RESUMO
Exploring a nanotheranostic agent with image guided highly efficient therapeutic properties is greatly significant for tumor screening and treatment. Herein, we construct a novel nanoplatform, composed of low cost bovine serum albumin (BSA), sulfonamides (SAs) and iron porphyrin nanoscale metal organic frameworks (NMOFs), which possesses the capability of active targeting to tumor cells and magnetic resonance imaging (MRI) can be used to guide synergetic photodynamic/photothermal therapy. These constructed BSA/SAs-NMOF nanoplatforms can be accumulated more at tumor sites due to modification of the nanoparticles with BSA/SA complexes, allowing this system to achieve long circulation in vivo and to actively target to carbonic anhydrase (CA) IX of tumor cells by the SAs. Moreover, the magnetic iron ion and porphyrin serve as the metal centre and organic ligand of novel NMOFs which exhibit a T1-T2 weighted MRI effect (r1 = 2.7 mM-1 s-1 and r2 = 19.68 mM-1 s-1) and allow synergetic photodynamic/photothermal therapy of tumors. In vitro reactive oxygen species (ROS) detection and photothermal temperature change results revealed that these BSA/SAs-NMOF nanoplatforms could exhibit a great PDT effect in tumor cells, even under hypoxic conditions, and a remarkable PTT effect with a photothermal conversion efficiency of 40.53%. What's more, there was a greater fatality rate of 4T1 cancer cells in the single wavelength induced PDT & PTT group (95%) than in the PDT or PTT monotherapy groups (nearly 80%), and the growth of a solid tumor was more effectively inhibited by PDT & PTT than by single PTT or PDT. This work provides a novel nanoplatform for targeting tumor hypoxia and achieved highly efficient treatment of tumors based on PDT and PTT.
RESUMO
Polypyrrole nanoparticle (PPy) based theranostic agents for magnetic resonance imaging (MRI) guided photothermal therapy (PTT) have received increasing attention in recent years. However, the limitations of cost and biocompability still offer us opportunities to improve these agents. Considering the versatile character of polydopamine (PDA), PEGylated PPy@Fe3+-chelated PDA nanocomposites (PPDEs) were designed and prepared in an easy way. PPDE with a uniform core-shell structure could be obtained by adjusting the ratio of dopamine and PPys. In this nanocomplex, the shells confer the nanoparticles with good biocompability and MRI signal enhancing ability. Moreover, the PPy cores play a role in photothermal ablation of tumors. Compared with pure PDA nanoparticles, the PPDEs have higher NIR absorbance and better photothermal capability benefitting from the high photothermal conversion of the cores. Additionally, the obtained PPDEs provide significant MRI signal enhancement for both in vitro and in vivo imaging with high longitudinal relaxivity (r1 = 5.055 mM-1 s-1). After intravenous injection, the PPDEs exhibited valid tumor accumulation, as revealed by MRI and verified by biodistribution analysis. Under NIR irradiation, the PPDEs showed highly effective photothermal ablation of 4T1 cells. Notably, excellent biocompability of the PPDEs was confirmed by a relevant MTT assay and histologic analysis. This work achieved an example of exploiting the inherent advantages of PPy and PDA within a single unit and exploring its potential for T1 MRI-guided PTT.