Preparation of new tissue engineering bone-CPC/PLGA composite and its application in animal bone defects

To investigate the feasibility of implanting the biocomposite of calcium phosphate cement(CPC)/polylactic acid-polyglycolic acid(PLGA) into animals for bone defects repairing,the biocomposite of CPC/PLGA was prepared and its setting time,compressive strength,elastic modulus,pH values,phase composition of the samples,degradability and biocompatibility in vitro were tested.The above-mentioned composite implanted with bone marrow stromal cells was used to repair defects of the radius in rabbits.Osteogenesis was histomorphologically observed by using an electron-microscope.The results show that compared with the CPC,the physical and chemical properties of CPC/PLGA composite have some differences in which CPC/PLGA composite has better biological properties.The CPC/PLGA composite combined with seed cells is superior to the control in terms of the amount of new bones formed after CPC/PLGA composite is implanted into the rabbits,as well as the speed of repairing bone defects.The results suggest that the constructed CPC/PLGA composite basically meets the requirements of tissue engineering scaffold materials and that the CPC/PLGA composite implanted with bone marrow stromal cells may be a new artificial bone material for repairing bone defects because it can promote the growth of bone tissues.

Preparation, Fundamental Characteristics and Biosafety Evalution of Compound rhBMP-2/CPC

To stndy the fundamental characteristics and biosafety of the compound bone morphogenetic protein （ BMP ） and rhBMP- 2/CPC , and to provide a theoretical basis for the compound biologically active artificial bone made of calcium phosphate cement （CPC） and bone morphogenetic protein, simplex CPC was taken as the control group, and the compound with the blending ratio of 1g CPC to 5mg rhBMP-2 was taken as the experimentation group to determine the setting time, compressive, strength, acute toxicological and sub acute toxicological properties. The osteogenic characteristic of compound rhBMP- 2/CPC was measured by making animal model of radio discontinuous defect. The setting time of the two groups meets the clinical requirements, and the compressive strength of the solidified body of bone cement increases along with increasing the immersion time. Compound rhBMP- 2/ CPC has a favorable ostengenic characteristic for animal model of radio discontinuous deject. The fundamental characteristics of the compound rhBMP- 2 phosphate bone cement are basically the same as that of CPC, and also have a favorable biosafety and osteogenesis.

Histologic Changes in the Sinus Membrane after Maxillary Sinus Augmentation with Simultaneous Implant Placement Using Engineered Bone Graft Material

The aim of the study was to analyze the histologic and ultrastructural changes after maxillary sinus augmentation with simultaneous implant placement using engineered bone graft material.In this study,calcium phosphate cement(CPC)scaffolds combined with goat bone marrow stromal cells(BMSCs)were used to fill goat sinus floor space after maxillary sinus floor elevation with simultaneous implant placement comparing with those not filled any grafted materials and used as controls.After a healing period of 3 months,the goat maxillary sinus membrane was examined using light microscopy and scanning electronic microscopy.The results showed that the connective tissue thickness and the epithelium thickness of mucosa were not statistically significant difference between two groups.The tissue engineered bone complex might be an ideal graft for the sinus floor elevation and have no influence on the sinus membrane under the histological and ultrastructural observation.