scholarly journals A biodegradable porous composite scaffold of PCL/BCP containing Ang-(1-7) for bone tissue engineering

Cerâmica ◽  
2012 ◽  
Vol 58 (348) ◽  
pp. 481-488 ◽  
Author(s):  
F. A. Macedo ◽  
E. H. M. Nunes ◽  
W. L. Vasconcelos ◽  
R. A. Santos ◽  
R. D. Sinisterra ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Composite Scaffold ◽  
Weight Ratio ◽  
High Porosity ◽  
X Rays ◽  
Solvent Casting

Highly porous three-dimensional biodegradable scaffolds was obtained from beta-tricalcium phosphate-hydroxyapatite bioceramic (BCP), PCL, and Angiotensin-(1-7). We used the solvent casting and particulate leaching methods (SC/PL). The processed scaffolds were characterized by X-ray microtomography (µ-CT). Biocompatibility tests in vitro were performed during three and seven days using MTT and Alkaline Phosphatase Activity (APA) assays. Both the MTT activity and APA were evaluated using a one-way ANOVA test. The µ-CT results showed that the increase of the PCL:BCP weight ratio leads to structures with lower pore sizes. The pore interconnectivity of the processed scaffolds was evaluated in terms of the fragmentation index (FI). We observed that the obtained composites present poorly connected structures, with close values of FI. However, as the polymer phase is almost transparent to the X-rays, it was not taken into consideration in the µ-CT tests. The MTT activity assay revealed that scaffolds obtained with and without Angiotensin-(1-7) present mild and moderate cytotoxic effects, respectively. The APA assay showed that the rat osteoblasts, when in contact for three days with the PCL composites, presented an APA similar to that observed for the control cells. Nevertheless, for an incubation time of seven days we observed a remarkable decrease in the alkaline phosphatase activity. In conclusion, using the solvent casting and salt leaching method we obtained 3D porous that are composites of PCL, BC and Ang-(1-7), which have suitable shapes for the bone defects, a high porosity and interconnect pores. Furthermore, the viability in vitro showed that the scaffolds have potential for drug delivery system and could be used in future in vivo tests.

scholarly journals Simultaneous autoradiographic and histochemical analysis of bone formed in vitro.

1986 ◽  
Vol 34 (6) ◽  
pp. 769-773 ◽  
Author(s):  
H C Tenenbaum ◽  
C A McCulloch ◽  
K Palangio
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Time Course ◽  
Bone Cell ◽  
Histochemical Demonstration ◽  
Thymidine Uptake ◽  
Kinetics In Vivo

The simultaneous histochemical demonstration of alkaline phosphatase activity and autoradiographic demonstration of [3H]-thymidine uptake is valuable for study of bone cell kinetics in vivo or in vitro. By use of this technique, it has been possible to detect changes induced by a single dose of dexamethasone (10(-7) M) in the time course of alkaline phosphatase activity, the number of alkaline phosphatase-positive cells, and [3H]-thymidine labeling in bone formed in vitro.

scholarly journals In vitro modulation of alkaline phosphatase activity in neutrophils from patients with chronic myelogenous leukemia by monocyte-derived activity

Blood ◽  
1986 ◽  
Vol 67 (2) ◽  
pp. 492-497 ◽  
Author(s):  
T Matsuo
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Chronic Myelogenous Leukemia ◽  
Alkaline Phosphatase Activity ◽  
Culture Medium ◽  
Underlying Mechanism ◽  
Myelogenous Leukemia ◽  
Neutrophil Alkaline Phosphatase

Abstract To clarify the underlying mechanism of low neutrophil alkaline phosphatase (NAP) activity in chronic myelogenous leukemia (CML), CML neutrophils were cultured in liquid medium with different numbers of monocytes. Alkaline phosphatase activity in CML neutrophils, assessed cytochemically, increased with the numbers of monocytes. NAP activity was not induced by the interaction between neutrophils and monocytes, but by the presence of a monocyte-derived soluble activity. NAP activity in normal neutrophils was also lowered by depletion of monocytes from culture medium. Under such monocyte-depleted conditions, both CML and normal neutrophils proliferated and differentiated to produce mature neutrophils. Thus induction of NAP activity can be modified in vitro by changing the amount of NAP-inducing activity released from monocytes. However, whether a reduction of NAP-inducing activity in CML neutrophil is the cause of low NAP activity in vivo remains uncertain.

