Objective Development in vitro test methods for drug release and particle release from drug coated baloon to address the disadvantages and inadequacy of existing assessment methods. Methods In vitro drug transfer test were carried out using the isolated porcine vessel as target site in the self-designed iliofemoral artery model, drug loss experiment during dilatation and retraction were added in drug release test, the particle test channel was subdivided and the size and number of the large particles were measured by microscopy combined with Image-Pro Plus software.Results The result shows that the method is feasible and the discrimination is good. The material balance can be achieved. More detailed data can be obtained.Conclusion The developed in vitro evaluation method provides a reference for formulation screening, in vitro bench testing and in vivo pre-clinical animal testing.

Objective To research the procedure for creating an animal model of mitral regurgitation by implanting a device through the apical artificial chordae tendineae, and to assess the stability and dependability of the device. Methods Twelve large white swines were employed in the experiments. Through a tiny hole in the apex of the heart, the artificial chordae tendineae of the mitral valve was inserted under the guidance of transcardiac ultrasonography. Before, immediately after, and one and three months after surgery, cardiac ultrasonography signs were noted. Results All models were successfully established. During the operation and the follow-up, no swines died. Immediately after surgery, the mitral valve experienced moderate regurgitation. Compared with preoperation, there was a variable increase in the amount of regurgitation and the values of heart diameters at a 3-month follow-up (P<0.05). Conclusion In off-pump, the technique of pulling the mitral valve leaflets with chordae tendineae implanted transapically under ultrasound guidance can stably and consistently create an animal model of mitral regurgitation.