A kind of factor slow-release neutral gel system for 3D printing or in situ injection and its preparation method

Abstract

The invention discloses a factor slow-release neutral gel system for 3D printing or in situ injection and a preparation method thereof, belonging to the technical field of biomaterials. The preparation process includes the preparation of pre-gel collagen, the preparation of collagen fibers, the preparation of activated heparin and the like. Among them, the pre-gel collagen can be kept stable at 4 degrees for several months, and has secondary gel performance, which simplifies the preparation process of traditional collagen gel. Collagen fibers-heparin is the carrier of growth factors, which makes the growth factors added to the gel system release slowly. This gel system can flexibly and conveniently release a variety of growth factors and add various cells. Since the collagen in the pre-gel state has good forming properties and gels rapidly at 37°C, the gel system can be used in addition to three-dimensional culture. In addition to its functions, it can be further applied to in situ injection and 3D bioprinting.

Description

technical field [0001] The invention relates to the technical field of biomaterials, in particular to a factor slow-release neutral gel system for 3D printing and in situ injection and a preparation method thereof. Background technique [0002] Collagen is a biomaterial with good biocompatibility, which is widely used in the fields of tissue engineering and regenerative medicine. Now a series of products such as collagen repair membrane and collagen bone scaffold have been approved for clinical application. In experimental research, rat tail collagen has been widely used. Undenatured collagen is dissolved in acidic solution, and after neutralization, it can form a gel at a certain salt concentration at 37°C. But the traditional collagen gel has the following disadvantages: 1. The concentration is low. The concentration of the widely used rat tail collagen is generally 3 mg / mL. When the concentration is increased, it is difficult to neutralize it evenly. This type of collage...

AI Technical Summary

Problems solved by technology

But the traditional collagen gel has the following disadvantages: 1. The concentration is low. The concentration of the widely used rat tail collagen is generally 3mg / mL. When the concentration is increased, it is difficult to neutralize it evenly.

This type of collagen has low viscosity and is not suitable for 3D printing and in situ injection

2. Fast gelation. Under neutral conditions, 3mg / mL rat tail collagen will completely gel within 20 minutes even at 4°C. When the concentration increases, the gelation speed will be accelerated. Not only does it need to be freshly prepared for each use , and limited operating time

However, the situation of immobilizing growth factors in cell-containing hydrogels is more complicated. First, the above-mentioned fixation method will destroy active cells, so it is not advisable.

Secondly, the collagen gel is assembled step by step in its triple helix structure. The traditional fixation method will affect the triple helix structure and cause the collagen to lose its gel performance.

In recent years, researchers have found that cells and factors play an important role in tissue regeneration and repair. Traditional dry collagen can no longer meet the requirements of cell therapy. Therefore, it is urgent to develop a clinically applicable loadable cell and collagen. Growth factor material system

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