Soft Matter
Paper
Conclusions
In summary, we prepared a series of novel shell cross-linked
micelles with detachable PEG corona, which self-assembled
from PEG-SS-PLys-PLeu copolymers. The micelles were stable in
PBS buffer, while they underwent destruction of the cross-
linked shell with detachment of PEG corona in the presence of
GSH due to the cleavage of disulde bonds. The cell internali-
zation experiment conrmed that the micelles could be
successfully internalized into HeLa cells. The in vitro drug
release study showed that the micelles exhibited reduced drug
loss in extracellular environments and accelerated drug release
at the cytoplasmic GSH level. These glutathione-responsive
micelles have great potential in intracellular drug delivery.
Fig. 9 Flow cytometric analysis of non-pretreated and GSH-OEt pretreated HeLa
cells incubated with CPT-loaded micelles for 4 h.
Acknowledgements
This work was nancially supported by the Ministry of Science
CPT-loaded SCL micelles. The cell viability is shown in Fig. 6b. and Technology of China (2011CB606202), National Natural
Noticeably, the cell viability of the cells pretreated with GSH-OEt Science Funds for Distinguished Young Scholar (51125014),
was much lower than that of the cells without pretreatment, Program for Changjiang Scholars and Innovative Research
which illustrated that the CPT-loaded SCL micelles showed Team in University (IRT1030) and the Fundamental Research
remarkably enhanced drug release in the cells pretreated with Funds for the Central Universities.
GSH-OEt.
Notes and references
Confocal laser scanning microscopy observation
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cell nucleus location by coloration with Hoechst 33258. From
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98 | Soft Matter, 2013, 9, 692–699
This journal is ª The Royal Society of Chemistry 2013