3D打印多孔钛／壳聚糖／羟基磷灰石复合支架的制备与体外生物相容性研究

Fabrication and in vitro biocompatibility of porous Ti/chitason/hydroxyapatite composite scaffold

目的探讨多孔钛／壳聚糖／羟基磷灰石（Ti／Ch／HA）复合结构支架的制备方法及其作为骨修复替代物的可行性。方法利用增材制造（3D打印）技术制造多孔钛支架作为支撑结构，结合冷冻干燥技术，在钛支架的宏观孔隙内制备具有良好细胞亲和性的Ch／HA海绵结构，形成一种多孔Ti／Ch／HA复合结构支架。取单纯多孔钛支架、Ti／Ch／HA复合支架进行体外细胞培养试验，将成骨细胞接种到支架上，培养7d后，利用扫描电镜和噻唑兰（MTT）法检测并对比细胞在两种支架上的黏附生长情况，包括细胞的形貌、细胞接种效率和增殖能力。结果Ti／Ch／HA复合结构支架扫描电镜（SEM）图示钛支架宏观孔隙中充满Ch／HA复合海绵结构，其微孔尺寸为50～200μm。与单纯多孔钛支架一样，多孔Ti／Ch／HA复合结构支架的抗压强度为168．2—192．6MPa，屈服强度为137．1．154．1MPa，弹性模量为3．21—4．51GPa；培养7d后，大量扁平状细胞黏附于钛支架表面，而黏附于Ti／Ch／HA复合支架上的细胞呈梭形。成骨细胞在Ti／Ch／HA复合支架上的接种率（73．218％±3．748％）明显高于单纯多孔钛支架（21．352％±4．365％）；Ti／Ch／HA复合支架上的OD值（0．783±0．043）显著高于多孔钛支架（0．382±0．036），以上项目比较差异均有统计学意义（P〈0．05）。结论Ti／Ch／HA复合结构支架的力学性能与人体骨组织力学性能的匹配，较单纯多孔钛更适合成骨细胞的黏附生长，是一种理想的承重部位骨缺损修复替代物。

Objective To evaluate the feasibility of the porous titanium/chitosan/hydroxyapatite （Ti/Ch/HA） composite scaffold as a bone repair substitute. Methods Additive manufacturing （3D printing） technology was used to fabricate porous Ti scaffolds as supporting structures. Chitosan/hydroxyapatite （Ch/HA） sponge was prepared within the macro-pores of Ti scaffolds using freeze drying technology. Thus, a kind of composite porous Ti/Ch/HA scaffold with good cell affinity was obtained. Osteoblastic cells were seeded and cultured in pure porous Ti scaffolds and composite Ti/Ch/HA scaffolds for 7 days. The cellular morphology, seeding efficiency and proliferation were examined and compared between the 2 kinds of scaffolds using scanning electron microscopy （SEM） and MTT assay. Results The SEM examination showed that the macro-pores of Ti/Ch/HA scaffolds were full of the composite sponge structure of Ch/HA, with a micropore size of 50 to 200 μm. Like the pure porous Ti scaffolds, composite Ti/Ch/HA ones have a compressive strength of 168.2 to 192. 6 MPa, a yielding strength of 137. 1 to 154.1 MPa, and a Young＇s modulus of 3.21 to 4.51 GPa. After culture for 7 days, a large number of flat cells adhered onto the surface of Ti scaffolds while the ceils adhering onto the Ti/Ch/HA composite scaffolds were fusiform. The seeding efficiency of osteoblastic ceils in the composite Ti/Ch/HA scaffolds （73. 218% ± 3. 748% ） was significantly higher than that in the pure porous Ti scaffolds （21.352%±4.365%） （P 〈0.05）; the OD value of the composite Ti/Ch/HA scaffolds （0. 783 ± 0. 043） was significantly higher than that of the pure porous Ti scaffolds （0. 382 ±0. 036） （ P 〈 0. 05）. Conclusions Ti/Ch/HA composite scaffolds can match human bone in mechanical properties. Compared with pure porous Ti scaffolds, the Ti/Ch/HA composite ones are more suitable for adhesion and proliferation of osteoblasts, making them an ideal kind of bone repair substitute.