title: Ten-fold augmentation of endothelial uptake of vascular endothelial growth factor with ultrasound after systemic administration.
abstract: OBJECTIVE
  In this study, the feasibility of delivering and enhancing the uptake of vascular endothelial growth factor (VEGF) into the intact endothelium by using ultrasound (US) facilitation was determined.
  
  
  BACKGROUND
  A limitation of tissue-targeted drug delivery is the need for direct arterial cannulation. We postulate a mechanism by which agents injected intravenously may be targeted to a tissue using US and ultrasonic contrast agents.
  
  
  METHODS
  We used a rat model to test the ability of US and an ultrasonic contrast agent perflurocarbon exposed sonicated dextrose albumin (PESDA) to increase uptake of VEGF in the myocardium. Continuous wave Doppler US (0.6 W/cm2 at 1 MHz for 15 min) was applied to the chest wall overlying the myocardium during intravenous injection with either VEGF (100 microg/kg) alone or a combination of VEGF and PESDA (0.1%). Control rats had VEGF infused without US or PESDA. The VEGF uptake was measured quantitatively in the heart, lung, liver and kidneys by enzyme-linked immunosorbent assay (ng/g of tissue) and morphologically by fluorescence microscopy.
  
  
  RESULTS
  There was an eight-fold increase in VEGF uptake in the heart by US alone (16.86 +/- 1.56 vs. 2.11 +/- 0.953 ng/g of tissue, p < 0.0001) and a 13-fold increase with US + PESDA (26.78 +/- 2.88 vs. 2.11 +/- 0.953 ng/g of tissue, p < 0.0001) compared with control rats. Fluorescence microscopy revealed deposition of VEGF in the endothelium of small intramyocardial arterioles.
  
  
  CONCLUSIONS
  These results show a marked increase in endothelial VEGF uptake with US and US + PESDA. Thus, US may be used to augment endothelial VEGF uptake 10-fold to 13-fold.
authors.affiliation: Cardiovascular Imaging Center, Department of Cardiology, The Cleveland Clinic Foundation, Ohio 44195, USA.
authors.forename: D
authors.initials: D
authors.lastname: Mukherjee
authors.forename: J
authors.initials: J
authors.lastname: Wong
authors.forename: B
authors.initials: B
authors.lastname: Griffin
authors.forename: S G
authors.initials: SG
authors.lastname: Ellis
authors.forename: T
authors.initials: T
authors.lastname: Porter
authors.forename: S
authors.initials: S
authors.lastname: Sen
authors.forename: J D
authors.initials: JD
authors.lastname: Thomas
mesh_terms: D000818:Animals; D016228:Endothelial Growth Factors / Q000008:administration & dosage / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000378:metabolism* / Q000473:pathology; D004797:Enzyme-Linked Immunosorbent Assay; D007275:Injections, Intravenous; D008222:Lymphokines / Q000008:administration & dosage / Q000378:metabolism*; D008297:Male; D008856:Microscopy, Fluorescence; D008955:Models, Cardiovascular; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D051381:Rats; D011921:Rats, Inbred WKY; D014018:Tissue Distribution; D018608:Ultrasonography, Doppler; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
chemical_list: D016228:Endothelial Growth Factors; D008222:Lymphokines; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors