OBJECTIVETo make ossicular prosthesis using little columnar acellular cancellous bone combined with bone morphogenetic protein 2 (BMP-2) and implant into rabbits' acoustic vesicle to observe the osteogenesis in situ.

METHODSTo prepare the acellular cancellous bone combined with BMP-2 as ossicular prosthesis, the same material without BMP-2 were used in the control group. By retroauricular approach, a hole was made in the posterolateral bone wall of the acoustic vesicle and the prepared materials was implanted. After 3 month, the osteogenesis of the prosthesis with macroscopical anatomy and pathology were observed.

RESULTSThe rabbits recovered soon after surgery, the implanted acellular cancellous bones were banded tightly with the bone of the acoustic vesicle bone wall. The surface of all materials was covered with mucosa while osteogenesis was found in the material with BMP-2.

CONCLUSIONThe acellular cancellous bone with BMP-2 could induce osteogenesis in acoustic vesicle, so this material might be use to reconstruct the defects of ossicular chain.

Animals ; Bone Morphogenetic Protein 2 ; administration & dosage ; Bone and Bones ; physiology ; Ossicular Prosthesis ; Rabbits ; Spine ; Swine ; Tissue Engineering ; methods

The chitosan thermosensitive hydrogel is liquid at room temperature but gels rapidly when heated to body temperature. This hydrogel are wildly used for cell encapsulation, drug delivery or tissue-engineered scaffolds. The system can sustain the release of macromolecules over a period of several hours to a few days. However, with low-molecular-weight compounds, the release is generally completed within 24 h. To prepare a functional chitosan thermosensitive hydrogel for slow release both broad-spectrum antibiotic chlorhexidine and growth factor recombined human bone morphogenetic protein-2 (rhBMP-2), The beta-cyclodextrin was used to prepare an inclusion complex with chlorhexidine, and then the latter was incorporated into the chitosan thermosensitive hydrogel system. Simultaneously, rhBMP-2 was added into the hydrogel system. By HAAKE viscosity measuring instrument, we contrasted the viscoelastic properties of system with or without objective factors. And the in vitro release kinetics of chlorhexidine and rhBMP-2 was investigated by HPLC (high performance liquid chromatography) and ELISA (enzyme-linked immunosorbent assay) respectively. The results showed that the addition of chlorhexidine/beta-cyclodextrin inclusion complex to the thermosensitive solution did not change the gelling behavior of the thermosensitive system. Further, the in vitro release profiles demonstrated that the release rate of chlorhexidine and rhBMP-2 from hydrogel became slower, controlled delivery over at least 1 month. By first preparing chlorhexidine/beta-cyclodextrin inclusion complex, and then mixing the IC and rhBMP-2 into the chitosan thermosensitive hydrogel, a functional chitosan thermosensitive hydrogel system with ability of slow release both rhBMP-2 and chlorhexidine is successfully made.
Bone Morphogenetic Protein 2 ; Bone Morphogenetic Proteins ; administration & dosage ; Chitosan ; chemistry ; Chlorhexidine ; administration & dosage ; Delayed-Action Preparations ; chemical synthesis ; Drug Carriers ; chemistry ; Drug Combinations ; Hydrogels ; chemistry ; Recombinant Proteins ; administration & dosage ; Temperature ; Transforming Growth Factor beta ; administration & dosage

OBJECTIVETo evaluate the effect of autologous bone marrow mesenchymal stem cells (BMSCs) seeded bio-derived bone materials (BBM) combined with recombinant human bone morphogenetic protein-2 (rhBMP-2) in repairing defect of osteonecrosis of femoral head (ONFH).

METHODSEarly-stage osteonecrosis in the left hip was induced in 36 adult New Zealand white rabbits (provided by the Animal Center of Guangxi Medical University, Nanning, China) after core decompression and delivery of liquid nitrogen into the femoral head. Then the animals were divided into three groups according to the type of implants for bone repair: 12 rabbits with nothing (Group I, the blank control group), 12 with BBM combined with rhBMP-2 (Group II), and 12 with BMSCs-seeded BBM combined with rhBMP-2 (Group III). At 4, 8, and 12 weeks after surgery, X-ray of the femoral head of every 4 rabbits in each group was taken, and then they were killed and the femoral heads were collected at each time point, respectively. Gross observation was made on the femoral heads. After hematoxylin and eosin staining, Lane-sandhu scores of X-ray and bone densitometry were calculated and the histomorphometric measurements were made for the new bone trabeculae.

