Synthesis and Application of Injectable Bioorthogonal Dendrimer Hydrogels for Local Drug Delivery


We developed novel dendrimer hydrogels (DHs) on the basis of bioorthogonal chemistry, in which polyamidoamine (PAMAM) dendrimer generation 4.0 (G4) functionalized with strained alkyne, i.e., dibenzocyclooctyne (DBCO), via a PEG spacer (Mn = 2000 g/mol) underwent strain-promoted azide-alkyne cycloaddition (SPAAC) with polyethylene glycol bisazide (PEG-BA) (Mn= 20 000 g/mol) to generate a dendrimer-PEG cross-linked network. This platform offers a high degree of functionality and modularity. A wide range of structural parameters including dendrimer generation, degree of PEGylation, loading density of clickable DBCO groups, PEG-BA chain length, as well as the ratio of clickable dendrimer to PEG-BA, and their concentrations can be readily manipulated to tune the chemical and physical properties of bioorthogonal DHs. We used this platform to prepare an injectable liquid DH. This bioorthogonal DH exhibited high cytocompatibility and enabled the sustained release of the physically loaded anticancer drug 5-fluorouracil (5-FU). Following intratumoral injection, the DH/5-FU formulation significantly suppressed tumor growth and improved the survival of HN12 tumor-bearing mice by promoting tumor cell death as well as by reducing tumor cell proliferation and angiogenesis.


Chemical and Biochemical Engineering


This work was supported, in part, by the National Science Foundation (CAREER award CBET0954957) and the National Institutes of Health (R01EY024072 and R01DE024381).

Keywords and Phrases

chemotherapy; copper-free click chemistry; hydrogel; local drug delivery; nanomedicine

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Article - Journal

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© 2017 American Chemical Society (ACS), All rights reserved.

Publication Date

14 Aug 2017