OBJECTIVETo evaluate application of the sponge of demineralized bone matrix (SDBM) in tissue engineering of bone.

METHODSSDBM was prepared from long bone of rabbits. Bone marrow cells were flushed from the bone shaft of femurs of a two-month-old New Zealand white rabbit. After the cells were cultured for 9 days, the flasks were added into dexamethasone (10(-8) mol/L), beta-glycerophosphate sodium (10 mmol/L) and L-ascorbic acid (50 micrograms/ml). After 5 weeks, the cultured cells were collected and marked by 5-Bromo-2'-dexyouridine (BrdU). The grand sum of cells seeded on a piece of SDBM was about (4-6) x 10(6). The composites of cells and SDBM (tissue engineered chip, TEC) were implanted into muscles and bone defects of radius in rabbits. A standard procedure was applied to make a 10 mm long defect bilaterally in the radius of nine skeletally mature male New Zealand white rabbits. All of the 18 defects were randomly divided into three groups: group I, six defects were grafted by TEC; group II, six defects were grafted with SDBM alone; group III, six defects were empty.

RESULTSThe results of radiographic and histological evaluation showed that all of the defects were repaired in group I and group II at 6 weeks, none of the defects was repaired in group III. The results of BrdU staining showed that the staining was positive in group I, but negative in group II. Biomechanical test showed that the compressive ultimate strength (CUS) of new bone in TEC implanted group was comparable with normal radius (P = 0.623) and in SDBM implanted group was significant lower than normal radius (P = 0.038).

CONCLUSIONSThe TEC can form cartilage and bone tissue in muscles and repair segmental bone defects. SDBM is a kind of effective natural scaffold in tissue engineering of bone.

Animals ; Bone Demineralization Technique ; Bone Marrow Cells ; cytology ; Bone Marrow Transplantation ; Bone Matrix ; Implants, Experimental ; Male ; Rabbits ; Radius Fractures ; surgery ; Random Allocation ; Stem Cells ; cytology ; Tissue Engineering

OBJECTIVETo establish a convenient, practical and high efficient method of DNA extraction of os cervi, and lay the foundation of identification of animal bones.

METHODThe bones of sika deer, red deer, cattle, dog and pig were used to extract DNA under different decalcification time (24,48,72 h) and decalcification temperature (4,25,37,56,70 degrees C), and extract method.

RESULTIt proved by experiments that demineralization process promotes the cracking of osteocyte. In a broad of decalcification time and temperature, DNA could be extracted from all bone samples successfully while the quantity varied slightly.

CONCLUSIONSamples (about 0.1 g) decalcify with 0. mol x L(-1) EDTA at 4 degrees C for 24 h, then water-bath for 1 h after lysis buffer added, DNA extracted via the method above is of high quality and can be used for PCR.

Animals ; Bone Demineralization Technique ; Bone and Bones ; chemistry ; metabolism ; Cattle ; DNA ; isolation & purification ; Deer ; Dogs ; Polymerase Chain Reaction ; Swine ; Temperature ; Time Factors

Canine mesenchymal cells (MSCs) derived from Wharton's jelly were co-cultured, then supplemented or not supplemented with platelet rich plasma (PRP) and demineralized bone matrix (DBM) to verify osteogenic differentiation. Osteoblastic differentiation followed by mineralized bone matrix production was found to be significantly higher (p < 0.05) when MSCs were associated with PRP/DBM in culture after 14-21-days of induction. Osteopontin and osteocalcin gene expression were significantly superior (p < 0.05) under the same culture conditions after 21 days of observation. In conclusion, addition of PRP to DBM co-cultured with MSCs successfully induced osteogenesis in vitro.
Animals ; Bone Demineralization Technique/veterinary ; Bone Matrix/*metabolism ; Cell Differentiation ; Cells, Cultured ; Coculture Techniques/veterinary ; Dogs ; Mesenchymal Stromal Cells/*metabolism ; *Osteogenesis ; Platelet-Rich Plasma/*metabolism ; Umbilical Cord/metabolism

OBJECTIVETo observe the osteoinductive activity of demineralized bone matrix (DBM) and deproteinized bone (DPB) made from human avascular necrotic femoral head.

METHODSThe femoral head was cut into pieces with the size of 3 mm x 3 mm x 5 mm, which were made into DBM and DPB. These two kinds of biomaterials were cocultured with human bone mesenchymal stem cells (hBMSCs). Monolayer cells without biomaterials were cultured as control. Proliferative activity of hBMSCs was evaluated on days 1, 3, 5, 7 and 14. The concentration of alkaline phosphatase (ALP), osteocalcin (OC), and Ca(2+) were detected on days 1, 7, 14 and 21.

RESULTSCells cultured in DBM showed higher proliferative activity than did in DPB and monolayer cells (F =39.773, P <0.01). DBM and DPB also had osteoinductive activity. The concentrations of ALP (F=93.162, P <0.01), OC (F =236.852, P < 0.01), Ca(2+)(F =80.711, P <0.01) of DBM group were significantly higher than that of DPB and control groups.

CONCLUSIONSIn vitro, DBM and DPB made from avascular necrotic femoral head have osteoinductive activity when cocultured with hBMSCs, and the former is stronger than the latter.

Alkaline Phosphatase ; analysis ; Biocompatible Materials ; Bone Demineralization Technique ; Bone Matrix ; cytology ; Bone and Bones ; cytology ; Calcium ; analysis ; Cell Proliferation ; Cells, Cultured ; Femur Head Necrosis ; Humans ; Mesenchymal Stromal Cells ; cytology ; Osteocalcin ; analysis ; Osteogenesis

BACKGROUND: Injectable calcium sulfate is a clinically proven osteoconductive biomaterial, and it is an injectable, resorbable and semi-structural bone graft material. The purpose of this study was to validate the clinical outcomes of injectable calcium sulfate (ICS) grafts as compared with those of a demineralized bone matrix (DBM)-based graft for filling in contained bony defects created by tumor surgery. METHODS: Fifty-six patients (41 males and 15 females) with various bone tumors and who were surgically treated between September 2003 and October 2007 were included for this study. The patients were randomly allocated into two groups, and either an ICS graft (28 patients) or a DBM-based graft (28 patients) was implanted into each contained defect that was developed by the surgery. The radiographic outcomes were compared between the two groups and various clinical factors were included for the statistical analysis. RESULTS: When one case with early postoperative pathologic fracture in the DBM group was excluded, the overall success rates of the ICS and DBM grafting were 85.7% (24/28) and 88.9% (24/27) (p > 0.05), respectively. The average time to complete healing was 17.3 weeks in the ICS group and 14.9 weeks in the DBM group (p > 0.05). Additionally, the ICS was completely resorbed within 3 months, except for one case. CONCLUSIONS: Although the rate of resorption of ICS is a concern, the injectable calcium sulfate appears to be a comparable bone graft substitute for a DBM-based graft, with a lower cost, for the treatment of the bone defects created during surgery for various bone tumors.
Absorbable Implants ; Adolescent ; Adult ; Biocompatible Materials/*administration & dosage ; Bone Demineralization Technique ; Bone Matrix/*transplantation ; Bone Neoplasms/radiography/surgery/*therapy ; Bone Substitutes/*administration & dosage ; Calcium Sulfate/*administration & dosage ; Child ; Child, Preschool ; Curettage ; Female ; Humans ; Infant ; Injections ; Male ; Middle Aged ; Wound Healing ; Young Adult