A COMPARATIVE STUDY ON VACUUM AND ATMOSPHERIC PLASMA SPRAYED TANTALUM COATINGS FOR THE MODIFICATION OF TITANIUM IMPLANTS

2019 ◽  
Vol 26 (08) ◽  
pp. 1950048
Author(s):  
DING DING ◽  
YOUTAO XIE ◽  
KAI LI ◽  
LIPING HUANG ◽  
XUEBIN ZHENG
Keyword(s):  
Bone Marrow ◽  
Elastic Modulus ◽  
Plasma Spraying ◽  
Chemical Stability ◽  
Titanium Implants ◽  
Vacuum Plasma Spraying ◽  
Significant Difference ◽  
Tantalum Coatings ◽  
Modification Of Titanium ◽  
Mechanical Compatibility

In order to improve the mechanical compatibility and cytocompatibility of titanium implants, tantalum coatings were prepared using plasma spraying technology. Tantalum coatings have been deposited via atmospheric plasama spraying (APS) and vacuum plasma spraying (VPS) methods, and then their morphologies, porosities, bonding strengths and elastic modulous were investigated. In vitro cytocompatibility of the two coatings was evaluated via human bone marrow stromal cells (hBMSCs). The results show that oxidation phenomenon was observed for the APS tantalum coatings, while less oxidation was found in the VPS tantalum coatings. Compared with APS tantalum coatings, the VPS tantalum coatings have a more compact microstructure and less impurity content, resulting in a better bonding with the titanium substrate. VPS tantalum coatings were measured to have a lower elastic modulus and a higher hardness than APS Tantalum coatings. Electrochemical corrosion of the coatings were examined and the VPS tantalum coating showed improved chemical stability. Besides, bone marrow stem cells (BMSCs) adhere to and spread well on the surface of both VPS and APS tantalum coatings without significant difference. The proliferation rate of BMSCs is higher on VPS tantalum coating surface than on APS tantalum coatings. Our results suggest that VPS tantalum coatings are more suitable for the application of surface modification of titanium implant due to their lower elastic modulus and better chemical stability for higher mechanical compatibility and cytocompatibility.

Electrical Property Characterization of Plasma Sprayed Polycrystalline Silicon

2009 ◽  
Vol 620-622 ◽  
pp. 303-306 ◽  
Author(s):  
Ya Ran Niu ◽  
Xuan Yong Liu ◽  
Yi Zeng ◽  
Xue Bin Zheng ◽  
Heng Ji ◽  
...  
Keyword(s):  
Electrical Property ◽  
Plasma Spraying ◽  
Air Plasma ◽  
Free Standing ◽  
Vacuum Plasma Spraying ◽  
Significant Difference ◽  
Plasma Sprayed ◽  
Silicon Based ◽  
Property Characterization

Silicon-based materials have been widely applied in industrial fields, such as microelectronic and solar power, for the specific electronic properties. In the present work, free-standing thick silicon coatings were fabricated by air plasma spraying (APS) and vacuum plasma spraying (VPS) technologies. The microstructure and electrical property of the coatings were characterized. It was found that the electrical resistance of APS-Si coating was higher than that of VPS-Si coating. The impedance spectroscopy results showed there was significant difference in impedance curves of APS-Si and VPS-Si coatings. The grain boundary semicircle appeared in the plot of VPS-Si coating, while did not appeared in that of APS-Si coating. It was thought that the electrical property difference of the two kind coatings was related with the oxidation and microstructure difference of the coatings.

Calcium-Suppressed Technique in Dual-Layer Detector Computed Tomography to Evaluate Knee Articular Cartilage

2020 ◽  
Vol 16 ◽  
Author(s):  
Qinglin Meng ◽  
Mengqi Liu ◽  
Weiwei Deng ◽  
Ke Chen ◽  
Botao Wang ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Bone Marrow ◽  
Articular Cartilage ◽  
Bone Marrow Edema ◽  
Knee Joints ◽  
Infrapatellar Fat Pad ◽  
Proton Density ◽  
Knee Cartilage ◽  
Significant Difference ◽  
Marrow Edema

