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BACKGROUND: Simple nanotube surface modification of titanium implant has been shown to promote adhesion, proliferation and differentiation of osteoblasts. Collagen coating can promote osteoblast adhesion and osseointegration in vivo. OBJECTⅠVE: To observe the effects of type collagen combined titanium dioxide nanotube composite coating modified titanium surface on osteoblast adhesion in vitro and osseointegration in vivo. METHODS: The titanium dioxide nanotube was fabricated on the pure titanium surface, then type Ⅰ collagen was combined with the nanotube structure to form composite coating. Scanning electron microscope observation was used to characterize the surface topography of the pure titanium, titanium dioxide nanotube and type Ⅰ collagen combined titanium dioxide nanotube surfaces. Contact angle test was employed to evaluate the hydrophilicity of different samples. MC3 T3-E1 murine preosteoblasts were seeded on the three kinds of materials for 4 hours. Cell adhesion morphology was examined by scanning electron microscope. Adherent cell counting was detected under inverted fluorescence microscope. Expression of actin cytoskeleton and vinculin was observed under laser scanning confocal microscope. The gene expression of vinculin and osteoprotegerin mRNA was detected by real-time quantitative PCR. The three kinds of samples were implanted into the tibia of Sprague-Dawley rats (provided by Laboratory Animal Center, Ⅰnstitute of Radiation Medicine, Chinese Academy of Medical Sciences) , and tibia samples were removed after 4 weeks of implantation for biological push-out test and histological observation. RESULTS AND CONCLUSⅠON: (1) Scanning electron microscope: There was mechanical scratch on the pure titanium surface. There was controllable, and uniform vertical arrangement of nanotubular structures with a diameter of approximately 70 nm on the titanium dioxide nanotube surface, and collagen adhered surrounding the nanotubular structures on the type Ⅰ collagen combined titanium dioxide nanotube substrate, and partial tubule orifices were closed. (2) The hydrophicility of type Ⅰ collagen combined titanium dioxide nanotube was significantly larger than those of the other two materials (P < 0.05) . (3) Compared with the pure titanium and titanium dioxide nanotube surfaces, the type Ⅰ collagen combined titanium dioxide nanotube substrate displayed increased adherent cell number, much well-organized cytoskeleton, enhanced immunofluorescence intensity of vinculin protein staining, and increased expression levels of vinculin and osteoprotegerin mRNA levels (all P < 0.05) . (4) Ⅰn vivo test revealed that the maximum push-out force in the type Ⅰ collagen combined titanium dioxide nanotube group was significantly higher than that in the pure titanium and titanium dioxide nanotube groups (P < 0.05) . Hematoxylin-eosin staining results showed that there were few bones, but many fibrous connective tissue surrounding the implant in the pure titanium group; there were more newly-born bones, and less fibrous connective tissue surrounding the implant in the titanium dioxide nanotube group; there were dense newly-born bones, and few thin fibrous connective tissue surrounding the implant in the type Ⅰ collagen combined titanium dioxide nanotube group. (5) These results indicate that type Ⅰ collagen combined titanium dioxide nanotube surface can facilitate osteoblast cell adhesion and promote osseointegration in vivo.
