The preparation of multimodal imaging embolization microspheres and its visualization experiment in vitro / 介入放射学杂志

ABSTRACT

Objective To develop a kind of gelatin microspheres which is capable of being visualized on radiography,CT and MR examinations.Methods Emulsion chemical cross-linking method was used to prepare gelatin microspheres that carried only solid Fe3O4 nanoparticles.Optical microscope was adopted to observe the morphology,particle diameter and the dispersity of the gelatin microspheres.Using thermogravimetric analysis method,the loading rate of Fe3O4 nanoparticles encapsulated in the gelatin microspheres was calculated.The multimodal visualization ability of the gelatin microspheres was evaluated by radiography,CT and MR examinations.The blood in rabbit heart and human vascular endothelial cells were used to make microsphere hemolysis test and in vitro cytotoxicity test.The elastic characteristics and the swelling characteristics of the gelatin microspheres were determined,and the sterile technique was tested.Results The optimal synthesis condition of microspheres was to use 21 of Fe3O4-to-gelatin quality ratio,under this situation,the microspheres showed a roundness appearance with satisfactory dispersion,the spherulization rate was high (up to 77％),the drug loading rate was very high (up to 73.27％),the particle diameter was moderate (199.78±142.90 μm),and the microspheres had multimodal visualization ability for radiography,CT and MR examinations.The optimization CT value of microspheres could be up to (1 028.0± 69.5) Hu (when concentration=25 mg/ml).Hemolysis test and in vitro cytotoxicity test showed that no statistically significant differences in the hemolysis rate and absorption value existed between the study group and the control group (P＞0.05).In acid solution,the microspheres exhibited swelling characteristics,while in ethanol the microspheres showed no swelling phenomenon.Conclusion Using solid Fe3O4 nanoparticles as visualization material as well as gelatin as polymer materials,a special gelatin microspheres can be prepared with emulsion chemical cross-linking method.This kind of microspheres carries the following featureshigh drug loading,regular in shape,smooth surface,not easy to agglomerate,stronger multimodal visualization ability (radiography,CT and MR),high biological safety and convenient disinfection.