Bone critical defect repair with poloxamine-cyclodextrin supramolecular gels

The aim of this study was to evaluate the osteoinductive capacity of a poloxamine (Tetronic (R) 908, T) and alpha-cyclodextrin (alpha CD) supramolecular gel (T-CD) as scaffold in a critical size defect in rat calvaria. The T-CD gel was evaluated solely and after being loaded with simvastatin (SV) and bone morphogenetic protein (BMP-2) separately and in combinations in order to reduce the doses of the active substances. Three doses of SV (7.5, 75, 750 mu g) and two doses of BMP-2 (3 and 6 mu g) were tested. The histology and histomorphometrical analysis showed improved bone repair with T-CD compared to T, probably due to better release control of both SV and BMP-2. In addition, as T-CD eroded more slowly than poloxamine alone, it remained longer in the defect site. Although synergism was not obtained with BMP-2 and SV, according to the observed regeneration of the defect, the dose of BMP-2 and SV can be reduced to 3 mu g and 7.5 mu g, respectively. (C) 2015 Elsevier B.V. All rights reserved.