RESULTSAt 12 weeks after surgery, two femoral heads collapsed in Group I, but none in Group II or Group III. X-ray examination showed that the femoral heads in Group I had defect shadow or collapsed while those in Group II had a low density and those in Group III presented with a normal density. Histologically, the defects of femoral heads were primarily filled with no new bone but fibrous tissues in Group I. In contrast, new bone regeneration and fibrous tissues occurred in Group II and only new bone regeneration occurrd in Group III. Lane-sandhu scores of X-ray, bone mineral density and rate of new bone in trabecular area in Group III were higher significantly than those of the other two groups.

CONCLUSIONSOur findings indicate a superior choice of repairing the experimental defect of ONFH with BMSCs- seeded BBM combined with rhBMP-2.

Animals ; Bone Morphogenetic Protein 2 ; Bone Morphogenetic Proteins ; administration & dosage ; Female ; Femur Head Necrosis ; pathology ; therapy ; Male ; Mesenchymal Stem Cell Transplantation ; methods ; Rabbits ; Recombinant Proteins ; administration & dosage ; Tissue Engineering ; methods ; Transforming Growth Factor beta ; administration & dosage

OBJECTIVETo study the effect of poly D,L-lactic acid (PDLLA) screws with PDLLA-rhBMP compound on bone regeneration in the screw holes and fracture ends of dog mandibles.

METHODSA self-control study was carried out in 4 dogs. PDLLA/rhBMP-2 compound screws were implanted to fix the mental fractures and PDLLA screws were used as control. The samples from mandibles were collected at 4, 8, 12, 16 weeks after implantation and observed by radiography and histology.

RESULTSAll dogs showed a greater degree of bone regeneration around PDLLA/rhBMP-2 screws than PDLLA ones and all fractures were fixed and healed well.

CONCLUSIONThe PDLLA-rhBMP screw has a better effect of inducing osteogenesis than PDLLA screw, and is able to exert a good fixation to fracture.

Animals ; Biocompatible Materials ; administration & dosage ; Bone Morphogenetic Protein 2 ; Bone Morphogenetic Proteins ; administration & dosage ; biosynthesis ; genetics ; Bone Screws ; Dogs ; Fracture Fixation, Internal ; methods ; Fracture Healing ; Lactic Acid ; administration & dosage ; Male ; Mandibular Fractures ; surgery ; Polyesters ; Polymers ; administration & dosage ; Recombinant Proteins ; administration & dosage ; biosynthesis ; genetics ; Transforming Growth Factor beta

The aim of this study was to develop a bioactive membrane for inducing bone regeneration. The membrane was composed of polylactic acid, collagen, recombinant human bone morphogenetic protein-2 (rhBMP-2). The PLA + collagen + rhBMP-2 membrane was fabricated by solvent-casting and cool-drying. The mechanic properties of this compound membrane were tested. The two surfaces of membrane were observed by SEM. Degradability of PLA was evaluated by SEM observation and molecular weight measure in vitro and in vivo. The compound membranes were implanted in rabbit muscles. The samples were obtained when animals were sacrificed at different periods: 2 weeks, 1, 2, 3, 6 months after surgery. The biodegradability and biocompatibility of the membrane were evaluated. The heterotopic bone inducing activity of BMP was identified. The results indicated that the strength at extension to failure of the compound membrane was 36.4MPa at 2.3% strain. The compound membrane was found bearing active factor on its coarse side, which can induce bone regeneration. After implantation in vivo, the membrane maintained the structure for three months and degraded in 6 months. Based on histological analysis, there was no obvious inflammation. Heterotopic bone was induced. We could conclude that the PLA + collagen + rhBMP-2 membrane is an absorbable compound membrane that possesses good biocompatibility, adequate mechanic properties and excellent property of bone induction. It could be applied as an ideal membrane for inducing bone regeneration.
Animals ; Biocompatible Materials ; Biodegradation, Environmental ; Bone Morphogenetic Protein 2 ; Bone Morphogenetic Proteins ; administration & dosage ; pharmacology ; Bone Regeneration ; drug effects ; Collagen ; administration & dosage ; pharmacology ; Guided Tissue Regeneration ; Lactic Acid ; administration & dosage ; pharmacology ; Male ; Membranes, Artificial ; Polyesters ; Polymers ; administration & dosage ; pharmacology ; Rabbits ; Transforming Growth Factor beta ; administration & dosage ; pharmacology

