New blood vessel formation and expression of VEGF receptors after implantation of platelet growth factor-enriched biodegradable nanocrystalline hydroxyapatite.
Vascular endothelial growth factor (VEGF) plays a key role for the interaction of osteoblasts and endothelial cells and, therefore, is an important factor for the osteointegration of bone substitutes. The aim of the current work was to study the effects of platelet growth factors (PLF) on new blood vessel formation and VEGF-receptors expression pattern in bone defects filled with nanocrystalline hydroxyapatite (HA) paste in miniature-pigs. Conventional histology, RT-PCR for VEGF and receptors mRNA, Western blot analysis, immunohistochemical staining and quantitative assessment of newly formed vessels was performed. HA enriched with platelet growth factor (HA/PLF+) led to an up-regulation of VEGF-R1 synthesis, a slightly enhanced number of newly formed vessels with higher sprouting activity compared with HA without PLF (HA/PLF-) filling defects. These observation are most likely attributable to a stimulating effect of TGF-ss from the platelet factor on VEGF expression in osteoblasts.
Kilian
Olaf
O
Department of Trauma Surgery, University of Giessen, Giessen, Germany. olaf.kilian@chiru.med.uni-giessen.de
Alt
Volker
V
Heiss
Christian
C
Jonuleit
Tarja
T
Dingeldein
Elvira
E
Flesch
Ingo
I
Fidorra
Ursula
U
Wenisch
Sabine
S
Schnettler
Reinhard
R
D000818:Animals; D001672:Biocompatible Materials; D001792:Blood Platelets / Q000378:metabolism; D015153:Blotting, Western; D018786:Bone Substitutes / Q000737:chemistry*; D001842:Bone and Bones / Q000187:drug effects*; D049109:Cell Proliferation; D003460:Crystallization; D017886:Durapatite / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism; D004815:Epidermal Growth Factor; D007150:Immunohistochemistry; D008024:Ligands; D018919:Neovascularization, Physiologic; D010006:Osteoblasts / Q000378:metabolism; D010012:Osteogenesis; D010982:Platelet-Derived Growth Factor / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012313:RNA / Q000378:metabolism; D040262:Receptors, Vascular Endothelial Growth Factor / Q000096:biosynthesis* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013552:Swine; D013556:Swine, Miniature; D014158:Transcription, Genetic; D015854:Up-Regulation; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
D001672:Biocompatible Materials; D018786:Bone Substitutes; D008024:Ligands; D010982:Platelet-Derived Growth Factor; D042461:Vascular Endothelial Growth Factor A; D004815:Epidermal Growth Factor; D012313:RNA; D017886:Durapatite; D040262:Receptors, Vascular Endothelial Growth Factor