The interaction of biomaterials and tissues has been the focus of biomaterial science for many years and formed the foundation of the subject of biocompatibility. The research about biomaterials provides better basis for biomedical devices by the understanding of biocompatibility phenomena. In this paper, over 50 years of experience with such devices is analysed and it is shown that, in the vast majority of circumstances, the sole requirement for biocompatibility in a medical device intended for long-term contact with the tissues of the human body is that no harm should be brought to those tissues. Only a few bio-active biomaterials has been applied successfully in clinics. This artical gives a review on the application of biomaterials in tissue engineering,sophisticated cells, drug and gene delivery systems and in biotechnology. Interactions between biomaterials and tissue components is discussed as well.

Objective To study the changes of gastrointestinal movement function in rats with chronic unpredictable mild stress(CUMS) and explore the mechanisms underlying it.Methods The rats were divided into stress model group and control group.The stress model rats were induced by 21-day chronic unpredictable mild stress as well as social-isolated fed.The rate of ink propulsion of gastrointestinal tract and the contraction of intestinal canal in rats were observed.Immunohistochemistry was adopted to detect the expression of OT in rats.Results (1) After the models were induced,weight-gain and sucrose preference of model group ((69.97 ± 9.81) g,(49.05± 5.98) g) were lower than those in control group ((116.27 ± 13.60) g,(83.51 ± 3.08) g) (P ＜ 0.001),and both the crossing-score and rearing-score ((24.00 ± 13.52),(3.90 ± 2.51)) were lower than those in control group ((53.60 ± 27.98),(11.50 ± 8.85)) in the open-field test.(2) The rate of ink propulsion of model group ((67.33 ± 6.24) ％) was decreased when compared to the control group ((76.83 ± 10.00) ％) (P ＜ 0.05),and the intestinal canal contraction amplitude and contraction frequency ((1.37 ± 0.18) g,(0.58 ± 0.02) S-1) were lower than those in control group ((1.88 ± 0.13) g),(0.62 ± 0.04) S-1) (P ＜ 0.05).(3) Compared with the control group (6.07 ± 3.71),OT immunoreactive substance was increased in model group (59.17 ± 16.08) of rats (P＜0.001).Conclusion Chronic stress can cause the decrease in gastrointestinal movement function of rats.These changes may be related to the increased expression of OT in paraventricular nucleus.

OBJECTIVETo study DNA damage, Bcl-2 and Bax expression, and ultrastructure change in spermatogenic cell of mice by cadmium exposure.

METHODSTwenty-four male mice were divided into 4 groups: 3 groups treated with cadmium chloride of 1, 5, 10 micromol x kg(-1) x d(-1) i.p. respectively for 5 days, and one normal saline control group. The DNA damage of spermatogenic cell by single-cell gel electrophoresis technology was detected. The expression positive rate of Bcl-2, Bax protein in spermatogenic cell by the immunohistochemical method was assayed, and the ultrastructural change of spermatogenic cell by the transmission electron microscope was observed.

RESULTSDNA damage rates of of spermatogenic cell in 1, 5, 10 micromol/kg cadmium chloride groups were higher than that of normal group (P < 0.001). Bcl-2 protein expression positive rates were lower than that of normal group (P < 0.001). Bax protein positive expression rate in 5 micromol/kg group was higher than those in normal group, and 1, 10 micromol/kg groups. The ultrastructure of karyotis, karyotheca, mitochondria, endoplasmic reticulum in three treated groups had different degree of damage and the degree of ultrastructural change was increasing with rising concentration of cadmium.

CONCLUSIONCadmium exposure will cause the DNA break, Bcl-2 and Bax protein abnormal expression and ultrastructural change in spermatogenic cell.

Animals ; Apoptosis ; Cadmium Chloride ; toxicity ; DNA Damage ; Male ; Mice ; Mice, Inbred ICR ; Proto-Oncogene Proteins ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; Spermatozoa ; drug effects ; metabolism ; ultrastructure ; bcl-2-Associated X Protein ; metabolism

Objective To study on quantitative analysis of the participation degree of injury and disease in forensics.Methods So far,There is no based and standard authentic explanations about the relationship between injury and disease.This paper attempt to make it clear by the literlly meaning of chinese based on many files and arguments.So as to clarify the primary and secondary.Results The relationship explanation between injury and desease is approved by the court by using the "five causes" (revoked,stimulated,triggered,secondary and coincident).Conclusions It's significantly effiective that using the literlly meaning of chinese to explain the relationship between injury and desease in judicatory practice.

