title: Ultrasonic destruction of albumin microbubbles enhances gene transfection and expression in cardiac myocytes.
abstract: BACKGROUND
  It has been proven that ultrasonic destruction of microbubbles can enhance gene transfection efficiency into the noncardiac cells, but there are few reports about cardiac myocytes. Moreover, the exact mechanisms are not yet clear; whether the characteristic of microbubbles can affect the gene transfection efficiency or not is still controversial. This study was designed to investigate whether the ultrasound destruction of gene-loaded microbubbles could enhance the plasmids carried reporter gene transfection in primary cultured myocardial cell, and evaluate the effects of microbubbles characteristics on the transgene expression in cardiac myocytes.
  
  
  METHODS
  The β-galactosidase plasmids attached to the two types of microbubbles, air-contained sonicated dextrose albumin (ASDA) and perfluoropropane-exposed sonicated dextrose albumin (PESDA) were prepared. The gene transfection into cardiac myocytes was performed in vitro by naked plasmids, ultrasound exposure, ultrasonic destruction of gene-loaded microbubbles and calcium phosphate precipitation, and then the gene expression and cell viability were analyzed.
  
  
  RESULTS
  The ultrasonic destruction of gene-loaded microbubbles enhanced gene expression in cardiac myocytes compared with naked plasmid transfection ((51.95 ± 2.41) U/g or (29.28 ± 3.65) U/g vs. (0.84 ± 0.21) U/g, P < 0.01), and ultrasonic destruction PESDA resulted in more significant gene expression than ASDA ((51.95 ± 2.41) U/g vs. (29.28 ± 3.65) U/g, P < 0.05). Ultrasonic destruction of microbubbles during calcium phosphate precipitation gene transfection enhanced β-galactosidase activity nearly 8-fold compared with calcium phosphate precipitation gene transfection alone ((111.35 ± 11.21) U/g protein vs. (14.13 ± 2.58) U/g protein, P < 0.01). Even 6 hours after calcium phosphate precipitation gene transfection, ultrasound-mediated microbubbles destruction resulted in more intense gene expression ((35.63 ± 7.65) U/g vs. (14.13 ± 2.58) U/g, P < 0.05).
  
  
  CONCLUSIONS
  Ultrasonic destruction of microbubbles might be a promising method for the delivery of non-viral DNA into cardiac myocytes, and the gene tranfection is related to the characteristics of microbubbles.
authors: Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart Lung and Vessel Diseases, Beijing 100029, China.
authors: Guo-zhong
authors: GZ
authors: Wang
authors: Jing-hua
authors: JH
authors: Liu
authors: Shu-zheng
authors: SZ
authors: Lü
authors: Yun
authors: Y
authors: Lü
authors: Cheng-jun
authors: CJ
authors: Guo
authors: Dong-hui
authors: DH
authors: Zhao
authors: Dong-ping
authors: DP
authors: Fang
authors: Dong-fang
authors: DF
authors: He
authors: Yuan
authors: Y
authors: Zhou
authors: Chang-jiang
authors: CJ
authors: Ge
mesh_terms: D000418:Albumins; D000818:Animals; D002470:Cell Survival / Q000235:genetics / Q000502:physiology; D002478:Cells, Cultured; D045423:Microbubbles; D032383:Myocytes, Cardiac / Q000166:cytology / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D014162:Transfection / Q000379:methods*; D014465:Ultrasonics / Q000379:methods*; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
chemical_list: D000418:Albumins; D001616:beta-Galactosidase