Development of a biocompatible and biodegradable hybrid hydrogel platform for sustained release of ionic drugs

In this study, we reported the development of a new drug encapsulation strategy and a robust hybrid hydrogel platform for controlled and sustained release of small and large molecule ionic drugs. A biodegradable, biocompatible and temperature stimuli responsive hybrid hydrogel platform was fabricated from arginine based unsaturated poly(ester amides) (Arg-UPEAs), Pluronic diacrylate (Pluronic-DA) and alginate by the UV photo-crosslinking method, combining the favorable properties of a hydrogel and a polyelectrolyte complex. The hydrogels were systematically characterized, including the swelling mechanics, mechanical properties, biodegradation and interior morphologies. In vitro biocompatibility study showed that the hydrogels could support the cell attachment and proliferation well. Some model drugs, such as hydrochloride salts of hydralazine, insulin and interleukin-12, were encapsulated into the hydrogels and the drug release behavior was investigated using HPLC, LC-MS, BCA assay and ELISA assay. The obtained release profiles indicated that the Pluronic/Arg-UPEA/alginate hybrid hydrogels could release ionic drugs over weeks in vitro via a sustained manner. The structure-function study of hydrogels indicated that the polymer structure, hydrogel composition and environmental temperature had strong effects on the hydrogel properties and their drug release profiles.