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Objective@#To investigate the effects of two nanotopographies of ultraviolet (UV)-treated titanium surface on macrophage biological behaviour and inflammatory cytokines secretion, and to provide basis for clinical application of UV-treatment in dental implant modification.@*Methods@#Titanium disks were allocated into two groups. Samples in one group were acid-etched in hydrofluoric acid (Acid Ti group), and those in the other group were acid-etched and anodized (Anodization group) to form two nanotopographies respectively. The surface morphology was evaluated by field-emission scanning electron microscopy (FE-SEM). The samples were stored in the dark for 8 weeks. Thirteen samples from each group were exposed to UV-irradiation for 48 h (Acid Ti+UV group and Anodization+UV group), UV-untreated samples from Acid Ti and Anodization groups served as control. Hydrophilicity of samples was measured using contact angle measuring device. After 4, 24 and 72 h of incubation, macrophage cell adhesion and proliferation were conducted using cell counting kit-8. Cytokine/chemokine secretions [tumor necrosis factor-α (TNF-α), monocyte chemotactic protein-1 (MCP-1) and macrophage inflammatory protein-1α (MIP-1α)] were measured from cell culture supernatants at 24 and 72 h using magnetic luminex assay. Cell morphology was examined using FE-SEM after 2 h of incubation.@*Results@#Micropitted/nanopillar and micropitted/nanotubular topographies were observed in Acid Ti group and Anodization group respectively. Contact angles in Acid Ti+UV and Anodization+UV groups (20.2°±2.8° and 0.0°±0.0°) were significantly smaller than those in the Acid Ti and Anodization groups (P<0.05). Cell adhesion and proliferation in all groups at 4 and 24 h showed no difference (P>0.05). Cell proliferation in Acid Ti+UV and Anodization+UV groups at 72 h were (0.92±0.13) and (1.10±0.08) respectively, which were significantly higher than those in Acid Ti and Anodization groups. TNF-α concentration in Acid Ti+UV and Anodization+UV groups at 72 h were (1.03±0.11) and (0.87±0.10) ng/L, MCP-1 were (301.7±50.3) and (240.8±18.7) ng/L, MIP-1α were (224.9±30.6) and (233.9±14.9) ng/L respectively, which were significantly lower than those in Acid Ti and Anodization groups (P<0.05).@*Conclusions@#UV treatment can increase hydrophilicity of two titanium surface topographies, especially of Anodization+UV group. UV-treated titanium surfaces can promote macrophage proliferation and reduce the inflammatory response in vitro.
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At present, the cats play a more and more important role in medical experiments as an experimental animal,especially for the studies of neurology,physiology and toxicology. Compared with rodent animals,the physiological characteristics, anatomical features, pathological and biochemical reactions of cats are closer to human beings, and compared with the primate animals,they have advantages of economy,abundant resources and so on. Therefore,cat has an extensive application prospect in animal models of human diseases. This article mainly reviews and summarizes the establishing method and research status of cats as an animal model of human diseases in ophthalmology, nervous system, tumor and other fields in recent years.
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<p><b>OBJECTIVE</b>To prepare a new dental topical anesthetics, lidocaine hydrochloride loaded trans-activator of transcription peptide conjugated nano-niosome (LID-TAT-N), and to evaluate its transdermal properties and topical anesthesia effects.</p><p><b>METHODS</b>LID-TAT-N was prepared using reverse-phase evaporation method, and lidocaine loaded conventional liposome (LID-CL) was prepared in the same manner as positive control. The diameter, ζ potential and encapsulation efficiency of LID-TAT-N and LID-CL were measured. The skin permeation of LID-TAT-N was examined, and compared with LID-CL and lidocaine injection (LID-IJ, as negative control), using a Franz diffusion cell mounted with depilated mouse skin in vitro for 12 hours. Each experiment was repeated six times. The anesthetic effect of the new topical anesthetic was investigated on the cornea of rabbits.</p><p><b>RESULTS</b>The mean diameter of LID-TAT-N was smaller than that of LID-CL [(152.7 ± 10.6) nm vs. (259.5 ± 15.5) nm, P < 0.01]. The 12 h cumulative permeation amount was significantly higher in LID-TAT-N group [(1 340.0 ± 97.5) µg · cm(-2)] than those of LID-CL and LID-IJ groups [(1 060.6 ± 80.2), (282.6 ± 65.1) µg · cm(-2), respectively, P < 0.05]. Rabbit corneal reflex results showed that LID-TAT-N had anesthetic effect and the duration of analgesia [(24.8 ± 2.8) min] was also longer than that of LID-IJ [(14.5 ± 2.3) min, P < 0.05].</p><p><b>CONCLUSIONS</b>LID-TAT-N had good transdermal ability, and the advanced skin penetration feature can improve its tropical anesthetic effect.</p>
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Animals , Mice , Rabbits , Administration, Cutaneous , Anesthesia, Dental , Anesthetics, Local , Pharmacokinetics , Blinking , Physiology , Cornea , Physiology , Lidocaine , Pharmacokinetics , Liposomes , Nanoconjugates , Chemistry , Peptides , Skin , Metabolism , Skin Absorption , Trans-Activators , Chemistry , PharmacokineticsABSTRACT
