The Synergetic Effect Of Surface Microarray And Element Doping On The Osteogenesis Of Hydroxyapatite Scaffolds

It is the core of new biomaterial surface design to regulate stem cells fate and realize tissue repair through the physical and chemical property of material surface.This paper aims at of biological compatibility about the bone tissue engineering scaffold material surface.In order to improve the osteogenic properties of HA scaffolds,the surface was designed optimally by modification about topological structure and chemical composition and the regulatory effect on osteogenic differentiation of stem cells is investigated.Based on 3D plotting technology,HA porous scaffolds with interconnected structure were prepared by the way of layer-by-layer in this paper,and the pore structure and size were precisely controllable.The interconnected pore structure could realize the timely transmission of nutrients and metabolites needed by cells,and provide a favorable microenvironment for the growth of cells and tissues.The 3D Plotted HA porous scaffolds were used as the substrate material.The hexagonal microarray was constructed in situ on the scaffold surface by hydrothermal reaction successfully.The microarray is highly oriented HA with uniform and ordered arrangement.Using ADSCs as seed cells,the effects of scaffolds topological structure on proliferation and osteogenic differentiation of ADSCs were studied.There was no significant cytotoxicity about the hexagonal microarray on the scaffolds surface.And the hexagonal microarray on the scaffolds surface can significantly up-regulate the expression of osteoblastic genes?such as BMP2,OCN,OPN,etc.?and proteins.The scaffolds surface microarray regulates the directional differentiation of stem cells through physical signals,which can improve the osteogenic performance of HA scaffolds.On this basis,Sr²⁺doped hexagonal microarray was constructed in situ on the surface of HA scaffolds,and the synergistic regulatory effects of Sr²⁺doped and hexagonal microarray on the osteogenic differentiation of ADSCs were studied.The results showed that the doping of Sr²⁺does not affect the crystal structure of hexagonal microarray,and the controlled release of Sr²⁺can be achieved.In addition,Sr²⁺doped surface microarray has good biocompatibility and can significantly promote the expression of osteoblastic related genes?such as ALP,BMP2,OCN,etc.?and proteins.The purpose of synergistically regulating the osteogenic performance of scaffold with Sr²⁺doped surface microarray was realized eventually.Modification of structure and chemistry composition of HA porous scaffolds surface was realized by hydrothermal reaction.The dual stimulation effect of physical and chemical signals on scaffold surface realized the coordinated regulation of the osteogenic performance of HA scaffolds.The research provides a new idea for the design of new biological compatible bone tissue engineering scaffolds.