title: A transendocardial delivery and intracardiac ultrasound irradiation treatment catheter.
abstract: OBJECTIVE
  This study introduces the structural design, working principles, performance testing and treatment effects of a newly developed ultrasonic irradiation delivery and treatment catheter system that integrates interventional catheterization technology.
  
  
  BACKGROUND
  Systemic administration method needs a high dose of gene and induces side effect of non-target organ delivery. Direct intramyocardial injection of a low-dose angiogenic gene followed by insonation treatment can enhance gene expression. So, a novel transendocardial gene delivery and intracardiac ultrasound irradiation strategy was tested.
  
  
  METHODS
  The medical interventional ultrasonic therapeutic apparatus is comprised of an ultrasonic irradiation catheter and a host. The ultrasonic irradiation catheter, which is equipped with an advance-and-retreat convenient miniature syringe needle and a miniature piezoelectric transducer on the tip, was used. Twelve dogs were divided into three groups: (1) EGFP and US (EGFP + US), (2) EGFP alone and (3) control group. In the EGFP + US group, EGFP plasmid DNA (500 µg) was injected and followed by intracardiac insonation. In the EGFP alone group, EGFP plasmid DNA (500 µg) was injected without insonation. In the control group, saline was injected.
  
  
  RESULTS
  The catheter can enter the heart through percutaneous intervention to realize intramyocardial injection, directly irradiate cardiac muscular tissues at close range and correctly control the ultrasonic irradiation energy delivered to cardiac muscular tissues. Compared with the EGFP gene group, an average sixfold enhancement in gene expression was achieved in the EGFP EGFP + US group (p < 0.05).
  
  
  CONCLUSIONS
  The experimental results confirmed that the treatment catheter was safe and reliable, which can realize transendocardial intramyocardial gene injection in the left ventricular chamber, and the ultrasonic parameter can increase gene expression after intracardiac ultrasonic irradiation. The intracardiac ultrasound irradiation treatment catheter may be a useful delivery and therapy tool in the future.
authors.affiliation: Department of Geriatrics, Southwest Hospital, the Third Military Medical University, Chongqing 400038, China.
authors.forename: Qiao-ying
authors.initials: QY
authors.lastname: Yuan
authors.forename: Jing
authors.initials: J
authors.lastname: Huang
authors.forename: Xue-jun
authors.initials: XJ
authors.lastname: Li
authors.forename: Jian-bing
authors.initials: JB
authors.lastname: Peng
authors.forename: Xing-sheng
authors.initials: XS
authors.lastname: Li
authors.forename: Zhong-pei
authors.initials: ZP
authors.lastname: Chen
authors.forename: Liang-yi
authors.initials: LY
authors.lastname: Si
mesh_terms: D000818:Animals; D057785:Catheters; D004285:Dogs; D004699:Endocardium / Q000378:metabolism*; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D049452:Green Fluorescent Proteins / Q000235:genetics; D008297:Male; D014465:Ultrasonics / Q000379:methods*
chemical_list: C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins