An intelligently regulated absorbable peripheral nerve repair catheter and preparation method thereof

Abstract

The invention provides an intelligent-control absorbable peripheral-nerve repairing conduit and a preparation method thereof. The intelligent-control absorbable peripheral-nerve repairing conduit hasa four-layer structure, wherein a first-layer supporting material and a second-layer supporting material are loaded with plasmin-sensitive microspheres; a third-layer supporting material and a fourth-layer supporting material are supporting layers with mechanical properties at the later period of conduit implantation, and the conduit is prepared by a 3D spinning and printing technology. The high-sensitivity and self-control 3D printing composite gradient conduit with slow-release micropheres has the beneficial effects that the nerve growth factor can be released by self control according to the nerve growth characteristics, and the synchronization of the nerve growth and material degradation can be realized, so that the problems of narrowness in the conduit and the like due to in-vivo implantation swelling in the existing nerve repairing conduit are solved, and the adverse influence of longer-time slow degradation on the biocompatibility after the nerve regeneration is finished can beavoided.

Description

technical field [0001] The invention belongs to the field of medical technology, and in particular relates to a peripheral nerve repair catheter and a preparation method thereof, in particular to an intelligently regulated absorbable peripheral nerve repair catheter and a preparation method thereof. Background technique [0002] Peripheral nerve injury is a common type of injury with a high incidence and disability rate, among which defect injury is the most common type of injury. A small number of defects can be sutured without tension at the ends, but for larger defects, autologous nerve transplantation is still the first choice for clinical treatment. However, the repair results of this method are not ideal, especially when the nerve defect is long ( >6mm). In recent years, the use of tissue engineering methods to repair peripheral nerve defects has become a research hotspot, that is, nerve stents are used to bridge the damaged ends of peripheral nerves and provide re...

AI Technical Summary

Problems solved by technology

The preparation of plasmin-sensitive drug delivery system can control the local release of nutrient factors along with nerve regeneration. The Chinese People's Liberation Army General Hospital has reported the preparation of plasmin-sensitive microspheres (plasmin-sensitive hydrogel microspheres). Preparation and Evaluation of Spheres, PLA Medical College, Master’s Dissertation), but the reported research has the following disadvantages: 1) The preparation method of microspheres is complicated, and the polypeptide is first modified with PEG derivatives, and then prepared by free radical polymerization; 2) The sensitive slow-release period is long, 120h releases 93.85%, and the release period is much longer than the concentration change period during the nerve growth process (such as the peak-to-trough interval of the biphasic expression of nerve growth factor NGF mRNA at the injury site ≤ 48h), so there is a problem of regulation lag ; 3) The amide bonds and ester bonds in the sustained-release microspheres will also be hydrolyzed in the absence of plasmin, resulting in the release of growth factors; 4) The encapsulation efficiency of nerve growth factors is only 73-75%;

However, this invention has the following disadvantages: (1) The degradation cycle of the polymer material is ignored, and it is difficult to avoid the expansion of the catheter material after the nerve catheter is implanted in the body, and the swollen catheter will cause narrowing or even closure in the tube, which will hinder the growth of the nerve

(2) The gradient release of nerve growth factor is completely based on the concentration of growth factor carrier balls, and its concentration can only be speculated based on theory, and cannot be released according to the actual needs of the nerve growth cycle

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