Silk bracket as well as preparation method and application thereof, and three-phase silk ligament graft and preparation method thereof

Abstract

The invention discloses a silk ilk bracket as well as a preparation method and application thereof, and a three-phase silk ligament graft and a preparation method thereof. Firstly, silks are woven into a net-shaped bracket with a macroporous structure; then the net-shaped silk bracket is divided into three areas: A. a ligament area, B. a cartilage modification area and C. a bone modification area; ligament cells, chondrocyte and osteoblast are respectively planted in the areas A, B and C; the net-shaped bracket modified by the divided areas is rolled to form a cylindrical ligament graft with a physiological transition structure. The structure gradually transited from soft tissues to hard tissues effectively avoids the problem of stress concentration due to direct connection of the soft and hard tissues, solves the problem of weak biological fixation of the ligament graft-bone combination part in the existing single-phase tissue engineering ligament, and solves the problem that the seed cells cannot enter the deep part of the ligament in the traditional ligament weaving method; the ligament graft has the complete weaving structure, and solves the problem of weak connection between layers in the existing three-phase tissue engineering ligament.

Description

technical field [0001] The invention belongs to the field of medical tissue engineering, in particular to the field of three-phase silk ligament graft capable of reconstructing the normal anatomical structure of the ligament-bone joint. Background technique [0002] Anterior cruciate ligament (ACL, anterior cruciate ligament) injury is a common disease of the knee joint. ACL injuries often lead to knee instability and degenerative osteoarthritis. Due to its limited ability to regenerate, it cannot repair itself after injury, so reconstruction must be through ligament grafting. There are two main sources of ligament grafts: ①autologous or allogeneic ligament transplantation; ②tissue engineered ligament. [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 taking materials. At present, 1 / 3 of the pa...

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Problems solved by technology

[0005] However, 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 term; The typical four-layer structure of the ligament-bone junction (collagen fibers, fibrocartilage, calcified fibrocartilage and bone) is regenerated, and in most cases, a direct connection between the ligament collagen fibers and bone tissue is formed; ③ A three-phase scaffold of PLGA is reported in the literature , 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 MSC implantation After just beginning to adhere to the surface of the material, the surface of the scaffold was completely covered by the secreted extracellular matrix after 1 week and 2 weeks of in vitro culture, while no cells entered the inside

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