To produce bionic bone material that is consistent with human bone in chemical composition and molecular structure using rat tail tendon collagen type Ⅰ.The type Ⅰcollagen derived from rat tail was extracted by acetic acid to form collagen fibers. The reconstructed collagen fibers were placed in the mineralized solution to mimic bone mineralization for 2-6 days. Bone mineralization was observed by transmission electron microscopy and electron diffraction.Collagen fibers with characteristic D-Band structure were reconstructed by using rat tail tendon collagen type Ⅰ extracted with acid hydrolysis method. Transmission electron microscopy and electron diffraction showed that calcium hydroxyapatite precursor infiltrated into the collagen fibers, and the collagen fibers were partially mineralized after 2 days of mineralization; the collagen fibers were completely mineralized and bionic bone material of typeⅠ collagen/calcium hydroxyapatite was formed after 6 days of mineralization.The collagen type Ⅰ can be extracted from rat tail tendon by acid hydrolysis method, and can be reformed and mineralized to form the bionic bone material which mimics human bone in chemical composition and the molecular structure.
Animals ; Biocompatible Materials ; chemical synthesis ; Bone Matrix ; chemistry ; growth & development ; Bone Substitutes ; chemical synthesis ; Bone and Bones ; anatomy & histology ; chemistry ; Calcification, Physiologic ; Collagen Type I ; biosynthesis ; chemistry ; ultrastructure ; Humans ; Hydroxyapatites ; chemistry ; Rats ; Tail ; Tendons ; chemistry ; ultrastructure ; Tissue Engineering ; methods

Animals ; Bone Matrix ; pathology ; Bone and Bones ; pathology ; Collagen Type I ; metabolism ; Collagen Type III ; metabolism ; Disease Models, Animal ; Humans ; Muscle, Skeletal ; metabolism ; pathology ; Osteoblasts ; pathology ; ultrastructure ; Osteoclasts ; pathology ; Osteocytes ; pathology ; Osteogenesis Imperfecta ; classification ; metabolism ; pathology ; Skin ; pathology

OBJECTIVETo investigate the expressions of mRNA and protein of p38, Osx, PI3K, Akt1 in the rats bone with chronic fluorosis.

METHODSDental fluorosis were observed and the fluoride contents in the urine and bone were detected by fluorin-ion selective electrode. The morphologic changes and ultrastructure of rats' bone were observed by light and electronic microscopy. The expressions of protein and mRNA of p38, Osx, PI3K and Akt1 were detected by immunohistochemistry and real-time PCR, respectively. The contents of BALP and BGP in serum were detected by ELISA.

RESULTSThe rates of dental fluorosis in the fluorosis rats were increased, and the fluoride contents in bone and urine of the fluorosis rats were increased compared to the control group, the difference was statistically significant (P < 0.05). The bone trabeculae thickness and density and the thickness of bone cortex in fluorosis rats were remarkably increased, the space of bone trabeculae was reduced, and in accordance with the matching morphometrical indices, the difference was statistically significant (P < 0.05) as compared with the control rats. The contents of BALP [(54.61 ± 2.27) U/L] and BGP [(2.38 ± 0.16) µg/L]in the fluoride groups were higher than those in the control group, the difference was statistically significant (P < 0.05). Ultrastructurally, the broadening of the osseouslacuna was observed. The reduced protuberances of the osteocytes, the unclear organelle structure, pyknosis, karyotheca increasation and edged chromatin were also observed. Compared to the control group, the expressions of protein and its mRNA of p38, Osx, PI3K and Akt1 were higher in the fluorosis rats than those in the control rats, and the difference was statistically significant (P < 0.05). There is no any expression of p38, Osx, PI3K and Akt1 in the osteocytes in fluorosis rats.

CONCLUSIONSThe over-expression of p38, Osx, PI3K and Akt1 in bone tissue of fluorosis rats may relate to the accumulation of fluorine in the body. The bone injury mainly occur in the stage of the differentiation and proliferation. The upregulation of P38MARK signal path and PI3K/Akt1 signal path may be involved in the pathogenesis of bone injury caused by fluoride.

Alkaline Phosphatase ; blood ; Animals ; Bone and Bones ; metabolism ; pathology ; ultrastructure ; Fluoride Poisoning ; metabolism ; pathology ; Fluorides ; metabolism ; urine ; Fluorosis, Dental ; metabolism ; pathology ; Immunohistochemistry ; Microscopy, Electron, Transmission ; Osteocalcin ; blood ; Phosphatidylinositol 3-Kinases ; genetics ; metabolism ; Proto-Oncogene Proteins c-akt ; genetics ; metabolism ; RNA, Messenger ; metabolism ; Rats ; Rats, Sprague-Dawley ; Real-Time Polymerase Chain Reaction ; Signal Transduction ; Sodium Fluoride ; toxicity ; Transcription Factors ; genetics ; metabolism ; p38 Mitogen-Activated Protein Kinases ; genetics ; metabolism

OBJECTIVETo comparatively investigate the inorganic composition and crystallographic properties of cortical and cancellous bone via thermal treatment under 700 °C.

