OBJECTIVES: This study aimed to compare the osteogenic performance differences of titanium surface coatings modified by dopamine or silanized graphene oxide, and to provide a more suitable modification scheme for titanium surface graphene oxide coatings. METHODS: Titanium was subjected to alkali-heat treatment and then modified with dopamine and silanization, respectively, followed by coating with graphene oxide. Control and experimental groups were designed as follows: pure titanium (Ti) group; titanium after alkali-heat treatment (Ti-NaOH) group; titanium after alkali-heat treatment and silanization modification (Ti-APTES) group; titanium after alkali-heat treatment and dopamine modification (Ti-DOPA) group; titanium with silanization-modified surface decorated with graphene oxide (Ti-APTES/GO) group; titanium with dopamine-modified surface decorated with graphene oxide (Ti-DOPA/GO) group. The physical and chemical properties of the material surfaces were analyzed using scanning electron microscopy (SEM), contact angle goniometer, X-ray photoelectron spectroscopy (XPS), and Raman spectrometer. The proliferation and adhesion morphology of mouse embryonic osteoblast precursor cells MC3T3-E1 on the material surfaces were observed by cell viability detection and immunofluorescence staining followed by laser confocal microscopy. The effects on the osteogenic differentiation of MC3T3-E1 cells were studied by alkaline phosphatase (ALP) staining, alizarin red staining and quantification, and real-time quantitative polymerase chain reaction. RESULTS: After modification with graphene oxide coating, a thin-film-like structure was observed on the surface under SEM. The hydrophilicity of all experimental groups was improved, among which the Ti-DOPA/GO group had the best hydrophilicity. XPS and Raman spectroscopy analysis showed that the modified materials exhibited typical D and G peaks, and XPS revealed the presence of a large number of oxygen-containing functional groups on the surface. CCK8 assay showed that all groups of materials had no cytotoxicity, and the proliferation level of the Ti-APTES/GO group was higher than that of the Ti-DOPA/GO group. Under the laser confocal microscope, the cells in the Ti-DOPA/GO and Ti-APTES/GO groups spread more fully. The Ti-DOPA/GO and Ti-APTES/GO groups had the deepest ALP staining, and the Ti-APTES/GO group had the most alizarin red-stained mineralized nodules and the highest quantitative result of alizarin red staining. In the Ti-DOPA/GO and Ti-APTES/GO groups, the expression of the early osteogenic-related gene RUNX2 reached a relatively high level, while in the expression of the late osteogenic-related genes OPN and OCN, the Ti-APTES/GO group performed better than the Ti-DOPA/GO group. CONCLUSIONS Ti-APTES/GO significantly outperformed Ti-DOPA/GO in promoting the adhesion, proliferation, and in vitro osteogenic differentiation of MC3T3-E1 cells.
Titanium/chemistry* ; Graphite/chemistry* ; Dopamine/chemistry* ; Animals ; Mice ; Osteogenesis ; Osteoblasts/cytology* ; Surface Properties ; Cell Proliferation ; Silanes/chemistry* ; Cell Adhesion ; Coated Materials, Biocompatible/chemistry* ; Cell Differentiation ; Alkaline Phosphatase/metabolism* ; Microscopy, Electron, Scanning

Objective:To investigate the effect of the sizes of osteon-like concentric microgroove structures on the osteoclastic differentiation of macrophages on titanium surfaces, and to provide reference for the surface modification of implants.Methods:The silicon wafers sputtered with titanium were selected as the control group (smooth surface specimens) and four concentric groups (concentric circles with the maximum diameter of 200 μm, the minimum diameter of 20 μ m, the spacing of concentric circles of 10 or 30 μm, the width of microgrooves of 10 or 30 μm, and the depth of microgrooves of 5 or 10 μm) specimens (the total sample size in each group was 27). The width of microgrooves of C10-5 and C10-10 groups was 10 μm, the depth was 5 and 10 μm, and the width of microgrooves of C30-5 and C30-10 groups was 30 μ m, the depth was 5 and 10 μ m, respectively. The physicochemical properties of the material surfaces were characterized using scanning electron microscopy and contact-angle measurement. The proliferation, adhesion of macrophage-like cell