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BACKGROUND: The polycaprolactone nanofiber scaffolds prepared by electrostatic spinning have a structure resembling extracellular matrix, but it is not conducive to cell adhesion, migration, proliferation and differentiation due to the poor hydrophilicity. OBJECTIVE: To fabricate attapulgite/polycaprolactone scaffolds via three-dimensional (3D) electrohydrodynamic printing and evaluate the biological effects and osteogenic induction ability on mouse bone marrow mesenchymal stem cells. METHODS: Attapulgite/polycaprolactone scaffolds with different concentration of attapulgite (0%, 0.5%, 1%, 2%) were prepared by 3D electrohydrodynamic, and the morphology and structure were observed by scanning electron microscope. The mouse bone marrow mesenchymal stem cells were co-cultured with four groups of scaffolds. The growth and morphology of bone marrow mesenchymal stem cells were observed with scanning electron microscope and Live/ Dead staining at 7 and 2 days, respectively. The proliferation of bone marrow mesenchymal stem cells was detected by CCK-8 assay at 1, 3 and 5 days. The mRNA expression levels of osteogenic marker genes were detected by real-time PCR at 3, 7, and 14 days. Alkaline phosphatase activity was detected at 3, 7 and 10 days of co-culture. RESULTS AND CONCLUSION: (1) Scanning electron microscopy results showed that four groups of scaffolds presented macropore morphology with the pore size of about 450 μm, and the surfaces of 0% and 0.5% attapulgite were smooth, while the scaffold surfaces in 1% and 2% attapulgite groups were rough. (2) Scanning electron microscopy showed that cells adhered and grew well on the surface of these scaffolds, and there were more cells grow in 1% attapulgite group than in other groups. (3) Live/Dead staining showed that cells adhered and grew well on the surface of four groups of scaffolds, among which 2% attapulgite group had the least cells. (4) The results of CCK-8 assay showed that the cell proliferation rate of 0.5% attapulgite group was higher than that of the other groups. (5) Real-time PCR showed that the expressions of alkaline phosphatase, osteocalcin, osteoblast-specific transcription factor and Runx-2 genes in 0.5% attapulgite group for 14 days were higher than those in the other groups. (6) The alkaline phosphatase activities of 0.5%, 1% and 2% attapulgite groups were all higher than 0% attapulgite group, in which the 0.5% attapulgite group was the highest at 3 and 7 days but 1% and 2% attapulgite groups were higher than other groups at 10 days of co-culture. (7) The 0.5% attapulgite scaffold has better biocompatibility and osteogenic induction potential. [ABSTRACT FROM AUTHOR]

BACKGROUND: With its excellent biocompatibility and osteoconductivity, hydroxyapatite is widely used as a material coating in tissue engineering, and its biological properties are strongly associated with the morphology caused by the manufacturing process. OBJECTIVE: To investigate the effects of plasma spraying and electrochemical deposition on the stent of hydroxyapatite coating on the proliferation, adhesion and osteogenic differentiation of bone marrow mesenchymal stem cells. METHODS: Hydroxyapatite coating was prepared on titanium stent using plasma spraying and electrochemical deposition. The titanium stent without coating was used as a control. Rat bone marrow mesenchymal stem cells were cocultured with three kinds of stents for 1, 3, 5, and 7 days. Cell proliferation was detected using CCK-8 assay for 5 days. Cell adhesion was observed using scanning electron microscope and confocal laser microscope. At 14 days, alkaline phosphatase staining was conducted; at 21 days, alizarin red staining was performed. At 14 and 21 days, real-time quantitative fluorescent polymerase chain reaction was conducted to analyze osteogenic differentiation of bone marrow mesenchymal stem cells. RESULTS AND CONCLUSION: (1) With the extension of the culture time, the cell proliferation rate of each group increased. The cell proliferation rate of the plasma spraying group was higher than that of the electrochemical deposition group and the control group (P < 0.05). (2) Scanning electron microscopy showed that cell adhesion was seen on the stents in the three groups. The plasma spraying group had the largest cell spreading area, and the control group had the smallest cell spreading area. The laser confocal microscope showed that the actin fibers in the plasma spraying group were the densest and the cells were in good extension; the electrochemical deposition group was relatively dense and the cells were in normal extension. In the control group, cytotactin was relatively sparse and the cells were not fully extended. (3) The alkaline phosphatase activity of the plasma spraying group was higher than that of the electrochemical deposition group and the control group, and calcium nodules were formed more than that of the electrochemical deposition group and the control group. (4) Real-time quantitative fluorescent polymerase chain reaction showed that the expression levels of osteopontin, type I collagen, osteocalcin and Runx2 mRNA in plasma spraying group were higher than those in electrochemical deposition group at the same time except that there was no difference between osteocalcin mRNA expression at 7 days and Runx2 mRNA expression at 14 days (P < 0.05). (5) The results showed that the morphology of plasma sprayed hydroxyapatite coating is more conducive to proliferation, adhesion and osteogenic differentiation of bone marrow mesenchymal stem cells. [ABSTRACT FROM AUTHOR]

