The Effect of Post-Treatment on the Mechanical Behavior of Plasma Sprayed HA Coating

Plasma-sprayed hydroxyapatite coating on metal substrate has been prepared, two kinds of post-treatment methods have been used: (1) Heating in air at 650°C for 30 min, (2) Heating in water vapor at 125°C, 0.15Mpa for 6 hours. XRD showed that the nanocrystals of HA coating increased after water vapor treated. The interfacial tensiles strength between HA and the substrate were 45.0±1.82MPa, 39.1±1.27MPa and 30.3±1.61MPa for as-received coatings, water vapor treated coatings and heated in air coatings respectively. After 3 months implant in dogs limbs, the push-out strength between implants and bone were 11.27±2.71 MPa, 11.63±3.11MPa, 23.92± 2.01MPa and 18.8±1.82 MPa for pure Ti implants, as-received coating implants, water vapor treated implants and heated in air implants respectively. The results showed that the water vapor post treated HA coating have better mechanical behavior in vitro and in vivo.

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The Mechanical Behavior of Water Vapor-Treated HA Coating Produced by Plasma Spraying Technique

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.288-289.355 ◽

2005 ◽

Vol 288-289 ◽

pp. 355-358

Author(s):

Y. Cao ◽

Bo Zhang ◽

Li Ping Wang ◽

Qiang Lin ◽

Xu Dong Li ◽

...

Keyword(s):

Water Vapor ◽

Bond Strength ◽

Mechanical Behavior ◽

Metal Substrate ◽

Ha Coating ◽

Plasma Sprayed ◽

Push Out ◽

Vapor Treatment

Plasma-sprayed hydroxyapatite coating on metal substrate was prepared. Two kind of post-treatment methods were been applied to the coating, treatment in air at 650°C for 30 min and treatment in water vapor at 125°C with a pressure of 0.15MPa for 6 hours. XRD showed that the HA nanocrystals increased after water vapor treatment. The interfacial tensile bond strength between HA and substrate was 45.0±1.82MPa, 39.1±1.27MPa and 30.3±1.61MPa for as-received coatings, water vapor treated coatings and heated in air coatings, respectively. 3 months after implantation in dogs limbs, the push-out strength between implants and bone was 11.27±2.71MPa, 11.63±3.11MPa, 23.92± 2.01MPa and 18.8± 1.82MPa for pure Ti implants, as-received coating implants, water vapor treated implants and heated in air implants, respectively. The results showed that the post-water vapor treated HA coating have better mechanical behavior in vitro and in vivo

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The Effect of Cell Behavior on Plasma Sprayed HA Coatings with Different Post Treatment

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.309-311.705 ◽

2006 ◽

Vol 309-311 ◽

pp. 705-708 ◽

Cited By ~ 1

Author(s):

Y. Cao ◽

Qiang Lin ◽

Min Tang ◽

X.Q. Ying ◽

Su Juan Pang ◽

...

Keyword(s):

Water Vapor ◽

Cell Activity ◽

Post Treatment ◽

Biological Behavior ◽

Hydroxyl Groups ◽

Surface Hydroxyl ◽

Ha Coating ◽

Surface Hydroxyl Groups ◽

Plasma Sprayed

The initial interactions of plasma-sprayed HA coating surface with osteoblasts was investigated. Two kind of post-treatment methods were been used for HA coating: (1) Heated in air at 650oC for 30 min, (2) Heated in water vapor at 125oC, 0.15Mpa for 6 hours. The third passage rabbit osteoblasts were cultured on the HA coating plates for 24 h. The results showed: The lower dissolution rate and more surface hydroxyl groups (OH-1) group in the HA coating resulted in greater numbers of adhered osteoblasts and higher cell activity, The post-water vapor treated HA coating have better biological behavior in vitro.

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The Effect of Post-Treatment on the Mechanical Behavior of Plasma Sprayed HA Coating

Bioceramics 17 - Key Engineering Materials ◽

10.4028/0-87849-961-x.337 ◽

2005 ◽

pp. 337-340

Author(s):

Y. Cao ◽

Bo Zhang ◽

Li Ping Wang ◽

Qiang Lin ◽

Xu Dong Li ◽

...

Keyword(s):

Mechanical Behavior ◽

Post Treatment ◽

Ha Coating ◽

Plasma Sprayed

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Study on Plasma Sprayed Calcium Silicate Coatings

Materials Science Forum ◽

10.4028/www.scientific.net/msf.475-479.2371 ◽

2005 ◽

Vol 475-479 ◽

pp. 2371-2374 ◽

Cited By ~ 2

Author(s):

Xue Bin Zheng ◽

Xuan Yong Liu ◽

Wei Chang Xue ◽

Chuan Xian Ding

Keyword(s):

Simulated Body Fluid ◽

Bond Strength ◽

Body Fluid ◽

Strength Test ◽

Dicalcium Silicate ◽

Cell Culturing ◽

Ha Coating ◽

Plasma Sprayed

Wollastonite and dicalcium silicate coatings have been prepared on Ti-6Al-4V substrate via plasma spraying. Bond strength test, simulated body fluid (SBF) immersion, in vitro cell culturing, and in vivo implantation were carried out to evaluate their mechanical and biological characteristics. The results obtained showed that both coatings possess higher bond strength as compared with hydroxyapatite (HA) coating. In the meanwhile, the good bioactivity and biocompatibility were confirmed in this study.

