A biofilm for eye surface repair and its preparation method

Abstract

A biofilm that can be used for ocular surface repair and its preparation method. The biofilm of the present invention is a dense collagen film structure, the main components are type I collagen, type III collagen and various active factors, and the thickness is 0.01 to 0.05 mm, the tensile strength is 30-60MPa, and the suture tear force is 5-15N, which has the effect of inhibiting scar and inflammation. Compared with existing products, the biomembrane of the present invention can retain various natural components and structures in the amniotic membrane, have the same therapeutic effect, have similar mechanical strength to fresh amniotic membrane, and ensure that the biomembrane has no hidden dangers of viruses. The biofilm of the invention is suitable for the repair of ocular surface burns and conjunctival injuries, has good functions of promoting epithelium, anti-inflammation, and inhibiting scars, and has good therapeutic effects.

Description

technical field [0001] The invention belongs to the technical field of tissue engineering medical biomaterials, and in particular relates to a biofilm used for ocular surface repair and a preparation method thereof. Background technique [0002] Amnion, derived from cytotrophoblast, is the inner layer of the embryonic double membrane, which is composed of epithelial cell layer, basement membrane and avascular matrix. Amniotic membrane contains various collagens as well as laminin, fibronectin, glycosamine Polysaccharides, hyaluronic acid, etc. It is the presence of these active substances that can promote the adhesion and migration of epithelial cells, induce epithelial differentiation, and prevent epithelial apoptosis, making amnion a "transplantable basement membrane" to promote epithelialization. In addition, amnion stroma also contains many growth factors, such as nerve growth factor (NGF), hepatocyte growth factor (HGF), keratinocyte growth factor (KGF), transforming g...

AI Technical Summary

Problems solved by technology

However, since this kind of amniotic membrane has not been treated with virus inactivation, its sterile state cannot be ensured, and there is a risk of virus transmission.

In recent years, there are also some amniotic membrane products at home and abroad, all of which are freeze-dried, decellularized or air-dried at room temperature; During the drying and storage process, there are many factors that induce protein denaturation (such as the choice of cryoprotectant and lyoprotectant, the choice of freezing rate, etc.), which makes the freeze-drying process difficult to control, time-consuming, high cost, and easy to cause protein denaturation 1. The amniotic membrane becomes brittle, which causes the amniotic membrane to be easily torn during the operation, and needs to be replaced repeatedly, prolonging the operation time; and the method of air drying and air drying at room temperature makes the water volatilization process longer, and the effect of drying and dehydration is not ideal (generally, the moisture content >13 %),; In addition, the amniotic membrane loses a large amount of natural collagen after decellularization, especially the active factor components, which affects the clinical use effect

[0004] The amniotic membrane products disclosed in U.S. Patents US006152142A and US006326019B1 are blunt separation and removal of chorion after cesarean section placenta is cleaned, and the epithelium is spread upward on the nitrocellulose filter paper, and then pressed Preserved in DMEM:glycerol at a ratio of 1:1, stored in a -80°C refrigerator, the prepared amnion has not been decellularized, dried and sterilized, so the integrity of the amnion’s composition and structure is preserved to the greatest extent; but there are The problems are: ①The storage cost is too high, and it is inconvenient to transport; ②It has been frozen at low temperature during storage, and needs to be thawed at room temperature when it is used. These two processes will cause damage to the amnion collagen structure and become fragile; ③ Nitrocellulose filter paper is used as the substrate in the preparation, and the amnion needs to be torn off during use, which makes the already fragile amnion more prone to tearing or curling, which brings a lot of inconvenience to clinical operations; Live processing, with potential for virus transmission

The prepared amnion, similar to the above-mentioned US patent, has undergone low-temperature freezing, which also damages the amnion to a certain extent, making it brittle and easy to tear in clinical use; it also uses nitrocellulose filter paper as a substrate , the amniotic membrane is not easy to remove when used, and it is prone to curling, which brings unnecessary trouble to the operation, consumes operation time, and delays the condition

[0006] Chinese patent application 201010113960.0 discloses a method of rebuilding and repairing the amniotic membrane matrix using Matrigel at low temperature (-20-4°C), dyeing with colored dyes, laying After the membrane is dried, it is sterilized with cobalt 60, thereby better preserving the amniotic membrane epithelium and substrate, but the reconstruction of the amniotic membrane matrix at a temperature below zero will still cause the amniotic membrane to become brittle; the amniotic membrane is torn off from the substrate after the membrane is laid It will cause tearing or curling, and it is difficult to identify the epithelial and basal surfaces of the amniotic membrane, which brings troubles to clinical operations

Images