An Optic/Proton Dual-Controlled Fluorescence Switch based on Novel Photochromic Bithienylethene Derivatives

A simple method for the synthesis of new bithienylethenes bearing a functional group on the cyclopentene moi- ety is developed. Three new photochromic compounds （4a, 4b, 4c） have been successfully synthesized through this simple method, and exhibit good photochromic properties with alternate irradiation of ultraviolet and visible light. Furthermore, the fluorescence of compound 4a, which bears a quinoline unit on the cyclopentene, can be modulated via optic and proton dual inputs. Upon excitation by 320 nm light, 4a emits a strong fluorescence at 404 nm. After irradiation with 254 nm light, the emission intensity is reduced due to the fluorescence resonance energy transfers （FRET） from quinoline unit to bithienylethene unit. Moreover, on addition of H~, the fluorescence is quenched completely due to the protonation of the quinoline. In addition, both the FRET and protonation process are reversi- ble, which indicates a potential application in molecular switches and logic gates.

An FPS-ZM1-encapsulated zeolitic imidazolate framework as a dual proangiogenic drug delivery system for diabetic wound healing

Inhibitors that target diabetes pathology-related signaling pathways have great therapeutic potential for diabetic wound healing.Metal–organic frameworks(MOFs)are increasingly popular drug delivery systems that have high loading capacity and can release their intrinsic metal ions to act as bioactive agents.In light of this,a receptor for advanced glycation end products(RAGE)inhibitor,4-chloro-N-cyclohexyl-N-(phenylmethyl)-benzamide(FPS-ZM1),was loaded into a cobalt(Co)-based MOF(zeolitic imidazolate framework-67,ZIF-67)to fabricate FPS-ZM1 encapsulated ZIF-67(FZ@ZIF-67)nanoparticles(NPs).As a result,FZ@ZIF-67 NPs could dually deliver Co ions and FPS-ZM1 in a controlled manner for over 14 days.Our in vitro study showed that FZ@ZIF-67 NPs not only enhanced angiogenesis by delivering Co ions but also released FPS-ZM1 to promote M2 macrophage polarization and attenuated high glucose(HG)-and/or inflammation-induced impairment of angiogenesis through RAGE inhibition.Moreover,in an in vivo study,FZ@ZIF-67 NPs markedly improved re-epithelialization,collagen deposition,neovascularization,and relieved inflammation in diabetic wounds in rats.This study not only provides a low-cost,effective,and synergistic proangiogenic bioactive agent but also demonstrates that targeting diabetes-related pathological signaling pathways is necessary to ameliorate vascularization impairment during diabetic wound healing.