In vitro study on porcine Mesenchymal Stem Cells from Buccal Fat Pad as a novel population for periodontal regeneration: comparison with ASCs from subcutaneous tissue

Introduction In our previous study we have characterized human mesenchymal stem cells from Bichat’s fat pad, and proposed them for future therapies of periodontal defects and oral bone regeneration [1]. Considering the swine an accepted model for preclinical study in tissue engineering applications, here we compare swine Adipose-derived Stem Cells (ASCs) from Buccal fat pad and from subcutaneous adipose tissue both alone and in combination with synthetic scaffolds Materials and Methods Cells isolated from subcutaneous interscapular site (ScI) and buccal fat pad (BFP) of 6 swine were characterized as previously described [1,2,3]. pASC interactions with titanium disk (Permedica S.p.A., Merate, Italy) and SIC–plasma-enhanced chemical vapour-deposition (SIC) fragments (CETEV – C.T.V. Carsoli - AQ, Italy) were also investigated, as well as cell growth in medium with porcine serum. Results 5.5x104±3.3x104 and 3.0x104±9.3x103 cells/ml were isolated from interscapular subcutaneous adipose tissue (ScI) and buccal fat pad (BFP) (n=6), respectively. All the ASCs, with a fibroblast-like shape, costantly proliferated (DT of 82.9±11.5 and 72.5±8.2 hours for ScI- and BFP-ASCs, respectively) and showed a high clonogenic ability (+10.1±1.4% for ScI- and +8.9±1.5% for BFP-ASCs). FACS analysis revealed that both cell populations are similar in size and granularity, and are CD90+, whereas CD14, CD45 and CD271 were not detectable. Furthermore, after osteogenic induction, both ASCs increased either collagen and calcified extracellular matrix (ECM) production of about 87% and 118% for ScI-, and of about 254% and 116% for BFP-ASCs, respect to CTRL cells. Alkaline phosphatase activity (+126% and +201% for ScI- and BFP-ASCs, respectively) and osteonectin expression (+336% for ScI- and +306% for BFP-ASCs) were also up-regulated. In addition, both cell types were able to differentiate towards the adipogenic and chondrogenic lineages, as revealed by lipid vacuoles formation and GAGs deposition. Interestingly, the osteoinduction of ASCs in the presence of titanium and SIC-PECVD, increased calcified ECM depot compared to CTRL; in vitro titanium is also osteoinductive per se (+91 and +284% for ScI- and BFP-ASCs). Finally, porcine sera, did not improve cell growth compared to the standard condition. Discussion and Conclusions No significant difference between stemness features and scaffold interactions of cells from the different harvesting sites was observed, suggesting that, as the human buccal fat pad (1), also porcine one contains mesenchymal stem cells. In conclusion, we propose porcine and human BFP-ASCs in allo- and xenogenic use in porcine model of periodontal diseases. Indeed, since the BFP is easily available for dentists and maxillofacial surgeons, these cells future use in these fields could be preferential. References 1. Broccaioli et al, Biores Open Access 2(2):107-17 2013_2. de Girolamo et al, Cytotherapy 11(4):793-803 2009_3. Quirici et al, Stem Cell Dev 19(6):915-25 2010.