Multifunctional hybrid 3D network based on hyaluronic acid and a copolymer containing pendant spiroacetal moieties.

The elasticity, soft consistency and similarity to the human body are important characteristics of the gels. Such similarities allow the hydrogels to be biocompatible and, as a consequence, they are very attractive to be applied as biomaterials. This study presents a new strategy for developing a biohybrid complex based on a natural/synthetic polymer conjugate as gel type structure enriched with quercetin, which can be a relevant biomaterial for its antimicrobial properties. There are evidenced the preparation possibilities for the natural/synthetic structure as complex gel based on hyaluronic acid conjugated with poly(itaconic anhydride‑co‑3,9‑divinyl‑2,4,8,10‑tetraoxaspiro[5.5] undecane) copolymer decorated with quercetin. The effects of the composition on various properties were assessed. The chemical composition of bioconjugate gels was confirmed by FTIR spectroscopy. It was established that the new gel structures have enhanced swelling capacity and a typical gel-like behavior. The investigations evidenced the gels responsiveness to stimuli and their high elasticity. The new structures were tested as drug delivery systems. The in vitro release shows the dependence of the mechanism of release on the composition of the gels, evidencing a transport behavior which varies from the Fickian to super case II. In vivo investigations demonstrated a good biocompatibility after systemic administration in mice.