line RAW264.7 and the formation of osteoclast actin-rings on the specimen surfaces were observed by cell counting kit-8 (CCK-8), immunofluorescence staining and laser confocal microscopy. Tartrate resistant acid phosphatase (TRAP) quantitative detection, real-time fluorescence quantitative PCR (RT-qPCR) and Western blotting were used to investigate the regulation of osteon-like concentric microgroove structures on the specimen surfaces on the osteoclastic differentiation of macrophages.Results:Macrophages aggregated and grew disorderly on the surface of the smooth group, and arranged in concentric circles along the microgroove structures on the surfaces of the concentric groups. After 5 days of culture, the cell proliferation of C30 groups (the A values of C30-5 group and C30-10 group were 1.335±0.018 and 1.340±0.033, respectively) was significantly higher than that of C10 groups (the A values of C10-5 group and C10-10 group were 0.967±0.015 and 1.182±0.020, respectively)(all P<0.05). The cell proliferation of the four concentric groups was significantly higher than that of the control group (the A value was 0.796±0.012), with statistical significance (all P<0.05). After osteoclastic induction for 5 days the osteoclasts induced in the C10-5 and C10-10 groups exhibited smaller actin rings and fewer numbers. The TRAP activity in each concentric group was significantly lower than that in the control group ( P<0.05). The expression levels of osteoclast differentiation-related genes TRAP (0.610±0.022) in the C10-10 group was lowest, and CtsK (0.489±0.136, 0.445±0.037) in the C10-5 and C10-10 groups were lower compared to the smooth group and other concentric groups, with statistical significance (all P<0.05), the expression levels of osteoclast differentiation-related proteins TRAP (0.648±0.041), MMP-9 (0.688±0.026) in the C10-10 group were lowest, and CtsK (0.491±0.016, 0.453±0.010) in the C10-10 and C30-10 groups were also lower compared to the smooth group and other concentric groups, with statistical significance (all P<0.05). Conclusions:The osteon-like concentric microgroove structures inhibit the osteoclastic differentiation of macrophage-like cell line RAW264.7, with the microgrooves 10 μm wide and 10 μm deep showing the most significant inhibitory effect on the osteoclastic differentiation.

Objective:To construct curved microgrooves with gradient surface roughness on polycaprolactone (PCL) members by regulating alkali etching time and to investigate the synergistic effect of surface roughness and curved microgrooves on the in vitro osteogenic differentiation of mouse pre-osteoblasts (MC3T3-E1), aiming to determine the optimal PCL surface modification strategy. Methods:Soft lithography and melt-casting techniques were used to fabricate PCL membranes with regularly arranged curved microgrooves (CMP). Alkali etching was performed for 24, 48, and 72 h. Groups: smooth PCL (control), CMP (curved microgrooves only), CMP-24 h, CMP-48 h, CMP-72 h (CMP etched for 24, 48, 72 h, respectively). Surface physicochemical properties were characterized: surface morphology was observed by scanning electron microscopy (SEM), surface roughness was measured by atomic force microscopy (AFM), and surface hydrophilicity was evaluated by contact angle measurement. MC3T3-E1 cells were cultured in vitro. Cell adhesion, proliferation, and osteogenic differentiation were assessed using cell counting (CCK-8), immunofluorescence staining, alkaline phosphatase (ALP) and Alizarin red staining with quantification. The mRNA expression levels of osteogenesis-related genes [ALP, collagen type Ⅰ (COL-1), Runt-related transcription factor 2 (RUNX-2), osteocalcin (OCN), osteopontin (OPN)] were detected by real-time fluorescence quantitative PCR (RT-qPCR). Results:Curved microgrooves were successfully fabricated on PCL membranes. Alkali treatment improved surface hydrophilicity and increased roughness. The CMP-72 h group exhibited the best hydrophilicity (contact angle: 33.2°±5.5°), with significant differences compared to all other groups (all P<0.05). The CMP-72 h group showed the highest roughness [(59.966±4.729) nm], which was significantly different from all other groups (all P<0.05). CCK-8 results on day 5 showed that both curved microgrooves and roughness promoted cell