title: PEG-functionalized iron oxide nanoclusters loaded with chlorin e6 for targeted, NIR light induced, photodynamic therapy.
abstract: Magnetic targeting that utilizes a magnetic field to specifically delivery theranostic agents to targeted tumor regions can greatly improve the cancer treatment efficiency. Herein, we load chlorin e6 (Ce6), a widely used PS molecule in PDT, on polyethylene glycol (PEG) functionalized iron oxide nanoclusters (IONCs), obtaining IONC-PEG-Ce6 as a theranostic agent for dual-mode imaging guided and magnetic-targeting enhanced in vivo PDT. Interestingly, after being loaded on PEGylated IONCs, the absorbance/excitation peak of Ce6 shows an obvious red-shift from ~650 nm to ~700 nm, which locates in the NIR region with improved tissue penetration. Without noticeable dark toxicity, Ce6 loaded IONC-PEG (IONC-PEG-Ce6) exhibits significantly accelerated cellular uptake compared with free Ce6, and thus offers greatly improved in vitro photodynamic cancer cell killing efficiency under a low-power light exposure. After demonstrating the magnetic field (MF) enhanced PDT using IONC-PEG-Ce6, we then further test this concept in animal experiments. Owing to the strong magnetism of IONCs and the long blood-circulation time offered by the condensed PEG coating, IONC-PEG-Ce6 shows strong MF-induced tumor homing ability, as evidenced by in vivo dual modal optical and magnetic resonance (MR) imaging. In vivo PDT experiment based magnetic tumor targeting using IONC-PEG-Ce6 is finally carried out, achieving high therapeutic efficacy with dramatically delayed tumor growth after just a single injection and the MF-enhanced photodynamic treatment. Considering the biodegradability and non-toxicity of iron oxide, our IONC-PEG-Ce6 presented in this work may be a useful multifunctional agent promising in photodynamic cancer treatment under magnetic targeting.
authors.affiliation: Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials Laboratory (FUNSOM), Soochow University, Suzhou, Jiangsu 215123, China.
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Li
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.forename: Liang
authors.initials: L
authors.lastname: Cheng
authors.forename: Hua
authors.initials: H
authors.lastname: Gong
authors.forename: Shengnan
authors.initials: S
authors.lastname: Yin
authors.forename: Qiufang
authors.initials: Q
authors.lastname: Gong
authors.forename: Yonggang
authors.initials: Y
authors.lastname: Li
authors.forename: Zhuang
authors.initials: Z
authors.lastname: Liu
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D002735:Chlorophyllides; D004705:Endocytosis / Q000187:drug effects; D005290:Ferric Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D006801:Humans; D007259:Infrared Rays; D051379:Mice; D008807:Mice, Inbred BALB C; D041681:NIH 3T3 Cells; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010778:Photochemotherapy; D011092:Polyethylene Glycols / Q000138:chemical synthesis / Q000737:chemistry*; D011166:Porphyrins / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D002735:Chlorophyllides; D005290:Ferric Compounds; D011166:Porphyrins; C000499:ferric oxide; D011092:Polyethylene Glycols; C062985:phytochlorin
keywords: Iron oxide nanoclusters; Magnetic resonance imaging; Magnetic tumor targeting; Near-infrared; Photodynamic therapy