Glucose Oxidase-Coated Calcium Peroxide Nanoparticles as an Innovative Catalyst for In Situ H₂O₂-Releasing Hydrogels

In situ forming and hydrogen peroxide (H₂O₂)-releasing hydrogels have been considered as attractive matrices for various biomedical applications. Particularly, horseradish peroxidase (HRP)-catalyzed crosslinking reaction serves efficient method to create in situ forming hydrogels due to its advantageous features, such as mild reaction conditions, rapid gelation rate, tunable mechanical strength, and excellent biocompatibility. Herein, a novel HRP-crosslinked hydrogel system is reported that can produce H₂O₂ in situ for long-term applications, using glucose oxidase-coated calcium peroxide nanoparticles (CaO₂@GOx NPs). In this system, CaO₂ gradually produced H₂O₂ to support the HRP-mediated hydrogelation, while GOx further catalyzed the oxidation of glucose for in situ H₂O₂ generation. As the hydrogel is formed rapidly is expected and the H₂O₂ release behavior is prolonged up to 10 days. Interestingly, hydrogels formed by HRP/CaO₂@GOx-mediated crosslinking reaction provided a favorable 3D microenvironment to support the viability and proliferation of fibroblasts, compared to that of hydrogels formed by either HRP/H₂O₂ or HRP/CaO₂/GOx-mediated crosslinking reaction. Furthermore, HRP/CaO₂@GOx-crosslinked hydrogel enhanced the angiogenic activities of endothelial cells, which is demonstrated by the in vitro tube formation test and in ovo chicken chorioallantoic membrane model. Therefore, HRP/CaO₂@GOx-catalyzed hydrogels is suggested as potential in situ H₂O₂-releasing materials for a wide range of biomedical applications.