Objective To explore the feasibility and safety of gene transfer into porcine myocardium via the pericardial cavity by a homemade easy device. Methods Replication-deficient recombinant adenoviral vector carrying LacZ report gene （Ad-LacZ） was constructed by the calcium phosphate precipitation method. Twelve healthy Chinese mini-swine were randomly divided into experimental group （n=6） and control group （n=6）. Acute myocardial infarction （AMI） model was established by balloon occlusion of the distal part of D1 branch of left anterior descending （LAD） artery

at the same time the intra-pericardial cavity injections were performed through the small incision of the abdominal wall below the xyphoid appendix using a homemade device. Then gene transfer was performed using a central venous catheter. The pericardium was pretreated with injection of a mixture of collagenase （1 200 U） and hyaluronidase （3 000 U） in both groups. Then 2.0×109 plaque formation unit （PFU） Ad-LacZ was injected into the pericardial cavity in experimental group

while 1 mL of normal saline was injected in the control group. The β-galactosidase activity detection and X-gal staining of the ischemic myocardium were performed on the 3rd

7th

and 28th day after injection. Results The LAD artery was occluded completely and infarction and ischemia were detected by histological assessment. In experimental group

the X-gal staining positive cells and β-galactosidase activity quantification were detectable on the 3rd day after injection

increased markedly on the 7th day

and then declined on the 28th day. The transfer efficiencies indicated by the positive myocardial cells were 16.7%

45.6%

22.8% on the 3rd

7th

28th day

respectively. In control group

no positive cells and β-galactosidase activity were observed. Conclusion Adenovirus can be transferred into ischemic myocardium and express target gene in the AMI model for four weeks with the homemade easy device via pericardial cavity pretreated by collagenase and hyaluronidase.