Background: Calcium-suppressed (CaSupp) technique involving spectral-based images has been used to observe bone marrow edema by removing calcium components from the image. Objective: This study aimed to evaluate the knee articular cartilage using the CaSupp technique in dual-layer detector computed tomography (DLCT). Methods: Twenty-eight healthy participants and two patients with osteoarthritis were enrolled, who underwent DLCT and magnetic resonance imaging (MRI) examination. CaSupp images were reconstructed from spectral-based images using a calcium suppression algorithm and were overlaid conventional CT images for visual evaluation. The morphology of the knee cartilage was evaluated, and the thickness of the articular cartilage was measured on sagittal proton density– weighted and CaSupp images in the patellofemoral compartment. Results: No abnormal signal or density, cartilage defect, and subjacent bone ulceration were observed in the lateral and medial femorotibial compartments and the patellofemoral compartment on MRI images and CaSupp images for the 48 normal knee joints. CaSupp images could clearly identify cartilage thinning, defect, subjacent bone marrow edema, and edema of the infrapatellar fat pad in the same way as MRI images in the three knee joints with osteoarthritis. A significant difference was found in the mean thickness of the patellar cartilage between MRI images and CaSupp images, while the femoral cartilage presented no significant difference in thickness between MRI images and CaSupp images over all 48 knee joints. Conclusion: The present study demonstrated that CaSupp images could effectively be used to perform the visual and quantitative assessment of knee cartilage.

In vivo study of the angiogenesis potential of bone marrow-derived mesenchymal stem cell aggregates in their niche like environment

2021 ◽  
pp. 039139882110255
Author(s):  
Sara Anajafi ◽  
Azam Ranjbar ◽  
Monireh Torabi-Rahvar ◽  
Naser Ahmadbeigi
Keyword(s):  
Tissue Engineering ◽  
Bone Marrow ◽  
Stem Cell ◽  
Mesenchymal Stem Cell ◽  
Cultured Cells ◽  
Morphological Evidence ◽  
Cell Aggregates ◽  
Plla Scaffold ◽  
Significant Difference

Background: Sufficient blood vessel formation in bioengineered tissues is essential in order to keep the viability of the organs. Impaired development of blood vasculatures results in failure of the implanted tissue. The cellular source which is seeded in the scaffold is one of the crucial factors involved in tissue engineering methods. Materials and methods: Considering the notable competence of Bone Marrow derived Mesenchymal Stem Cell aggregates for tissue engineering purposes, in this study BM-aggregates and expanded BM-MSCs were applied without any inductive agent or co-cultured cells, in order to investigate their own angiogenesis potency in vivo. BM-aggregates and BM-MSC were seeded in Poly-L Lactic acid (PLLA) scaffold and implanted in the peritoneal cavity of mice. Result: Immunohistochemistry results indicated that there was a significant difference ( p < 0.050) in CD31+ cells between PLLA scaffolds contained cultured BM-MSC; PLLA scaffolds contained BM-aggregates and empty PLLA. According to morphological evidence, obvious connections with recipient vasculature and acceptable integration with surroundings were established in MSC and aggregate-seeded scaffolds. Conclusion: Our findings revealed cultured BM-MSC and BM-aggregates, capacity in order to develop numerous connections between PLLA scaffold and recipient’s vasculature which is crucial to the survival of tissues, and considerable tendency to develop constructs containing CD31+ endothelial cells which can contribute in vessel’s tube formation.

Evaluation of genotoxicity of pan masala employing chromosomal aberration and micronucleus assay in bone marrow cells of the mice

2009 ◽  
Vol 25 (7) ◽  
pp. 467-471 ◽  
Author(s):  
BN Mojidra ◽  
K. Archana ◽  
AK Gautam ◽  
Y. Verma ◽  
BC Lakkad ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Chromosome Aberration ◽  
Chromosomal Aberration ◽  
Bone Marrow Cells ◽  
Micronucleus Assay ◽  
Control Group ◽  
Genotoxic Potential ◽  
Polychromatic Erythrocytes ◽  
Significant Difference ◽  
Marrow Cells

