Study on Construction of Nano tPA Plasmid to Prevent Thrombosis After Mechanical Valve Replacement in Dogs

[Objective] To elucidate the transfection of nano tPA gene plasmid to prevent thrombosis after tricuspid mechanical valve replacement in dogs. [Methods] A dog model of tricuspid mechanical valve replacement was constructed. A constructed chitosan nano tPA gene plasmid was used to transfect the dog cardiocytes at the same time of tricuspid replacement.The effect of this gene on survival time of dogs, anticoagulation result (prothrom-bin time, INR and D-dimer contents, thrombosis in heart), the expressions of tPA were observed with the methods of chnical laboratory, routine pathology and immunohistochemical stain. [Results] Nano tPA gene plasmid was successfully constructed and transfected into cadiocytes. The gene could significantly increased the survival time and serum level of D-dimer (P <0.01) and could prevent thrombosis of mechanical valve, but there was not significant difference of prothrombin time and INR between two groups (P >0.05). [Conclusion] The constructed nano tPA gene plasmid could prevent thrombosis after mechanical valve replacement, which provide the bases for prevention of human disease using genetic drugs.