IADR Abstract Archives
Regeneration of Palatal Cleft-Like Surgical Defects in Rabbits Using Poly (Glycerol Sebacate) Elastomer Scaffold
Objectives: To evaluate the bone regenerative capacity of a load-transducing elastomeric scaffold-Poly (glycerol sebacate) (PGS) - in surgically created cleft-like palatal defects in New Zealand white rabbits.
Methods: In phase Iof the study,three different defect dimensions were evaluatedradiographically and histologically immediate post-operatively and after two weeks(n=7). The optimal defect dimensions of 5x2.5x4mm3 with intact nasal mucosa were maintained in phase II, to compare between the sham (n=5) and PGS (n=6) groups after 4 and 8 weeks usingCBCT, histological and histomorphometric analyses.
Results: At 8 weeks,both CBCT and histomorphometric assessmentsshowed that the remaining defect dimensions in PGS group significantlydecreased than the sham group. This indicated bone resorption in the sham defects opposite to longerterm remodeling and bone regeneration in the PGS group. The PGS group showed significantly higher bone density (and mean bone fill% (than the sham group (( these values increasedin PGS defects from 4 to 8 weeks,they decreased for the sham group demonstratingprogressive bone resorption. Histologically, PGS defectsshowed almost closure of the defect and preservation of the external contourat 8 weeks withhigher recruitment of mesenchymal progenitorcellsand significantly higher number of blood vessels. The PGS group also showed more tissue organization of the suture area.
Conclusions: 5x2.5x4mm3surgically created palatal defects in rabbitspreserved vital structures and maintained a reliable defect size that did not heal after two weeks. To our knowledge, this is the first study to incorporate PGS –an elastomer and load-transducing scaffold- in the maxillofacial region where development, growth and remodelingare highly influenced by occlusal forces and the load on the craniofacial bones. .Being similar in stiffness to developmental osteoid tissue, PGS could trigger the recruitment of osteoprogenitor cells and direct their commitment stimulating osteogenesis. PGS also preserved external contour and sutures which are all critical keys in cleft palate management.
Methods: In phase Iof the study,three different defect dimensions were evaluatedradiographically and histologically immediate post-operatively and after two weeks(n=7). The optimal defect dimensions of 5x2.5x4mm3 with intact nasal mucosa were maintained in phase II, to compare between the sham (n=5) and PGS (n=6) groups after 4 and 8 weeks usingCBCT, histological and histomorphometric analyses.
Results: At 8 weeks,both CBCT and histomorphometric assessmentsshowed that the remaining defect dimensions in PGS group significantlydecreased than the sham group. This indicated bone resorption in the sham defects opposite to longerterm remodeling and bone regeneration in the PGS group. The PGS group showed significantly higher bone density (and mean bone fill% (than the sham group (( these values increasedin PGS defects from 4 to 8 weeks,they decreased for the sham group demonstratingprogressive bone resorption. Histologically, PGS defectsshowed almost closure of the defect and preservation of the external contourat 8 weeks withhigher recruitment of mesenchymal progenitorcellsand significantly higher number of blood vessels. The PGS group also showed more tissue organization of the suture area.
Conclusions: 5x2.5x4mm3surgically created palatal defects in rabbitspreserved vital structures and maintained a reliable defect size that did not heal after two weeks. To our knowledge, this is the first study to incorporate PGS –an elastomer and load-transducing scaffold- in the maxillofacial region where development, growth and remodelingare highly influenced by occlusal forces and the load on the craniofacial bones. .Being similar in stiffness to developmental osteoid tissue, PGS could trigger the recruitment of osteoprogenitor cells and direct their commitment stimulating osteogenesis. PGS also preserved external contour and sutures which are all critical keys in cleft palate management.