Preparation method and application of silk bracket, and three-phase silk ligament graft and preparation method thereof

Abstract

The invention discloses a preparation method and application of a silk bracket, and a three-phase silk ligament graft and a preparation method thereof. Silks are woven into a net-shaped bracket with a macroporous structure; the bracket is divided into three areas: a ligament area, a cartilage area and a bone area; mesenchymal stem cells, mesenchymal stem cells carrying with TGF-beta gene lentiviral transfection and mesenchymal stem cells carrying with BMP-2 gene lentiviral transfection are respectively planted in the three areas; the net-shaped bracket modified by the divided areas is rolled to form a bionic ligament graft with a physiological transition structure. The method avoids the problem of stress concentration due to direct connection of the soft and hard tissues; the planting gene-modified mesenchymal stem cells have excellent directional differentiation features, so that the cultivating time and steps of planting a plurality of different cells are saved, and the problem of weak biological fixation of the ligament graft-bone combination part in the existing single-phase tissue engineering ligament and the problem of the traditional method incapable of enabling the cells to grow deeply are solved.

Description

technical field [0001] The invention belongs to the field of medical tissue engineering, in particular to the field of preparation of tissue engineering ligaments for reconstructing the anatomical structure of ligament-bone joints. Background technique [0002] The anterior cruciate ligament (ACL) is an important intracapsular ligament of the knee joint, which plays a very important role in the normal movement and stability of the knee joint. Anterior cruciate ligament injury is a common disease of the knee joint. The very low ability to heal after an ACL injury results in the need for graft reconstruction in most patients. The sources of ligament grafts mainly include autologous or allogeneic ligament grafts and tissue engineered ligaments. [0003] At present, autologous ligament transplantation is mostly used clinically, but the source of autologous ligament transplantation is insufficient, and autologous ligament transplantation will cause many complications after taki...

AI Technical Summary

Problems solved by technology

[0009] The current artificial ligament still has certain limitations: ①Because the artificial ligament is not a biological reconstruction, it is prone to creep, fatigue, and mechanical failure in the long run; ②The current single-phase structure (that is, a single structure) of the ligament scaffold is difficult to regenerate in the bone tunnel A typical four-layer structure of the ligament-bone junction (collagen fibers, fibrocartilage, calcified fibrocartilage, and bone) forms a direct connection between ligament collagen fibers and bone tissue in most cases; The combination between the layers is not good, and the mechanical properties of the ligament part cannot meet the requirements of ACL reconstruction (Spalazzi JP, Doty SB, Moffat KL, et al. Development of controlled matrix heterogeneity on a triphasic scaffold for orthopedic interface tissue engineering.Tissue Eng2006;12:3497–508.); ④ Although silk scaffolds prepared by traditional weaving methods can obtain mechanical strength similar to that of ACL, MSCs can also adhere, proliferate and differentiate on the scaffolds (Altman GH, Horan RL, Lu HH, Moreau J, Martin I, Richmond JC, et al.Silk matrix for tissue engineered anterior cruciate ligaments.Biomaterials2002;23:4131–41), but the porosity between silk fibers in this weaving method is small, and the bone marrow is filled Mesenchymal stem cells began to adhere to the surface of the material after implantation. After 1 week and 2 weeks of in vitro culture, the surface of the scaffold was completely covered by the secreted extracellular matrix, and no cells entered the inside.

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