Abstract

Background Gelatin methacryloyl (GelMA) hydrogel is a biomaterial used for osteogenesis, supporting bone repair and angiogenesis. Deferoxamine (DFO), an Fe 3 + -chelating hypoxia-mimetic agent, activates hypoxia-inducible factor 1-alpha (HIF-1α) to promote angiogenesis and osteogenesis but suffers from toxicity, instability, and short half-life. This study aimed to conjugate DFO to GelMA to enhance its stability and reduce cytotoxicity. Methods Chemically conjugated GelMA hydrogel with DFO (GelMA@DFO) was synthesized via 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride/N-Hydroxysuccinimide (EDC/NHS)-mediated conjugation. Proton nuclear magnetic resonance ( 1 H NMR) is employed to detect the incorporation of methacryloyl groups. Scanning electron microscopy (SEM) serves to examine the association between GelMA and DFO. The dialysis method is applied to analyze the release profile of DFO. Cell viability and the ratio of live/dead cells are assessed using the Cell Counting Kit-8 (CCK-8) and Calcein-AM/PI staining. Angiogenesis was assessed via Matrigel tube formation and wound healing assays in human umbilical vein endothelial cells (HUVECs). Gene expression was analyzed by reverse transcription quantitative polymerase chain reaction (RT-qPCR), and protein levels were measured using enzyme-linked immunosorbent assay (ELISA). Fourier transform infrared spectroscopy (FT-IR), rheology, ultraviolet-visible spectroscopy (UV-Vis) spectroscopy, and in vitro degradation assays were performed to characterize the chemical structure, mechanical properties, optical features, and stability of the hydrogels. Results 1 H NMR and SEM confirmed successful GelMA-DFO synthesis. FT-IR, UV-Vis spectroscopy, and rheological analysis further confirmed the structural integrity and enhanced mechanical stability of GelMA@DFO, while in vitro assays demonstrated that DFO conjugation significantly slowed hydrogel degradation. DFO release was slower post-conjugation. GelMA@DFO redu