METHODSThermogravimetric measurement, infrared spectrometer, X-ray diffraction, chemical analysis and X-ray photo-electron spectrometer were used to test the physical and chemical properties of cortical and cancellous bone at room temperature 250 °C, 450 °C, and 650 °C, respectively.

RESULTSThe process of heat treatment induced an extension in the a-lattice parameter and changes of the c-lattice parameter, and an increase in the crystallinity reflecting lattice rearrangement after release of lattice carbonate and possible lattice water. The mineral content in cortical and cancellous bone was 73.2wt% and 71.5wt%, respectively. For cortical bone, the weight loss was 6.7% at the temperature from 60 °C to 250 °C, 17.4% from 250 °C to 450 °C, and 2.7% from 450 °C to 700 °C. While the weight loss for the cancellous bone was 5.8%, 19.9%, and 2.8 % at each temperature range, the Ca/P ratio of cortical bone was 1.69 which is higher than the 1.67 of stoichiometric HA due to the B-type CO₃²⁻ substitution in apatite lattice. The Ca/P ratio of cancellous bone was lower than 1.67, suggesting the presence of more calcium deficient apatite.

CONCLUSIONThe collagen fibers of cortical bone were arrayed more orderly than those of cancellous bone, while their mineralized fibers ollkded similar. The minerals in both cortical and cancellous bone are composed of poorly crystallized nano-size apatite crystals with lattice carbonate and possible lattice water. The process of heat treatment induces a change of the lattice parameter, resulting in lattice rearrangement after the release of lattice carbonate and lattice water and causing an increase in crystal size and crystallinity. This finding is helpful for future biomaterial design, preparation and application.

Animals ; Bone Density ; physiology ; Bone and Bones ; chemistry ; ultrastructure ; Crystallography ; Spectrophotometry, Infrared ; Swine

Trabecular microstructure is an important factor that influences the bone biomechanical properties. In this paper, studies on digital image analysis of trabecular microstructure are reviewed with special emphases on the serials parameters as well as on the measurement methods of trabecular microstructure characteristic. The future researches and advances are also prospected.
Algorithms ; Bone and Bones ; anatomy & histology ; ultrastructure ; Computer Simulation ; Finite Element Analysis ; Humans ; Image Enhancement ; methods ; Image Interpretation, Computer-Assisted ; methods ; Imaging, Three-Dimensional ; Magnetic Resonance Imaging ; Tomography, X-Ray Computed

Osteoporosis is a common metabolic disease which is characteristic of less bone mass and impaired bone microarchitecture, leading to the decreasing of bone strength as well as to the increasing of brittle bones and the risk of fracture. It was found that bone quality, including bone microarchitecture, the composition of mineral and organic matrix, microdamage and the status of bone repair, can influence bone strength as bone mineral density can do. Since the compositions of tissue material are generally similar in people, microarchitecture is used as the important index for the assessment of bone mechanical properties. Currently the none-invasive detective methods in use for bone have become a research topic. Such methods as ultrasonic imaging, computer tomography, magnetic resonance imaging and finite element analysis are reviewed in this paper.
Bone Density ; Bone and Bones ; physiology ; ultrastructure ; Finite Element Analysis ; Humans ; Magnetic Resonance Imaging ; Osteoporosis ; diagnosis ; diagnostic imaging ; Tomography, X-Ray Computed ; Ultrasonography

OBJECTIVETo study the compatibility between human adipose-derived mesenchymal stem cells and porcine bone scaffolds.

METHODSPorcine bone tissues were co-cultured with adipose-derived mesenchymal stem cells, and the complex was observed under scanning electron microscope. The viability and alkaline phosphatase (ALP) activity of the cells were examined with the cells co-cultured with human bone scaffold as the control.

RESULTSAt 4 and 10 days after the co-culture, the adipose-derived mesenchymal stem cells were observed to extend pseudopodia to adhere to the two scaffold materials. MTT assay showed that the cell proliferation on both of the materials increased with time, and the two cell complexes exhibited similar pattern of changes in ALP activity.

CONCLUSIONAs the seed cells, human adipose-derived mesenchymal stem cells exhibit good comparability with porcine bone scaffold, suggesting their potential of constructing tissue-engineered bone graft.