OBJECTIVETo study the cell biocompatibility of porous biphasic calcium phosphate nanocomposite in vitro.

METHODSBone marrow mesenchymal cell (BMSCs) obtained from SD rat bone marrow were in vitro induced and proliferated. Afler their osteoblast phenotypes were verified, BMSCs were seeded onto prepared porous biphasic calcium phosphate nanocomposite (Experiment group) and common porous hydroxyapatite (Control group). The cell adhesion was evaluated by scanning electron microscope. Synthesis of alkaline phosphatase enzyme (ALP) and osteocalcin were detected and cell cycle was detected by flow cytometry.

RESULTSBMSCs could fully attach to and extend on the material in experiment and control group, Moreover, experiment group were superior to control group in adhesion, proliferative abilities and osteogenic activity.

CONCLUSIONBMSCs can differentiate to osteoblast phenotype; the porous biphasic calcium phosphate nanocomposite as bone tissue engineering scaffold has good cell biocompatibility.

Alkaline Phosphatase ; Animals ; Bone Marrow Cells ; Bone and Bones ; Cell Adhesion ; Durapatite ; Hydroxyapatites ; Materials Testing ; Nanocomposites ; Osteoblasts ; Osteocalcin ; Rats ; Tissue Engineering ; Tissue Scaffolds

OBJECTIVETo investigate the feasibility of repairing bone defect with methods of tissue-engineering and human bone morphogenetic protein-2 (hBMP-2) gene transfection in osteoporotic rats.

METHODSTwenty-four 6-month-old female Sprague-Dawley rats underwent ovariectomy, while 8 rats received sham-operations. Three months later, bone mesenchymal stem cells (BMSC) harvested from osteoporotic rats were divided into two groups randomly. Experimental group were transfected by recombinant plasmid carrying hBMP-2 gene, and control group left untreated. All BMSC were seeded into coralhydroxyapatite scaffolds. Then the cell/scaffold constructs were implanted into the defect site created in the ramus of mandible of osteoporotic rats respectively.

RESULTSPositive results were confirmed by immunohistochemistry and in situ hybridization in experimental group. New bone formation was found at the margin of the defect treated with the BMSC modified by hBMP-2 gene transfer at 4 weeks after implantation and appeared mature 8 weeks after the treatment. However, the amount of newly formed bone was much less and there was some adipose tissue at defect margins 8 weeks after implantation in control group.

CONCLUSIONSThe results of this experiment indicate that BMSC-mediated rhBMP-2 gene therapy in conjunction with bone tissue engineering may allow for successful treatment of large bone defects in osteoporosis rats.

Animals ; Bone Marrow Cells ; cytology ; Bone Morphogenetic Protein 2 ; genetics ; Female ; Genetic Therapy ; Humans ; Mandibular Diseases ; surgery ; Mesenchymal Stromal Cells ; cytology ; Osteogenesis ; physiology ; Osteoporosis, Postmenopausal ; therapy ; Rats ; Rats, Sprague-Dawley ; Tissue Engineering ; methods ; Transfection

OBJECTIVETo culture human dental papilla cells (HDPCs)and to study its cytobiological characters in vitro.

METHODSHDPCs were isolated and cultured with explant culture technique in vitro; Type I collagen, fibronection and laminin were detected in HDPCs and its secreted matrix with the immunocyto-chemical stain; HDPCs were incubated in mineralized promoting solution containing 10 mmol/L beta-glycerophosphate, 100 mg/L of ascorbic acid and 10 nmol/L dexamethasone supplemented with 10% FBS and the form of mineralized nodules was tested with Alizarin Red S stainning.

RESULTSCultured HDPCs in vitro were well growing in DMEM/F12. Type I collagen, fibronection and laminin staining were all positive in both HDPCs and its secreted matrix, and laminin was stained with bunchiness in matrix. Mineralized nodules formed after cultured 27 days by Alizarin Red S stainning.

CONCLUSIONHDPCs isolated and cultured are well growing in vitro, have a capability of synthesizing and secreting matrix and in mineralized promoting solution, are able to form mineralizer, so, HDPCs have a capacity of seed cell of tissue engineering regeneration tooth.

Cell Culture Techniques ; Cells, Cultured ; Collagen Type I ; Dental Papilla ; Dexamethasone ; Glycerophosphates ; Humans ; In Vitro Techniques ; Tissue Engineering ; Tooth

OBJECTIVETo study the biological features and osteoblast/adipocyte phenotypes of bone marrow stromal cells (BMSCs) of Sprague-Dawley (SD) rats with Type I osteoporosis by induced culture.

