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ABSTRACT: Calcium phosphate cement (CPC) is a promising material for use in minimally invasive surgery for bone defect repairs due to its bone-like apatitic final setting product, biocompatibility, bioactivity, self-setting characteristics, low setting temperature, adequate stiffness, and easy shaping into complicated geometrics. However, even though CPC is stable in vivo, the resorption rate of this bone cement is very slow and its long setting time poses difficulties for clinical use. Calcium sulfate dehydrate (CSD) has been used as a filler material and/or as a replacement for cancellous bone grafts due to its biocompatibility. However, it is resorbed too quickly to be optimal for bone regeneration. This study examines the in vivo response of a hydroxyapatite (HA), [apatitic phase (AP)]/calcium sulfate (CSD) composite using different ratios in the mandibular premolar sockets of beagles. The HA (AP)/CSD composite materials were prepared in the ratios of 30/70, 50/50, and 70/30 and then implanted into the mandibular premolar sockets for terms of 5 and 10 weeks. The control socket was left empty. The study shows better new bone morphology and more new bone area in the histological and the histomorphometric study of the HA (AP)/CSD in the 50/50 ratio. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Journal of Biomedical Materials Research Part A 03/2013; · 2.63 Impact Factor
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ABSTRACT: The aim of this study was to assess the cryoprotective effect of static magnetic fields (SMFs) on human erythrocytes during the slow cooling procedure. Human erythrocytes suspended in 20% glycerol were slowly frozen with a 0.4-T or 0.8-T SMF and then moved to a -80°C freezer for 24 hr. The changes in survival rate, morphology, and metabolites of the thawed erythrocytes were examined. To understand possible cryoprotective mechanisms of SMF, membrane fluidity and dehydration stability of SMF-exposed erythrocytes were tested. For each test, sham-exposed erythrocytes were used as controls. Our results showed that freezing coupled with 0.4-T or 0.8-T SMFs significantly increased the relative survival ratios of the frozen-thawed erythrocytes by 10% and 20% (p<0.001), respectively. The SMFs had no effect on erythrocyte morphology and metabolite levels. However, membrane fluidity of the samples exposed to 0.8-T SMF decreased significantly (p<0.05) in the hydrophobic regions. For the dehydration stability experiments, the samples exposed to 0.8-T SMF exhibited significantly lower (p<0.05) hemolysis. These results demonstrate that a 0.8-T SMF decreases membrane fluidity and enhances erythrocyte membrane stability to resist dehydration damage caused by slow cooling procedures.
PLoS ONE 01/2013; 8(3):e58988. · 4.09 Impact Factor
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ABSTRACT: Purpose: The aim of this study was to test whether or not a strong static magnetic field (SMF) had a positive effect on the survival rate of frozen erythrocytes. Materials and methods: Human erythrocytes were slow freezing at a rate of -1°C/min, to a final temperature of -20°C. During the freezing process, the cells were simultaneously exposed to an SMF with a magnetic induction of 0.2 or 0.4 T. After the cells were thawed, the survival rate, morphology, and function of the thawed erythrocytes were evaluated. Furthermore, tests of membrane fluidity were performed to assess the effect of the SMF on the cell membrane. Results: The slow freezing process coupled with an SMF increased the survival rate of frozen erythrocytes, without any negative effect on the cell morphology or function. The increases in relative survival rates of frozen erythrocytes were 5.7% and 9.1% when the cells were frozen in 0.2 T and 0.4 T groups, respectively. In addition, the 0.4 T group significantly increased the membrane rigidity of the erythrocytes. Conclusions: Slow freezing coupled with a strong SMF produced positive effects on the survival rate of thawed erythrocytes, without changing their normal function.
International Journal of Radiation Biology 08/2012; · 2.28 Impact Factor
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ABSTRACT: The aim of this study was to test whether Er:YAG laser-etched enamel of human teeth could act as a biologically active scaffold for tissue regeneration.
Hydroxylapatite (HA) with rough surface created by acid etching treatment has been used as a scaffold for tissue engineering. However, whether tooth HA can be a scaffold for osteoblastic cell seeding is still unclear.
