The Effect And Mechanism Of Chiral Self-Assembling Peptides On The Repair Process Of Anterior Cruciate Ligament Injury

This study investigated the effects of chiral self-assembled peptides Sciobio Ⅱ and Sciobio Ⅳ on three-dimensional culture of ligament fibroblasts and repair of anterior cruciate ligament injury.The secondary structure and structural components of short peptides after self-assembly were analyzed by UV spectrometer,infrared spectrometer and circular dichrograph.The ability of hydrogel formation and themacrostructure of peptides before and after self-assembly were detected by aniline blue and Congo red staining.Transmission electron microscope were used to observe the microstructure of peptides after self-assembly and after adding growth factors.In cell experiments,the self-assembled peptides Sciobio Ⅱ and Sciobio Ⅳ were applied to ligament fibroblasts culture.The cytoskeleton of HLF cells in three-dimensional environment was observed by FITCphalloidin staining,and the activity of HLF cells in three-dimensional environment was detected by CCK-8,fluorescence staining and flow cytometry.The differences in m RNA expression of related growth factors and protein molecules in two-dimensional and three-dimensional environments were detected by fluorescence quantitative PCR.The rabbit model of anterior cruciate ligament injuries was established,and the pathological changes of the ligament healing process were analyzed by HE staining,Masson staining,and immunohistochemistry.The expression of protein genes related to the ligament repair process was detected by PCR.The results showed that the self-assembled peptides formed stable β-sheets after self-assembly in PBS for 24 hours,and further self-assemble into nanofiber network structure,which is suitable for 3D cell culture.HLF cells maintained a round shape and grow vigorously in the 3D cell culture media constructed by self-assembling peptides.q PCR results showed that the peptides enhanced the expression of VEGFA;regulate the expression of ERK2.Animal experiments showed that the self-assembled peptides promoted the repair of rabbit ACL injury to a certain extent.HE staining showed that the peptides promoted the activation and proliferation of fibroblasts.The results of immunohistochemistry and q PCR showed that the peptides group up-regulated the expression of Col1A1 and Col3A1 compared with the control group,promoted the expression of CollagenⅠ and CollagenⅢ,and regulated the expression of MMP-8 and MMP-13.In summary,the self-assembled peptides can be applied to 3D culture of ligament fibroblasts,can gel at the wound,can control the release of growth factors,and promote the repair of ACL injury.It has the potential for minimally invasive applications,can become a potential treatment for patients with ACL injury,and has clinical application prospects.