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Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Porcine-derived xenogeneic bone (PDXB) was derived from cancellous bone of adult porcine. Its morphology and structure were characterized by SEM, FTIR and XRD. A series of composite films consisting of PDXB and poly(glycolide-co-lactide-co-caprolactone) (PGLC) polymer were prepared. Because of the introduction of PGLC polymer, the PDXB/PGLC composites especially PDXB/PGLC(30/70) and PDXB/PGLC(50/50) showed good processability and mechanical properties. In addition, the hydrophilicity of the composites was enhanced as well since the PDXB component was hydrophilic. Osteoblast-like cells (OCT-1) were used as an in-vitro model to assess the affinity of the PDXB/PGLC composites. It was found that compared with the pure PGLC film, PDXB/PGLC(30/70) and PDXB/PGLC(50/50) composite films promoted cell attachment, proliferation and ALP (alkaline phosphatase) activity obviously. In addition, the cells preferred growing on the areas of exposed PDXB. It was considered that the hydrophilicity, osteoconductivity and appropriate surface roughness (Sa=3.30, 4.00 microm) induced by PDXB facilitate cell growth. However, the introduction of too much PDXB, such as PDXB/PGLC(70/30) film, would obtain an adverse effect on the cell growth since the value of Sa was up to 7.33 microm. It indicated that only the composites with appropriate surface topography could favor cell growth. Surface topography probably has a more important effect on cell growth process than surface chemistry.
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PMID:Porcine-derived xenogeneic bone/poly(glycolide-co-lactide-co-caprolactone) composite and its affinity with rat OCT-1 osteoblast-like cells. 1605 84

To investigate the effect of three kinds of polymeric scaffolds on attachment, proliferation and differentiation of bone marrow mesenchymal stem cells, the cells were different polymeric scaffolds of PLA-PEG, PLA, PLGA, respectively. The proliferation of cell was evaluated by cell count; the attachment and morphology of BMSCs were observed by SEM; and differentiation was detected by alkaline phosphatase activity, fluorescence, and RT-PCR methods. Results showed that the cells in PLGA group spread better among BMSCs adhered to the three polymeric scaffolds. The activity of ALP was detected after 3 days culture in these three groups. There were no significant differences between PLA-PEG and PLGA groups, but the activity of ALP was higher than PLA group. The gene expressions of osteocalicin and collagen I were also observed in the early culture time. Calcium nodes formation in these polymeric scaffolds were detected. BMSC spreading first, then overlapping growth and secretion of matrix around the bottom and surface of scaffolds were observed through SEM. In summary, PLA-PEG and PLGA are better polymeric scaffolds for the bone tissue engineering, compared with PLA.
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PMID:[Effect of polymeric scaffolds on attachment and growth of bone marrow mesenchymal stem cells]. 1642 95

Hydroxyapatite (HA) has been widely used as a bone graft substitute. In this study, we investigated whether the addition of osteogenic protein-1 (OP-1) further enhanced the weak osteoinductive properties of hydroxyapatite when loaded with human mesenchymal stem cells (h-MSCs). Over a 14 day period, cell proliferation in both groups was assessed qualitatively using SEM and quantitatively using alamar blue assay. Cell differentiation was also evaluated by measurement of ALP activity, which was expressed against total DNA. HA/MSC loaded with OP-1 demonstrated a statistically significant increase (p<0.001) in cell proliferation at all time points in comparison to unloaded samples. ALP activity per DNA was also significantly enhanced (p<0.001) in loaded samples when compared to unloaded controls. SEM demonstrated increased cellular attachment and proliferation into HA pores at all time points in the loaded samples. Our study suggests that the osteoinductive potential of HA can be improved in vitro by the combined incorporation of MSCs and OP-1.
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PMID:Enhancing the osteoinductive properties of hydroxyapatite by the addition of human mesenchymal stem cells, and recombinant human osteogenic protein-1 (BMP-7) in vitro. 1696 59