Enamel samples from human teeth were pretreated with an Er:YAG laser to create a rough surface. Then the surface of the laser-treated enamel was examined using a surface roughness profilometer and a scanning electron microscope. In addition, static water contact angles of the Er:YAG laser-treated enamel samples were measured using goniometry. To observe the effects of cell behavior on an Er:YAG laser-roughened enamel surface, we cultured MG63 osteoblast-like cells on the surface-modified enamel samples. Alkaline phosphatase activity, a marker of cell proliferation and differentiation, was monitored and compared with that in untreated control and acid-etched enamel samples.
Er:YAG laser treatment significantly improved the surface roughness of the enamel samples. Furthermore, MG63 osteoblast-like cells cultured on the Er:YAG laser-roughened enamel surface expressed more alkaline phosphatase activity and exhibited greater degrees of cellular differentiation than did cells that had been cultured on untreated enamel samples.
These results demonstrate that Er:YAG laser-roughened enamel promotes osteoblastic differentiation. This finding suggests that Er:YAG laser-roughened enamel surfaces can potentially serve as a scaffold for tissue engineering.
Photomedicine and laser surgery 07/2012; 30(9):516-22. · 1.76 Impact Factor
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Hen-Yu Liu,
Jeng-Fong Chiou,
Alexander T H Wu,
Ching-Yu Tsai,
Jyh-Der Leu,
Lai-Lei Ting,
Ming-Fu Wang,
Hsuan-Yu Chen, Che-Tong Lin,
David F Williams,
Win-Ping Deng
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ABSTRACT: Adipose-derived stem cells (ADSCs) have been shown to be pluoripotent and explored for their usage in tissue engineering. Previously, we have established a cell-based approach comprised of platelet-enriched plasma and osteo-progenitor cells for treating osteoporosis in an ovariectomized-senescence-accelerated mice (OVX-SAMP8) model. In the present study, we intend to explore the feasibility of using ADSCs as a cell-based therapeutic approach for treating osteoporosis, and to examine the effects of aging on the pluoripotency of ADSCs and the efficiency of bone formation both in vitro and in vivo. Flow cytometry was used to characterize ADSCs isolated from young and aged female SAMP8 mice and showed that the highly positive expression of surface markers such as CD44 and CD105 and negative for CD34 and CD45. Therefore, to compare the aging effects on the growth kinetics and differentiation potential of young and aged ADSCs, we found that there was a significant decline in both the proliferation rate (approximately 13.3%) and osteo-differentiation potential in aged ADSC. Subsequently, young and aged ADSCs were transplanted into the bone marrow of osteoporotic mice (OVX-SAMP8) to evaluate their bone formation ability. ADSC transplants were shown effective in restoring bone mineral density in the right/left knees, femurs and spine, 4 months post-transplantation; mice which received young ADSC transplants showed significantly higher bone regeneration (an average of 24.3% of improved BMD) over those received aged ADSCs. In conclusion, these findings showed that aging impedes osteoporosis-ameliorating potential of ADSC by diminishing osteogenic signal, and that ADSC could be used as a potential cell-based therapy for osteoporosis.
Biomaterials 06/2012; 33(26):6105-12. · 7.40 Impact Factor
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ABSTRACT: Hydroxyapatite (Ca(10)(PO(4))(6)(OH)(2)), with its high biocompatibility and good bioaffinity, stimulates osteoconduction and is slowly replaced by the host bone after implantation. However, clinical use of HA as a bone substitute has proved problematic. It is difficult to prevent dispersion of the HA granules and to mold the granules into the desired shape. Calcium sulfate as a bone graft substitute is rapidly resorbed in vivo releasing calcium ions, but fails to provide a long-term, three-dimensional framework to support osteoconduction. The setting properties of calcium sulfate, however, allow it to be applied in a slurry form, making it easier to handle and apply in different situations. This study examines the in vivo response of a (Hydroxyapatite, apatitic phase)/calcium sulfate dehydrate (CSD) composite using different ratios in the mandibular premolar sockets of the beagle. The HA (AP)/CSD composite materials prepared in ratios of 30/70, 50/50, and 70/30 were implanted into the mandibular premolar sockets for 5 and 10 weeks. The control socket was empty. The authors compared the radiographic properties and the changes in height and width of the mandibular premolar sockets in the beagle. The composite graft in the 30/70 ratio had the best ability to form new bones.