OBJECTIVETo study the effects of rhBMP-2 on bone formation of mandibular distraction osteogenesis in rabbits.

METHODSBilateral mandibular osteotomies were performed in 12 mature rabbits. 5 mg rhBMP-2 with the collagen carrier was implanted in the osteotomy site of one side of the mandibles. Only the collagen sponge was placed in the contra-lateral side as control. The mandibles of 8 rabbits were lengthened by 6mm using a custom-made distractor. At 4 weeks after the end of distraction, all animals were killed and the distracted calluses were harvested and processed for histological, scanning electron microscopic, as well as Ca/P ratio analysis.

RESULTSThe regenerated bone was found in the distraction gap after mandibular lengthening. The mandibular side treated with rhBMP-2 had greater amounts of new bone formation and earlier mineralization than contra-lateral side (non-rhBMP-2 treated).

CONCLUSIONRecombinant human BMP-2 appears to be able to accelerate bone formation of mandibular distraction osteogenesis in rabbits.

Animals ; Bone Morphogenetic Protein 2 ; Bone Morphogenetic Proteins ; administration & dosage ; pharmacology ; Bone Regeneration ; drug effects ; Calcification, Physiologic ; drug effects ; Collagen ; metabolism ; Female ; Male ; Mandible ; diagnostic imaging ; drug effects ; ultrastructure ; Osteogenesis ; Osteogenesis, Distraction ; Rabbits ; Radiography ; Recombinant Proteins ; administration & dosage ; pharmacology ; Transforming Growth Factor beta ; administration & dosage ; pharmacology

Bone morphogenetic protein-2 (BMP-2) is used to promote bone regeneration. However, the bone regeneration ability of BMP-2 relies heavily on the delivery vehicle. Previously, we have developed heparin-conjugated fibrin (HCF), a vehicle for long-term delivery of BMP-2 and demonstrated that long-term delivery of BMP-2 enhanced its osteogenic efficacy as compared to short-term delivery at an equivalent dose. The aim of this study was to compare the bone-forming ability of the BMP-2 delivered by HCF to that delivered by clinically utilized BMP-2 delivery vehicle collagen sponge. An in vitro release profile of BMP-2 showed that HCF released 80% of the loaded BMP-2 within 20 days, whereas collagen sponge released the same amount within the first 6 days. Moreover, the BMP-2 released from the HCF showed significantly higher alkaline phosphatase activity than the BMP-2 released from collagen sponge at 2 weeks in vitro. Various doses of BMP-2 were delivered with HCF or collagen sponge to mouse calvarial defects. Eight weeks after the treatment, bone regeneration was evaluated by computed tomography, histology, and histomorphometric analysis. The dose of BMP-2 delivered by HCF to achieve 100% bone formation in the defects was less than half of the BMP-2 dose delivered by collagen sponge to achieve a similar level of bone formation. Additionally, bone regenerated by the HCF-BMP-2 had higher bone density than bone regenerated by the collagen sponge-BMP-2. These data demonstrate that HCF as a BMP-2 delivery vehicle exerts better osteogenic ability of BMP-2 than collagen sponge, a clinically utilized delivery vehicle.
Alkaline Phosphatase/metabolism ; Animals ; Bone Density ; *Bone Morphogenetic Protein 2/administration & dosage/genetics ; Bone Regeneration/*genetics ; Cells, Cultured ; Collagen Type I/chemistry/metabolism ; *Fibrin/chemistry/metabolism ; *Gene Transfer Techniques ; *Heparin/chemistry/metabolism ; Mice ; Osteogenesis/genetics ; Rats ; Rats, Sprague-Dawley