Objective To study the influence of different kinds of disinfection methods on antibacterial activity of TiO2 nanotubes. Methods TiO2 nanotubes were fabricated with 0.5%wt HF on pure titanium to acid-etching combined with an? odization as experimental group. The pure Ti was control group. They were disinfected by three kinds of disinfection meth?ods, which were alcohol immersion, autoclaving and UV irradiation. The bacterial adhesion ability was evaluated by observ?ing the morphology of samples, measuring the roughness and contracting angle. The film contact method was used to evaluate the antibacterial activity of samples with Staphylococcus aureus (Sa) after different infection treatment. The bacterial morphol?ogy was observed by field emission scanning electron microscope (FE-SEM). Results The treatment group has higher sur?face roughness. The bacterial adhesion ability of experimental group was stronger compared with that of control group. The contracting angle of samples exposed to UV irradiation was smaller than that of alcohol immersion and autoclaving treatment group. The viable count and FE-SEM showed that there were more bacteria and more complete morphology on the sample surface after alcohol immersion. The viable count was less and bacterial morphology suffered some damage on the sample sur?face after high pressure steam sterilization. The least viable count and the most complete destruction of bacterial morphology were found after ultraviolet (UV) germicidal irradiation. Conclusion UV irradiation shows the best antibacterial activity, the second is autoclaving and the worst is alcohol immersion.
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PURPOSE: Rheumatoid arthritis (RA) is an inflammatory joint disorder, the progression of which leads to the destruction of cartilage and bone. Chemokines are involved in RA pathogenesis. In this study, we investigated the chemokine signaling pathway associated with CCL2 in peripheral blood (PB) and synovial tissues (ST) of RA patients based on our previous work about chemokine signaling pathway involved in the activation of CCL2 production in collagen-induced arthritis rat ST. MATERIALS AND METHODS: Total RNA was isolated from PB leukocytes and synovium of the knee joint in both RA patients and control populations. Real-time polymerase chain reaction was used to determine CCL4, CCR5, c-Jun, c-Fos, and CCL2 expressions. Serum level of CCL2 was assessed by enzyme-linked immunosorbent assay, and the production of CCL2 in ST was analyzed immunohistochemically. RESULTS: The expressions of CCL4, CCR5, c-Jun, c-Fos, and CCL2 messenger RNA in RA patients were significantly higher than those in healthy controls, both in ST and on PB leukocyte. Serum CCL2 levels were elevated in RA patients. Histological examination of rheumatoid joints revealed extensive CCL2 expression in RA ST. CONCLUSION: CCL2, CCL4, c-Jun, c-Fos, and CCR5 may play an important role in the recruitment of PB leukocytes into the RA joints. These data provide evidence that the chemokine signaling pathway is involved in CCL2 expression in RA patient tissues, which may contribute to chronic inflammation associated with RA. Targeting this signaling pathway may provide a novel therapeutic avenue in RA.
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Adult , Animals , Female , Humans , Male , Middle Aged , Rats , Arthritis, Rheumatoid/blood , Case-Control Studies , Chemokine CCL2/blood , Chemokines/metabolism , Enzyme-Linked Immunosorbent Assay , Gene Expression , RNA, Messenger/genetics , Real-Time Polymerase Chain Reaction , Signal Transduction , Synovial Membrane/metabolismABSTRACT
BACKGROUND:Nanostructure formation on titanium surface by anodic oxidation has good biocompatibility with bone tissue. OBJECTIVE:To observe the surface morphology and crystal ine constitution of nanopores microstructure on titanium surface formed by anodic oxidation and to further observe its influence on the MC3T3-E1 osteoblast cells’ biological behavior and the gene expression of osteoprotegerin. METHODS:Nanopores forming on titanium surface by anodic oxidation was prepared as experimental group and polished titanium as control group (12 samples for each group). Mouse MC3T3-E1 osteoblasts were co-cultured with polished pure titanium plate group and anodic oxidation nanopores group. After 7 days of inoculation, cellmorphology was observed using scanning electron microscopy, MTT method was used for the cellproliferation test and the growth curve was made. Gene expression of osteoprotegerin was also detected. RESULTS AND CONCLUSION:After anodic oxidation, a homogeneous and uniform array of nanopores formed;however it had no significant influence on the crystal ine phase of the titanium sample surfaces. Titanium surface with nanopore structure was more favorable than polished titanium surface for cellattachment and spreading. cells on the anodized surface with nanopores had higher celldensity and bigger metal coverage area. cells on the nanopores surface also exhibited a polygonal shape with many filopodia extending in al directions. MTT method showed that the anodized nanopore surface had higher cellamount than the as-polished titanium, and the former was about 1.4 times of the latter group after 7 days of culture. The gene expression level of osteoprotegerin in the MC3T3-E1 cells cultured on anodized titanium surface with nanopores was significantly higher than that on the as-polished titanium (P<0.01). The anodic oxidation treatment is more advantageous for the osteoblasts adhesion and gene expression of osteoprotegerin, thereby promoting the growth of osteoblasts.