Journal of Biomedical Materials Research Part A 05/2012; 100(10):2726-31. · 2.63 Impact Factor
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ABSTRACT: 2-Methyl-1,4-naphthoquinone (menadione or vitamin K3; EPO) and K3-2,3-epoxide (EPO1), but not vitamin K3-3-OH (EPO2), exhibited cytotoxicity that caused DNA fragmentation and chromatin condensation in U87 and C6 cells. EPO1 showed more-potent cytotoxicity than EPO, and the IC(50) values of EPO and EPO1 in U87 cells were 37.5 and 15.7μM, respectively. Activation of caspase 3 enzyme activity with cleavage of caspase 3 protein was detected in EPO1-treated U87 and C6 cells, and the addition of the caspase 3 peptidyl inhibitor, DEVD-FMK, reduced the cytotoxic effect of EPO1. An increase in the intracellular ROS level by EPO1 was observed in the DCHF-DA analysis, and EPO1-induced apoptosis and caspase 3 protein cleavage were prevented by adding the antioxidant, N-acetyl-cysteine (NAC), with decreased ROS production elicited by EPO1. Activation of ERK and JNK, but not p38, via phosphorylation induction was identified in EPO1- but not EPO- or EPO2-treated U87 and C6 cells, and this was blocked by adding NAC. However, the ERK inhibitor, PD98059, and the JNK inhibitor, SP600125, showed no effect on EPO1-induced cytotoxicity in either cell type. Our findings demonstrate that 2,3-epoxide substitution significantly potentiates the apoptotic effect of vitamin K3 via stimulating ROS production, which may be useful in the chemotherapy of glioblastoma cells.
Chemico-biological interactions 03/2011; 193(1):3-11. · 2.46 Impact Factor
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ABSTRACT: There is emerging interest in the use of standardized virally inactivated human platelet lysate preparations rich in GFs (growth factors) for cell cultures, cell therapy and clinical applications. In the present paper, we report a simple process to prepare a virally inactivated platelet lysate preparation rich in TGF-β1 (transforming growth factor-β1), EGF (epidermal growth factor) and IGF (insulin-like growth factor) and depleted of PDGF (platelet-derived growth factor) and VEGF (vascular endothelial growth factor). Apheresis platelet concentrates were treated by the S/D (solvent/detergent) viral inactivation procedure, then subjected to an oil extraction followed by adsorption with activated charcoal and finally sterile-filtered. The resulting preparation contained a mean of 368.4, 2.4 and 54.7 ng/ml of TGF-β1, EGF and IGF respectively. PDGF-AB and VEGF were essentially completely removed by the charcoal treatment. The mean albumin, IgG, IgM and IgA and fibrinogen contents were approx. 40.0, 8.5, 0.87, 1.66 and 2.65 mg/ml respectively, cholesterol and triglycerides were at 15 and 20.7 mg/ml respectively and TnBP (tri-n-butyl phosphate) and Triton X-45 were at 8.7 and 8.8 p.p.m. respectively. Supplementing MEM (minimum essential medium) with 1–10% of this S/D-treated platelet lysate promoted the proliferation of MG63 and SIRC cell lines as well as, or better than, 10% (v/v) FBS (fetal bovine serum), as based on the MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] assay. The process used to prepare such S/D-treated platelet lysates is easily scalable for industrial production. Our results open up the possibility to evaluate the potential of this new preparation for stem cell expansion and/or bone tissue engineering and regeneration.
Biotechnology and Applied Biochemistry 12/2010; 56(4):151 - 160. · 1.53 Impact Factor
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ABSTRACT: This study investigated the effects of static magnetic fields on the differentiation of MG63 cells cultured on the surface of poly-L-lactide (PLLA) substrates. The cells were continuously exposed to a 4,000 Gauss-static magnetic field (SMF) for 5 days. The proliferation effects of the SMF were measured by MTT assay. Morphologic changes and extracellular matrix release were observed by scanning electron microscopy. The effects of the SMF on alkaline phosphatase activity levels were compared between exposed and unexposed cells. The SMF-exposed cells exhibited decreased MTT values after 1 and 3 days of culture. In addition, SMF exposure promoted the expression of extracellular matrix in MG63 cells on the PLLA substrate. After 1 day, the alkaline phosphatase-specific activity of SMF-exposed MG63 cells was significantly increased (P < 0.05) with a ratio of 1.5-fold. These results show that MG63 cells, seeded on a PLLA disc and treated with SMF, had a more differentiated phenotype.
