The Study Of The Iodine-containing Polymer As Radiopaque Embolizing Materials

Polymers such as PVA particles, Onyx and sodium alginate microspheres, currently used for embolization procedures are radiolucent. So they are invisible on X-ray images, and consequently, the interventional docters have to resort to angiography to monitor the fate of the polymer. It's difficult that docters diagnose patients'focus of illnesses during and after the embolization procedure.The radiopaque polymer was prepared by copolymerization of cellulose acetate and the iodinated monomer 2-methacryloyloxyethyl(2,3,5-triiodobenzoate). and characterized by-'H-NMR, FTIR, GPC, DSC and X-ray. It has been shown that the polymer should contain at least 20 wt% iodine for clinically relevant X-ray visibility.The liquid embolizing agent was made from the radiopaque polymer dissolved in an appropriate solvent. In vitro transportation model and embolism model were established to sift the best embolic conditions. The embolizing agents of different concentrations were transported through the transportation model, and the embolizing agents of feasible concentrations were choiced. Those were used in the embolism model in different conditions. By observing the effectiveness of the embolizing agents, we found the best feasible conditions which included the concentration of the agents, the injection speed and the end point of the embolization. The result provides a basis data for the next process of animal experiments and clinical trials.To establish a sterilization method suitable for the liquid embolizing agent, we sterilized the material by moist heat sterilization(1), Co-60 radiation sterilization(2) and membrane filtration method(3), respectively. The iodine content of the material was tesed by titration method. The results show that three methods can sterilize effectivly all. However, the iodine content of the material decreased significantly when sterilized by the methodl or2, and did not change when sterilized by the method3. The membrane filtration method is the optimal sterilization method for the liquid embolizing agent.According to GB/T16886.1, we studied the Biological evaluation of the liquid embolizing agent, to study the safety of the material. The evaluation tests, including Cytotoxicity, Delayed-type hypersensitivity, Irritation, Systemic toxicity (acute), Subacute and subchronic toxicity, Genotoxicity, Haemocompatibility and so on, were carried out. The results prove that the liquid embolizing agent is a biocompatible material.