Preparation Of Kartogenin Encapsulated P(LLA-CL)/Collagen Nanofibrous Scaffolds Fabricated By Electrospining For Tracheal Cartilage Repair

Tracheal carcinoma,stenosis,tracheobronchial malacia and the ingestion of harmful substances can cause the disorders of the trchea,leading to serious health complications of patients.In adults,only half of the tracheal length,approximately 6 cm,and in children where only one-third of the length of the trachea can be successfully treated by resection.However,there is no clinically viable option available for patients with long segmental airway disorders.Tracheal cartilage is mainly responsible for holding airway passage open between the larynx and the lungsa and prevent the collapse of airway.Tracheal cartilage is difficult to repair itself because tracheal cartilage is an aneural and avascular tissue.With the development of tissue engineering,electrospinning technology can combine growth factors or compounds and nanofibers to mimic the biologic and mechanical functions of the natural extracellular matrices(ECM),which can promote proliferation and chondrogenic differentiation of mesenchymal stem cells to rapir cartilage tissue.In this study,P(LLA-CL)/Collagen nanofibers containing KGN were fabricated by coxial electrospinning technology.The structure and surface morphology of nanofibrous scaffolds were evaluated by scanning electron microscope(SEM),transmission electron microscope(TEM),water contact angle and mechanical testing.The cumulative release profiles of KGN were evaluated by sustained release experiments in vitro.The activity of KGN released from scaffolds was tested by evaluating its effect on maintain the synthesis of COL2 and GAG by chondrocyte.Cytotoxicity assays in vitro were used to assess the cell compatibility of nanofibrous scaffolds.The induction experiments in vitro were used to assess the inductive effect of the sustained release KGN.The experimental results showed that the nanofibrous scaffolds containing KGN had a good surface morphology and "core-shell" structure.KGN was successfully loaded into the nanofibers and had good mechanical properties.The KGN released from the scaffolds in a sustained and stable manner for about 2 months.KGN was no toxicity to chondrocyte and can effectively maintain the phenotype of chondrocytes.The nanofibrous scaffolds containing KGN had a good biocompatibility and promoted the chondrogenic differentiation ability of BMSCs.On the basis of the above research,we study the difference of the release behavior and the inductive effect of KGN encapsulated nanofibrous scaffold fabricated by bended electrospinning and KGN encapsulated nanofibrous scaffold fabricated by coxial electrospinning.We also study the difference of properties of chondroitin sulfate(CS)coated nanofibrous scaffolds and uncoated nanofibrous scaffolds.The nanofibrous scaffolds were evaluated by scanning electron microscopy,transmission electron microscopy,contact angle test and tensile mechanical test.Degradation experiments and sustained release experiments were respectively used to assess the degradation properties and the release behavior of different nanofibrous scaffolds.Cell proliferation assays were used to assess the cellular compatibility of different nanofibrous scaffolds.In vitro induction tests were used to assess the induction properties of CS coated nanofibrous scaffolds and uncoated nanofibrous scaffolds.The results showed that the mechanical properties of CS coated nanofibrous scaffolds were better than uncoated.CS coated nanofibrous scaffolds had a better biocompatibility than uncoated.The chondrogenic differentiation for BMSCs on CS coated nanofibrous scaffolds was better than on uncoated.The sustained release time of KGN encapsulated nanofibers fabricated by bended electrospinning was less than KGN encapsulated nanofibers fabricated by coxial electrospinning.The chondrogenic differentiation for BMSCs on KGN encapsulated nanofibers fabricated by bended electrospinning had no significant difference cpmpared to KGN encapsulated nanofibers fabricated by coxial electrospinning.