Medical & Biological Engineering 08/2010; 48(8):793-8. · 1.76 Impact Factor
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ABSTRACT: There is emerging interest in the use of standardized virally inactivated human platelet lysate preparations rich in GFs (growth factors) for cell cultures, cell therapy and clinical applications. In the present paper, we report a simple process to prepare a virally inactivated platelet lysate preparation rich in TGF-beta1 (transforming growth factor-beta1), EGF (epidermal growth factor) and IGF (insulin-like growth factor) and depleted of PDGF (platelet-derived growth factor) and VEGF (vascular endothelial growth factor). Apheresis platelet concentrates were treated by the S/D (solvent/detergent) viral inactivation procedure, then subjected to an oil extraction followed by adsorption with activated charcoal and finally sterile-filtered. The resulting preparation contained a mean of 368.4, 2.4 and 54.7 ng/ml of TGF-beta1, EGF and IGF respectively. PDGF-AB and VEGF were essentially completely removed by the charcoal treatment. The mean albumin, IgG, IgM and IgA and fibrinogen contents were approx. 40.0, 8.5, 0.87, 1.66 and 2.65 mg/ml respectively, cholesterol and triglycerides were at 15 and 20.7 mg/ml respectively and TnBP (tri-n-butyl phosphate) and Triton X-45 were at 8.7 and 8.8 p.p.m. respectively. Supplementing MEM (minimum essential medium) with 1-10% of this S/D-treated platelet lysate promoted the proliferation of MG63 and SIRC cell lines as well as, or better than, 10% (v/v) FBS (fetal bovine serum), as based on the MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] assay. The process used to prepare such S/D-treated platelet lysates is easily scalable for industrial production. Our results open up the possibility to evaluate the potential of this new preparation for stem cell expansion and/or bone tissue engineering and regeneration.
Biotechnology and Applied Biochemistry 08/2010; 56(4):151-60. · 1.53 Impact Factor
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ABSTRACT: Human platelet concentrates (PCs) may be a source material to produce purified growth factors (GFs) for clinical use or cell therapy. However, no fractionation process of therapeutic-grade GF from PCs has ever been developed.
PCs were virally inactivated by solvent/detergent (S/D) treatment, subjected to oil extraction to remove part of the S/D agents, and fractionated on a SP-Sepharose (SP) chromatographic column equilibrated in a phosphate-buffered saline (PBS) buffer, pH 7.5. The breakthrough was recovered, and the column was washed with the PBS buffer and then eluted by a 0.7 mol/L NaCl-PBS buffer pH 7.5 (SP-eluate). The SP-breakthrough and SP-eluate were characterized for their content in GF, proteins, lipids, and S/D agents. The MTS value of three cell lines cultivated in a medium containing 10% fetal bovine serum supplemented with 1% to 3% of SP-eluate or recombinant human (rHu) platelet-derived growth factor (PDGF)-BB was compared.
The SP-eluate contained a mean of 47, 17, and 6 ng/mL PDGF-AB, -BB, and -AA, respectively, and 0.26 ng/mL vascular endothelial growth factor (VEGF). It was largely depleted of transforming growth factor-β1 (2.33 ng/mL), epidermal growth factor (0.09 ng/mL), insulin-like growth factor (3.40 ng/mL), albumin, immunoglobulin (Ig)G, IgM, IgA, and fibrinogen, which were mostly in the breakthrough. tri-n-butyl phosphate and Triton X-45 were less than 2 ppm. Cell growth-promoting activity of the SP-eluate was at least as good as that of rHu-PDGF-BB.
Human PC can be fractionated into a purified, virally inactivated PDGF and VEGF concentrate, opening perspectives for the development of a new range of blood products for clinical use and cell therapy procedures.
