Research And Manufacturing Of A Mechanical Artificial Bladder And Biocompatibility Evaluation Of The Prototype's Related Materials

Objective: Bladder cancer is a malignant tumor of the bladder mucosa,it is one of the common malignancies of the urogenital system.The major approach of bladder cancer's treatment is surgery,and radical cystectomy is still the gold standard for the treatment of invasive bladder cancer and recurrent high-risk non-invasive bladder cancer.Currently there is still no standard precept for urinary diversion after radical cystectomy,but ideal urinary diversion should meet the requirements of low postoperative complications,protection of renal function and high quality of patients' life etc.Radical cystectomy usually has big surgical trauma and postoperative complications are common,this seriously reduces the patients' life quality.In order to improve the quality of patients' life and make the patients' life more similar to a common life,we attempt to develop an artificial bladder that can realize the function of a natural bladder and can be a kind of substitution of natural bladder.In a broad sense,the related research on bladder function's reconstruction can be traced back to the early 20 th century.Researchers did numerous experiments and clinical practices in many areas such as surgical reconstruction,nerve connection,cell reconstruction and artificial material reconstruction etc.While making continuous progress and achievements,different methods still have certain limitations.So far there has been no method that can completely restore bladder physiological functions such as autonomic diastole,contraction and perception of urination signal.Our research attempts to develop a mechanical artificial bladder,use the motor,drive mechanism,sensors and other mechanical components to realize the bladder physiological functions such as autonomic diastolic,contraction,and sending urination signal etc.We also attempt to evaluate the feasibility of the prototype's in vivo experiment by studying the biocompatibility of prototype's manufacturing materials.Methods: 1.Study the morphology,structure and physiological function of natural bladder and summarize its characteristics.According to these characteristics,complete the overall design of artificial bladder by applying related knowledge such as mechanical design and automatic control etc.2.Refer to the request of animal experiment,the actual manufacturing capability,and the design of different mechanical artificial organs,develop a mechanical artificial bladder prototype by accomplishing the works such as components selection,mechanical structure design and manufacture,control circuit design and manufacture,programming,assemble etc.3.Use tissue mass method to extract the ureteral epithelial cells of experimental rabbits.Culture the rabbit ureteral epithelial cells by using extract liquid of artificial blood vessels,extract liquid of polytetrafluoroethylene materials and ordinary medium respectively,and evaluate the cytotoxicity of the materials.4.Use extract liquid of silica gel materials to culture 3T3 cells.Use the methods of cells counting,MTS,FDA fluorescence staining and scanning electron microscopy respectively to analyze the cells' adhesion and proliferation on silica gel materials,finally evaluate the cytotoxicity of silica gel materials.5.Implant silica gel material in the abdominal cavity and ureter of the experimental rabbits to observe the tissue reaction to the material,and evaluate whether the material is suitable to be implanted in the body,and to explore whether the silica gel material can be used for ureteral anastomosis instead of artificial blood vessels.Results: 1.Completed the prototype design of implantable mechanical artificial bladder.2.Completed the manufacture of the mechanical artificial bladder prototype.3.The cytotoxicity of PTFE materials was not higher than artificial blood vessels.4.The cytotoxicity of silica gel materials was from grade 0 to grade 1,but the cells could not adhere and proliferate on it.5.The postoperative diet and mental state of the experimental rabbits were normal,and the blood test indexes were basically normal too.The inflammation was severe in the first 2 weeks after the implantation,and the inflammation decreased or even disappeared in the third and fourth week.Conclusion: The prototype of the mechanical artificial bladder can realize the physiological function of a natural bladder in vitro,and the manufacturing materials have good biocompatibility.It can be implanted into experimental animals for a short time to observe and evaluate whether it can work in vivo and replace the natural bladder.