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Objective Comparing the effects of steam sterilization on cyclic fatigue of stainless steel files. Meth-ods Fifty instruments of 25# stainless steel K files were randomly divided into 5 groups, which include 10 in each group. Group 1 was the blank control group, group 2 to 5 were subjected to 1, 3, 4, 5 steam sterilization cycles, then the files were tested by a custom-made device to assess cyclic fatigue and the number of cycles of failure (NCF) was calculated. Microstruc-ture of each file’s fracture surface was analyzed by Scanning Electron microscope (SEM). Results NCF in the 5 groups were 4 345.2 ± 384.2,3 937.9 ± 645.4,3 812.9 ± 532.5,3 626.2 ± 380.0,3 625.9 ± 565.6 respectively, and the differences among 5 groups were significantly different(F=2.598, P<0.05). After 4 or 5 times of steam sterilization, cyclic fatigue de-creased if compared with that in control group (P<0.05). Fracture surface in group 1 and group 2 was tough dimple structure and large numbers of regular, deep dimples were distributed on the surface. You could also see micro cavities clearly formed by fracture;Fracture surface in group 4 was dimple structure in brittle intergranular morphology. It is characterized by the presence of thin brittle precipitates, clean and smooth crystal interface, and a great sense of polyhedral stereo. Conclusion After 4 times of steam sterilization, cyclic fatigue strength of 25# stainless steel K files declined, which possessed the poten-tial risk of fracture.
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BACKGROUND:Titanium has been widely used in dental implantation because of its good biocompatibility, mechanical properties and its similar elastic modulus to the bone. OBJECTIVE:To summarize three strategies for surface modification of titanium implants:physical modification, chemical modification and biochemical modification. METHODS:PubMed and CNKI databases were searched for articles published from January 2007 to February 2013, and the key words were“titanium, implant, surface modification, osseointegration”in English and Chinese, respectively. Articles which are closely related to titanium implant surface modification and osseointegration were included, and repetitive articles were removed. RESULTS AND CONCLUSION:After preliminary search, 199 articles were found. According to the inclusion criteria and exclusion criteria, 76 articles were further analyzed. Titanium implant is a bioinert material, and thus the researchers focus on surface modification to activate the titanium implant so as to possess biological function and achieve early osseointegration. Implant surface modification strategies include three perspectives:physical modification, chemical modification and biochemical modification which can shorten the period of implant therapy and achieve early osseointegration and higher binding strength. The future research trend is to combine three strategies and to further explore the molecular basis of mechanism at the interface between implant and organism cel and the tissue in order to use better surface modification technology to fulfil the early and more stable osseointegration between the implant and bone tissue.
