Bone regeneration with adipose derived stem cells: animal model.

摘要

Objectives: Stem cells have given copiously proof to be able to calcificate both in vitro and in vivo implanted under the skin, if conveniently differentiated. However nowadays, it doesn't exist yet in scientific literature a study on their efficiency in the osseous regeneration, and this very task is the real aim of this experimentation. Materials and Methods: 8 White Rabbit New Zealand, have been submitted to a first operation which consisted in a sampling of adipose tissue interscapular, from which have been isolated, expanded and differentiated towards the osteogenic line some adult stem cells, following the protocol published by Kakudo (Kakudo et al., 2008). In a second operation have been created 5 different defects on every animal's calvarium, which had a 0,6 cm diameter and were 0,2 cm deep (this measures have been taken by an appropriate caliber). 4 defects have been regenerated using 2 different conveniently modified scaffolds produced by Geistlich~R, with and without the aid of stem cells. After the insertion the part has been covered with a collagen membrane fixed by 5 modified titan pins (Altapin ~R). The defect in the front has been left empty on purpose as an internal control to each animal. These animals have been sacrificed in pairs, respectively after 2, 4, 6, 10 weeks. The samples have been submitted through MicroCT analysis to a synchrotron light, through the attainment of 1200 slices for every sample. Once slices have been binarizated through an Otsu algorithm, stereo-logic parameters have been calculated and after that each sample has been submitted to histological analysis. Results: Histological analysis: Regeneration has occurred in an optimal way in every sample treated with scaffolds. The use of adult stem cells combined with scaffolds, seems to accelerate some steps of the normal osseous regeneration: in fact we assist to a precocious new deposition and calcification of the extra-cellular. Only the non-regenerated defect shows a deficit in the calcification of the sample up to the 10th week. MicroCT analysis: When comparing the histograms obtained for both Bioss and Bioss with stem cells, the quantity of new bone for the Bioss+ stem cells samples is higher than for the Bioss alone ones, when the age is considered. The same conclusion was obtained by the histological analysis. Conclusions: Next studies on this subject will individuate the best biomaterial to sustain the potential shown by these cells and will quantify the effective contribution to the regeneration.