METHODSSix-month-old SD rats were used in this study. 16 female rats were randomly divided into two groups. Eight rats were ovariectomied as experimental group to establish the modle of Type I osteoporosis, while other rats received sham-operation. Three month later BMSCs of 16 rats were isolated by discontinueous gradient centrifugation and then plated in alpha-MEM medium as primary culture. Secondary harvested cells were cultured for 14 days in alpha-MEM medium supplemented with dexamethasone, ascorbic acid, vitamin D3, beta-glycerophosphate or dexamethasone, 3-isobutyl-1-methylxanthine, insuline, and indomethine. The cells were screened by inverted microscope each day and cell growth was studied with cell counting. The osteoblast and adipocyte phenotypes were verified by cytochemistry staining, counted the percentage of positive stained cells.

RESULTSThe weight and bone mineral density of rats were statistically different between experimental group and control group. Gomori and Von Kossa's staining demonstrated positive osteoblast phenotypes of alkaline phosphatase and mineralized nods by osteogenic inducer, while Oil Red O staining identified BMSCs treated with adipogenic medium resulted in adipocyte formation and there was no significant difference in the percentage of positive stained cells between two groups.

CONCLUSIONThe model of Type I osteoporosis has been established successfully. BMSCs from SD rats with osteoporosis maintain their differentiation potential.

Adipocytes ; Animals ; Bone Density ; Bone Marrow Cells ; Cell Differentiation ; Cell Proliferation ; Cells, Cultured ; Female ; Mesenchymal Stromal Cells ; Osteoblasts ; Osteoporosis ; physiopathology ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo isolate human adipose tissue-derived stromal cells and study the potential of osteogenic differentiation after inductive culture.

METHODSLiposuction human adipose tissues were minced and digested with collagenase type I. The obtained stromal cells were plated in BGJb medium as primary culture for ten days. The second passage cells were harvested and plated in DMEM/F12 medium supplemented with 10% FBS, 5% horse serum and 50 micromol/L hydrocortisone for myogenic induction culture. The cell-anchored slips were removed and fixed in 4% formaldehydam polymerisatum. Toluidine blue, Mallory's phosphotungstic hematoxylin staining and monoclonal antibody to human skeletal muscle myosin heavy chain immunocytochemical methods were used to assay the differentiation of cells.

RESULTSIt was observed that the size and shape of induced cells were much different from those of non-induced cells. Toluidine blue, Mallory's phosphotungstic hematoxylin staining demonstrated there were many basophilic striations within cytoplasm and multinucleated myotubes were formed. Immunocytochemical stain indicated that characterastic skeletal myosin heavy chain was positive in myogenic induced cells.

CONCLUSIONIt seems that human adipose tissue represents an abundant reservoir of adult stem cells that have multi-germline potential to differentiate into myoblasts. Adipose tissue derived stromal cells will be another alternative source for cell-based tissue engineering in skeletal muscle reconstruction.

Adipose Tissue ; cytology ; Adult Stem Cells ; cytology ; Cell Differentiation ; Cell Separation ; Cells, Cultured ; Culture Media ; Humans ; Myoblasts ; cytology ; Myosin Heavy Chains ; metabolism ; Stromal Cells ; cytology

OBJECTIVETo investigate the chondrogenisis by alginate gelatin and rats' bone marrow stromal cells (BMSCs) chondrogenicly induced in vitro.

METHODSThirty-two male adult SD rats were assigned randomly to experimental and control groups. In experimental group, bone marrow was obtained from the right tibias of all the rats. After expanding and culturing 3 passages, induced BMSCs by chondrogenic culture medium for 10 days. Suspended induced cells in alginate gelatin, and injected the complex into the hypodermic tissue of the backs of rats autogenously. In control group only alginate gelatins were injected. The grafts were taken out for examinations 4 and 8 weeks after the operations.

RESULTSConsiderable cartilage appeared in experimental group 8 weeks after operations. Regular HE staining and alcian blue staining showed a great deal of cartilage holding chondrocyte masses surrounded by abundant matrix. Alginate gelatin decompounded obviously, and the rest distributed among newly formed cartilage. No cartilage appeared in control group all through.

CONCLUSIONBMSCs and alginate gelatin have a beautiful future in cartilage tissue engineering.

Alginates ; Animals ; Chondrogenesis ; Gelatin ; Glucuronic Acid ; Hexuronic Acids ; Male ; Mesenchymal Stromal Cells ; Rats ; Rats, Sprague-Dawley ; Tissue Engineering