Upconversion emission dynamics have long been believed to be determined by the activator and its interaction with neighboring sensitizers. Herein this assumption is, however, shown to be invalid for nanostructures. We demonstrate that excitation energy migration greatly affects upconversion emission dynamics. “Dopant ions’ spatial separation” nanostructures are designed as model systems and the intimate link between the random nature of energy migration and upconversion emission time behavior is unraveled by theoretical modelling and confirmed spectroscopically. Based on this new fundamental insight, we have successfully realized fine control of upconversion emission time behavior (either rise or decay process) by tuning the energy migration paths in various specifically designed nanostructures. This result is significant for applications of this type of materials in super resolution spectroscopy, high‐density data storage, anti‐counterfeiting, and biological imaging.
Efficient
and cancer cell-targeted delivery of photosensitizer (PS) and therapeutic
protein has great potentiality for improving the anticancer effects.
Herein, zeolitic imidazolate framework-8 (ZIF-8) nanoparticles, one
of the most attractive metal–organic framework materials, were
used for coencapsulating the chlorin e6 (Ce6, a potent PS) and cytochrome c (Cyt c, a protein apoptosis inducer);
then the nanoparticle was subsequently decorated with the hyaluronic
acid (HA) shell to form cancer cell-active targeted nanoplatform (Ce6/Cyt c@ZIF-8/HA). The in vitro and in
vivo experiments show the cancer cell targeting capability
and pH-responsive decomposition and the release behavior of Ce6/Cyt c@ZIF-8/HA. Upon light irradiation, the released Ce6 produced
cytotoxic reactive oxygen species for photodynamic therapy. Meanwhile,
the released Cyt c-induced programmed cell death
for protein therapy. Furthermore, the Cyt c worked
normally under hypoxia conditions and could decompose H2O2 to O2 (with peroxidase-/catalase-like activity),
resulting in synergistically improved therapeutic efficiency. These
small molecules and protein codelivery nanoplatforms would promote
the development of complementary and synergetic modes for biomedical
applications.
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