Tough Composite Hydrogels with High Loading and Local Release of Biological Drugs

Jianyu Li; Eckhard Weber; Sabine Guth‐Gundel; Michael Schuleit; Andreas Kuttler; Christine Halleux; Nathalie Accart; Arno Doelemeyer; Anne Basler; Bruno Tigani; Kuno Wuersch; Mara Fornaro; Michaela Kneissel; Alexander Stafford; Benjamin R. Freedman; David J. Mooney

Index: 10.1002/adhm.201701393

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Abstract

Hydrogels are under active development for controlled drug delivery, but their clinical translation is limited by low drug loading capacity, deficiencies in mechanical toughness and storage stability, and poor control over the drug release that often results in burst release and short release duration. This work reports a design of composite clay hydrogels, which simultaneously achieve a spectrum of mechanical, storage, and drug loading/releasing properties to address the critical needs from translational perspectives. The clay nanoparticles provide large surface areas to adsorb biological drugs, and assemble into microparticles that are physically trapped within and toughen hydrogel networks. The composite hydrogels demonstrate feasibility of storage, and extended release of large quantities of an insulin‐like growth factor‐1 mimetic protein (8 mg mL−1) over four weeks. The release rate is primarily governed by ionic exchange and can be upregulated by low pH, which is typical for injured tissues. A rodent model of Achilles tendon injury is used to demonstrate that the composite hydrogels allow for highly extended and localized release of biological drugs in vivo, while demonstrating biodegradation and biocompatibility. These attributes make the composite hydrogel a promising system for drug delivery and regenerative medicine.