Research on the guidance of bone regeneration by microchannel porous scaffolds loaded with deferoxamine.

This study addresses the challenges of slow and inadequate bone formation during the repair of bone defects by developing a novel porous biological scaffold with a vertical microchannel structure, loaded with the angiogenesis-promoting drug Deferoxamine (DFO). Utilizing 3D printing technology, cylindrical porous templates made of PLGA were manufactured, followed by the integration of Linear Wire Arrays (LWAs) technology and freeze-drying techniques to fabricate scaffolds with microchannels. The scaffolds' surface morphology was characterized using scanning electron microscopy, while their porosity, water absorption properties, and mechanical strength were quantified. The in vitro release kinetics of DFO were assessed using a UV spectrophotometer. Further, the scaffolds' cytotoxicity, angiogenic, and osteogenic potentials were evaluated through in vitro cell experiments. In vivo experiments involved the creation of a rat cranial bone defect model; following eight weeks of scaffold implantation, assessments were conducted using MicroCT scanning and HE staining to evaluate new bone formation. The findings indicate that the scaffolds, characterized by large channel diameters, high porosity, and robust compressive strength with continuous through channels, showed no cytotoxicity and significantly enhanced the proliferation of MC3T3-E1 cells. DFO loading improved tube formation in vascular endothelial cells most effectively at a concentration of 50μM. Additionally, the scaffolds increased ALP activity in MC3T3-E1 cells, promoting osteogenic differentiation. After eight weeks, the volume of new bone in the rat cranial bone defects implanted with the microchannel scaffolds reached 53 %, with the newly formed tissue being rich in blood vessels, demonstrating effective osteogenic performance. This scaffold provides a novel basis for the tissue engineering repair of bone defects.