Anti-inflammatory effect of ibuprofen-loaded embolization beads in sheep uterus

Embolization of blood vessels may result in a variety of side effects which can include pain and inflammation. The objective of this study was to assess the release and effect of ibuprofen (IBU) from Bead Block microspheres (BB) loaded with IBU (IBU-BB) on the foreign body inflammatory reaction in a sheep uterine artery model. Both uterine arteries of 12 hormonally cycled ewes were embolized with 0.5 mL of 500-700 microm BB (n = 6) or IBU-BB (n = 6). Animals were sacrificed at 1 week (1W) or 3 weeks (3W) (n = 3 each group). The gross examination of the organs was performed and distribution of the beads in the tissue was assessed. Inflammation was estimated histologically by quantitative and semiquantitative classification of inflammatory cells on HES and MGG stains and use of videoanalysis after immunohistolabeling with CD-antibodies to a variety of inflammatory cells. At 1W, a significant decrease of inflammatory response was observed for IBU-BB relative to BB in terms of number of lymphocytes and of immunohistochemical staining for CD172a, MHC-II, CD3, and CD4. At 3W, the inflammatory response for IBU-BB was similar to that for BB at 1W in terms of cell populations and moderate intensity. There was no or low amounts of staining for CD8 and CD45RA and none for CD21 in all four groups. Immunohistochemical detection of IBU showed that some drug was still present in the beads at 1W but none was detectable at 3W suggesting it had all eluted. These results signify that the inflammatory response is dampened by the action of IBU eluted from the beads and that IBU-BB can delay postembolization inflammatory reaction.