Effect of graphene-oxide-modified osteon-like concentric microgrooved surface on the osteoclastic differentiation of macrophages / 华西口腔医学杂志

OBJECTIVES@#This study aimed to investigate the effect of new biomimetic micro/nano surfaces on the osteoclastic differentiation of RAW264.7 macrophages by simulating natural osteons for the design of concentric circular structures and modifying graphene oxide (GO).@*METHODS@#The groups were divided into smooth titanium surface group (SS), concentric microgrooved titanium surface group (CMS), and microgroove modified with GO group (GO-CMS). The physicochemical properties of the material surfaces were studied using scanning electron microscopy (SEM), contact-angle measurement, atomic force microscopy, X-ray photoelectron spectroscopy analysis, and Raman spectroscopy. The effect of the modified material surface on the cell biological behavior of RAW264.7 was investigated by cell-activity assay, SEM, and laser confocal microscopy. The effect on the osteoclastic differentiation of macrophages was investiga-ted by tartrate-resistant acid phosphatase (TRAP) immunofluorescence staining and quantitative real-time polymerase chain reaction (qRT-PCR) experiments.@*RESULTS@#Macrophages were arranged in concentric circles along the microgrooves, and after modification with GO, the oxygen-containing groups on the surface of the material increased and hydrophilicity increased. Osteoclasts in the GO-CMS group were small in size and number and had the lowest TRAP expression. Although it promoted the proliferation of macrophages in the GO-CMS group, the expression of osteoclastic differentiation-related genes was lower than that in the SS group, and the difference was statistically significant (P<0.05).@*CONCLUSIONS@#Concentric circular microgrooves restricted the fusion of osteoclasts and the formation of sealing zones. Osteomimetic concentric microgrooves modified with GO inhibited the osteoclastic differentiation of RAW 264.7 macrophages.

Effects of femtosecond laser treatment on surface characteristics and flexural strength of zirconia / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the effects of femtosecond laser treated microgrooved surface on microscopic topography, phase transformation, and three-points flexural strength of zirconia, and to provide reference for surface microstructure optimization of zirconia implant.@*METHODS@#According to different surface treatment methods, 57 computer aided design/computer aided manufacture (CAD/CAM) zirconia bars (20.0 mm×4.0 mm×1.4 mm) were evenly divided into three groups: sintered group, no treatment after sintering, taken as control; sandblasted group, sandblasted with 110 μm aluminium oxide (Al2O3) after sintering; microgrooved group, femtosecond laser fabricated microgrooves with 50 μm width, 30 μm depth, and 100 μm pitch. Surface microscopic topography was observed with scanning electron microscope (SEM) and 3D laser microscope. Further, surface roughness in each group and microgroove size were measured. Crystal phase was analyzed with X-ray diffraction. Specimens were subjected to three- points flexural strength test, and Weibull distribution was used to analyze their strength characteristics.@*RESULTS@#SEM showed that sintered surface was flat with clear grain structure; sandblasted surface exihibited bumps and holes with sharp margins and irregular shape; microgrooves were regularly aligned without evident defect, and nano-scale particles were observed on the surface inside of the microgrooves. Ra value of microgrooved group [(9.42±0.28)] μm was significantly higher than that of sandblasted group [(1.04±0.03) μm] and sintered group [(0.60±0.04) μm], and there was statistical difference between sandblasted group and sintered group (P < 0.001). The microgroove size was precise with (49.75±1.24) μm width, (30.85±1.02) μm depth, and (100.58±1.94) μm pitch. Crystal phase analysis showed that monoclinic volume fraction of sandblasted group (18.17%) was much higher than that of sintered group (1.55%), while microgrooved group (2.21%) was similar with sintered group. The flexural strength of sandblasted group (986.22±163.25) MPa had no statistical difference with that of sintered group (946.46±134.15) MPa (P=0.847), but the strength in microgrooved group (547.92±30.89) MPa dropped significantly compared with the other two groups (P < 0.001). Weibull modulus of sintered, sandblasted, microgrooved groups were 7.89, 6.98, and 23.46, respectively.@*CONCLUSION@#Femtosecond laser was able to form micro/nanostructured microgrooves on zirconia surface, which deleteriously affected the flexural strength of zirconia.