proliferation: CMP-24 h (0.292±0.003) and CMP-72 h (0.383±0.004) were significantly higher than those in the smooth group (0.270±0.005) (all P<0.05). Immunofluorescence staining revealed that curved microgrooves induced significant contact guidance of cells; this effect weakened with increasing etching time. ALP and Alizarin red staining indicated the deepest osteogenic staining in the CMP-48 h group. Both ALP activity (0.013 021±0.000 032) and Alizarin red quantification (0.290±0.003) were highest in the CMP-48 h group, significantly different from all other groups (all P<0.05). RUNX-2 expression in CMP-24 h and CMP-48 h groups (1.845±0.087 and 1.837±0.027, respectively) was significantly higher than in other groups (all P<0.05), with no significant difference between these two groups ( P>0.05). CMP-48 h group exhibited the highest mRNA expression of all osteogenic genes tested, specifically ALP (2.194±0.028), COL-1 (1.983±0.024), OCN (7.644±0.156), and OPN (2.648±0.031), all significantly greater than other groups (all P<0.05). Conclusions:Both curved microgrooves and surface roughness modification enhance the in vitro osteogenic differentiation of cells on PCL membranes. Among the tested strategies, alkali etching of curved microgrooves for 48 hours (CMP-48h) provided the optimal enhancement of osteogenic capability for MC3T3-E1 cells and represented a promising surface modification strategy for future PCL membranes.

Objective This study aimed to compare the osteogenic performance differences of titanium surface coat-ings modified by dopamine or silanized graphene oxide,and to provide a more suitable modification scheme for ti-tanium surface graphene oxide coatings.Methods Tita-nium was subjected to alkali-heat treatment and then modified with dopamine and silanization,respectively,followed by coating with graphene oxide.Control and ex-perimental groups were designed as follows:pure titanium(Ti)group;titanium after alkali-heat treatment(Ti-NaOH)group;titanium after alkali-heat treatment and silanization modification(Ti-APTES)group;titanium after alkali-heat treatment and dopamine modification(Ti-DOPA)group;titanium with silanization-modified surface decorated with gra-phene oxide(Ti-APTES/GO)group;titanium with dopamine-modified surface decorated with graphene oxide(Ti-DOPA/GO)group.The physical and chemical properties of the material surfaces were analyzed using scanning electron micros-copy(SEM),contact angle goniometer,X-ray photoelectron spectroscopy(XPS),and Raman spectrometer.The prolifera-tion and adhesion morphology of mouse embryonic osteoblast precursor cells MC3T3-E1 on the material surfaces were observed by cell viability detection and immunofluorescence staining followed by laser confocal microscopy.The effects on the osteogenic differentiation of MC3T3-E1 cells were studied by alkaline phosphatase(ALP)staining,alizarin red staining and quantification,and real-time quantitative polymerase chain reaction.Results After modification with gra-phene oxide coating,a thin-film-like structure was observed on the surface under SEM.The hydrophilicity of all experi-mental groups was improved,among which the Ti-DOPA/GO group had the best hydrophilicity.XPS and Raman spec-troscopy analysis showed that the modified materials exhibited typical D and G peaks,and XPS revealed the presence of a large number of oxygen-containing functional groups on the surface.CCK8 assay showed that all groups of materials had no cytotoxicity,and the proliferation level of the Ti-APTES/GO group was higher than that of the Ti-DOPA/GO group.Under the laser confocal microscope,the cells in the Ti-DOPA/GO and Ti-APTES/GO groups spread more fully.The Ti-DOPA/GO and Ti-APTES/GO groups had the deepest ALP staining,and the Ti-APTES/GO group had the most alizarin red-stained mineralized nodules and the highest quantitative result of alizarin red staining.In the Ti-DOPA/GO and Ti-APTES/GO groups,the expression of the early osteogenic-related gene RUNX2 reached a relatively high level,while in the expression of the late osteogenic-related genes OPN and OCN,the Ti-APTES/GO group performed better than the Ti-DOPA/GO group.Conclusion Ti-APTES/GO significantly outperformed Ti-DOPA/GO in promoting the adhesion,proliferation,and in vitro osteogenic differentiation of MC3T3-E1 cells.