Titanium is the most widely used material for dental implants. The natural formation, in presence of oxygen, of different oxide films (passivation films) is correlated to titanium implant biocompatibility, resistance to corrosion and is responsible for implant bacteriostatic action. Surface roughness is another surface property of Ti-implants that, affecting implant-to-bone contact, improves integration. In the present study data concerning composition, surface roughness and biocompatibility of Ghimas implants and mini-implants undergoing sandblasting with Calcium Magnesium Carbonate (CaMg(CO3)2) are reported. AFM, SEM/EDX, XRD analyses and morpho-functional tests (MTT and ALP) were performed. Cell actin cytoskeletal modification (fluorescence phalloidin staining) was also observed with confocal laser microscopy (CLSM). Data related to surface geometry and chemical properties, associated with evidence of high purity of all the tested materials (XRD and EDX), highlighted the elevated biocompatibility of tested implants and mini-implants. CLSM investigation confirmed osteoblast features of an active cell behavior able to fit cell to chemico-mechanical stimuli present at the bone/implant interface and suggests an effective implant/alveolar bone integration in vivo.
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PMID:In vitro evaluation of bio-functional performances of Ghimas titanium implants. 1721 23

The purpose of this study was to evaluate the effect of osteogenic differentiation of bone marrow stromal stem cells (BMSCs) on bone formation in a novel interconnected porous calcium hydroxyapatite (IP-CHA). BMSCs/IP-CHA composites, as a cell-hybrid artificial bone, were made by injecting BMSCs solution into IP-CHA scaffolds. To induce osteogenic differentiation, BMSCs/IP-CHA composites were subcultured for three, seven, 10, and 14 days. At the end of each subculture period, BMSCs/IP-CHA composites were examined by SEM and ALP staining. BMSCs/IP-CHA composites of different osteogenic groups of subculture were also placed into bone sockets in the right femur of beagle dogs. After four weeks, same placement procedure was done in the left femur. BMSCs/IP-CHA subcultured for 10 and 14 days were ALP-positive as opposed to those of three and seven days. At four weeks after placement, bone formation was superior at the 10- and 14-day subculture groups. Based on the results obtained, it was suggested that osteogenic differentiation periods with 10 and 14 days of subculture for BMSCs/IP-CHA as a cell-hybrid artificial bone were beneficial in promoting bone formation.
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PMID:Development of cell-hybrid artificial bone: effect of osteogenic differentiation of bone marrow stromal stem cells on bone formation with newly developed interconnected porous calcium hydroxyapatite. 1762 30

Nanocrystalline diamond (NCD) has a great potential for prosthetic implants coating. Nevertheless, its biocompatibility still has to be better understood. To do so, we employed several materials characterization techniques (SEM, AFM, micro-Raman spectroscopy) and cell culture assays using MG63 osteoblast-like and human bone marrow cells. Biochemical routines (MTT assays, Lowry's method, ALP activity) supported by SEM and confocal microscopy characterization were carried out. We used silicon nitride (Si3N4) substrates for NCD coatings based on a previous demonstration of the superior adhesion and tribological performance of these NCD coated ceramics. Results demonstrate an improved human osteoblast proliferation and the stimulation of differentiated markers, like ALP activity and matrix mineralization, compared with standard polystyrene tissue culture plates. The nanometric featuring of NCD, associated to its chemical affinity are key points for bone regeneration purposes.
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PMID:Nanocrystalline diamond: In vitro biocompatibility assessment by MG63 and human bone marrow cells cultures. 1808 49

The generation of effective tissue engineered bone grafts requires efficient exchange of nutrients and mechanical stimulus. Bioreactors provide a manner in which this can be achieved. We have recently developed a biaxial rotating bioreactor with efficient fluidics through in-silico modeling. Here we investigated its performance for generation of highly osteogenic bone graft using polycaprolactone-tricalcium phosphate (PCL-TCP) scaffolds seeded with human fetal mesenchymal stem cell (hfMSC). hfMSC scaffolds were cultured in either bioreactor or static cultures, with assessment of cellular viability, proliferation and osteogenic differentiation in vitro and also after transplantation into immunodeficient mice. Compared to static culture, bioreactor-cultured hfMSC scaffolds reached cellular confluence earlier (day 7 vs. day 28), with greater cellularity (2x, p<0.01), and maintained high cellular viability in the core, which was 2000 microm from the surface. In addition, bioreactor culture was associated with greater osteogenic induction, ALP expression (1.5x p<0.01), calcium deposition (5.5x, p<0.001) and bony nodule formation on SEM, and in-vivo ectopic bone formation in immunodeficient mice (3.2x, p<0.001) compared with static-cultured scaffolds. The use of biaxial bioreactor here allowed the maintenance of cellular viability beyond the limits of conventional diffusion, with increased proliferation and osteogenic differentiation both in vitro and in vivo, suggesting its utility for bone tissue engineering applications.
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PMID:A biaxial rotating bioreactor for the culture of fetal mesenchymal stem cells for bone tissue engineering. 1922 70

