Guided bone regeneration using injectable vascular endothelial growth factor delivery gel.
BACKGROUND
Vascularization underlies the success of guided bone regeneration (GBR) procedures. This study evaluates the regenerative potential of GBR in combination with vascular endothelial growth factor (VEGF) delivery via an injectable hydrogel system.


METHODS
Critical-sized defects were created in rat calvariae, and GBR procedures were performed with a collagen membrane alone (control), or plus bolus delivery of VEGF, or plus application of VEGF-releasing hydrogels (VEGF-Alg). Four and 8 weeks after treatment, defect sites were evaluated with microcomputed tomographic and histomorphometric analyses for blood vessel and bone formation.


RESULTS
At 4 weeks, relative to the control condition, the bolus addition of VEGF did not affect blood vessel density within the defect site, yet the application of VEGF-Alg significantly (P <0.05) increased blood vessel density. Although there was no difference in bone regeneration at 4 weeks, at 8 weeks there was a significant (P <0.05) increase in bone regeneration in the VEGF-Alg-treated defects.


CONCLUSIONS
These data demonstrate that the application of VEGF-Alg enhanced early angiogenesis, whereas at a later time point, it enhanced bone regeneration. Controlled delivery approaches of angiogenic growth factors used adjunctively with GBR may be a promising strategy for enhancing outcomes of GBR.
Department of Periodontics and Oral Medicine, University of Michigan, Ann Arbor, MI 48109, USA. dkaigler@umich.edu
Darnell
D
Kaigler
Eduardo A
EA
Silva
David J
DJ
Mooney
D000464:Alginates / Q000737:chemistry; D000818:Animals; D001808:Blood Vessels / Q000187:drug effects / Q000473:pathology; D001847:Bone Diseases / Q000601:surgery; D001861:Bone Regeneration / Q000187:drug effects; D003094:Collagen; D003692:Delayed-Action Preparations; D016503:Drug Delivery Systems; D048091:Guided Tissue Regeneration / Q000379:methods*; D020100:Hydrogels / Q000737:chemistry; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D007267:Injections; D008567:Membranes, Artificial; D018919:Neovascularization, Physiologic / Q000187:drug effects; D010012:Osteogenesis / Q000187:drug effects; D051381:Rats; D011916:Rats, Inbred F344; D011994:Recombinant Proteins; D012886:Skull / Q000187:drug effects / Q000473:pathology; D013997:Time Factors; D042461:Vascular Endothelial Growth Factor A / Q000008:administration & dosage*; D055114:X-Ray Microtomography / Q000379:methods
D000464:Alginates; D003692:Delayed-Action Preparations; D020100:Hydrogels; D008567:Membranes, Artificial; D011994:Recombinant Proteins; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D003094:Collagen