摘要
Iron oxide nanoparticles(IONPs)possess unique magnetism and good biocompatibility,and they have been widely applied as contrast agents(CAs)for magnetic resonance imaging(MRI).Traditional CAs typically show a fixed enhanced signal,thus exhibiting the limitations of low sensitivity and a lack of specificity.Nowadays,the progress of stimulus-responsive IONPs allows alteration of the relaxation signal in response to internal stimuli of the tumor,or external stimuli,thus providing an opportunity to overcome those limitations.This review summarizes the current status of smart IONPs as tumor imaging MRI CAs that exhibit responsiveness to endogenous stimuli,such as pH,hypoxia,glutathione,and enzymes,or exogenous stimuli,such as magnets,light,and so on.We discuss the challenges and future opportunities for IONPs as MRI CAs and comprehensively illustrate the applications of these stimuli-responsive IONPs.This review will help provide guidance for designing IONPs as MRI CAs and further promote the reasonable design of magnetic nanoparticles and achieve early and accurate tumor detection.
基金
supported by the National Natural Science Foundation of China(32000983,22027810)
the National Key R&D Program of China(2021YFA1200900)
the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB36000000)
the CAS Key Research Program for Frontier Sciences(ZDBS-LY-SLH039)
the CAMS Innovation Fund for Medical Sciences(CIFMS 2019-I2M-5-018)
the Research and Development Project in Key Areas of Guangdong Province(2019B090917011)
the Beijing Municipal Administration of Hospitals’Ascent Plan(DFL20190203).
