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Pyropheophorbide A and c(RGDyK) Comodified Chitosan-Wrapped Upconversion Nanoparticle for Targeted Near-Infrared Photodynamic Therapy
journal contribution
posted on 2012-06-04, 00:00 authored by Aiguo Zhou, Yanchun Wei, Baoyan Wu, Qun Chen, Da XingNear-infrared (NIR)-to-visible upconversion nanoparticle
(UCNP)
has shown promising prospects in photodynamic therapy (PDT) as a drug
carrier or energy donor. In this work, a photosensitizer pyropheophorbide
a (Ppa) and RGD peptide c(RGDyK) comodified chitosan-wrapped NaYF4:Yb/Er upconversion nanoparticle UCNP-Ppa-RGD was developed
for targeted near-infrared photodynamic therapy. The properties of
UCNP-Ppa-RGD, such as morphology, stability, optical spectroscopy
and singlet oxygen generation efficiency, were investigated. The results
show that covalently linked pyropheophorbide a molecule not only is
stable but also retains its spectroscopic and functional properties.
In vitro studies confirm a stronger targeting specificity of UCNP-Ppa-RGD
to integrin αvβ3-positive U87-MG
cells compared with that in the corresponding negative group. The
photosensitizer-attached nanostructure exhibited low dark toxicity
and high phototoxicity against cancer cells upon 980 nm laser irradiation
at an appropriate dosage. These results represent the first demonstration
of a highly stable and efficient photosensitizer modified upconversion
nanostructure for targeted near-infrared photodynamic therapy of cancer
cells. The novel UCNP-Ppa-RGD nanoparticle may provide a powerful
alternative for near-infrared photodynamic therapy with an improved
tumor targeting specificity.