Adipose Tissue ; cytology ; Adult ; Alkaline Phosphatase ; metabolism ; Animals ; Bone and Bones ; cytology ; metabolism ; Cell Proliferation ; Coculture Techniques ; Humans ; Materials Testing ; Mesenchymal Stromal Cells ; cytology ; enzymology ; metabolism ; ultrastructure ; Microscopy, Electron, Scanning ; Swine ; Time Factors ; Tissue Scaffolds

OBJECTIVETo investigate the effect of androgen on microstructure and mechanics nature of bone in orchiechtomied (ORX) male rats and reveal its mechanism by using the Micro CT analysis, bone biomechanics test, bone histomorphometric parameter test, and total body bone mineral density (BMD) measured by dual-energy X-ray absorptiomery (DXA).

METHODSThirty 12-month-old male Wister rats were randomly divided into three groups including ORX, sham-operated (Sham) and androgen (AD) group, ten rats in every group. Total body BMD was measured by DXA. Femurs and vertebrae were then harvested at the 12 th week after ORX for micro-computed tomography (Micro CT), histology and biomechanical were tested.

RESULTSThe administration of testosterone may reverse the decreasing BMD of total body and may prevent the decreasing weight. The biomechanical values of Maximum load, Enery, Maximum stress, Elastic Modulus of AD group significantly enhanced compared with ORX group (P < 0.05). The results of histomorphometric parameters showed that cancellous bone volume, osteoblast-osteoid interface, linear extent of bone formation, mineralizing surfaces, mineral apposition rate increased in the therapy group.

CONCLUSIONAndrogen can accelerate cancellous bone formation and bone turnover, improve bone microstructure and enhance bone intensity and BMD.

Androgens ; pharmacology ; Animals ; Biomechanical Phenomena ; Body Weight ; drug effects ; Bone Density ; drug effects ; Bone and Bones ; drug effects ; ultrastructure ; Imaging, Three-Dimensional ; Male ; Orchiectomy ; Osteoporosis ; etiology ; Rats ; Rats, Wistar

OBJECTIVE: To explore the differences in Haversian system between human and animal bones through imaging analysis and morphology description. METHODS: Thirty-five slices grinding from human being as well as dog, pig, cow and sheep bones were observed to compare their structure, then were analysed with the researchful microscope. RESULTS: Plexiform bone or oeston band was not found in human bones; There were significant differences in the shape, size, location, density of Haversian system, between human and animal bones. The amount of Haversian lamella and diameter of central canal in human were the biggest; Significant differences in the central canal diameter and total area percentage between human and animal bones were shown by imaging analysis. CONCLUSION (1) Plexiform bone and osteon band could be the exclusive index in human bone; (2) There were significant differences in the structure of Haversian system between human and animal bones; (3) The percentage of central canals total area was valuable in species identification through imaging analysis.
Adult ; Animals ; Bone and Bones/ultrastructure* ; Cattle ; Dogs ; Haversian System/ultrastructure* ; Humans ; Image Processing, Computer-Assisted ; Microscopy, Electron ; Sheep ; Species Specificity ; Swine ; Tibia/ultrastructure*

OBJECTIVETo compare the biocompatibility and osteoinductive behavior of HA (hydroxyapatite) and HA/UHMWPE (ultra-high molecular weight polyethtlene) composite in orbital implantation.

METHODSOsteoectomy of the upper orbital rim was perform on 24 adult New Zealand rabbits. The animals were randomly divided into 4 groups with 6 of each. The HA, HA/UHMWPE composite or UHMWPE (10 mm x 10 mm x 3 mm in size) was implanted to the upper orbital defect of the animal in respective group. Animals were sacrificed at 1, 4, 8, 12 weeks. Histopathologic sections of the implants were evaluated and compared with light and transmission electron microscopy study.

RESULTSDuring the experimental period of 12 weeks, there was no implant extrusion or displacement. In the groups of HA and HA/UHMWPE composite, vascular ingrowth and fibroblasts were observed shortly and osteocytes were seen at 8 weeks. Calcium deposition of the implants showed a laminar fashion at 12 weeks. In the group of UHMWPE, fibrous membranes were seen around the implant at 1 week. Transmission electron microscopy study showed that in the HA and HA/UHMWPE groups, fibroblasts and vascular ingrowth could be seen, but osteocytes were not observed.

CONCLUSIONHA/UHMWPE composite demonstrated biocompatibility and osteoinductive property. It would be a good substitute for bone, particularly for orbital bone.

Animals ; Biocompatible Materials ; pharmacology ; standards ; Bone Substitutes ; pharmacology ; standards ; Bone and Bones ; cytology ; drug effects ; ultrastructure ; Durapatite ; pharmacology ; standards ; Materials Testing ; methods ; Microscopy, Electron, Transmission ; Models, Animal ; Orbital Implants ; Osteogenesis ; drug effects ; Polyethylene ; pharmacology ; standards ; Rabbits ; Random Allocation ; Treatment Outcome