Transfusion 04/2010; 50(8):1702-11. · 3.22 Impact Factor
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Cheng-Jeng Tai,
Alexander Th Wu,
Jeng-Feng Chiou,
Hsun-Jin Jan,
Hon-Jian Wei,
Chung-Huei Hsu, Che-Tong Lin,
Wen-Ta Chiu,
Cheng-Wen Wu,
Horng-Mo Lee,
Win-Ping Deng
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ABSTRACT: Invasiveness and metastasis are the most common characteristics of non small cell lung cancer (NSCLC) and causes of tumour-related morbidity and mortality. Mitogen-activated protein kinases (MAPKs) signalling pathways have been shown to play critical roles in tumorigenesis. However, the precise pathological role(s) of mitogen-activated protein kinase phosphatase-1 (MKP-1) in different cancers has been controversial such that the up-regulation of MKP-1 in different cancers does not always correlate to a better prognosis. In this study, we showed that the induction of MKP-1 lead to a significant retardation of proliferation and metastasis in NSCLC cells. We also established that rosiglitazone (a PPARgamma agonist) elevated MKP-1 expression level in NSCLC cells and inhibited tumour metastasis.
Both wildtype and dominant negative forms of MKP-1 were constitutively expressed in NSCLC cell line H441GL. The migration and invasion abilities of these cells were examined in vitro. MKP-1 modulating agents such as rosiglitazone and triptolide were used to demonstrate MKP-1's role in tumorigenesis. Bioluminescent imaging was utilized to study tumorigenesis of MKP-1 over-expressing H441GL cells and anti-metastatic effect of rosiglitazone.
Over-expression of MKP-1 reduced NSCLC cell proliferation rate as well as cell invasive and migratory abilities, evident by the reduced expression levels of MMP-2 and CXCR4. Mice inoculated with MKP-1 over-expressing H441 cells did not develop NSCLC while their control wildtype H441 inoculated littermates developed NSCLC and bone metastasis. Pharmacologically, rosiglitazone, a peroxisome proliferator activated receptor-gamma (PPARgamma) agonist appeared to induce MKP-1 expression while reduce MMP-2 and CXCR4 expression. H441GL-inoculated mice receiving daily oral rosiglitazone treatment demonstrated a significant inhibition of bone metastasis when compared to mice receiving sham treatment. We found that rosiglitazone treatment impeded the ability of cell migration and invasion in vitro. Cells pre-treated with triptolide (a MKP-1 inhibitor), reversed rosiglitazone-mediated cell invasion and migration.
The induction of MKP-1 could significantly suppress the proliferative and metastatic abilities of NSCLC both in vitro and in vivo. Therefore, MKP-1 could be considered as a potential therapeutic target in NSCLC therapy and PPARgamma agonists could be explored for combined chemotherapy.
BMC Cancer 03/2010; 10:95. · 3.01 Impact Factor
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ABSTRACT: While the effects of static magnetic fields (SMFs) on osteoblastic differentiation are well demonstrated, the mechanotransduction pathways of SMFs are still unclear. The aim of this study was to explore the role of calmodulin in the biophysical effects of SMFs on osteoblastic cells. MG63 cells were exposed to a 0.4 T SMF. The expression of phosphodiesterase RNA in the cytoplasm was tested using real-time polymerase chain reaction. The differentiation of the cells was assessed by detecting changes in alkaline phosphatase activity. The role of calmodulin antagonist W-7 was used to evaluate alterations in osteoblastic proliferation and differentiation after the SMF simulations. Our results showed that SMF exposure increased alkaline phosphatase activity and phosphodiesterase 1C gene expression in MG63 cells. Addition of W-7 significantly inhibited the SMF-induced cellular response. We suggest that one possible mechanism by which SMFs affects osteoblastic maturation is through a calmodulin-dependent mechanotransduction pathway.
Bioelectromagnetics 12/2009; 31(4):255-61. · 1.84 Impact Factor
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ABSTRACT: Disseminated intravascular coagulation (DIC) is a complex systemic thrombohemorrhagic disorder involving intravascular coagulation and hemorrhage. The aim of this study is to test whether static magnetic field (SMF) is effective in attenuating lipopolysaccharide (LPS)-induced DIC.
In vivo experiments were performed in this study using male BALB/cByJ mice. An intraperitoneal injection of 50 mg/kg LPS was shown to lead to approximately 50% mortality and this dose was used in subsequent experiments. To test the effects of SMF on the survival rate of LPS-induced animals, the mice were exposed to 0.25-T SMF for 2 h before LPS injection. In addition, the effect of a 2-h SMF treatment on the production of anti-inflammatory cytokines was evaluated.
