title: Quantification of horseradish peroxidase delivery into the arterial wall in vivo as a model of local drug treatment: comparison between a porous and a gel-coated balloon catheter.
abstract: OBJECTIVE
  To quantify horseradish peroxidase (HRP) delivery into the arterial wall, as a model of local drug delivery, and to compare two different percutaneous delivery balloons.
  
  
  METHODS
  Perforated and hydrophilic hydrogel-coated balloon catheters were used to deliver HRP in aqueous solution into the wall of porcine iliac arteries in vivo. HRP solutions of 1 mg/ml were used together with both perforated and hydrophilic hydrogel-coated balloon catheters and 40 mg/ml HRP solutions were used with the hydrogel-coated balloon only. The amount of HRP deposited in the arterial wall was then determined photospectrometrically.
  
  
  RESULTS
  Using the 1 mg/ml HRP solution, the hydrogel-coated balloon absorbed 0.047 mg HRP into the coating. Treatment with this balloon resulted in a mean vessel wall concentration of 7.4 microg HRP/g tissue +/- 93% (standard deviation) (n = 7). Treatment with the hydrogel-coated balloon that had absorbed 1.88 mg HRP into the coating (using the 40 mg/ml HRP solution) led to a mean vessel wall concentration of 69.5 microg HRP/g tissue +/- 74% (n = 7). Treatment with the perforated balloon using 1 mg/ml aqueous HRP solution led to a mean vessel wall concentration of 174 microg/g +/- 81% (n = 7). Differences between the hydrogel-coated and perforated balloons (1 mg/g solutions of HRP) and between hydrogel-coated balloons (0.047 mg vs 1.88 mg absorbed into the balloon coating) were significant (p < 0.05; two-sided Wilcoxon test).
  
  
  CONCLUSIONS
  The use of a perforated balloon catheter allowed the delivery of a higher total amount of HRP compared with the hydrogel-coated balloon, but at the cost of a higher systemic HRP application. To deliver 174 microg HRP per gram of vessel wall with the perforated balloon, 6.5 +/- 1.5 mg HRP were lost into the arterial blood (delivery efficiency range = 0.2%-0.3%). With 0.047 mg HRP loaded into the coating of the hydrogel balloon, 7.4 microg HRP could be applied to 1 g of vessel wall (delivery efficiency 1.7%), and with 1.88 mg HRP loaded into the coating of the hydrogel balloon, 69.5 microg HRP could be applied per gram of vessel wall (delivery efficiency 0.6%).
authors.affiliation: Department of Diagnostic Radiology, University of Technology Aachen, Pauwelsstrasse 30, D-52057 Aachen, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Dick
authors.forename: W
authors.initials: W
authors.lastname: Kromen
authors.forename: E
authors.initials: E
authors.lastname: Jüngling
authors.forename: S
authors.initials: S
authors.lastname: Grosskortenhaus
authors.forename: H
authors.initials: H
authors.lastname: Kammermeier
authors.forename: D
authors.initials: D
authors.lastname: Vorwerk
authors.forename: R W
authors.initials: RW
authors.lastname: Günther
mesh_terms: D000818:Animals; D015415:Biomarkers; D002404:Catheterization / Q000295:instrumentation*; D016503:Drug Delivery Systems / Q000295:instrumentation*; D006735:Horseradish Peroxidase / Q000008:administration & dosage* / Q000032:analysis; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D007083:Iliac Artery; D007261:Infusions, Intra-Arterial; D018709:Statistics, Nonparametric; D013552:Swine
chemical_list: D015415:Biomarkers; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D006735:Horseradish Peroxidase