Injectable foam-like scaffolds release glucose oxidase-integrated metal–organic framework hybrids for diabetic bone defects

•The GOx-MOF/HAP-GelMA composite hydrogel is manufactured for diabetic bone regeneration and repair.•HAP-GelMA foaming hydrogel combines HAP NWs, with UV-curable GelMA to various bone defects while maintaining ideal hardness.•Mg-MOF loaded with GOx enables sustained release of therapeutic agents regulating hyperglycemia microenvironment.•Mg2+ promoting osteogenesis and angiogenesis while regulating the immune response. Diabetic bone defect repair remains a significant clinical challenge due to the impact of glucose fluctuations, reactive oxygen species (ROS) damage, and the inflammatory microenvironment, all of which impede the normal bone repair process. In this study, we have developed a biological scaffold material aimed at localized regulation of the diabetic microenvironment within bone defect sites. Our approach involves the creation of an injectable, UV-curable, gas-foamed multifunctional hydrogel, incorporating methacrylic anhydride gelatine (GelMA) and hydroxyapatite nanowires (HAP NWs). This hydrogel is further enhanced with Gallic acid and magnesium ion (Mg²⁺) metal-organic frameworks (MOF) loaded with glucose oxidase (GOx), forming the GOx-MOF/HAP-GelMA composite. It can be injected and immediately cured to assume various customized shapes, while maintaining desirable hardness. It's noteworthy that the controlled release of Gallic acid within GOx-MOF actively engages in a cascade reaction, efficiently eliminating the H2O2 generated by GOx-catalyzed glucose decomposition, thus optimizing the benefits of GOx while minimizing potential harm. The developed composite demonstrates remarkable capabilities in blood sugar regulation, ROS elimination, inflammation modulation, and the facilitation of osteogenesis and angiogenesis. This study represents a major step in precisely controlling the microenvironment for diabetic bone regeneration and provides a minimally invasive solution for addressing bone defects. [Display omitted]