Topological structure of electrospun membrane regulates immune response, angiogenesis and bone regeneration

The fate of biomaterials is orchestrated by biocompatibility and bioregulation characteristics, reported to be closely related to topographical structures. For the purpose to investigate the topography of fibrous membranes on the guided bone regeneration performance, we successfully fabricated poly (lactate-co-glycolate)/fish collagen/nano-hydroxyapatite (PFCH) fibrous membranes with random, aligned and latticed topography by electrospinning. The physical, chemical and biological properties of the three topographical PFCH membranes were systematically investigated by in vitro and in vivo experiments. The subcutaneous implantation of C57BL6 mice showed an acceptable mild foreign body reaction of all three topological membranes. Interestingly, the latticed PFCH membrane exhibited superior abilities to recruit macrophage/monocyte and induce angiogenesis. We further investigated the osteogenesis of the three topographical PFCH membranes via the critical-size calvarial bone defect model of rats and mice and the results suggested that latticed PFCH membrane manifested promising performance to promote angiogenesis through upregulation of the HIF-1α signaling pathway; thereby enhancing bone regeneration. Our research illustrated that the topological structure of fibrous membranes, as one of the characteristics of biomaterials, could regulate its biological functions, and the fibrous structure of latticed topography could serve as a favorable surface design of biomaterials for bone regeneration. STATEMENT OF SIGNIFICANCE: In material-mediated regeneration medicine, the interaction between the biomaterial and the host is key to successful tissue regeneration. The micro-and nano-structure becomes one of the most critical physical clues for designing biomaterials. In this study, we fabricated three topological electrospun membranes (Random, Aligned and Latticed) to understand how topological structural clues mediate bone tissue regeneration. Interestingly, we found that the Latticed topographical PFCH membrane promotes macrophage recruitment, angiogenesis, and osteogenesis in vivo, indicating the fibrous structure of latticed topography could serve as a favorable surface design of biomaterials for bone regeneration.