Preparation Of Polycaprolactone/elastin Nanofiber Composite Scaffold And Its Application In Tendon Tissue Engineering

In clinic,tendon injuries caused by various traumas and diseases are very common.Tendon repair is often very slow and hard to regenerate perfectly due to the insufficient of cells and vascularization in tendon tissue.At present,the methods used to repair tendon defects have their own disadvantages.Tissue engineering has been recognized as a promising strategy for regenerative tendon repair.As an important component of tissue-engineered tendon,scaffold materials have been widely studied.At present,the main problem of tendon tissue engineering scaffolds is that it is difficult to make the scaffolds have good mechanical properties and biological activities at the same time,and there are few reports on the elastic properties of scaffolds.In recent years,electrospinning has attracted much attention because of its ability to fabricate nanoscale fiber scaffolds.Polycaprolactone(PCL)is the most commonly used synthetic material for tissue engineering scaffolds with good mechanical properties.Elastin has good elasticity and bioactivity and has been widely studied in the field of biomaterials.Therefore,in this study,the polyhexolactone / methylacrylated elastin nanofiber composite scaffold(PCL/EMA-NCS)was prepared by electrospinning technology,and the effects of EMA composite ratio on the physicochemical and biological properties of scaffolds were investigated.On this basis,Gel MA was introduced according to the optimized proportion to further improve the comprehensive performance of the scaffold.The main contents of this research were as follows:(1)The modified EMA was successfully prepared by grafting methacrylate anhydride,and PCL/EMA-NCS with different proportions of uniform morphology and size was prepared by electrospinning.The average diameter of the fiber has ranged from 203 nm to 502 nm.The physicochemical properties of these PCL/EMA-NCS were characterized.The results showed that the elastic modulus and ultimate tensile strength of PCL/EMA-NCS have been significantly improved compared with the pure PCL scaffolds,and the energy loss has been comparable to that of natural tendons.Moreover,with the increase of EMA proportion,the energy loss of the scaffold has decreased,indicating that EMA has endowed the scaffold with good mechanical and elastic properties.(2)The biocompatibility and the ability to promote tenogenic differentiation of stem cells of these PCL/EMA-NCS were studied.The results showed that PCL/EMA-NCS has promoted the adhesion,proliferation and tenogenic differentiation of human bone marrow mesenchymal stromal cells(h BMSCs).Among all groups,the 50% PCL/EMA-NCS has showed the best biocompatibility and tenogenic differentiation ability of stem cells.(3)On this basis,the PCL/EMA/Gel MA-NCS was prepared by electrospinning technology,and the physicochemical and biological properties of the scaffold were studied.The results showed that the introduction of Gel MA has further improved the mechanical property of the scaffold,and the elastic modulus has been up to 94.6± 5.7 MPa.The hydrophilicity of the scaffold has been improved.The cell experiments in vitro showed that PCL/EMA/Gel MA-NCS could promote the adhesion,growth,proliferation and tenogenic differentiation of h BMSCs.In this paper,a kind of nanofiber composite scaffold based on polycaprolactone/elastin has been successfully prepared.The composite scaffold has good mechanical properties and biological activities,which is expected to become a new tendon repair material.