Preparation method for medical metal implant surface chitosan quaternary ammonium salt/collagen composite coating

Abstract

The invention discloses a preparation method for a medical metal implant surface chitosan quaternary ammonium salt / collagen composite coating. The method includes the steps that an electrolyte containing calcium, phosphorus, collagen and chitosan quaternary ammonium salt is prepared; a platinum sheet serves as a counter electrode; a metal substrate washed through acid serves as a work electrode; and electrochemical deposition is performed in a multi-potential-step manner. The positive and negative condition and the amplitude of each step work electrode potential and deposition time of each segment are adjusted, so that deposition does not need to be performed multiple times, the purpose of controllable space distribution of the chitosan quaternary ammonium salt in a mineralized collagen coating on the surface of the substrate can be quickly and easily achieved, and in other words, the inner layer and the outer layer of the collagen coating are rich in chitosan quaternary ammonium salt. The feature that the chitosan quaternary ammonium salt is provided with positive charges and biological growth factors are carried in different space positions of the collagen coating, so that the biological growth factor release behavior can be controlled and adjusted. Meanwhile, the capacity of the coating for carrying biological growth factors is improved and the method has the wide application prospect in hard-bone tissue regeneration field.

Description

technical field [0001] The invention relates to a method for preparing a surface coating of a medical metal implant, in particular to a method for preparing a mineralized collagen coating on the surface of a medical metal implant. Background technique [0002] In the process of bone repair, the body's own cells produce different growth factors at different stages to regulate the smooth progress of osseointegration, and the release behavior of growth factors often determines the success of bone repair. Therefore, for new metal implant materials, it should not only have good biocompatibility, but also have good growth factor or drug loading capacity and controllable release behavior of the growth factors it carries. Usually, a layer of organic substances with slow-release function is coated on the surface of metal implants and growth factor agents are embedded to meet the requirements of biocompatibility, growth and bearing capacity, and release behavior control. However, coa...

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Problems solved by technology

However, according to the deposition mechanism of mineralized collagen, a pH gradient will be generated near the substrate during the electrochemical deposition process, and chitosan will lose protons at a certain depth deposited to the coating as the pH increases, and the chitosan that loses protons responds to the electric field However, the property of chitosan decreased sharply, and the enrichment of chitosan in the inner or outer layer of the mineralized collagen coating could not be controlled, which limited the control of the coating on the bearing space of growth factors, and at the same time lost the chitosan and growth factors of protons. The Coulomb force between them drops sharply, which limits the improvement of the load-carrying capacity of the entire coating to growth factors, etc.

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