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<p><b>OBJECTIVE</b>To study the effect of genistein on the expression of heme oxygenase-1 (HO-1) in rats with pulmonary arterial hypertension (PAH) induced by monocrotaline (MCT).</p><p><b>METHODS</b>Sixty male Sprague-Dawley rats were randomly divided into 4 groups (n=15), namely the control group, model group, low-dose (20 µg/kg) genistein group and high-dose (80 µg/kg) genistein group. The hemodynamic parameters were measured and the remodeling of pulmonary small arteries was observed by electron microscope (EM). The expression of HO-1 in the lung tissues were detected by Western blotting.</p><p><b>RESULTS</b>Compared with the model group, genistein treatment significantly reduced the elevated mean pulmonary arterial pressure, improved the right ventricular hypertrophy index, and increased the expression of HO-1 in a dose-dependent manner.</p><p><b>CONCLUSION</b>Genistein attentuates pulmonary arterial hypertension in MCT-treated rats possibly by up-regulation of HO-1 in the lung tissues.</p>
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Animals , Male , Rats , Genistein , Pharmacology , Therapeutic Uses , Heme Oxygenase (Decyclizing) , Metabolism , Hypertension, Pulmonary , Drug Therapy , Lung , Pathology , Monocrotaline , Rats, Sprague-Dawley , Up-RegulationABSTRACT
BACKGROUND: Nanohydroxyapatite reinforced polyamide 66 (n-HA/PA66) prepared using the novel process based on nanohydroxyapatite (n-HA) sol may promote the biocompatibility due to the well distribution of n-HA in the polyamide66 (PA66) matrix and chemical bond at organic-inorganic interface, n-HA/PA66 composite has been proposed as a premising bone repair biomaterial.OBJECTIVE: To investigate the biocompatibility of the novel material both in vitro and in vivo.METHODS: Primarily cultured osteoblasts were co-cultured with n-HA/PA66 and PA66. The cell attachment and morphology were studied using phase contrast light microscope (PCLM) and field-emission scanning electron microscope (FE-SEM).Moreover, n-HA/PA66 pins, with PA66 pins as control, were implanted into the right and left (control group) shinbone shafts of the rabbits, respectively. Materials were harvested at weeks 2, 8 and tissue sections were observed.RESULTS AND CONCLUSION- n-HA/PA66 and PA66 exhibited no cytotoxicity with osteoblasts, while the cellular morphology near the samples was better in the test group than in the control one. Moreover, the cell density attached on n-HA/PA66 was higher than that on PA66 and the cell number were especially different after co-culturing for 3 days (P < 0.01 ). The osteoblasts at the interface between the host bone and n-HA/PA66 also had a higher activity during the earlier period after implantation.Meanwhile the bone formation process was faster and effective in the experimental group. Results suggested that n-HA/PA66 prepared base on the n-HA sol has a better biocompatibility as compared with PA66.
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Objective To evaluate the clinical effects and clinical classification of occlusal rehabilitation in elderly patients with abnormal occlusion, and to discuss the diagnosis principles and the practical techniques of the dental prosthesis for occlusal rehabilitation. Methods Forty two elderly patients with abnormal occlusion were treated with occlusal rehabilitation with fixed dentures, fixed-removable dentures and removable partial dentures. Eight patients among them simultaneously had temporomandibular joint(TMJ) disorder. After the clinical procedures including examination, diagnosis, prosthesis design, manufacture, application of occlusal rehabilitation and post-treatment evaluation, the using condition of dentures, patients' satisfaction ratings, TMJ functions and abutment teeth healthy status were examined before and after treatment. Results All the patients were satisfied with their dentures' general functions 1 year after treatment. Compared with the removable partial dentures, the other two types of prosthesis showed better clinical outcomes (χ2=4.15,P<0.05) and compacts on phonation of the dentures (χ2=4.71,P<0.05). In the 8 patients with TMJ disorder, 7 cases were cured completely. The treatment effects of TMJ pain (χ2=0.031, P<0.05)and TMJ click (χ2=0.038, P<0.05)had statistical differences. 30 teeth of the 203 abutment teeth (14.8%) had the problems of periodontal diseases and secondary caries and the incidences of these problems were higher in using removable partial dentures treatment than in the other two methods. Conclusions After the systematic diagnosis and the prosthesis design procedures of occlusal rehabilitation, it is important to choose a proper prostheses for the elderly patients according to their physical and psychological features, which may give the patients satisfactory results.