Pan masala is commonly consumed in south-east Asian and other oriental countries as an alternate of tobacco chewing and smoking. Genotoxic potential of pan masala (pan masala plain and pan masala with tobacco known as gutkha) was evaluated employing chromosome aberration (CA) and micronucleus (MN) assay in vivo. Animals were exposed to three different doses (0.5%, 1.5% and 3%) of pan masala plain (PMP) and gutkha (PMT) through feed for a period of 6 months and micronucleus and chromosomal aberrations were studied in the bone marrow cells. Induction of mean micronuclei in polychromatic erythrocytes (MNPCE) and normochromatic erythrocyte (MNNCE) was higher in both types of pan masala treated groups with respect to control group. Both pan masala plain and gutkha treatment significantly induced the frequency of MNPCE and MNNCE in the bone marrow cells, indicating the genotoxic potential. Furthermore, slight decline in the ratio of polychromatic erythrocytes to normochromatic erythrocytes was also noticed, suggesting the cytotoxic potential even though the ratio was statistically non significant. A dose-dependent, significant increase in chromosome aberration was observed in both types of pan masala treated mice with respect to control. However, no significant difference in micronucleus and chromosomal aberration induction was noticed between two types of pan masala exposed (PMP and PMT) groups. Results suggest that both types of pan masala, i.e. plain and gutkha, have genotoxic potential.

scholarly journals Clinical observations of bone marrow transfusion for promoting bone marrow reconstruction after chemotherapy for AIDS-related lymphoma

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Yixuan Liu ◽  
Suhong Xie ◽  
Lei Li ◽  
Yanhui Si ◽  
Weiwei Zhang ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Immune System ◽  
T Lymphocytes ◽  
Peripheral Blood ◽  
Autologous Bone Marrow ◽  
Control Group ◽  
Peripheral Vein ◽  
Significant Difference ◽  
Autologous Bone ◽  
Aids Related Lymphoma

Abstract Background This study investigates the effect of autologous bone marrow transfusion (BMT) on the reconstruction of both bone marrow and the immune system in patients with AIDS-related lymphoma (ARL). Methods A total of 32 patients with ARL participated in this study. Among them, 16 participants were treated with conventional surgery and chemotherapy (control group) and the remaining 16 patients were treated with chemotherapy followed by autologous bone marrow transfusion via a mesenteric vein (8 patients, ABM-MVI group) or a peripheral vein (8 patients, ABM-PI group). Subsequently, peripheral blood and lymphocyte data subsets were detected and documented in all patients. Results Before chemotherapy, no significant difference in indicators was observed between three groups of ARL patients. Unexpectedly, 2 weeks after the end of 6 courses of chemotherapy, the ABM-MVI group, and the ABM-PI group yielded an increased level of CD8+T lymphocytes, white blood cells (WBC), and platelet (PLT) in peripheral blood in comparison to the control group. Notably, the number of CD4+T lymphocytes in the ABM-PI group was significantly higher than that in the other two groups. Additionally, no significant difference in haemoglobin levels was observed before and after chemotherapy in both the ABM-MVI and ABM-PI groups, while haemoglobin levels in the control group decreased significantly following chemotherapy. Conclusions Autologous bone marrow transfusion after chemotherapy can promote the reconstruction of both bone marrow and the immune system. There was no significant difference in bone marrow recovery and reconstruction between the mesenteric vein transfusion group and the peripheral vein transfusion group.

scholarly journals Effect of Oral Losartan on Orthobiologics: Implications for Platelet-Rich Plasma and Bone Marrow Concentrate—A Rabbit Study

2020 ◽  
Vol 21 (19) ◽  
pp. 7374
Author(s):  
Gilberto Y. Nakama ◽  
Sabrina Gonzalez ◽  
Polina Matre ◽  
Xiaodong Mu ◽  
Kaitlyn E. Whitney ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Osteochondral Defect ◽  
Platelet Rich Plasma ◽  
Control Group ◽  
Bone Marrow Concentrate ◽  
Significant Difference ◽  
Losartan Group ◽  
Group 2 ◽  
And Control ◽  
Tgf Β1

Recent efforts have focused on customizing orthobiologics, such as platelet-rich plasma (PRP) and bone marrow concentrate (BMC), to improve tissue repair. We hypothesized that oral losartan (a TGF-β1 blocker with anti-fibrotic properties) could decrease TGF-β1 levels in leukocyte-poor PRP (LP-PRP) and fibrocytes in BMC. Ten rabbits were randomized into two groups (N = 5/group): osteochondral defect + microfracture (control, group 1) and osteochondral defect + microfracture + losartan (losartan, group 2). For group 2, a dose of 10mg/kg/day of losartan was administrated orally for 12 weeks post-operatively. After 12 weeks, whole blood (WB) and bone marrow aspirate (BMA) samples were collected to process LP-PRP and BMC. TGF-β1 concentrations were measured in WB and LP-PRP with multiplex immunoassay. BMC cell populations were analyzed by flow cytometry with CD31, CD44, CD45, CD34, CD146 and CD90 antibodies. There was no significant difference in TGF-β1 levels between the losartan and control group in WB or LP-PRP. In BMC, the percentage of CD31+ cells (endothelial cells) in the losartan group was significantly higher than the control group (p = 0.008), while the percentage of CD45+ cells (hematopoietic cells-fibrocytes) in the losartan group was significantly lower than the control group (p = 0.03).

