The experimental study of cryopreserved osteoblasts combined with bioactive glass repairing mandibular defects in rabbits

Wanye Tan, MD,(a) Fengcai Wei, MD,(a) Shanzhen Sun, MD,(b) and Mingxia Sun, MD(b)

(a)Department of Stomatology, Qi-Lu Hospital, Shandong University, and (b)School of Dentistry, Shandong University, Jinan, P. R. China

Purpose: The purpose of this study was to observe the biological character of cultured periosteal-derived osteoblasts (POBs) preserved in liquid nitrogen in vitro, and to have a preliminary study on the osteogenetic capability of bioactive glass ceramics (BGC) combined with POBs.
Materials and Methods: The POBs were acquired from New Zealand big white rabbit and after several generations culture some of them were kept in liquid nitrogen. The cryopreserved cells for six months were cultured in DMEM medium and examined by morphological and histological observation. Then those growing well in vitro were seeded into the porous BGC materials. A week later, the combined materials were implanted into the bone defects of rabbits’ mandible, the control groups were implanted into the single BGC (no cells). After two, four, eight, and 12 weeks of operation, the specimens were respectively excised and examined by X-ray and histological chemistry observation.
Results: The cryopreserved POBs grew well in vitro and also had the typical characters of mature osteoblasts. Cultured with BGC materials, the cells could attach grow and proliferate well on the surface of most endopores. After four weeks of operation the transplanted osteoblasts began to form new osteoid or bone-like tissue in most pores of implanted BGC, and the bone defects were repaired better and earlier.
Conclusion: It was practical to use the cryopreserved osteoblasts as seeded cell for further study on bone tissue engineering. It suggested that the “living” bone substitute would get more application and play a more important role in bone restoration and reconstruction.
(Int Chin J Dent 2003; 3: 91-99.)

Clinical Significance: The results of this study demonstrate that the porous bioactive glass ceramics combined with cryopreserved osteoblasts can repair the bone loss of rabbits’ mandible, and what we have done will do good to future clinical application.
Key Words: bioactive glass ceramics, bone tissue engineering, bone defcents, cell culture, cryopreserved osteoblast.