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0.05).The ENaC-? mRNA and protein expression level in A549 cells in 6,12 and 24 h after treatment with ulinastatin (at the concentration of 5 000 U/ml) + TNF-? was significantly increased compared with that after treatment with TNF-? (P
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Objective To explore the relationship between the loss of the heterozygosity of nm23-H_1 and the lymph node metastasis in no-small-cell lung cancer (NSCLC). Methods The loss of the heterozygosity of nm23-H_1 gene of cancer tissue and peri-cancerous tissue was detected in 39 patients with NSCLC by Southern blotting. Results The heterozygosity gene of nm23-H_1 is 7.6 kb and 2.3 kb. The LOH rate of the patients with lymph node metastasis (48%, 12/25) was higher than those without lymph node involvement (8%, 1/11) (P
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Objective To investigate the effects of adenosine receptor A2a on the expression of epithelial sodium channel ?-subunit (?-ENaC) in alveolar epithelium A549 cells and the effects of adenosine receptor A2a in acute lung injury/aute respiratory distress syndrome. Methods After alveolar epithelium A549 Cells were incubated with 0,0.1,1,10 and 100 ?mol/L adenosine receptor A2a agonist CGS-21680 for 8 h or with 100 ?mol/L CGS-21680 for 0,1,4,8,24 and 48 h respectively,the mRNA and protein levels of ?-ENaC were determined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis respectively. Results After A549 cells were incubated with CGS-21680 at different doses for 8 h,the mRNA and protein levels of ?-ENaC were elevated significantly at 0.1 ?mol/L CGS-21680 treatment compared with the control group (P
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<p><b>OBJECTIVE</b>To establish a kind of molecular biology clinical detective method to cariogenic S. mutans.</p><p><b>METHODS</b>Using the coamplification of target and reference genes. One pair of specific primers were designed according to a portion of the dextranase (dexA) gene of S. mutans. The reference gene was plasmid pET23b DNA. The saliva samples of 196 children were quantitative detected. The PCR method was compared with the routine culture method.</p><p><b>RESULTS</b>The rate of S. mutans counts >/= 10(8) CFU/L (colony-forming unit per millilitre) saliva by quantitative PCR was 91.3%. The results of coincidence rate between the new method and the routine way was 94.9%.</p><p><b>CONCLUSIONS</b>The new quantitative detective method is fast and provides with high scoincidence rate and high specificity, so have extensive clinical practice foreground.</p>
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Humans , DNA Primers , Polymerase Chain Reaction , Saliva , Sensitivity and Specificity , Streptococcus mutans , Genetics , Streptococcus sobrinus , GeneticsABSTRACT
<p><b>OBJECTIVE</b>To study micro morphology and element-mixing distribution of different alloys welded in laser and analyze the feasibility of laser welding different alloys.</p><p><b>METHODS</b>Alloys and titanium were matched into 4 groups: Au-Pt with Ni-Cr; Au-Pt with pure Ti; pure Ti with Ni-Cr; Ni-Cr with Co-Cr. They were welded in laser. Changes in metallography after hybridization of crystalline grain, ranges of heat-affected zone and pores were observed through SEM with ultra-thin windowed X-ray energy atlas. Meanwhile 10 testing points were chosen with area of 300 micro m x 900 micro m along the welding surface from the side A alloy to the side B alloy, than the element mixing distribution and tendency were analyzed with X-ray energy atlas.</p><p><b>RESULTS</b>1. Hybridization of different alloys: (l) in the group of Au-Pt with Ti, there was titanium element mixing into Au-Pt tissue gradually and evenly on the Au-Pt side of the interface without clear boundary and increasing in size of crystalline grain. However, there was titanium crystalline grain increasing in size, irregular morphology and small sacks on the titanium side with clear boundary. (2) in the group of Ni-Cr with Ti, there was mixing regularly, slow transition and interlocks between crystalline grains on the Ni-Cr side of the in terface. Poor transition, clear boundary and small cracks were observed on titanium side. (3) in the group of Co-Cr with Ni-Cr, there was good transition, obscure boundary on both sides resulting from network, cylinder and branch structure growing. 2. Element-mixing distribution of different alloys. In fusion zone, the metal elements in matched groups mixed well and hybridized into new alloys except titanium blocks. The location of wave peak depended on the composition of alloys. Most of elements were from the alloy far from the fusion zone.</p><p><b>CONCLUSION</b>The hybridization between pure titanium and any other alloys is not good The effect of laser welding different alloys is ideal except with pure titanium.</p>