Experimental Thrombosis in Rabbits: Evidence that Alkaline Phosphatase Enhances the Thrombogenic Effect of the Injected Ellagic Acid

1966 ◽  
Vol 16 (03/04) ◽  
pp. 645-656 ◽  
Author(s):  
P. G Iatridis ◽  
J. H Ferguson
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Ellagic Acid ◽  
Plasma Samples ◽  
Electrophoretic Study ◽  
Negative Results ◽  
Thrombotic Tendency

SummaryIntravenous injection of ellagic acid plus alkaline phosphatase in rabbits, induces a thrombotic tendency, which correlates with a hypercoagulability of the blood revealed by thrombelastography. Either ellagic acid (which suboptimally activates Hageman factor) or alkaline phosphatase, separately, gave negative results concerning the incidence of thrombosis. This clearly indicates that alkaline phosphatase in vivo, as was previously shown in vitro, acts only in the presence of an active SF. The electrophoretic study of the distribution of alkaline phosphatase, in platelet-poor plasma samples secured from rabbits, with and without injection of an alkaline phosphatase preparation, suggests the probability that it is the alkaline phosphatase activity which is located in the “beta” fraction that contributes the responsible co-factor for the thrombogenesis.

Osteogenic protein-1 enhances phenotypic expression in ROS 17/2.8 cells

1995 ◽  
Vol 269 (5) ◽  
pp. E918-E926 ◽  
Author(s):  
A. M. Kitten ◽  
J. C. Lee ◽  
M. S. Olson
Keyword(s):  
Alkaline Phosphatase ◽  
Parathyroid Hormone ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Thymidine Incorporation ◽  
Phenotypic Expression ◽  
Proliferating Cells ◽  
Osteogenic Protein

Osteogenic protein-1 (OP-1) stimulates bone morphogenesis in vivo and modulates osteoblast growth and differentiation in vitro. Treatment of ROS 17/2.8 cells with OP-1 resulted in a time- and concentration-dependent inhibition of [3H]thymidine incorporation. In contrast, OP-1 treatment stimulated phenotypic differentiation in ROS 17/2.8 cells, as indicated by enhanced 1) alkaline phosphatase activity (4-fold); 2) alkaline phosphatase mRNA (5-fold); 3) parathyroid hormone receptor mRNA (2-fold), and 4) parathyroid hormone-stimulated adenosine 3',5'-cyclic monophosphate accumulation (2-fold). OP-1-induced changes in cell growth and gene expression were sensitive to cycloheximide and actinomycin D. Measurement of [3H]thymidine incorporation and alkaline phosphatase activity in situ revealed heterogeneity in the cellular responses to OP-1. Proliferating cells exhibited less alkaline phosphatase activity than nonproliferating cells, whereas cells expressing high levels of alkaline phosphatase incorporated little [3H]thymidine. Our data delineating the responses of mature differentiated osteoblasts to OP-1 suggest that potentiation of osteoblast differentiated function is an important component of bone morphogenesis in vivo.

scholarly journals In vitro modulation of alkaline phosphatase activity in neutrophils from patients with chronic myelogenous leukemia by monocyte-derived activity

Blood ◽  
1986 ◽  
Vol 67 (2) ◽  
pp. 492-497
Author(s):  
T Matsuo
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Chronic Myelogenous Leukemia ◽  
Alkaline Phosphatase Activity ◽  
Culture Medium ◽  
Underlying Mechanism ◽  
Myelogenous Leukemia ◽  
Neutrophil Alkaline Phosphatase

