| Objective:The bone defect caused by tumor,trauma,congenital malformation and infection will not only affect the exterior beauty and function,but also bring inconvenience to the patients and even threaten life in clinic.At present,the gold standard for bone defect treatment is autologous bone graft,but its available parts are limited,and cause damage to the original healthy parts,causing two damage to the patient[1].The application of allograft bone graft is limited by its immune response[2].As a result,tissue engineering is designed to guide the formation of new tissues by combining cells,biomaterials and appropriate biochemical factors.In the ideal state,the scaffold as a carrier,is the most basic and indispensable part of the tissue engineering[3].Previous studies have shown that the bioactive materials of hydroxyapatite?HA?and?-phosphate??-tcp?are biphasic calcium phosphate?BCP?,the chemical composition is similar to the inorganic composition of bone tissue,and it solves the problem that HA is difficult to degrade and the?-tcp degradation is too fast,and it has the bone inducement of HA and?-tcp.,bone conduction and biocompatibility are widely used in the study of scaffold of bone tissue engineering[4].Chitosan?CS?is the only natural alkaline polysaccharide with positive charge in nature,which is biodegradable and antibacterial,and supports cell adhesion,proliferation and differentiation,high bonding strength and superior processing properties.However,its mechanical performance is poor,so it can not be used as tissue engineering scaffolds alone[5].Both of these materials conform to the characteristics of bone tissue engineering materials,and can theoretically complement each other,so we choose the two materials and discuss their development potential in tissue engineering scaffold materials.Methods:1.A biphasic calcium phosphate?BCP?stent?Weight ratio of HA/?-BCP is 3/7?was prepared by 3D printing,the Chitosan solution was prepared by chemical method,and then the Chitosan solution was prepared by a vacuum incubator to cover a BCP/CS composite scaffolds.2.The characterization of BCP/CS scaffolds and BCP scaffolds was observed using scanning electron microscopy and atomic force micros-copy.3.The average weighing method was used to determine the water absorption rate of BCP/CS scaffolds and BCP scaffolds.4.Culture of Mouse anterior osteoblast?mc3t3-e1?.5.Using CCK-8 method to detect the toxicity of stent extract.The experiment was divided into three groups,the experimental group 1 was the BCP/CS scaffolds extract,the experimental group 2 was the BCP scaffolds extract,the control group was a pure medium,and the absorption values of the three groups were detected by the cell incubation box for 1 days,3 days and 5 days,then passed the National standard?GB/T16886.5-2003?rated the relative increment rate of cells in two experimental groups.6.Using CCK-8 method to detect the proliferation of stents.The experiments were divided into BCP/CS scaffolds Group,BCP scaffolds Group and blank group?no material?,and the cell proliferation of three groups was detected in vitro incubation box culture 1d,3d,5d and 7d.7.Using SPSS 20.0 software for analysis,using single factor variance analysis to compare the differences between the groups,p<0.05that the difference is statistically significant?p<0.05?.Results:1.The fabricated scaffolds has a good three-dimensional pore structure and has a rough surface and a cuboid size of 1cm.2.AFM observation of the scaffolds surface,BCP/CS scaffolds and BCP scaffolds surface is uneven,BCP/CS scaffolds surface roughness is710nm?contour arithmetic average difference?,BCP stent surface roughness is 860nm?contour arithmetic average difference?.3.The scanning electron microscope observed that the pores of the BCP/CS scaffolds communicated with each other,and the pore size was between 250-300?m.The bracket is coarse and uneven,with many pores.The BCP scaffolds has a smooth surface and a large pore relative to the BCP/CS,about 350-450?m.4.The water absorption rate of BCP scaffolds is 32%.The water absorption rate of BCP/CS scaffolds is 37.75%.5.Two kinds of scaffolds in vitro culture 1 days,3 days,5 days,the toxicity level is 0,1,1 grade respectively.This indicates that both the BCP/CS scaffolds and the BCP scaffolds have no cytotoxicity.6.The cell proliferation experiment showed that the number of cells in each group increased with time.After a total of 1 days of cultivation,The number of cells in the experimental and control groups was slightly lower than in the blank group?p<0.05?,at 3 days,the number of cells in the experimental group and the control group was significantly lower than that in the blank group?p<0.05?,and after 5 days,there was no significant difference in the number of cells between the experimental group and the Blank Group?p>0.05?and the control group?p<0.05?,when cultured to 7 The number of cells in the experimental group was significantly higher than that in the control group and the blank group?p<0.05?.Conclusion:The experimental results show that the BCP/CS scaffolds meets the basic requirements of bone tissue engineering scaffolds and can promote cell proliferation and nutrient delivery.The surface cover CS reduces the pore size,increases the surface area,makes it have better physical and chemical properties and promotes the cell adhesion multiplication.CS itself has a variety of plasticity,and has been used as carrier and microspheres in the clinical application of the method,the preliminary test of BCP/CS scaffolds in bone tissue engineering application potential for further improvement of stent and follow-up experiments to provide a basis. |
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