The effect on bone regeneration of a liposomal vector to deliver BMP-2 gene to bone grafts in peri-implant bone defects.
Successful bone-implant osseointegration in large peri-implant bone defects is often difficult, even through autologous bone grafting. Recently, cell-mediated regional gene therapy was introduced to deliver potent morphogens or growth factors in regenerative medicine. We applied liposomal vectors carrying bone morphogenetic protein (BMP)-2 cDNA directly into freshly created peri-implant bone defects on pig calvariae, with or without autologous bone graft. The BMP-2 gene was efficiently introduced into immigrating cells and trabecular cells lining the marginal bone surrounding the bony defect. After 1 week, abundant BMP-2 protein was detected throughout the peri-implant bone defect by immunohistochemistry. At 4 weeks, BMP-producing cells were still present in the defect and peri-implant area, which significantly enhanced new bone formation, compared with the control groups. Interestingly within a week of BMP-2 gene delivery with bone grafts, most osteoblastic cells lining the grafted bone chips also produced BMP-2. Particulated bone was immediately reorganized into newly formed trabecular bone. Grafted bone without BMP-2 gene delivery was still scattered and new bone matrix formation was not detected until 4 weeks after bone grafting. In conclusion, direct application of the BMP-2 gene using a liposomal vector enhanced bone regeneration in a bony defect and gene delivery combined with bone graft could induce a rapid osseointegration of the bone-implant interface at earlier stage.
Park
J
J
Department of Oral and Maxillofacial Surgery, University of Erlangen-Nuremberg, Glueckstrasse 11, Erlangen, Germany. jung.park@mkg.imed.uni-erlangen.de
Lutz
R
R
Felszeghy
E
E
Wiltfang
J
J
Nkenke
E
E
Neukam
F W
FW
Schlegel
K A
KA
D000818:Animals; D001857:Bone Matrix / Q000166:cytology; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000008:administration & dosage* / Q000235:genetics*; D001861:Bone Regeneration / Q000502:physiology*; D016025:Bone Transplantation / Q000379:methods*; D001842:Bone and Bones / Q000002:abnormalities*; D002113:Calcification, Physiologic / Q000502:physiology; D018014:Gene Transfer Techniques; D005822:Genetic Vectors / Q000008:administration & dosage*; D006801:Humans; D008081:Liposomes; D019736:Prostheses and Implants; D044968:Regenerative Medicine; D017154:Stromal Cells / Q000166:cytology; D013552:Swine; D016212:Transforming Growth Factor beta / Q000008:administration & dosage* / Q000235:genetics*
C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D008081:Liposomes; D016212:Transforming Growth Factor beta