In the first set of experiments, we found that the survival rate was higher in the SMF-exposed group than in the sham-exposed group. The circulating platelet (PLT) counts in the SMF-exposed mice were significantly higher than in the unexposed animals. However, no significant changes in inflammatory cytokine, including tumour necrosis factor-alpha (TNF-alpha), interleukin-1alpha (IL-1alpha), interleukin-6 (IL-6) and monocyte chemotactic protein 1 (MCP-1), in plasma were found after SMF treatment. The results from the second experiment showed that the plasma levels of interleukin-1 receptor antagonist (IL-1ra) were higher in the SMF-exposed group than in the sham group.
Exposure to an SMF increases the plasma levels of IL-1ra. This effect may inhibit the reduction in PLT in plasma, resulting in prevention in LPS induced DIC.
International Journal of Radiation Biology 08/2009; 85(7):633-40. · 2.28 Impact Factor
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ABSTRACT: The aim of this study was to develop a cell-based bone-regeneration approach evaluated by molecular imaging and immunohistochemistry.
Genetically modified NIH3T3 embryonic fibroblasts carrying enhanced green fluorescent protein (NIH3T3-G) were predifferentiated into osteoblastlike cells using platelet-rich plasma (PRP) medium, followed by intraosseous transplantation into ovariectomized senescence-accelerated mouse prone substrain 8 (OVX-SAMP8 mice).
PRP-conditioned NIH3T3-G (PRP/NIH3T3-G) engraftment prevented the development of osteoporosis. Molecular imaging and immunohistochemistry demonstrated the migration of NIH3T3-G cells from the implantation site throughout the skeleton. In situ analyses revealed coexpression of osteopontin and green fluorescent protein in the newly formed bone tissue, demonstrating that the transplant restored the bone trabecular architecture and mineral density in treated OVX-SAMP8 mice. Interestingly, the life span of OVX-SAMP8 mice receiving PRP/NIH3T3-G transplantation was significantly prolonged and similar to that of the congenic senescence-resistant strain of mice.
This unique and yet simple approach could potentially be applied to the treatment of senile postmenopausal osteoporosis and perhaps inborn genetic syndromes associated with accelerated aging, such as Hutchinson-Gilford progeria syndrome, and for the prolongation of life expectancy in general.
Journal of Nuclear Medicine 05/2009; 50(5):765-73. · 6.38 Impact Factor
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ABSTRACT: Osteoarthritis is characterized by an imbalance in cartilage homeostasis, which could potentially be corrected by mesenchymal stem cell (MSC)-based therapies. However, in vivo implantation of undifferentiated MSCs has led to unexpected results. This study was undertaken to establish a model for preconditioning of MSCs toward chondrogenesis as a more effective clinical tool for cartilage regeneration.
A coculture preconditioning system was used to improve the chondrogenic potential of human MSCs and to study the detailed stages of chondrogenesis of MSCs, using a human MSC line, Kp-hMSC, in commitment cocultures with a human chondrocyte line, hPi (labeled with green fluorescent protein [GFP]). In addition, committed MSCs were seeded into a collagen scaffold and analyzed for their neocartilage-forming ability.
Coculture of hPi-GFP chondrocytes with Kp-hMSCs induced chondrogenesis, as indicated by the increased expression of chondrogenic genes and accumulation of chondrogenic matrix, but with no effect on osteogenic markers. The chondrogenic process of committed MSCs was initiated with highly activated chondrogenic adhesion molecules and stimulated cartilage developmental growth factors, including members of the transforming growth factor beta superfamily and their downstream regulators, the Smads, as well as endothelial growth factor, fibroblast growth factor, insulin-like growth factor, and vascular endothelial growth factor. Furthermore, committed Kp-hMSCs acquired neocartilage-forming potential within the collagen scaffold.
These findings help define the molecular markers of chondrogenesis and more accurately delineate the stages of chondrogenesis during chondrocytic differentiation of human MSCs. The results indicate that human MSCs committed to the chondroprogenitor stage of chondrocytic differentiation undergo detailed chondrogenic changes. This model of in vitro chondrogenesis of human MSCs represents an advance in cell-based transplantation for future clinical use.