We have synthesized methacrylate-endcapped caprolactone networks with tailored water sorption ability, poly(CLMA-co-HEA), in the form of three-dimensional (3D) scaffolds with the same architecture but exhibiting different hydrophilicity character (x(HEA)=0, 0.3, 0.5), and we investigated the interaction of goat bone marrow stromal cells (GBMSCs) with such structures. For this purpose, GBMSCs were seeded and cultured for 3, 7, 14, 21, and 28 days onto the developed scaffolds. Cells have proliferated throughout the whole scaffold volume. Cell adhesion and morphology were analyzed by SEM, whereas cell viability and proliferation was assessed by MTS test and DNA quantification concluding that numbers of cells increased as a function of the culturing time (until day 14) and also with the hydrophobic content in the samples (from 50 to 100% of CLMA). No significant difference between samples with 100% and 70% of CLMA were detected in some cases. Osteoblastic differentiation was followed by assessing the alkaline phosphatase activity of cells, as well as type I collagen and osteocalcin expressions levels until day 21. The three markers were positive at days 14 and 21 when cells were cultured in 100% CLMA substrates which suggests osteoblastic differentiation of mesenchymal stem cells within these scaffolds. On the other hand, when the CLMA content decreases (until 50%), type I collagen and osteocalcin were positive but ALP was negative indicating that the differentiation process is affected by hydrophilic content. We suggest that such system may be useful to extract information on the effect of materials' wettability on the corresponding biological performance in a 3D environment. Such general insights may be relevant in the context of biomaterials selection for tissue engineering strategies.
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PMID:Proliferation and differentiation of goat bone marrow stromal cells in 3D scaffolds with tunable hydrophilicity. 1944 Nov 19

We fabricated composite fibrous scaffolds from blends of poly(lactide-co-glycolide) (PLGA) and nano-sized hydroxyapatite (HA) via electrospinning. SEM-EDX and AFM analysis demonstrated that HA was homogeneously dispersed in the nanofibers, and the roughness increased along with the amount of incorporated HA. When hMSCs were cultured on these PLGA/HA composite nanofibers, we found that incorporation of HA on the nanofibers did not affect cell viability whereas increased ALP activity and expression of osteogenic genes as well as the calcium mineralization of hMSCs. Our results indicate that the composite nanofibers can be offered as a potential bone regenerative biomaterial for stem cell based therapies.
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PMID:Control of osteogenic differentiation and mineralization of human mesenchymal stem cells on composite nanofibers containing poly[lactic-co-(glycolic acid)] and hydroxyapatite. 1968 98

In this experimental study, the RGD-containing peptide was used to modify the surface of biomimetic PLGA-(ASP-PEG) matrix, and bone marrow stromal cells (BMSCs) were seeded onto these modified surfaces for three weeks. The effects of modified surfaces of matrix on the adhesion, proliferation and differentiation of BMSCs were explored. BMSCs were harvested from whole bone marrow of Sprague-Dawley (SD) rats in vitro, then were seeded onto peptide surface-modified matrix (Experiment group, EG) and matrices without modification (Control group, CG) respectively for three weeks. The number of adhesive cells was counted by using precipitation method after 4 h and 12 h incubation; the cells cytoskeletons were stained with FITC-conjugated phalloidin after 24h incubation; the cell density was investigated after 1 d, 2 d and 3 d of incubation; ALP activity of BMSCs was measured after 7 d, 14 d and 21 d of incubation with osteogenic medium. The cells from bone marrow were BMSCs and their purity was beyond 90% using flow cytometry (FCM) analysis. Sulphur binding energy in EG was shown by XPS to be 164 eV. BMSCs adhered on peptide surface-modified matrix were observed with SEM. Cell adhesion efficiency and quality in EG was better than that in CG, and cell cytoskeleton was more robust in EG. ALP activity was higher in EG than in CG. Peptide surface-modified PLGA-(ASP-PEG) was noted to have good compatibility with BMSCs and to promote cell adhesion and differentiation.
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PMID:[Effects of the surface of PLGA-(ASP-PEG) modified with RGD and K16-containing peptide on the adhesion and differentiation of bone marrow stromal cells]. 2009 87


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