Study on construction of nano tPA plasmid to prevent thrombosis after mechanical valve replacement in dogs.

Background: Mechanical valve is inclined to induce thrombosis. We intend to elucidate the transfection of nano tissue-type plasminogen activator (tPA) gene plasmid to prevent thrombosis after tricuspid mechanical valve replacement in dogs.

Methods: A dog model of mechanical tricuspid valve replacement was constructed. A constructed chitosan nano tPA gene plasmid was used to transfect the dog cardiocytes at the same time of tricuspid valve replacement. The effect of this gene on the survival of dogs, anticoagulation (prothrombin time, INR and D-dimer contents, thrombosis in heart), and the expressions of tPA were observed.

Results: Nano tPA gene plasmid was successfully constructed and transfected into cardiocytes. The gene could significantly increase the survival of animals and the contents of D-dimer (P < 0.01), and could prevent thrombus formation on mechanical valves, but there was no significant difference of prothrombin time and INR between two groups (P > 0.05).

Conclusion: The constructed nano tPA gene plasmid could prevent thrombus formation after mechanical valve replacement, which provides a clue for clinical use.