Preparation And Performance Study Of Oxidized Konjac Glucomannan/chitosan/antibacterial Calcium Hydrogen Phosphate Dihydrate Scaffol

In recent years,with the intensification of population aging,the number of people with bone defects caused by diseases such as osteoporosis has increased.Although bone tissue has a certain degree of self-healing ability,it cannot heal when the bone tissue defect is too large.Therefore,it is particularly important to find a suitable type of bone tissue engineering support material.With the development of medical biomaterials,many scholars have found that both metal materials,polymer materials,and inorganic materials have certain defects when used alone,which cannot fully meet all the properties of ideal materials.Therefore,it is necessary to design ideal and suitable bone tissue engineering scaffolds for the human body.As one of the medical ceramic materials,calcium hydrophosphate dihydrate(DCPD)has good biocompatibility and better degradability than hydroxyapatite.However,traditional DCPD does not have antibacterial properties.This article uses the introduction of silver ions to modify it,making it have antibacterial properties.It is then compounded with oxidized konjac glucomannan(OKGM)/chitosan(CS)organic materials to prepare a porous bone tissue engineering scaffold with good antibacterial,mechanical,and degradation properties,as follows:(1)Antibacterial ADCPD was prepared by co deposition method and analyzed by XRD,SEM,and antibacterial performance testing.The results showed that silver ions did not change the morphology and crystal structure of the original dicalcium phosphate dihydrate,and with the increase of silver ion content,the bacteriostatic performance was significantly improved,the minimum concentration of bacteriostasis was 3%,and the inhibitory effect of ADCPD on Escherichia coli was greater than that of Staphylococcus aureus.(2)The oxidized konjac glucomannan(OKGM)was obtained by the oxidation of konjac glucomannan with hydrogen peroxide,which had an aldehyde structure.The OKGM/CS hydrogel was tested and characterized.FT-IR was used to analyze the oxidation reaction of konjac glucomannan and the Schiff base reaction with chitosan.The best OKGM: CS mass ratio of 1:1 was explored through gel time,mechanical property tests and other experiments.(3)Using ADCPD,OKGM,and CS as raw materials,an antibacterial bone tissue engineering scaffold with a through-hole array was prepared by extrusion molding method.Its porosity is above 50%,and the main pore size is 400μm(the average size of human Osteon is about 223μm)。The porous structure of the scaffold is conducive to the generation of blood vessels and the transport of nutrients.The compressive strength of the antibacterial porous scaffold can reach over 7 MPa.After about three months of in vitro degradation,the compressive strength of the scaffold is always greater than 2 MPa,meeting the minimum requirement for compressive strength of human cancellous bone,and the degradation rate is between 50%～60%,without collapse.The experiment proves that the scaffold has good antibacterial performance and no cytotoxicity.The antibacterial porous bone tissue engineering scaffold prepared in this experiment has good antibacterial properties,mechanical properties,in vitro degradation performance,and porous structure,which is expected to be applied in the field of bone repair...