To train applied stomatology students, a stomatology practice education system was created and practiced in conjunction with post competency in the context of New Medicine. The practice teaching system is featured by six progressive stages and integration of knowledge and practice, uses student-centered and ability-oriented teaching model throughout the education, integrates the curriculum ideology system of working together in the same direction and cultivating talents with high moral standards, and forms a multi-cooperative and people-oriented evaluation system. The stomatology practice education system led by the New Medicine with collaboration of multiple elements such as "medicine, teaching, research, and innovation" has contributed to the comprehensive improvement of post competency in stomatology students. This system has played an important supportive role in the training of applied stomatology talents in the new era.

Objective:To investigate the effect of the sizes of osteon-like concentric microgroove structures on the osteoclastic differentiation of macrophages on titanium surfaces, and to provide reference for the surface modification of implants.Methods:The silicon wafers sputtered with titanium were selected as the control group (smooth surface specimens) and four concentric groups (concentric circles with the maximum diameter of 200 μm, the minimum diameter of 20 μ m, the spacing of concentric circles of 10 or 30 μm, the width of microgrooves of 10 or 30 μm, and the depth of microgrooves of 5 or 10 μm) specimens (the total sample size in each group was 27). The width of microgrooves of C10-5 and C10-10 groups was 10 μm, the depth was 5 and 10 μm, and the width of microgrooves of C30-5 and C30-10 groups was 30 μ m, the depth was 5 and 10 μ m, respectively. The physicochemical properties of the material surfaces were characterized using scanning electron microscopy and contact-angle measurement. The proliferation, adhesion of macrophage-like cell line RAW264.7 and the formation of osteoclast actin-rings on the specimen surfaces were observed by cell counting kit-8 (CCK-8), immunofluorescence staining and laser confocal microscopy. Tartrate resistant acid phosphatase (TRAP) quantitative detection, real-time fluorescence quantitative PCR (RT-qPCR) and Western blotting were used to investigate the regulation of osteon-like concentric microgroove structures on the specimen surfaces on the osteoclastic differentiation of macrophages.Results:Macrophages aggregated and grew disorderly on the surface of the smooth group, and arranged in concentric circles along the microgroove structures on the surfaces of the concentric groups. After 5 days of culture, the cell proliferation of C30 groups (the A values of C30-5 group and C30-10 group were 1.335±0.018 and 1.340±0.033, respectively) was significantly higher than that of C10 groups (the A values of C10-5 group and C10-10 group were 0.967±0.015 and 1.182±0.020, respectively)(all P<0.05). The cell proliferation of the four concentric groups was significantly higher than that of the control group (the A value was 0.796±0.012), with statistical significance (all P<0.05). After osteoclastic induction for 5 days the osteoclasts induced in the C10-5 and C10-10 groups exhibited smaller actin rings and fewer numbers. The TRAP activity in each concentric group was significantly lower than that in the control group ( P<0.05). The expression levels of osteoclast differentiation-related genes TRAP (0.610±0.022) in the C10-10 group was lowest, and CtsK (0.489±0.136, 0.445±0.037) in the C10-5 and C10-10 groups were lower compared to the smooth group and other concentric groups, with statistical significance (all P<0.05), the expression levels of osteoclast differentiation-related proteins TRAP (0.648±0.041), MMP-9 (0.688±0.026) in the C10-10 group were lowest, and CtsK (0.491±0.016, 0.453±0.010) in the C10-10 and C30-10 groups were also lower compared to the smooth group and other concentric groups, with statistical significance (all P<0.05). Conclusions:The osteon-like concentric microgroove structures inhibit the osteoclastic differentiation of macrophage-like cell line RAW264.7, with the microgrooves 10 μm wide and 10 μm deep showing the most significant inhibitory effect on the osteoclastic differentiation.