Arthritis & Rheumatism 02/2009; 60(2):450-9. · 7.87 Impact Factor
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ABSTRACT: To improve the bioactivity of titanium surfaces, glow discharge was used to facilitate collagen grafting on titanium disks. Titanium test specimens were pre-treated by glow discharge fed with a mixture of argon and allylamine (AA) gases. Treated titanium disks were then grafted with type I collagen using glutaraldehyde (GA) as a crosslinking agent. The surfaces of collagen-grafted titanium disks were evaluated using scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and X-ray photoelectron spectroscopy (XPS). MG-63 osteoblast-like cells were cultured on the grafted titanium surfaces to examine the effect of collagen grafting in terms of cell morphology. Our results demonstrated that collagen component elements could be detected on the titanium surfaces. Morphology of the cells on the surfaces of collagen-grafted titanium disks indicated differentiation. These findings showed that type I collagen could be successfully grafted onto titanium surfaces using glow discharge technology, with enhanced biofunctionality demonstrated on osteoblastic cells.
Dental Materials Journal 06/2008; 27(3):340-6. · 1.14 Impact Factor
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ABSTRACT: This investigation studies how nano-(
,
, and
) phases affect the formation of multi-nano-titania film by anodization and cathodic pretreatment. Nano-titanium hydrides
and substoichiometric nano-titanium hydrides were formed during cathodization. A multi-nanoporous titania film was formed
on the titanium during anodization. The nanohydrides are directly transformed to multi-nanoporous titania film by dissolution
following anodization. Anodization with cathodic pretreatment not only yields a titanium surface with a multi-nanostructure,
but also transforms the titanium surface into a nanostructured titania surface. Formation of nanohydrides by cathodization
and oxidation by anodization are believed to promote biocompatibility and improve bone-to-interface contact, accelerating
initial osseointegration and re-osseointegration.
Journal of The Electrochemical Society. 05/2008; 155(6):E79-E84.
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ABSTRACT: Lipopolysaccharide (LPS) is one of the major substances initiating the immune host response in microbial infections that results in cytotoxicity. In terms of treatment of the immune response, research has been conducted on physical environments that can reduce LPS-induced damage. In this experiment, a long-term continuous static magnetic field (SMF) was used as a physical resource to reduce LPS-induced immune host response.
Cultured fibroblasts were challenged with LPS to initiate an inflammatory reaction. Cell viability and various proinflammatory cytokine levels were detected and compared between SMF and sham-exposed groups.
Our in vitro study revealed that, with LPS challenge, fibroblasts continuously exposed to a 0.4-T SMF for 12 h demonstrated higher cell viability compared to unexposed analogs. From cytokine test, the levels of LPS-induced interleukin-1beta (IL-1beta) in the SMF-exposed groups were significantly lower relative to their unexposed counterparts (p < 0.05). By contrast, SMF exposure tended to increase the level of LPS-induced IL-1 receptor antagonist (IL-1Ra) and IL-6.
Our results suggest that SMF stimulation inhibits LPS-induced cytotoxicity through reduction of proinflammatory cytokines and increase in anti-inflammatory cytokines of NIH-3T3 cells.
International Journal of Radiation Biology 04/2008; 84(3):219-26. · 2.28 Impact Factor
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ABSTRACT: The effects of residual intra-substrate stress distribution on cell behavior have not been systematically investigated. Thus, the objective of this research was to analyze the relationship between cell distribution and internal stress patterns. A photoelastic method was used for residual stresses identification. Poly-L-lactide (PLLA) discs were prepared using an injection molding technique. MG-63 and NIH-3T3 cells were cultured on the surface of the PLLA disc. The cell distributions for high and low-stress regions were measured and compared. There were significantly more cells in the low-stress regions relative to high-stress analogs (p < 0.05). Further, linear relationships were demonstrated for both MG-63 and NIH-3T3 models with high correlation coefficients of 0.80 and 0.95, respectively. These results suggest that the distribution of residual stress in substrates affect cell behavior. These findings may provide greater insight into the interaction between cells and substrates, and may serve as a useful reference in future clinical study.
Annals of biomedical engineering 04/2008; 36(3):513-21. · 2.41 Impact Factor
