ABSTRACT
BACKGROUND:Fol owing physicochemical treatment and high-temperature calcinations, heterogeneous biological bone becomes a ceramic-like heterologous bone forming a similar structure to the human bone that is a natural network pore structure, which is conducive to seed cel adhesion and proliferation. OBJECTIVE:To observe the feasibility of constructing tissue-engineered bone through combination of sintered bone and bone marrow mesenchymal stem cel s to repair alveolar defects. METHODS:Sheep bone marrow mesenchymal stem cel s as seed cel s were combined with the high temperature sintered bone as scaffold materials to construct tissue-engineered bone. Under general anesthesia, sheep bilateral mandibular first premolars were removed in batches, the alveolar ridge space between the distal root and mesial root of the second premolar to form a bone defect area of 5 mm×5 mm×5 mm. Twelve experimental sheep were equal y randomized into tissue-engineered bone group and sintered bone group, which were implanted with tissue-engineered bone and sintered bone, respectively, at the left surgical area of the mandible. The right surgical area was considered as blank control group. RESULTS AND CONCLUSION:After high-temperature calcinations, the sintered bone was chalk in color, exhibiting a porous structure as the natural cancel ous bone. The porosity was (66.10±1.32)%, and the pore size was between 137.44μm and 538.72μm. After 24 hours of bone marrow mesenchymal stem cel s inoculated to the sintered bone, a large number of cel s are visible adherent to the scaffold;up to day 7, extracel ular matrix was secreted and there was no clear boundary between the cel s and the matrix. X-ray films showed that the tissue-engineered bone and pure sintered bone implants were embedded in the surgical area, and there was a low-density shadow at the edge of the sintered bone. Hematoxylin-eosin staining showed bone trabecular formation at the experimental side, but no obvious bone formation at the control ed side. Tissue-engineered bone prepared by bone marrow mesenchymal stem cel s and sintered bone can better repair sheep alveolar bone defects, which is an ideal seed cel and scaffold material for smal range bone defects.
ABSTRACT
Objective To prepare a new osteoinduction hydroxyapatite crystal material using sintered bovine bone combined with bone morphogenetic protein(BMP2)-derived peptide and type Ⅰ collagen,and to study their biological characteristics for developing biomaterials for orthopaedic tissue engineered bone.Methods Sintered bovine bone combined with BMP2-derived peptide and type Ⅰ collagen was as experimental group.and Sintered bovine bone combined with Type Ⅰ collagen Wag as control group.Formation of hydmxyapatite crystals was inveati gated under environmental scanning electron microscopy(ESEM),energy-dispersive spectroscopy(EDS)and X-ray diffraction(XRD).The ceil-material complex Wag observed and cell adhesion rate on each materials WaS calculated using the method of indirect cell count to evaluate the interaction between cells and materials.Results By ESEM,formation of hydroxyapatite crystals in collagen surface was observed in experimental group but none was observed in control group.By EDS and XRD,the contents of calcium and phosphorus elements from mineralized bone surface were 16.23% and 7.76%respectively.The atom percentages of calcium and phosphorus elements were 6.34%and 3.88%respectively.The cell adhesion rate of experimental group after 24 hours co-culture was significantly higher than that of control group (α＜0.05).Conclusion BMP2-derived peptide can induce the formation of hydroxyapatite crystals at the surface of sintered bovine bone combined with type Ⅰcollagen.It can also elevate the osteoinduction and cell adhesion rate and is an ideal scaffold material by combining with sintered bovine bone for the bone tissue engineering.