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Hierarchical self-assembly of magnetic nanoclusters for theranostics: Tunable size, enhanced magnetic resonance imagability, and controlled and targeted drug delivery

Paper ID Volume ID Publish Year Pages File Format Full-Text
31 4 2016 9 PDF Available
Title
Hierarchical self-assembly of magnetic nanoclusters for theranostics: Tunable size, enhanced magnetic resonance imagability, and controlled and targeted drug delivery
Abstract

Nanoparticle-based imaging and therapy are of interest for theranostic nanomedicine. In particular, superparamagnetic iron oxide (SPIO) nanoparticles (NPs) have attracted much attention in cancer imaging, diagnostics, and treatment because of their superior imagability and biocompatibility (approved by the Food and Drug Administration). Here, we developed SPIO nanoparticles (NPs) that self-assembled into magnetic nanoclusters (SAMNs) in aqueous environments as a theranostic nano-system. To generate multi-functional SPIO NPs, we covalently conjugated β-cyclodextrin (β-CD) to SPIO NPs using metal-adhesive dopamine groups. Polyethylene glycol (PEG) and paclitaxel (PTX) were hosted in the β-CD cavity through high affinity complexation. The core-shell structure of the magnetic nanoclusters was elucidated based on the condensed SPIO core and a PEG shell using electron microscopy and the composition was analyzed by thermogravimetric analysis (TGA). Our results indicate that nanocluster size could be readily controlled by changing the SPIO/PEG ratio in the assemblies. Interestingly, we observed a significant enhancement in magnetic resonance contrast due to the large cluster size and dense iron oxide core. In addition, tethering a tumor-targeting peptide to the SAMNs enhanced their uptake into tumor cells. PTX was efficiently loaded into β-CDs and released in a controlled manner when exposed to competitive guest molecules. These results strongly indicate that the SAMNs developed in this study possess great potential for application in image-guided cancer chemotherapy.Statement of SignificanceIn this study, we developed multi-functional SPIO NPs that self-assembled into magnetic nanoclusters (SAMNs) in aqueous conditions as a theranostic nano-system. The beta-cyclodextrin (β-CD) was immobilized on the surfaces of SPIO NPs and RGD-conjugated polyethylene glycol (PEG) and paclitaxel (PTX) were hosted in the β-CD cavity through high affinity complexation. We found that nanocluster size could be readily controlled by varying the SPIO/PEG ratio in the assemblies, and also demonstrated significant improvement of the functional nanoparticles for theranostic systems; enhanced magnetic resonance, improved cellular uptake, and efficient PTX loading and sustained release at the desired time point. These results strongly indicate that the SAMNs developed in this study possess great potential for application in image-guided cancer chemotherapy.

Graphical abstractImmobilization of cyclodextrins (CDs) on superparamagnetic iron oxide (SPIO) nanoparticles via catechol-derivative anchors enables efficient formation of magnetic nanoclusters with a tunable size. CDs were complexed with arginine–glycine–aspartic acid (RGD) peptide–conjugated poly(ethylene glycol) (RGD–PEG) to stabilize the nanoclusters and enhance uptake into tumor cells. Paclitaxel (PTX) was also loaded into the CDs and released at the desired time point.Figure optionsDownload full-size imageDownload high-quality image (94 K)Download as PowerPoint slide

Keywords
Self-assembled magnetic nanoclusters; Superparamagnetic iron oxide; Cyclodextrin; Poly(ethylene glycol); Paclitaxel; MRI; Controlled drug delivery; Theranostics
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Hierarchical self-assembly of magnetic nanoclusters for theranostics: Tunable size, enhanced magnetic resonance imagability, and controlled and targeted drug delivery
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Publisher
Database: Elsevier - ScienceDirect
Journal: Acta Biomaterialia - Volume 35, 15 April 2016, Pages 109–117
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us