The effects of microgroove surface form of titanium on the adhesion and cell cycle progression of human gingival fibroblasts / 实用口腔医学杂志

Objective:To investigate the effect of microgroove surfaces of titanium on the adhesion and cell cycle progression of human gingival fibroblasts(HGFs).Methods:Microgroove titanium surfaces were fabricated on silicon plate by photolithography with parallel grooves:1 5,30 and 60 μm in width and 5 μm and 1 0 μm in depth,the groups were denoted as T1 5 /5,T1 5 /1 0,T30 /5,T30 /1 0, T60 /5 and T60 /1 0,respectively.Smooth titanium surfaces (T0)were used as the controls.Surface topography were observed by ES-EM.HGFs were cultured on the microgroove surfaces.Morphology of “contact guidance”was observed by immunofluorescence tech-nique.Cell cycle distribution was analyzed by Flow cytometry.Results:HGFs on the microgroove surfaces had “contact guidance”par-allel to the microgrooves,whereas the cells on T0 were oriented randomly.T60 /1 0 group had the highest percentage of S phase cells, followed by T30 group and T1 5 group,but still higher than that in the control group.In groups with higher groove width (T60 group and T30 group),the increase of groove depth benefited the increase of S phase percentage,while in T1 5 group,the increase of groove width decreased the S phase percentage.Conclusion:Surfaces of microgrooves with different dimensions achieved “contact guidance”for the cultured HGFs.The surfaces with increasing groove width and depth benefit the cell cycle progression.

Effect of microgroove surface morphology on the adhesion and proliferation of human gingival fibroblasts / 实用口腔医学杂志

Objective:To investigate the effects of microgroove surface morphology on the adhesion and proliferation of the human gin-gival fibroblasts(HGFs).Methods:Microgroove surfaces of titanium were fabricated by photolithography with parallel grooves of 15,30 or 60 μm in width and 5 μm or 10 μm in depth.The groups of the samples were denoted as T15 /5,T15 /10,T30 /5,T30 /10,T60 /5 and T60 /10.Smooth titanium surface(T0)was used as the control.The surface topography was observed by enviroment SEM(ES-EM).HGFs were cultured on the topographically modified surfaces.Morphology was observed by SEM.Cell proliferation was examined by CCK-8 kit.Results:HGFs on the microgroove surfaces had “contact guidance”parallel to the microgrooves,whereas the cells on T0 were oriented randomly.Cell proliferation was promoted and kept for longer period on T60 /10 surface.Conclusion:Surfaces of mi-crogrooves with increasing groove width and depth may achieve “contact guidance”for HGFs and promote cell proliferation.

Surface microgrooves of thirty micrometers in width on titanium substrata enhance proliferation and alter gene expression of cultured human gingival fibroblasts / 대한치과보철학회지

STATEMENT OF PROBLEM: Surface microgrooves on Ti substrata have been shown to alter the expression of genes responsible for various biological activities of cultured fibroblasts. However, their effect on enhancing cell proliferation is not yet clear. PURPOSE: The purpose of this study was to determine the dimension of surface microgrooves on Ti substrata that enhances proliferation and alters gene expression of cultured human gingival fibroblasts. MATERIAL AND METHODS: Commercially pure Ti discs with surface microgrooves of monotonous 3.5 micrometerin depth and respective 15 and 30 micrometer in width were fabricated using photolithography and used as the culture substrata in the two experimental groups in this study (TiD15 and TiD30), whereas the smooth Ti was used as the control substrata (smooth Ti group). Human gingival fibroblasts were cultured on the three groups of titanium substrata and the proliferation, DNA synthesis, and gene expression of theses cells were analyzed and compared between all groups using XTT assay, BrdU assay, and reverse transcriptase-polymerase chain reaction (RTPCR), respectively. RESULTS: From the XTT assay at 48 h incubation, the proliferation of human gingival fibroblasts in TiD30 was significantly enhanced compared to that in smooth Ti and TiD15. The results from the BrdU assay showed that, at 24 h incubation, the DNA synthesis was significantly enhanced in TiD30 compared to that in smooth Ti. In RT-PCR, increase in the expression of PCR transcripts of fibronectin, CDK6, p21cip1 genes was noted at 48h incubation. CONCLUSION: Surface microgrooves 30 micrometer in width and 3.5 micrometer in depth on Ti substrata enhance proliferation and alter gene expression of cultured human gingival fibroblasts.

Measurement of Smooth Muscle Cell Migration on the Micromachined Groove Topology

PURPOSE: The spreading, orientation, and chemotaxis with the gradient of a chemoattractant of smooth muscle cells (SMCs) were studied on the micro-grooved substrata by the light, fluorescence and scanning electron microscopy. METHOD: Vertical-walled grooves were produced in silicon wafers by the micromachining technique. All grooves were 4~20micrometer deep and 10~80 micrometer wide. SMCs were cultured on each microgroove and examined under stereo-microscope. RESULT: Cell clusters were markedly oriented by all the grooved substrata examined. Time-lapse images acquired from CCD (Charge Coupled Device) showed that the grooves directed the migration of SMCs. There was no prominent difference in the migration speed of SMCs according to the grooves. All the cytoskeletal fibers were reorganized in the same direction with grooves. Especially the alignments of microtubule and intermediate filaments were distinguished in the SMCs on the micro grooves. CONCLUSION: These results could be applied to the analysis of vascular restenosis and the development of artificial blood vessels.