To clarify the underlying mechanism of low neutrophil alkaline phosphatase (NAP) activity in chronic myelogenous leukemia (CML), CML neutrophils were cultured in liquid medium with different numbers of monocytes. Alkaline phosphatase activity in CML neutrophils, assessed cytochemically, increased with the numbers of monocytes. NAP activity was not induced by the interaction between neutrophils and monocytes, but by the presence of a monocyte-derived soluble activity. NAP activity in normal neutrophils was also lowered by depletion of monocytes from culture medium. Under such monocyte-depleted conditions, both CML and normal neutrophils proliferated and differentiated to produce mature neutrophils. Thus induction of NAP activity can be modified in vitro by changing the amount of NAP-inducing activity released from monocytes. However, whether a reduction of NAP-inducing activity in CML neutrophil is the cause of low NAP activity in vivo remains uncertain.

The inhibitory effects of vancomycin on rat bone marrow–derived mesenchymal stem cell differentiation

2021 ◽  
pp. 1-5
Author(s):  
Kari Hanson ◽  
Carly Isder ◽  
Kristen Shogren ◽  
Anthony L. Mikula ◽  
Lichun Lu ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Alkaline Phosphatase ◽  
Osteogenic Differentiation ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
High Dose ◽  
Inhibitory Effects ◽  
Alizarin Red ◽  
Osteogenic Factors

OBJECTIVE The use of intrawound vancomycin powder in spine surgery has been shown to decrease the rate of surgical site infections; however, the optimal dose is unknown. High-dose vancomycin inhibits osteoblast proliferation in vitro and may decrease the rate of solid arthrodesis. Bone marrow–derived mesenchymal stem cells (BMSCs) are multipotent cells that are a source of osteogenesis in spine fusions. The purpose of this study was to determine the effects of vancomycin on rat BMSC viability and differentiation in vitro. METHODS BMSCs were isolated from the femurs of immature female rats, cultured, and then split into two equal groups; half were treated to stimulate osteoblastic differentiation and half were not. Osteogenesis was stimulated by the addition of 50 µg/mL l-ascorbic acid, 10 mM β-glycerol phosphate, and 0.1 µM dexamethasone. Vancomycin was added to cell culture medium at concentrations of 0, 0.04, 0.4, or 4 mg/mL. Early differentiation was determined by alkaline phosphatase activity (4 days posttreatment) and late differentiation by alizarin red staining for mineralization (9 days posttreatment). Cell viability was determined at both the early and late time points by measurement of formazan colorimetric product. RESULTS Viability within the first 4 days decreased with high-dose vancomycin treatment, with cells receiving 4 mg/mL vancomycin having 40%–60% viability compared to the control. A gradual decrease in alizarin red staining and nodule formation was observed with increasing vancomycin doses. In the presence of the osteogenic factors, vancomycin did not have deleterious effects on alkaline phosphatase activity, whereas a trend toward reduced activity was seen in the absence of osteogenic factors when compared to osteogenically treated cells. CONCLUSIONS Vancomycin reduced BMSC viability and impaired late osteogenic differentiation with high-dose treatment. Therefore, the inhibitory effects of high-dose vancomycin on spinal fusion may result from both reduced BMSC viability and some impairment of osteogenic differentiation.

The influence of titanium surfaces treated by alkalis on macrophage and osteoblast-like cell adhesion and gene expression in vitro

RSC Advances ◽  
2015 ◽  
Vol 5 (99) ◽  
pp. 81378-81387 ◽  
Author(s):  
Ting Ma ◽  
Xi-Yuan Ge ◽  
Sheng-Nan Jia ◽  
Xi Jiang ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Alkaline Phosphatase ◽  
Cell Adhesion ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Related Gene ◽  
Titanium Surfaces

The effect of alkali-treated titanium surfaces on inflammation-related gene expression of macrophages and alkaline phosphatase activity of osteoblast-like cells.

Sign in / Sign up

Export Citation Format

Share Document