In vitro degradation, swelling, and bioactivity performances of in situ forming injectable chitosan‐matrixed hydrogels for bone regeneration and drug delivery

Abstract

njectable, tissue mimetic, bioactive, and biodegradable hydrogels offer less invasiveregeneration and repair of tissues. The monitoring swelling and in vitro degradationcapacities of hydrogels are highly important for drug delivery and tissue regenerationprocesses. Bioactivity of bone tissue engineered constructs in terms of mineralized apatiteformation capacity is also pivotal. We have previously reported in situ forming chitosan‐based injectable hydrogels integrated with hydroxyapatite and heparin for boneregeneration, promoting angiogenesis. These hydrogels were functionalized by glyceroland pH to improve their mechano‐structural properties. In the present study,functionalized hybrid hydrogels were investigated for their swelling, in vitro degradation,and bioactivity performances. Hydrogels have degraded gradually in phosphate‐bufferedsaline (PBS) with and without lysozyme enzyme. The percentage weight loss of hydrogelsand their morphological and chemical properties, and pH of media were analyzed. Theswelling ratio of hydrogels (55%–68%(wt), 6 h of equilibrium) indicated a high degree ofcross‐linking, can be suitable for controlled drug release. Hydrogels have graduallydegraded reaching to 60%–70% (wt%) in 42 days in the presence and absence oflysozyme, respectively. Simulated body fluid (SBF)‐treated hydrogels containinghydroxyapatite‐induced needle‐like carbonated‐apatite mineralization was furtherenhanced by heparin content significantly.