Light-Controlled Chemical Reaction Pathways in Disulfide-Based Nonequilibrium Systems

Pathway selection in a complex chemical reaction network(CRN)enables organisms to adapt,evolve,and even learn in response to changing environments.Inspired by this,herein we report an artificial system,where light signal was used to manipulate the reaction pathways in a disulfide-based nonequilibrium CRN.By changing the photon energy and irradiation window,the anion or new radical-mediated pathways were selectively triggered,resulting in a user-defined evolution pathway.Additional photodissipative cycles were achieved by UV(365 nm)irradiation,increasing the total number of reactions from 3 to 7.The emerging pathway selection of the CRN is accurately predictable and controllable even in complex organo-hydrogel materials.We demonstrate up to five-state autonomous sol-gel transitions and the formation of fuel-driven dissipative organo-hydrogel through both chemical and light input.This work represents a new approach to allowing CRNs to communicate with the environment that can be used in the development of materials with lifelike behaviors.

Molecular imaging of advanced atherosclerotic plaques with folate receptor-targeted 2D nanoprobes

Vulnerable atherosclerotic plaques are responsible for most cardiovascular diseases(CVDs).Folate receptor(FR)positive activated macrophages were thought to be a prominent component in the development of vulnerable plaque.The objective of this study is to develop folate conjugated two-dimensional(2D)Pd@Au nanomaterials(Pd@Au-PEG-FA)for targeted multimodal imaging of the FRs in advanced atherosclerotic plaques.Pharmacokinetic and imaging studies(single photon emission computed tomography(SPECT),computed tomography(CT)and photoacoustic(PA)imaging)were performed to confirm the prolonged blood half-life and enrichment of radioactivity in atherosclerotic plaques.Strong signals were detected in vivo with SPECT,CT and PA imaging in heavy atherosclerotic plaques,which were significantly higher than those of the normal aortas after injection of Pd@Au-PEG-FA.Blocking studies with preinjection of excess FA could effectively reduce the targeting ability of Pd@Au-PEG-FA in atherosclerotic plaques,further demonstrating the specific binding of Pd@Au-PEG-FA for plaque lesions.Histopathological characterization revealed that the signal of probe was in accordance with the high-risk plaques.In summary,the Pd@Au-PEG-FA has favorable pharmacokinetic properties and provides a valuable approach for detecting high-risk plaques in the presence of FRs in atherosclerotic plaques.