Study On The Sustained And Controlled Release Characteristics Of Coaxial Drug Loading Tissue-engineered Bone Scaffolds

Background and significance: As we all know,the incidence of tuberculosis is high at home and abroad,and it is difficult to treat,especially bone tuberculosis.Its incidence was as high as 50% of extrapulmonary tuberculosis,especially in Xinjiang.At present,the primary method is oral or injection drug treatment for treating bone tuberculosis,or to clear the lesion,and then autologous bone transplantation,but this treatment method was more flawed;during the treatment process,there are oral or injection drugs that cannot reach the lesion efficiently,and cannot Quickly and completely eliminate the tuberculosis bacteria at the lesion,which has great toxic and side effects on nerves,liver and kidney organs,and is easy to produce adverse reactions such as immune system rejection;and incomplete debridement may infect other bone tissues,and excessive removal will cause bone Tissue defects cause great difficulties for bone healing.Autologous bone transplantation is difficult to remove,and the source of allogeneic bone is insufficient,which is currently a clinically difficult problem to solve.In recent years,with the deepening of tissue engineering bone scaffold research,it has provided a new idea for the clinical treatment of bone tuberculosis,but the tissue engineering bone preparation process parameters are complex and variable.With the changes of materials and equipment and other factors,it is impossible to form a unified At the same time,with the successful development of drug-loaded microspheres,the harm of oral and injection drugs to the body is reduced,but how to prepare the best performance of drug-loaded microspheres and how to make drug-loaded microspheres and tissues compound preparation of engineering bone scaffolds.After tissue engineering bone is implanted in human body,how to control the effective therapeutic concentration of drugs and slowly release the drugs is a big problem to be solved urgently for the clinical treatment of bone tuberculosis with tissue engineering bone scaffolds.Based on the above problems,this study studies the performance and process parameters of drug-loaded microspheres;optimizes the process parameters for preparing tissue engineering bone by extrusion deposition molding technology;meanwhile,explores the performance of tissue engineering bone drug sustained release system.Methods: First,emulsification method was used to prepare drug-loaded microspheres.Five factors and four levels of orthogonal experiments were set up to adjust the preparation process parameters of drug-loaded microspheres to prepare drug-loaded microspheres with the best performance.Secondly,establish a three-dimensional model of coaxial drug-loading microspheres tissue engineering bone scaffolds,and optimize the extrusion molding process parameters based on the Taguchi method;the best performance of drug-loading microspheres and bone scaffold materials are compounded by a certain amount to obtain coaxial load Tissue engineering bone scaffolds with drug microspheres,and characterize the related properties of bone scaffolds.Finally,the basic characteristics of the composite bone scaffold such as micro-morphology,porosity,pore size and water absorption were characterized,and the in vitro degradation and drug release simulation tests of the coaxial drug-loading and drug-loading microsphere tissue engineering bone scaffold revealed the bone scaffold in vitro the law of degradation and drug release.Conclusion:(1)The prepared silk fibroin-loaded microspheres have good drugloading rate,encapsulation rate and slow-release performance without violent burst.(2)The prepared coaxial drug-loaded microsphere tissue engineering bone scaffold has good molding quality and mechanical properties.(3)The prepared coaxial bone scaffold drug sustained and controlled release system has good sustained release performance and degradation performance,which lays a certain foundation for clinical treatment of bone tuberculosis.