Facile approach to prepare pH and redox-responsive nanogels via Diels-Alder click reaction

• Published in: Express polymer letters Vol. 12; no. 8; pp. 688 - 698
• Main Authors: Le, C. M. Q., Cao, X. T., Tu, T. T. K., Gal, Y-S., Lim, K. T.
• Format: Journal Article
• Language: English
• Published: Budapest Budapest University of Technology and Economics, Faculty of Mechanical Engineering, Department of Polymer Engineering 01-08-2018; Budapest University of Technology
• Subjects: Anhydrides; Biomedical materials; Block copolymers; Cancer; Carboxylates; Chemical reactions; Chemical synthesis; Chemistry; Chromatography; Copolymers; Crosslinking; Diels-Alder Click; Doxorubicin; Drug Delivery; Drug delivery systems; Glutathione; Ionic interactions; Maleic anhydride; Nanogels; Nanomaterials; Permeability; Polyethylene glycol; Polymers; Polystyrene resins; Smart polymers
• ISSN: 1788-618X; 1788-618X
• DOI: 10.3144/expresspolymlett.2018.59

A novel pH and redox responsive system of sub-100 nm nanogels was prepared by arm-first approach via DielsAlder click reaction. First, well-defined poly(ethylene glycol)-block-poly(styrene-alt-maleic anhydride) (PEG-b-PSM) was synthesized and subsequently functionalized with furfuryl amine, leading to the formation of the dual-functional block copolymer of PEG-b-PSMf. The furfuryl groups in the PSMf block were employed to incorporate a redox-responsive linkage and the carboxylic acid moieties generated through functionalization acted as a pH-responsive part. The Diels-Alder click reaction between a bismaleimide crosslinker and PEG-b-PSMf was conducted at 60 °C, affording star-like nanogel structures. Doxorubicin, a model anticancer drug, was loaded into to the core of the nanogels primarily by the ionic interaction with carboxylates of core blocks and a highest drug loading capacity of 38.1% was obtained. Furthermore, the in vitro profile showed a low release percentage (11.2%) of DOX at PBS pH 7.4, whereas a burst release (62%) at pH 5.0 in the presence of 10 mM glutathione, indicating the effective pH and redox responsive characteristic of the PEG-b-PSMf nanogels.