A Study Of Comparing The Ability Of Periodontal Tissue Regeneration Between Periodontal Ligament Cells And Bone Marrow Stromal Cells

Objective To compare the ability of periodontal tissue regeneration between periodontal ligament cells (PDLCs) and bone marrow stromal cells (BMSCs), to provide foundation for periodontal tissue regeneration.Methods 1. BMSCs derived from 6 Beagle dogs were harvested, growing inα-MEM, DMEM-LG and RPMI 1640 media respectively. Then the proliferation, attachment rate and mineralized nodules of the cells in three media were observed and compared. 2. The biocompatibility of acellular dermal matrix (ADM ) and BMSCs was observed in vitro. The BMSCs under induction were seeded onto ADM and implanted subcutaneously in nude mice, and the control group was implanted with only ADM. Formed tissues were harvested for histologycal analysis at 4 and 8weeks after implantation. 3. Realtime PCR, immunocytochemistry, Von Kossa and some other ways were employed to compare the ability of tissue regeneration between PDLCs and BMSCs in vitro. 4. 12 nude mice were randomly divided into two groups, 6 mice in each group. Three different complex, ADM, BMSCs+ADM, PDLCs+ADM were implanted subcutaneously in every nude mice. After 4 and 8 weeks, subjects were sacrificed and the regeneration of tissue-engineered compound was evaluated by histology and immunohistochemistry, to compare the ability of tissue regeneration between PDLCs and BMSCs in vivo.Results 1. Of the three media, cells cultured byα-MEM showed the highest attachment rate. After eliminating the difference of adherent rate, there was no obvious difference in the proliferation betweenα-MEM and DMEM. Inα-MEM group, the expression of alkaline phosphate (ALP) was the highest, while the number of mineralized nodules was the least. DMEM group exhibited the most mineralized nodules among the three media. 2. In the experimental group, histological analysis demonstrated obvious degradation of ADM, good growth of BMSCs on it, extensive formation of new tissue and also some osteoid at 4 weeks after surgery. The degradation of ADM was even more obvious at 8 weeks after surgery, and more extensive formation of osteoid was observed. 3. Data of Realtime PCR showed that the levels of collagenⅫand osteoprotegerin (OPG) in PDLCs were higher than in BMSCs (P<0.05), but there was no significant difference between them in the expression of ALP (P>0.05). Immunocytochemistry results showed that the expression of collogenⅫin PDLCs was higher than in BMSCs (P<0.05). But the expression of OPG, the activity of ALP and the result of Von Kossa showed that the osteogenic potential of BMSCs was higher than PDLCs. 4. After 4 weeks and 8 weeks, histology and immunohistochemistry results demonstrated that the osteogenic potential of BMSCs was higher than PDLCs, but the ability of forming periodontal ligament was lower than PDLCs in vivo.Conclusion 1. The culture medium DMEM-LG may be more suitable for dog BMSCs cultured in vitro. 2. BMSCs had good biocompatibility with ADM. It was feasible for ADM as a transplantation scaffold for BMSCs of Beagle dogs. 3. It was showed that the osteogenic potential of BMSCs was higher than PDLCs, but the ability of forming periodontal ligament was lower than PDLCs in vitro and in vivo.