Abstract:

BACKGROUND: Our previous studies have demonstrated that cryopreserved bone marrow stromal cells (BMSCs) still maintain high survival rate, cell proliferation and osteogenic differentiation potentials after thawing. However, this result needs confirmed in vivo environment. 
OBJECTIVE: To explore the effects of cryopreserved BMSCs and collagenic membrane BME-10X complex on type Ⅰ collagen synthesis in vivo.
METHODS: Beagle dog BMSCs were cultured in vitro and cryopreserved for 12 months, which were thawed and prepared complexes with collagenic membrane. The complexes were cultured with mineralization induction medium or normal medium for 5 days, followed by implanting into nude mice. The specimens were harvested and analyzed by gross observation, histopathological and immunohistochemistry at 4 weeks after implantation. The collagenic membrane cultured with mineralization induction medium served as controls.
RESULTS AND CONCLUSION: In the control group, the boundary of collagenic membrane was distinctly, without cell growth around boundary or intra collagenic membrane, additionally, there was little type Ⅰ collagen. In the non-induction group, cells grew into collagenic membrane, trabes-like collagen formed, and type Ⅰ collagen distribution increased at 4 weeks. In the induction group, scaffold degraded, more cells grew, and plenty of collagen formed osteoid-like tissues. The distribution of typeⅠcollagen was obviously increased than that of other groups. The findings demonstrated that cryopreserved BMSCs possess strong osteogenic differentiation potentials after proliferation and induction combined with collagenic membranes in vitro.