Objective:To construct curved microgrooves with gradient surface roughness on polycaprolactone (PCL) members by regulating alkali etching time and to investigate the synergistic effect of surface roughness and curved microgrooves on the in vitro osteogenic differentiation of mouse pre-osteoblasts (MC3T3-E1), aiming to determine the optimal PCL surface modification strategy. Methods:Soft lithography and melt-casting techniques were used to fabricate PCL membranes with regularly arranged curved microgrooves (CMP). Alkali etching was performed for 24, 48, and 72 h. Groups: smooth PCL (control), CMP (curved microgrooves only), CMP-24 h, CMP-48 h, CMP-72 h (CMP etched for 24, 48, 72 h, respectively). Surface physicochemical properties were characterized: surface morphology was observed by scanning electron microscopy (SEM), surface roughness was measured by atomic force microscopy (AFM), and surface hydrophilicity was evaluated by contact angle measurement. MC3T3-E1 cells were cultured in vitro. Cell adhesion, proliferation, and osteogenic differentiation were assessed using cell counting (CCK-8), immunofluorescence staining, alkaline phosphatase (ALP) and Alizarin red staining with quantification. The mRNA expression levels of osteogenesis-related genes [ALP, collagen type Ⅰ (COL-1), Runt-related transcription factor 2 (RUNX-2), osteocalcin (OCN), osteopontin (OPN)] were detected by real-time fluorescence quantitative PCR (RT-qPCR). Results:Curved microgrooves were successfully fabricated on PCL membranes. Alkali treatment improved surface hydrophilicity and increased roughness. The CMP-72 h group exhibited the best hydrophilicity (contact angle: 33.2°±5.5°), with significant differences compared to all other groups (all P<0.05). The CMP-72 h group showed the highest roughness [(59.966±4.729) nm], which was significantly different from all other groups (all P<0.05). CCK-8 results on day 5 showed that both curved microgrooves and roughness promoted cell proliferation: CMP-24 h (0.292±0.003) and CMP-72 h (0.383±0.004) were significantly higher than those in the smooth group (0.270±0.005) (all P<0.05). Immunofluorescence staining revealed that curved microgrooves induced significant contact guidance of cells; this effect weakened with increasing etching time. ALP and Alizarin red staining indicated the deepest osteogenic staining in the CMP-48 h group. Both ALP activity (0.013 021±0.000 032) and Alizarin red quantification (0.290±0.003) were highest in the CMP-48 h group, significantly different from all other groups (all P<0.05). RUNX-2 expression in CMP-24 h and CMP-48 h groups (1.845±0.087 and 1.837±0.027, respectively) was significantly higher than in other groups (all P<0.05), with no significant difference between these two groups ( P>0.05). CMP-48 h group exhibited the highest mRNA expression of all osteogenic genes tested, specifically ALP (2.194±0.028), COL-1 (1.983±0.024), OCN (7.644±0.156), and OPN (2.648±0.031), all significantly greater than other groups (all P<0.05). Conclusions:Both curved microgrooves and surface roughness modification enhance the in vitro osteogenic differentiation of cells on PCL membranes. Among the tested strategies, alkali etching of curved microgrooves for 48 hours (CMP-48h) provided the optimal enhancement of osteogenic capability for MC3T3-E1 cells and represented a promising surface modification strategy for future PCL membranes.

To train applied stomatology students, a stomatology practice education system was created and practiced in conjunction with post competency in the context of New Medicine. The practice teaching system is featured by six progressive stages and integration of knowledge and practice, uses student-centered and ability-oriented teaching model throughout the education, integrates the curriculum ideology system of working together in the same direction and cultivating talents with high moral standards, and forms a multi-cooperative and people-oriented evaluation system. The stomatology practice education system led by the New Medicine with collaboration of multiple elements such as "medicine, teaching, research, and innovation" has contributed to the comprehensive improvement of post competency in stomatology students. This system has played an important supportive role in the training of applied stomatology talents in the new era.

