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Effects of Δ 12 ‐prostaglandin J 2 on bone regeneration and growth factor expression in rats
Author(s) -
Damrongsri Damrong,
Geva Sarah,
Salvi Giovanni E.,
Cooper Lyndon F.,
Limwongse Visaka,
Offenbacher Steven
Publication year - 2006
Publication title -
clinical oral implants research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.407
H-Index - 161
eISSN - 1600-0501
pISSN - 0905-7161
DOI - 10.1111/j.1600-0501.2005.01181.x
Subject(s) - regeneration (biology) , prostaglandin , chemistry , microbiology and biotechnology , biology , endocrinology
Objectives: Cyclopentenone prostaglandins have been shown to promote osteoblast differentiation in vitro . The aim of this study was to examine in a rat model the effects of local delivery of Δ 12 ‐prostaglandin J 2 (Δ 12 ‐PGJ 2 ) on new bone formation and growth factor expression in (i) cortical defects and (ii) around titanium implants. Material and methods: Standardized transcortical defects were prepared bilaterally in the femur of 28 male Wistar rats. Ten microliters of Δ 12 ‐PGJ 2 at 4 concentrations (10 −9 , 10 −7 , 10 −5 and 10 −3 mol/l) in a collagen vehicle were delivered inside a half‐cylindrical titanium chamber fixed over the defect. Contralateral defects served as vehicle controls. Ten days after surgery, the amount of new bone formation in the cortical defect area was determined by histomorphometry and expression of platelet‐derived growth factor (PDGF)‐A and ‐B, insulin‐like growth factor (IGF)‐I/II, bone morphogenetic protein ( BMP)‐2 and ‐6 was examined by immunohistochemistry. In an additional six rats, 24 titanium implants were inserted into the femur. Five microliters of carboxymethylcellulose alone (control) or with Δ 12 ‐PGJ 2 (10 −5 and 10 −3 mol/l) were delivered into surgically prepared beds prior to implant installation. Results: Δ 12 ‐PGJ 2 (10 −5 and 10 −3 mol/l) significantly enhanced new bone formation (33%, P <0.05) compared with control cortical defects. Delivery of Δ 12 ‐PGJ 2 at 10 −3 mol/l significantly increased PDGF‐A and ‐B and BMP‐2 and ‐6 protein expression ( P <0.05) compared with control defects. No significant difference was found in IGF‐I/II expression compared with controls. Administration of Δ 12 ‐PGJ 2 also significantly increased endosteal new bone formation around implants compared with controls. Conclusion: Local delivery of Δ 12 ‐PGJ 2 promoted new bone formation in the cortical defect area and around titanium implants. Enhanced expression of BMP‐2 and ‐6 as well as PDGF‐A and ‐B may be involved in Δ 12 ‐PGJ 2 ‐induced new bone formation.