Preparation And Properties Of PLA/PCL Micro/Nanofibrous Composite Electrospinning Tissue Engineering Scaffolds

Tissue engineering is one of the most effective means to the treatment of tissue or organ defects and functional barriers.Tissue engineering scaffold is one of the three elements of tissue engineering.The nanofibrous scaffolds prepared by electrospinning can well simulate the extracellular matrix,which means it was an ideal method for preparing tissue engineering scaffolds.However,the conventional electrospinning method has some limitations such as small pore size,low porosity,difficult to form a three-dimensional structure.Therefore,the development of three-dimensional scaffolds with good biocompatibility,large pore size and high porosity has become the research difficulty and research hotspot in the field of tissue engineering scaffold.In this paper,a polylactide / polycaprolactone(PLA/PCL)micro/nanofibrous composite three-dimensional tissue engineering scaffold was prepared by designing a new type of electrospinning system,and compared with the traditional electrospinning nanofibrous composite scaffolds.The biological properties of the scaffolds were evaluated by cell experiments.(1)The electrospinning water bath receiving device and the roller receiving device are integrated to form a new type of electrospinning receiving system.A three-dimensional micro / nanofibrous composite scaffold is prepared by this system,and the formation process of the composite scaffold is analysed.In the same electrospinning time,the designed receiving system can collect the thickness of much larger than the traditional method of electrospinning,showing a distinct three-dimensional structure.(2)SEM,porosity,pore size,water contact angle and mechanical properties of nanofibrous composite scaffolds and micro / nanofibrous composite scaffolds with PLA / PCL ratio of 1: 1 were analyzed.The results showed that the micro / nanofibrous composite scaffolds consisted of aligned micrometer fibers and randomly oriented nanofibers.The porosity of micro / nanofibrous composite scaffold was 91.89 ± 3.48% and the pore size was 33.54 ± 5.82μm,better than nanofibrous composite scaffolds(with porosity of 83.4 ± 1.79% and pore size of 18.07 ± 3.13μm).The contact angle of the micro / nanofibrous composite scaffold was 109.74 ± 3.02°,which was lower than the nanofibrous scaffolds(127.4 ± 3.19°).In short,the hydrophilicity of the composite scaffold has improved.The micrometer fiber bundle also brings mechanical properties anisotropy to the composite scaffolds.The mechanical properties in the orientation direction are superior to the nanofibrous composite scaffolds.(3)HaCaT cells were used to evaluate the biocompatibility of nanofibrous composite scaffolds and micro / nanofibrous composite scaffolds.SEM,fluorescence staining experiments cell proliferation assay showed that the cells were better adhered and proliferated on micro / nanofibrous scaffolds.Micro / nanofibrous composite scaffolds have better biocompatibility than nanofibrous composite scaffolds,and are more suitable as tissue engineering scaffolds.