates the long-term dissolution of multiresponsive fluorinated implants designed for prolonged release. Implants were detected for 14 (intramuscular injection) and 20 (subcutaneous injection) months by 19F MR at 4.7 T, showing favorable MR relaxation times, biochemical stability, biological compatibility and slow, long-term dissolution. Thus, polymeric implants may become a platform for long-term local theranostics.

Recent Research Progress of 19 F Magnetic Resonance Imaging Probes: Principle, Design, and Their Application

Visualization of biomolecules, cells, and tissues, as well as metabolic processes in vivo is significant for studying the associated biological activities. Fluorine magnetic resonance imaging (19 F MRI) holds potential among various imaging technologies thanks to its negligible background signal and deep tissue penetration in vivo. To achieve detection on the targets with high resolution and accuracy, requirements of high-performance 19 F MRI probes are demanding. An ideal 19 F MRI probe is thought to have, first, fluorine tags with magnetically equivalent 19 F nuclei, second, high fluorine content, third, adequate fluorine nuclei mobility, as well as excellent water solubility or dispersity, but not limited to. This review summarizes the research progresses of 19 F MRI probes and mainly discusses the impacts of structures on in vitro and in vivo imaging performances. Additionally, the applications of 19 F MRI probes in ions sensing, molecular structures analysis, cells tracking, and in vivo diagnosis of disease lesions are also covered in this article. From authors' perspectives, this review is able to provide inspirations for relevant researchers on designing and synthesizing advanced 19 F MRI probes.

Enhanced Coloration Time of Electrochromic Device Using Integrated WO3@PEO Electrodes for Wearable Devices

Electrochromic technologies that exhibit low power consumption have been spotlighted recently. In particular, with the recent increase in demand for paper-like panel displays, faster coloration time has been focused on in researching electrochromic devices. Tungsten trioxide (WO₃) has been widely used as an electrochromic material that exhibits excellent electrochromic performance with high thermal and mechanical stability. However, in a solid film-type WO₃ layer, the coloration time was long due to its limited surface area and long diffusion paths of lithium ions (Li-ions). In this study, we attempted to fabricate a fibrous structure of WO₃@poly(ethylene oxide) (PEO) composites through electrospinning. The fibrous and porous layer showed a faster coloration time due to a short Li-ion diffusion path. Additionally, PEO in fibers supports Li-ions being quickly transported into the WO₃ particles through their high ionic conductivity. The optimized WO₃@PEO fibrous structure showed 61.3 cm²/C of high coloration efficiency, 1.6s fast coloration time, and good cycle stability. Lastly, the electrochromic device was successfully fabricated on fabric using gel electrolytes and a conductive knitted fabric as a substrate and showed a comparable color change through a voltage change from -2.5 V to 1.5 V.