title: Cardiac-targeting transfection of tissue-type plasminogen activator gene to prevent the graft thrombosis and vascular anastomotic restenosis after coronary bypass.
abstract: OBJECTIVE
  To observe the tissue-type plasminogen activator gene (t-PA) plasmid packaged with albumin nanoparticles crosslinked to albumin ultrasound microbubbles for targeting transfection to myocardium to prevent the graft thrombosis and vascular anastomotic restenosis after coronary bypass.
  
  
  METHODS
  A dog model of coronary bypass using the autoallergic saphenous vein as the graft was made. A highly expressive t-PA gene plasmid packaged with albumin nanoparticles crosslinked to albumin ultrasound microbubbles was constructed. Targeting myocardial transfection was performed with this gene vector under the aid of therapeutic ultrasound(1MHz, 1.5 w/cm2, 6minutes, intravenously) after the bypass. The expression of t-PA in myocardium was detected with a multiclonal antibody to t-PA by the indirect immunohistochemical method. Venous blood t-PA and D-dimer contents were tested before and 1, 2 and 4weeks after the operation. The effects of this gene vector on thrombosis of the grafts and the coronary intimal hyperplasia around the anastomotic stoma were observed using a routine pathological examination, a morphometry for intimal thickness and area and the immuno-histochemical stain with a monoclonal antibody to PCNA for estimating the intimal SMC proliferation.
  
  
  RESULTS
  The effective expression of t-PA protein by myocardium was obtained, followed by the persistent raises of blood t-PA and D-dimer 1, 2 and 4weeks after the transfection. Thrombosis of the grafts was successfully restrained. The expression of PCNA by coronary intimal vSMCs and intimal hyperplasia were remarkablely reduced.
  
  
  CONCLUSIONS
  This t-PA gene targeting vector could be used to prevent the dog thrombosis, which provided the experimental identification for prevention on human thrombotic diseases.
authors: Department of Pathology, Shenzhen Sun Yat-Sen Cardiovascular Hospital, Shenzhen 518020, Guangdong, China.
authors: Jun
authors: J
authors: Ji
authors: Cardiovascular Surgery, Shenzhen Sun Yat-Sen Cardiovascular Hospital, Shenzhen 518020, Guangdong, China. Electronic address: yangjianan@hotmail.com.
authors: Jian-An
authors: JA
authors: Yang
authors: Department of Pathology, Shenzhen Sun Yat-Sen Cardiovascular Hospital, Shenzhen 518020, Guangdong, China.
authors: Xia
authors: X
authors: He
authors: Department of Pathology, Shenzhen Sun Yat-Sen Cardiovascular Hospital, Shenzhen 518020, Guangdong, China.
authors: Wen-Ping
authors: WP
authors: Ling
authors: Department of Pathology, Shenzhen Sun Yat-Sen Cardiovascular Hospital, Shenzhen 518020, Guangdong, China.
authors: Xiao-Ling
authors: XL
authors: Chen
mesh_terms: D000818:Animals; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D004285:Dogs; D015316:Genetic Therapy / Q000379:methods; D006083:Graft Occlusion, Vascular / Q000209:etiology / Q000235:genetics / Q000517:prevention & control*; D006801:Humans; D008297:Male; D045423:Microbubbles; D053758:Nanoparticles / Q000737:chemistry; D010957:Plasmids / Q000008:administration & dosage / Q000235:genetics / Q000627:therapeutic use*; D013927:Thrombosis / Q000209:etiology / Q000235:genetics / Q000517:prevention & control*; D010959:Tissue Plasminogen Activator / Q000235:genetics*; D014162:Transfection / Q000379:methods; D014465:Ultrasonics
chemical_list: D010959:Tissue Plasminogen Activator
keywords: Coronary bypass; Tissue-type plasminogen activator; albumin nanoparticles; thrombosis; ultrasound microbubbles