This research sought to asses the efficacity of a new type of tissue engineering bone developed by PDLLA/ PLA-PEG-PLA and BMP as a kind of bone graft substitute in the rabbit model of mandibular defects; 15 mm x 6 mm bilateral mandibular periosteum bone defects were made surgically in 20 New Zealand adult rabbits. The porous scaffolds impregnated with rhBMP-2 were used for the purpose, and the scaffolds without rhBMP-2 were used as control. The methods adopted in this research were: macroscopy, histomorphologic exam, X-ray exam, SEM micrography, computer-aided analysis and graphics. The experimental group was shown to have an earlier inception of bone forming. New bone formation was seen along the border of the original mandibular bone and in the middle. At 12 weeks after surgery,the defects were almost filled with new bone. In the control group, the defects could not be repaired in its entirety, and there was no new bone in the middle. The porous scaffold is a promising carrier for BMP. This kind of bone graft substitute can serve as an osteoconductive and osteoinductive matrix.
Animals ; Bone Morphogenetic Protein 2 ; administration & dosage ; Bone Substitutes ; metabolism ; Female ; Implants, Experimental ; Lactic Acid ; administration & dosage ; Male ; Mandibular Injuries ; surgery ; Osteogenesis ; Polyesters ; administration & dosage ; Polyethylene Glycols ; administration & dosage ; Polymers ; administration & dosage ; Rabbits ; Recombinant Proteins ; administration & dosage ; Tissue Engineering ; Tissue Scaffolds

OBJECTIVETo investigate the effect of Huogu II Formula (II) with medicinal guide Radix Achyranthis Bidentatae (Ach) on bone marrow stem cells (BMSCs) homing to necrosis area after osteonecrosis of the femoral head (ONFH) frozen by liquid nitrogen in rabbit as well as to explore the mechanism of prevention and treatment for ONFH.

METHODSThe animal model of ONFH was established by liquid nitrogen frozen on the rabbit left hind leg. Forty-eight Japanese White rabbits were randomly assigned to sham-operated group, model group, Huogu II group, and Huogu II plus Ach group, with 12 rabbits in each. During the course of ONFH animal model establishment, all rabbits were subcutaneously injected with recombinant human granulocyte colony-stimulating factor [rhG-CSF, 30 μg/(kg·day) for continuous 7 days]. Meanwhile, normal saline and decoction of the two formulae were administrated by gavage, respectively. White blood cells (WBC) were counted in peripheral blood before and after injection of rhG-CSF. Materials were drawn on the 2nd and 4th weeks after model built; bone glutamine protein (BGP) and bone morphogenetic protein 2 (BMP2) levels in serum were tested. Histopathologic changes were observed by hematoxylin and eosin (HE) staining. BMP2 mRNA levels were detected with in situ hybridization (ISH) staining. 5-Bromo-2'-deoxyuridine (BrdU) and stromal cell derived factor 1 (SDF-1) were measured by immunohistochemical assay in femoral head of the left hind leg.

RESULTSCompared with the shamoperated group, the ratio of empty lacuna, serum BGP, and SDF-1 level in the model group increased significantly, and BMP2 in both serum and femoral head decreased significantly. However, in comparison with the model group, the empty lacuna ratio of Huogu II group and Huogu II plus Ach group decreased obviously in addition to the levels of serum BGP and BMP2, and the expressions of BMP2 mRNA, BrdU, and SDF-1 increased significantly. Above changes were particularly obvious in Huogu II plus Ach group. BGP and SDF-1 on the 2nd week and empty lacuna rate and serum BMP2 level on the 4th week in Huogu II group significantly exceeded their counterparts. On the 2nd week, only in Huogu II plus Ach group that the BrdU counting rose significantly. On the 4th week, empty lacuna rate and serum BMP2 level in Huogu II plus Ach group exceeded those in Huogu II group distinctively.

CONCLUSIONSTo a certain extent, the medicinal guide Ach improves the preventive and therapeutic effects of Huogu II Formula on experimental ONFH model. The possible mechanism of this is related to its promoting effect on directional homing of BMSCs to the necrosis area.

