posted on 2020-03-12, 13:35authored byArif Gulzar, Zhao Wang, Fei He, Dan Yang, Fangmei Zhang, Shili Gai, Piaoping Yang
Photodynamic therapy (PDT) is commonly
employed in clinics to treat
the cancer, but because of the hypoxic tumor microenvironment prevalent
inside tumors, PDT therapeutic efficiency is not adequate hence limiting
the effectiveness of PDT. Therefore, we designed a nanocomposite consisting
of reduced nanographene oxide (rGO) modified with polyethylene glycol
(PEG), manganese dioxide (MnO2), upconversion nanoparticles
(UCNPs), and Chlorin e6 (Ce6) to spark oxygen production from H2O2 with the aim of relieving the tumor hypoxic
microenvironments. For in vivo tumor PDT and photothermal
therapy (PTT), UCNPs-Ce6-labeled rGO-MnO2-PEG nanocomposites
were used as a therapeutic agent, augmenting the therapeutic efficiency
of PDT via redox progression through the catalytic H2O2 decomposition pathway and further achieving excellent tumor
inhibition. It is important to mention that degradation of MnO2 in an acidic cellular microenvironment leads to the creation
of a massive volume of Mn2+ which was employed as a contrast
mediator for magnetic resonance imaging (MRI). Our research postulates
an approach to spark O2 formation through an internal stimulus
to augment the efficiency of MRI- and computerized tomography (CT)-imaging-guided
PDT and PTT.