Objective The aim of this study was to evaluate the effects of collagen modification on the osteogenic performance of different surface-modified titanium,including alkaline etching,alkaline etching followed by silaniza-tion,and alkaline etching followed by dopamine modifi-cation.The proliferation,adhesion,and osteogenic differ-entiation abilities of MC3T3-E1 cells on the surfaces with collagen modification were analyzed and compared.Methods Collagen was immobilized on the surfaces of pure titanium(Ti-C),alkaline-etched titanium(Ti-Na-C),alkaline-etched and silanized titanium(Ti-A-C),and alkaline-etched and dopamine-modified titanium(Ti-D-C),with pure titanium(Ti)as the control group.The surface morphology was observed by scanning electron microscopy(SEM),and the surface elemental composition was analyzed by X-ray photoelectron spectroscopy(XPS).Contact angle measurements were conducted to evaluate the hydrophilicity of the surfaces.MC3T3-E1 cells were cultured on the surfaces,and their proliferation,adhesion,and osteogenic differentiation abilities were assessed using CCK-8 assay,laser scanning confocal microscope,alkaline phosphatase(ALP)staining,Alizarin red staining and quantitative analysis,as well as real-time quan-titative polymerase chain reaction(RT-qPCR)to evaluate the mRNA expression levels of osteogenic-related genes,includ-ing ALP,typeⅠcollagen(COL-1),osteocalcin(OCN),osteopontin(OPN).Results SEM and XPS results confirmed the successful immobilization of collagen on the titanium surfaces,with the Ti-Na-C group exhibiting a higher amount of col-lagen modification.Contact angle measurements showed improved hydrophilicity of the surfaces after collagen modifica-tion.CCK-8 results indicated good compatibility of the materials with MC3T3-E1,with enhanced cell proliferation on the collagen-modified surfaces.Cell fluorescence staining revealed better cell spreading on the collagen-modified surfaces,and ALP and Alizarin red staining results suggested that the Ti-Na-C group exhibited the best osteogenic performance,with significantly higher absorbance values in the Alizarin red quantification analysis.RT-qPCR analysis showed that the Ti-Na-C group had the highest expression of the osteogenic-related gene OPN.Conclusion Among the different colla-gen modification approaches employed in this study,collagen modification on alkaline-etched titanium surfaces showed the most conducive effects on MC3T3-E1 cell adhesion,spreading,proliferation,and osteogenic differentiation.This ap-proach can be considered as the optimal collagen modification strategy for enhancing osteogenesis on titanium surfaces.

Objective:To compare the effects of gelatin(Gel)and polydopamine(PDA)modification of polycaprolactone(PCL)on the biological behaviour and osteogenic function of osteoblasts.Methods:PCL electrospun membranes were prepared by electrostatic spinning technique,PCL surface was modified by Gel and PDA respectively as G/PCL and D/PCL with chemical self-assembly tech-nique,and the physicochemical properties of the electrospun membranes were characterized by scanning electron microscopy(SEM),Fourier infrared spectroscopy(FTIR),X-ray photoelectron spectroscope(XPS)and contact angle measurement.The MC3T3-E1 cell adhesion morphology was observed by SEM,immunofluorescence staining followed by confocal microscopy(CLSM),cell proliferation at 1,3 and 5 d was tested by CCK-8 assay,alkaline phosphatase(ALP)staining,alizarin red staining and qRT-PCR were used to detect osteogenic gene expression of the cells.Results:A coating of PDA particles was observed on the surface of D/PCL film.FTIR and XPS showed that the characteristic peaks of Gel and PDA,and there was no obvious droplets on the surface of G/PCL and D/PCL ob-served by contact angle test.Cell density of G/PCL group was higher,the adhesion morphology was good and pseudopods were obvi-ous.CCK-8 assay showed the highest proliferation of the cells on G/PCL(P＜0.05).ALP and alizarin red staining of the cells were stronger in D/PCL group than in the other 2 groups.qRT-PCR results showed that the mRNA expression of ALP,COL-1,RUNX2 and OCN was higher in the D/PCL group than in the other 2 groups.Conclusion:Both Gel and PDA modification can enhance the cell adhesion,proliferation and osteogenic properties of PCL scaffolds,Gel modification may induce a more pronounced proliferative effect and PDA modification more pronounced osteogenic effect.