BACKGROUND: Relevant studies have shown that adding an appropriate amount of graphene oxide can improve the mechanical properties, hydrophilicity, and cell compatibility of the fiber scaffold, and has a certain ability to promote bone formation. OBJECTIVE: To prepare egg white/polyvinyl alcohol/graphene oxide composite fiber scaffolds with different concentrations of graphene oxide and preliminary explore the biocompatibility of composite fiber scaffold in vitro. METHODS: Electrospinning was used to prepare egg white/polyvinyl alcohol/graphene oxide composite fiber scaffolds containing 0, 0.5, 1, and 1.5 g/L graphene oxid. The morphology of the scaffold was observed by scanning electron microscope, and the mechanical properties, contact angle and equilibrium swelling ratio of the scaffold were also tested. Human umbilical vein endothelial cells and human bone marrow mesenchymal stem cells were respectively inoculated on the surface of four groups of scaffolds. The CCK-8 assay was used to detect the proliferation of the two types of cells. Live/Dead fluorescent staining was used to observe the viability of the two types of cells. The scratch test and rhodamine phalloidin staining were used to observe the migration and morphology of human umbilical vein endothelial cells. RESULTS AND CONCLUSION: (1) Scanning electron microscope showed that with the increase of graphene oxid content, the fiber diameter of the composite scaffold increased. (2) With the increase of graphene oxid content, the hydrophilicity of the composite scaffold first decreased and then increased, and the hydrophilicity of the composite scaffold containing 0.5 g/L graphene oxid was the lowest. (3) With the increase of graphene oxid content, the Young's modulus and tensile strength of the composite scaffold first increased and then decreased, and the Young's modulus and tensile strength of the composite scaffold containing 0.5 g/L graphene oxid were the largest. (4) CCK-8 assay showed that the proliferation rate of human bone marrow mesenchymal stem cells on the composite scaffold containing 1.5 g/L graphene oxid was faster than that of the other three groups of scaffold (P < 0.05), and the proliferation rate of human umbilical vein endothelial cells on the composite scaffold containing 1 g/L graphene oxid was faster than the other three groups of scaffolds (P < 0.05). (5) With the increase of graphene oxid content, the survival rate of human bone marrow mesenchymal stem cells on the composite scaffold increased; the survival rate of human umbilical vein endothelial cells on the composite scaffold containing 1 g/L graphene oxid was the highest. (6) Scratch experiment and rhodamine phalloidin staining proved that the composite scaffold containing 1 g/L graphene oxid was most conducive to the migration and morphological expansion of human umbilical vein endothelial cells. (7) The results show that the egg white/polyvinyl alcohol/graphene oxide fiber scaffold containing 1 g/L graphene oxid has excellent fiber structure, hydrophilicity, mechanical properties and cell compatibility. [ABSTRACT FROM AUTHOR]

BACKGROUND: Based on the need of in situ tissue engineering regeneration in the field of meniscus regeneration, three-dimensional (3D) bioprinting technology can be used to construct a scaffold which can effectively combine recruitment bioactive factors and excellent materials. OBJECTIVE: To optimize the preparation process of polycaprolactone/methacrylate anhydride gelatin/meniscus extracellular matrix (PCL/GelMA/MECM) 3D bioprinting scaffold loaded with platelets derived growth factor-BB (PDGF-BB), and to test the sustained release properties of the growth factor and its effect on the migration and proliferation of the synovial mesenchymal stem cells. METHODS: Photosensitive bio-ink was prepared by GelMA/MECM. PCL scaffold and PCL/GelMA/MECM bio-scaffold were prepared by 3D bioprinting technology. Finally, PDGF-BB was loaded to fabricate functional bioprinting PCL/GelMA/MECM/PDGF scaffold, and then its mechanical properties and sustained release properties were tested. New Zealand white rabbit synovial mesenchymal stem cells were isolated and cultured. Transwell and CCK-8 assays were used to explore the effects of PCL scaffold, PCL/GelMA/MECM scaffold and PCL/GelMA/MECM/PDGF scaffold on the migration and proliferation of synovial mesenchymal stem cells, and single medium cultured cells were used as negative control. The third passage of synovial mesenchymal stem cells was inoculated on PCL scaffold, PCL/GelMA/MECM scaffold and PCL/GelMA/MECM/PDGF scaffold respectively. The viability, adhesion and growth of the cells on the three scaffolds were observed by confocal microscope and scanning electron microscope. RESULTS AND CONCLUSION: (1) There was no significant difference in tensile modulus and compression modulus between PCL/GelMA/MECM scaffolds and PCL scaffolds (P > 0.05). (2) PCL/GelMA/MECM/PDGF scaffolds had good sustained release performance, and PDGF-BB could be released continuously for up to 28 days. (3) Compared with the negative control group, PCL/GelMA/MECM scaffolds and PCL/GelMA/MECM/PDGF scaffolds could promote the migration of synovial mesenchymal stem cells, among which PCL/GelMA/MECM/PDGF scaffolds were more effective. (4) Compared with the negative control group, the cells cultured with PCL/GelMA/MECM scaffolds and PCL/GelMA/MECM/PDGF scaffolds proliferated faster after 4 and 7 days (P < 0.001), and the proliferative effect of PCL/GelMA/MECM/PDGF scaffolds was more obvious. (5) Dead/Live staining showed that the cells in each group had good activity, and the number of cells on the PCL/GelMA/MECM/PDGF scaffold was the highest. (6) Scanning electron microscope showed that the cells were attached to the surface of the three groups of scaffolds, and the cells on PCL/GelMA/MECM scaffolds and PCL/GelMA/MECM/PDGF scaffolds adhered to a large number of cells and secreted a large amount of extracellular matrix. (7) These results showed that the 3D bioprinted meniscus scaffold loaded with PDGF-BB had good mechanical properties and biocompatibility and could promote the migration and proliferation of synovial mesenchymal stem cells. [ABSTRACT FROM AUTHOR]