A kind of articular cartilage graft and preparation method thereof

Abstract

An articular cartilage graft and a preparation method thereof. The articular cartilage graft prepared by the present invention consists of three layers from the outside to the inside: superficial layer, middle layer and deep layer, and the thickness, shape and size of each layer are matched with the cartilage damage site, No need for preoperative shaping, after implantation, it corresponds to the distribution of the surrounding normal cartilage layers, which is conducive to the signal transmission, transduction and regulation between cells, and can better integrate with the surrounding normal cartilage tissue; it has a structure consistent with natural cartilage Features, from the superficial layer to the deep layer, the content of type II collagen gradually decreases, the content of GAG gradually increases, and the compression resistance and abrasion resistance are good; the chondrocytes in the cartilage graft are wrapped by extracellular matrix, and the immunogenicity is low, avoiding implantation After immune rejection occurs, it can survive and function for a long time, and improve the long-term curative effect of cartilage repair.

Description

technical field [0001] The invention belongs to the technical field of tissue engineering medical biomaterials, and in particular relates to an articular cartilage graft and a preparation method thereof. Background technique [0002] Articular cartilage is hyaline cartilage composed of chondrocytes, cartilage fibers, and cartilage matrix. Cartilage tissue has the characteristics of heterogeneous layer distribution, which is divided into superficial layer (10-20%), middle layer (40-60%) and deep layer (20-30%) from top to bottom. In recent years, studies have found that each region of cartilage has a different structure, different protein components, and performs different functions. The gene expression and growth rate of chondrocytes obtained from different regions are different. The density of chondrocytes in the superficial, middle and deep layers decreases in turn, among which the chondrocytes in the superficial layer are closely arranged in the horizontal direction and ...

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Problems solved by technology

[0006] After retrieval, Chinese patents 02136560.1, 03147950.2, and 200310109203.6 disclose methods for constructing tissue engineered cartilage derived from allogeneic cells, but none of them carry out subregional construction according to the structure and function of normal cartilage, which may cause the prepared tissue engineered cartilage to be different from the surrounding normal cartilage and cartilage. The lower osseointegration is not good, and the wear resistance and compression resistance consistent with natural cartilage cannot be obtained. The patent also does not take effective measures to reduce the risk of immune rejection of allogeneic cells, and cannot guarantee the survival and function of cells in the recipient

Chinese patents 200610026862.7 and 200810102842.2 respectively use adipose-derived mesenchymal stem cells and umbilical cord mesenchymal stem cells to induce differentiation into chondrocytes as seed cells. Although mesenchymal stem cells come from a wide range of sources, mesenchymal stem cells induced in the direction of cartilage may be involved in gene expression, Extracellular matrix secretion, cell signal transduction, etc. cannot be exactly the same as normal chondrocytes, and it is uncertain whether mesenchymal stem cells induced in the direction of chondrocytes can maintain the characteristics of hyaline cartilage stably for a long time

In addition, when constructing tissue engineered cartilage, the biocompatibility of artificially synthesized scaffold materials is poor, and the degradation products may have adverse effects on the body

Without the use of scaffold materials, it is impossible to provide a three-dimensional space for the growth of chondrocytes, and it is impossible to solve the problems of chondrocyte aging and fibrosis during the culture process

Chinese patent 200710078264.9 constructs a bionic function interface osteochondral composite tissue integrated engineering scaffold with cartilage layer, calcification layer and subchondral bone layer, but the corresponding thickness of each layer is not set according to the thickness of normal cartilage, which is easy to cause The thickness of each layer of the constructed scaffold is inconsistent with that of the surrounding normal tissue during clinical application. After implantation, each layer of the constructed scaffold is mismatched with each layer of the surrounding normal cartilage, which affects the integration effect

In addition, because chondrocytes are surrounded by a large amount of extracellular matrix, cell migration is difficult. Simple scaffold materials used for cartilage tissue repair can only achieve fibrocartilage repair, and the long-term effect is not good.

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