title: Observations on the microvasculature of bone defects filled with biodegradable nanoparticulate hydroxyapatite.
abstract: The microvascularization of metaphyseal bone defects filled with nanoparticulate, biodegradable hydroxyapatite biomaterial with and without platelet factors enrichment was investigated in a minipig model. Results from morphological analysis and PECAM-1 immunohistochemistry showed the formation of new blood vessels into the bone defects by sprouting and intussusception of pre-existing ones. However, no significant differences were observed in the microvascularization of the different biomaterials applied (pure versus platelet factors-enriched hydroxyapatite), concerning the number of vessels and their morphological structure at day 20 after operation. The appearance of VEGFR-2 positive endothelial progenitor cells in the connective tissue between hydroxyapatite particles was also found to be independent from platelet factors enrichment of the hydroxyapatite bone substitute. In both groups formation of lymphatic vessels was detected with a podoplanin antibody. No differences were noted between HA/PLF- and HA/PLF+ implants with respect to the podoplanin expression level, the staining pattern or number of lymphatic vessels. In conclusion, the present study demonstrates different mechanisms of blood and lymphatic vessel formation in hydroxyapatite implants in minipigs.
authors.affiliation: Department of Trauma Surgery, University of Giessen, Rudolf-Buchheim-Strasse 7, 35392 Giessen, Germany. olaf.kilian@chiru.med.uni-giessen.de
authors.forename: Olaf
authors.initials: O
authors.lastname: Kilian
authors.forename: Sabine
authors.initials: S
authors.lastname: Wenisch
authors.forename: Srikanth
authors.initials: S
authors.lastname: Karnati
authors.forename: Eveline
authors.initials: E
authors.lastname: Baumgart-Vogt
authors.forename: Anne
authors.initials: A
authors.lastname: Hild
authors.forename: Rosemarie
authors.initials: R
authors.lastname: Fuhrmann
authors.forename: Tarja
authors.initials: T
authors.lastname: Jonuleit
authors.forename: Elvira
authors.initials: E
authors.lastname: Dingeldein
authors.forename: Reinhard
authors.initials: R
authors.lastname: Schnettler
authors.forename: Ralf-Peter
authors.initials: RP
authors.lastname: Franke
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000378:metabolism / Q000627:therapeutic use; D015153:Blotting, Western; D001847:Bone Diseases / Q000473:pathology / Q000628:therapy*; D018786:Bone Substitutes / Q000378:metabolism / Q000627:therapeutic use*; D017886:Durapatite / Q000378:metabolism / Q000627:therapeutic use*; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D007150:Immunohistochemistry; D020007:Implants, Experimental; D008297:Male; D008833:Microcirculation / Q000187:drug effects; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D053758:Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D018919:Neovascularization, Physiologic / Q000187:drug effects; D016348:Osseointegration / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013552:Swine
chemical_list: D001672:Biocompatible Materials; D018786:Bone Substitutes; D017886:Durapatite