Cranial repair-promoting effect of oxidised sodium alginate/amino gelatine injectable hydrogel loaded with deer antler blood peptides

This study aimed to enhance the treatment of bone defects and increase peptide bioavailability. To achieve this, antioxidant-active peptides (DBPs) were extracted from deer antler blood and incorporated into an oxidised sodium alginate/amino gelatine injectable hydrogel (OSA/N-Gel). This bioscaffold was created through the Schiff base reaction, resulting in the development of an injectable hydrogel comprising OSA, amino gelatine, and deer antler blood peptides (OSA/N-Gel/DBP). OSA/N-Gel/DBP is characterised by a loose and porous structure that enhances nutrient flow and confers good degradability, enabling the gradual release of DBP to meet the long-lasting treatment requirements for bone repair. In vitro , 5-Ethynyl-2′-deoxyuridine (EDU), alkaline phosphatase (ALP), and Alizarin Red S (ARS) staining showed the pro-proliferative and pro-mineralising abilities of OSA/N-Gel and OSA/N-Gel/DBP on osteoblasts (MC3T3). OSA/N-Gel/DBP effectively promoted the expression of osteogenesis-related genes, such as ALP and vascular endothelial growth factor (CD31), and deposition of collagen (COL-1), and activated the wingless-related integration site (Wnt) signalling pathway, thereby promoting bone regeneration. The effect of OSA/N-Gel/DBP was significantly superior to that of the OSA/N-Gel group, indicating that DBP has good osteogenic properties. We successfully repaired bone defects and broadened the application of antler blood, thereby providing a novel approach to treating bone defects.