title: Biocompatibility and recanalization characteristics of hydrogel microspheres with polyzene-F as polymer coating.
abstract: The objective of this study was to evaluate inflammatory response and recanalization after embolization with a new spherical embolic agent based on a core and shell design with a hydrogel core of polymethylmethacrylate (PMMA) and a Polyzene-F nanoscale coating in a porcine kidney model. Thirty-six minipigs were enrolled for superselective renal embolization. Polyzene-F-coated PMMA particles and uncoated PMMA particles with a diameter of 300-600 mum were used. Either 4 or 12 weeks post-embolization, arteriography of the embolized kidneys was performed and then compared with pre- and immediate post-embolization arteriograms using a specific recanalization score to determine the extent of recanalization. Using a microscopic inflammation score (Banff classification), the embolized organs were examined for local inflammatory effects which occurred in response to the embolic agent. In Polyzene-F-coated particles, the Banff classification showed an average inflammation score of 0.26 +/- 0.58 at 4 weeks and of 0.08 +/- 0.28 at 12 weeks. In uncoated particles, the Banff score measured 0.37 +/- 0.6 at 4 weeks, which was higher, but without a statistically significant difference. According to the recanalization score used in this study, mild angiographic recanalization was evident in all groups, without statistically significant differences (3.0 +/- 0.71 in coated particles, 3.09 +/- 0.81 in uncoated particles; p = 0.74). We conclude that both uncoated hydrogel particles and Polyzene-F-coated embolic agents triggered virtually no inflammatory response and effectively occluded target arteries. This study demonstrates good biocompatibility of the new embolic material. As in other spherical embolic agents, recanalization can occur to some degree.
authors.affiliation: Department of Diagnostic Radiology, University of Heidelberg Medical Center, Heidelberg, Germany.
authors.forename: Sibylle
authors.initials: S
authors.lastname: Stampfl
authors.forename: Ulrike
authors.initials: U
authors.lastname: Stampfl
authors.forename: Nadine
authors.initials: N
authors.lastname: Bellemann
authors.forename: Christof M
authors.initials: CM
authors.lastname: Sommer
authors.forename: Heidi
authors.initials: H
authors.lastname: Thierjung
authors.forename: Boris
authors.initials: B
authors.lastname: Radeleff
authors.forename: Ruben
authors.initials: R
authors.lastname: Lopez-Benitez
authors.forename: Irina
authors.initials: I
authors.lastname: Berger
authors.forename: Guenter W
authors.initials: GW
authors.lastname: Kauffmann
authors.forename: Goetz M
authors.initials: GM
authors.lastname: Richter
mesh_terms: D000180:Acrylic Resins; D000792:Angiography / Q000379:methods; D000818:Animals; D001167:Arteritis / Q000000981:diagnostic imaging / Q000473:pathology*; D020099:Coated Materials, Biocompatible; D004195:Disease Models, Animal; D004621:Embolization, Therapeutic / Q000379:methods*; D005780:Gelatin; D020100:Hydrogels / Q000494:pharmacology; D007668:Kidney / Q000098:blood supply / Q000000981:diagnostic imaging / Q000473:pathology; D010316:Particle Size; D011108:Polymers / Q000494:pharmacology; D019904:Polymethyl Methacrylate / Q000494:pharmacology*; D011336:Probability; D011897:Random Allocation; D012077:Renal Artery / Q000000981:diagnostic imaging / Q000473:pathology*; D012079:Renal Circulation / Q000502:physiology; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D013552:Swine; D013556:Swine, Miniature
chemical_list: D000180:Acrylic Resins; D020099:Coated Materials, Biocompatible; D020100:Hydrogels; D011108:Polymers; C496735:trisacryl gelatin microspheres; D005780:Gelatin; D019904:Polymethyl Methacrylate