Achyranthes ; Animals ; Bone Marrow Cells ; cytology ; drug effects ; Bone Morphogenetic Protein 2 ; blood ; genetics ; Bromodeoxyuridine ; metabolism ; Cell Movement ; Chemokine CXCL12 ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Enzyme-Linked Immunosorbent Assay ; Femur Head ; drug effects ; pathology ; Femur Head Necrosis ; blood ; genetics ; pathology ; therapy ; Gene Expression Regulation ; drug effects ; Granulocyte Colony-Stimulating Factor ; administration & dosage ; pharmacology ; Humans ; Leukocyte Count ; Male ; RNA, Messenger ; genetics ; metabolism ; Rabbits ; Radioimmunoassay ; Stem Cell Transplantation ; Stem Cells ; cytology ; drug effects

OBJECTIVETo investigate the effect of Ermiao Recipe (, EMR) with medicinal guide Angelicae Pubescentis Radix (APR) on the homing of bone marrow stem cells (BMSCs) to focal zone in osteoarthritis (OA) rats.

METHODSForty-eight Sprague-Dawley rats were randomly assigned to the sham-operated, model, EMR, and EMR plus APR groups (12 rats in each group). The OA rat model was induced by anterior cruciate ligament transection and medial meniscus resection. All rats were injected with recombinant human granulocyte colonystimulating factor [rhG-CSF, 30 μg/(kg·d) for continuous 7 days], and rats in the EMR and EMR plus APR groups were treated with EMR or EMR plus APR at 1.6 or 1.9 g/(kg·d) for 3 or 6 weeks, respectively. Cartilage histopathologic changes were observed by hematoxylin and eosin staining. Chondrocytes apoptosis and cartilage matrix components were tested by transferase-mediated deoxyuridine triphosphate-biotin nick end labeling assay and special staining. Interleukin-1β (IL-1 β), tumor necrosis factor α (TNF-α), bone morphogenetic protein 2 (BMP-2), and transforming growth factor beta-1 (TGF-β1) in serum were detected by enzyme-linked immunosorbent assay or radioimmunoassay assay. Matrix metalloproteinase (MMP)-13, tissue inhibitors of metalloproteinase (TIMP)-1, bromodeoxyuridine (BrdU), cluster of differentiation 34 (CD34), and stromal cell derived factor 1 (SDF-1) were measured by immunohistochemistry assay.

RESULTSEMR and EMR plus APR significantly inhibited articular cartilage damage and synovium inflammation in OA rats at 3 or 6 weeks of treatment, the most obvious changes in these parameters were found in the EMR plus APR group. At 6 weeks, compared with EMR treatment, EMR plus APR remarkably inhibited chondrocytes apoptosis and the release of IL-1β and TNF-α, obviously decreased MMP-13 expression, and significantly increased expressions of proteoglycan, collagen, type II collagen and TIMP-1, serum levels of BMP-2 and TGF-β1 as well as expressions of BrdU, CD34 and SDF-1 in cartilage articular (P<0.01 or P<0.05).

CONCLUSIONThe medicinal guide APR improved the therapeutic effects of EMR on OA rats by promoting directional homing of BMSCs to focal zone.

Animals ; Apoptosis ; drug effects ; Bone Marrow Cells ; drug effects ; Bone Morphogenetic Protein 2 ; blood ; Bromodeoxyuridine ; metabolism ; Cartilage, Articular ; drug effects ; enzymology ; pathology ; Chemokine CXCL12 ; metabolism ; Chondrocytes ; drug effects ; pathology ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Granulocyte Colony-Stimulating Factor ; administration & dosage ; pharmacology ; Humans ; Interleukin-1beta ; blood ; Knee Joint ; drug effects ; pathology ; Male ; Matrix Metalloproteinase 13 ; metabolism ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase Type II ; blood ; Osteoarthritis ; blood ; drug therapy ; pathology ; Rats, Sprague-Dawley ; Synovial Membrane ; pathology ; Tissue Inhibitor of Metalloproteinase-1 ; metabolism ; Transforming Growth Factor beta1 ; blood ; Tumor Necrosis Factor-alpha ; blood