同轴电纺P3HB4HB/聚乙烯醇复合支架的制备及其生物相容性

Preparation of a poly(3-hydroxybutyrate-4-hydroxybutyrate)/polyvinyl alcohol composite scaffold by coaxial electrospinning and its biocompatibility

背景:聚(3-羟基丁酸酯-co-4-羟基丁酸酯)[poly(3-hydroxybutyrate-4-hydroxybutyrate),P3HB4HB]是一种能够完全降解,具有良好的成膜性、物理性能的高分子材料,但其亲水性较差。目的:制备同轴电纺P3HB4HB/聚乙烯醇复合支架,通过体外实验探讨支架的物理属性及生物相容性。方法:分别制备P3HB4HB电纺支架、聚乙烯醇电纺支架及同轴电纺P3HB4HB/聚乙烯醇复合支架,检测3组支架的形貌、接触角及拉伸力学性能。将第4代SD大鼠骨髓间充质干细胞分别接种于3组支架上,接种1,3,6 h,检测细胞黏附率;接种第1,3,5,7天,MTT法检测细胞增殖;接种7 d后,荧光染色观察细胞活性。将第4代SD大鼠骨髓间充质干细胞分别接种于3组支架上,成骨及成软骨诱导分化14 d后,进行茜素红、甲苯胺蓝染色。结果与结论:(1)支架形貌:扫描电镜下,3组支架呈三维网状相互连通的结构,相互交错,P3HB4HB电纺支架、复合支架纤维直径较为均一,排列规整;透射电镜下仅复合支架可见明显的芯-壳结构;(2)支架表征:P3HB4HB电纺支架、复合支架的拉伸强度、拉伸弹性模量及拉伸最大力明显高于聚乙烯醇电纺支架(P<0.05);复合支架的接触角<90°;(3)细胞黏附率:聚乙烯醇电纺支架组>复合支架组>P3HB4HB电纺支架组(P<0.05);(4)细胞增殖及活性:复合支架组接种5,7 d的细胞增殖快于其余两组(P<0.05);接种7 d后,聚乙烯醇电纺支架、复合支架上的活细胞多于P3HB4HB电纺支架;(5)细胞分化:复合支架组细胞的成骨和成软骨特异性染色强于其余两组;(6)结果表明:同轴电纺P3HB4HB/聚乙烯醇复合支架具有良好生物相容性和有一定力学强度。

BACKGROUND:Poly(3-hydroxybutyrate-4-hydroxybutyrate)(P3HB4HB)is a kind of polymer material that can be completely degraded,has good film-forming property and physical properties,but has poor hydrophilicity.OBJECTIVE:To prepare P3HB4HB/polyvinyl alcohol(PVA)coaxial electrospun scaffolds,and to investigate the physical properties and biocompatibility of scaffolds in vitro.METHODS:We prepared P3HB4HB electrospun scaffold,PVA electrospun scaffold and P3HB4HB/PVA coaxial electrospun composite scaffold,and then detected the morphology and characterization,contact angle,and tensile mechanical properties of the scaffolds.Passage 4 bone marrow mesenchymal stem cells(BMSCs)from Sprague-Dawley rats were seeded on the three kinds of scaffolds.Cell adhesion rate was detected at 1,3,6 hours after seeding;cell proliferation was detect at 1,3,5,7 days after seeding;and cell viability was observed fluorescence staining at 7 days after seeding.Passage 4 BMSCs were seeded onto the three kinds of scaffolds followed by 14 days of osteogenic and chondrogenic induction.Then,alizarin red staining and toluidine blue staining were used to verify BMSCs differentiation potentials.RESULTS AND CONCLUSION:(1)Scaffold morphology:Under the scanning electron microscope,the structure of the scaffold in each group was a three-dimensional interconnected network.The fiber diameters of P3HB4HB electrospun scaffold and P3HB4HB/PVA electrospun scaffold were homogeneous and ordered.The P3HB4HB/PVA scaffold showed an obvious core-shell structure under the transmission electron microscope.(2)Scaffold characterization:The tensile strength,tensile modulus and maximum stress of the P3HB4HB and P3HB4HB/PVA scaffolds were significantly higher than those of the PVA electrospun scaffold(P<0.05).The contact angle of the P3HB4HB/PVA composite scaffold was less than 90°.(3)Cell adhesion rate was ranked as follows:PVA electrospun scaffold group>P3HB4HB/PVA composite scaffold group>P3HB4HB electrospun scaffold group(P<0.05).(4)Proliferation and activity of cells:The cell proliferation of the P3HB4HB/PVA composite scaffold group was faster than that of the other two groups at 5 and 7 days(P<0.05).There were more viable cells on the PVA electrospun scaffold and composite scaffold than on the P3HB4HB electrospun scaffold.(5)Cell differentiation:Osteogenesis and cartilage specific staining of the composite scaffold were stronger than those in the other two groups.Overall,the P3HB4HB/PVA coaxial electrospun scaffold has good biocompatibility and a certain mechanical strength.