Nanocomposites of ionic copolymer integrating Gd-containing polyoxometalate as a multiple platform for enhanced MRI and pH-response chemotherapy. Issue 30 (20th July 2020)

• Record Type: Journal Article
• Authors: Zhou, Tingting; Wan, Guofeng; Li, Bao; Wu, Lixin
• Is Part Of: Journal of materials chemistry. Volume 8:Issue 30(2020)
• Page Start: 6390
• Page End: 6401
• Publication Date: 2020-07-20
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Biomedical materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d0tb00782j
• Languages: English
• ISSNs: 2050-750X

Abstract

Abstract : Nanocomposites from the co-assemblies of block copolymers and a gadolinium-grafting inorganic cluster were constructed as a multifunctional platform for MRI enhancement, drug loading, and environment-response release at local positions. Abstract : This article describes the fabrication of nanosized paramagnetic drug carriers via the assembly of a pH-responsive hydrophilic block copolymer poly(polyethylene glycol methyl ether methacrylate)- b -poly(methacrylic acid- co -trimethyl ammonium bromide propyl methacrylate) (PPMT) and polyoxometalate K13 [Gd(β2 -SiW11 O39 )2 ] (GdSiW11 ) through electrostatic interaction. Owing to the hydrophilicity, large molecular weight, and high content of the GdSiW11 cluster bearing in the nanocomposites, the organic–inorganic nanocomposite exhibited an impressive longitudinal relaxivity as a contrast agent for magnetic resonance imaging (MRI). The surplus negative charges from the polyoxometalate cluster in the polymer nanocomposites facilitated the capture of the anti-tumor drug doxorubicin (DOX). The DOX-loaded nanocomposites were stable under the physiological environment, whereas a responsive release of DOX was achieved at pH values similar to the tumor microenvironment due to the regulation of the polyoxometalate and carboxyl groups. The DOX-loaded PPMT2 –GdSiW11 nanocomposites were observed to enrich effectively at tumor sites through MRI after intravenous injection. Furthermore, the DOX-loaded composites manifested enhanced in vivo anti-tumor therapeutic efficacy and sustainable circulation time of more than 5 h, which were favourable for imaging measurement. With the advantages of the designed composite system, the present experiments propose a strategy for developing a new multiple imaging-drug delivery-local therapy platform for synergistic diagnosis and therapy.