scholarly journals Influence of the Thermal Treatment to Address a Better Osseointegration of Ti6Al4V Dental Implants: Histological and Histomorphometrical Study in a Rabbit Model

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Antonio Scarano ◽  
Ezio Crocetta ◽  
Alessandro Quaranta ◽  
Felice Lorusso
Keyword(s):  
Thermal Treatment ◽  
Dental Implants ◽  
Bone Healing ◽  
Rabbit Model ◽  
Titanium Implants ◽  
Control Group ◽  
Left Femur ◽  
Bone Response ◽  
First Choice ◽  
Significant Difference

Background. Pure titanium continues to be the first choice for dental implants and represents the gold standard for their biocompatibility and physical and mechanical characteristics, while the titanium alloy (Ti6Al4V) has good mechanical properties. The surface structure of the titanium oxide layer formation on the surface influences and improves the bone response around dental implants. Purpose. The purpose of this study is to evaluate the influence of a thermal treatment of Ti6Al4V implant surfaces and the bone healing response in a rabbit model. Methods. Altogether sixteen implants with same design were inserted into the distal femoral metaphysis. A screw (13 mm long, 4 mm in diameter) was inserted in an implant bed. Each rabbit received two implants, one in the left femur and one in the right femur. The samples were histologically and histomorphometrically evaluated at 8 weeks. Results. A statistically significant difference (p = 0.000034) was present histologically in the percentages of bone-implant contact (BIC) between the test group (BIC = 69.25±4.49%.) and control group (BIC = 56.25 ± 4.8%) by one-way analysis of variance (ANOVA). Significance was set at p ≤ 0.05. Conclusions. The outcome of the present study indicates a novel approach to improving bone healing around titanium implants.

scholarly journals FDG-PET vs. chemical shift MR imaging in differentiating intertrabecular metastasis from hematopoietic bone marrow hyperplasia

2021 ◽  
Author(s):  
Nozomi Oki ◽  
Yohei Ikebe ◽  
Hirofumi Koike ◽  
Reiko Ideguchi ◽  
Daisuke Niino ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Chemical Shift ◽  
Fdg Pet ◽  
Standardized Uptake Value ◽  
Roc Curve Analysis ◽  
Cutoff Value ◽  
Significant Difference ◽  
Histopathological Studies ◽  
Fdg Pet Ct ◽  
Hematopoietic Bone Marrow

Abstract Purpose To evaluate the utility of SUVmax on FDG-PET and chemical shift imaging (CSI) on MRI in the differentiation of intertrabecular metastasis (ITM) from hematopoietic bone marrow hyperplasia (HBMH). Patients and methods We retrospectively evaluated 54 indeterminate focal bone marrow lesions in 44 patients detected on FDG-PET. The lesions were assigned to the metastasis group (M group, 29 lesions of 24 patients) and the non-metastasis group (non-M group, 25 lesions of 20 patients) based on the follow-up or the histopathological studies. The lesions were assessed with the maximum standardized uptake value (SUVmax) on FDG-PET CT images and signal change ratio (SCR) on CSI. Results The median SUVmax were 5.62 and 2.91; the median SCR were − 0.08 and − 34.8 in M and non-M groups respectively, with significant difference (p < 0.001). With ROC curve analysis, the optimal cutoff value of SUVmax was 4.48 with a sensitivity of 72.4%, a specificity of 100%, and AUC of 0.905. The cutoff value of SCR was − 6.15 with a sensitivity of 82.8%, a specificity of 80%, and AUC of 0.818. Conclusion FDG-PET and CSI on MRI are useful in distinguishing ITM from HBMH. Though their sensitivities are similar, the specificity of FDG-PET was higher than that of MRI.

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