title: Exploratory study on the effect of osteoactivin on bone formation in the rat critical-size calvarial defect model.
abstract: OBJECTIVE
  Osteoactivin is a novel glycoprotein shown to exhibit an important role in regulating osteoblast differentiation and function. The aim of the present study was to evaluate the potential of osteoactivin to support bone regeneration using an established defect model.
  
  
  METHODS
  Critical-size, 8-mm-diameter through-and-through calvarial osteotomy defects were created in 60 adult male Sprague-Dawley rats. Test animals received 0.1 mL of osteoactivin in phosphate-buffered saline (50 μg/mL) soak-loaded onto an absorbable collagen sponge. Controls received 0.1 mL of phosphate-buffered saline soak-loaded onto the absorbable collagen sponge or no further intervention (sham-surgery). The animals were euthanized 2 and 4 wk after treatment and histometric analyses were performed.
  
  
  RESULTS
  The absorbable collagen sponge control (mean ± standard deviation: 40.9 ± 26.9%) showed borderline significant greater bone fill compared with sham-surgery (22.9 ± 15.8%; p = 0.10) and osteoactivin (20.2 ± 11.8%; p = 0.07) treatments at 2 wk. In contrast, osteoactivin (84.7 ± 15.8%) showed significantly greater bone fill than sham-surgery (28.4 ± 9.6%; p < 0.001) and absorbable collagen sponge (41.8 ± 22.1%; p < 0.001) at 4 wk. No animals receiving sham-surgery or absorbable collagen sponge exhibited complete bone fill at 4 wk while 70% of the animals receiving osteoactivin showed complete bone fill.
  
  
  CONCLUSIONS
  Osteoactivin demonstrates a significant potential to support bone regeneration/formation. Studies using discriminating large animal models are necessary to explore clinical application for periodontal and craniofacial indications.
authors.affiliation: Tri-Service Orthodontic Residency Program, Wilford Hall Medical Center, Lackland Air Force Base, San Antonio, TX, USA.
authors.forename: J P
authors.initials: JP
authors.lastname: Bateman
authors.forename: F F
authors.initials: FF
authors.lastname: Safadi
authors.forename: C
authors.initials: C
authors.lastname: Susin
authors.forename: U M E
authors.initials: UM
authors.lastname: Wikesjö
mesh_terms: D000818:Animals; D001847:Bone Diseases / Q000188:drug therapy* / Q000473:pathology; D001861:Bone Regeneration / Q000187:drug effects; D003399:Craniotomy; D004337:Drug Carriers; D005781:Gelatin Sponge, Absorbable; D008297:Male; D008562:Membrane Glycoproteins / Q000627:therapeutic use*; D010012:Osteogenesis / Q000187:drug effects*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012886:Skull / Q000187:drug effects* / Q000473:pathology; D013997:Time Factors
chemical_list: D004337:Drug Carriers; C503043:Gpnmb protein, rat; D008562:Membrane Glycoproteins