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MRSA-Induced Endothelial Permeability and Acute Lung Injury are Attenuated by FTY720 S-Phosphonate

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00100.2021 ◽

2021 ◽

Author(s):

Lichun Wang ◽

Eleftheria Letsiou ◽

Huashan Wang ◽

Patrick Belvitch ◽

Lucille Meliton ◽

...

Keyword(s):

Acute Lung Injury ◽

Lung Injury ◽

Neutrophil Infiltration ◽

Post Treatment ◽

Fiber Formation ◽

Actin Stress Fiber ◽

Intratracheal Administration ◽

Barrier Disruption

Disruption of the lung endothelial barrier is a hallmark of acute respiratory distress syndrome (ARDS), for which no effective pharmacologic treatments exist. Prior work has demonstrated that FTY720 S-phosphonate (Tys), an analog of sphingosine-1-phosphate (S1P) and FTY720, exhibits potent endothelial cell (EC) barrier protective properties. In this study we investigated the in vitro and in vivo efficacy of Tys against methicillin-resistant Staphylococcus aureus (MRSA), a frequent bacterial cause of ARDS. Tys protected human lung EC from barrier disruption induced by heat-killed MRSA (HK-MRSA) or staphylococcal α-toxin and attenuated MRSA-induced cytoskeletal changes associated with barrier disruption, including actin stress fiber formation and loss of peripheral VE-cadherin and cortactin. Tys inhibited Rho and MLC activation after MRSA and blocked MRSA-induced NF-κB activation and release of the pro-inflammatory cytokines, IL-6 and IL-8. In vivo, intratracheal administration of live MRSA in mice caused significant vascular leakage and leukocyte infiltration into the alveolar space. Pre- or post-treatment with Tys attenuated MRSA-induced lung permeability and levels of alveolar neutrophils. Post-treatment with Tys significantly reduced levels of BAL VCAM-1 and plasma IL-6 and KC induced by MRSA. Dynamic intravital imaging of mouse lungs demonstrated Tys attenuation of HK-MRSA-induced interstitial edema and neutrophil infiltration into lung tissue. Tys did not directly inhibit MRSA growth or viability in vitro. In conclusion, Tys inhibits lung EC barrier disruption and pro-inflammatory signaling induced by MRSA in vitro and attenuates acute lung injury induced by MRSA in vivo. These results support the potential utility of Tys as a novel ARDS therapeutic strategy.

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Comparative Evaluation of the Bioactive Behavior of HA and ZrO2 Reinforced Coatings

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.493-494.447 ◽

2011 ◽

Vol 493-494 ◽

pp. 447-452

Author(s):

George Theodorou ◽

Ourania Menti Goudouri ◽

Lambrini Papadopoulou ◽

Nikolaos Kantiranis ◽

Subramaniam Yugeswaran ◽

...

Keyword(s):

Steel Substrate ◽

In Vitro Bioactivity ◽

Biological Fixation ◽

Metal Implants ◽

Ha Coating ◽

Biological Responses ◽

Before And After ◽

Sbf Solution ◽

Plasma Sprayed

The clinical use of plasma-sprayed hydroxyapatite (HA) coatings on metal implants has been widely investigated as the HA coating can achieve the firm and direct biological fixation with the surrounding bone tissue. It is shown in previous studies that the mechanical properties of HA coatings are improved by the addition of ZrO2 particles during the deposition of the coating on the substrate. Subsequently, the cohesive and adhesive strengths of plasma-sprayed hydroxyapatite (HA) coatings were strengthened by the ZrO2 particles addition as a reinforcing agent in the HA coating (HA+ZrO2 composite coating). The aim of the present work is to investigate and evaluate the in vitro bioactivity assessment of HA and HA/ZrO2 coatings, on stainless steel substrate, soaked in c-SBF, in order to study and compare their biological responses. The coatings were produced using vapor plasma spraying (VPS). The characterization of the surface of the coatings before and after soaking in SBF solution was performed using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and X-ray Diffraction analysis (XRD). All samples were smoothed before insertion in the medium and the in vitro bioactivity of all coating samples was tested in conventional Simulated Body Fluid (c-SBF) solution for various immersion times.

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In Silico Performance of a Recellularized Tissue-Engineered Transcatheter Aortic Valve

Journal of Biomechanical Engineering ◽

10.1115/1.4043209 ◽

2019 ◽

Vol 141 (6) ◽

Cited By ~ 3

Author(s):

Christopher Noble ◽

Joshua Choe ◽

Susheil Uthamaraj ◽

Milton Deherrera ◽

Amir Lerman ◽

...

Keyword(s):

Mechanical Behavior ◽

Heart Valves ◽

Mechanical Response ◽

Mechanical Performance ◽

Fe Analysis ◽

Model Parameters ◽

Biaxial Testing ◽

Principal Stresses

Commercially available heart valves have many limitations, such as a lack of remodeling, risk of calcification, and thromboembolic problems. Many state-of-the-art tissue-engineered heart valves (TEHV) rely on recellularization to allow remodeling and transition to mechanical behavior of native tissues. Current in vitro testing is insufficient in characterizing a soon-to-be living valve due to this change in mechanical response; thus, it is imperative to understand the performance of an in situ valve. However, due to the complex in vivo environment, this is difficult to accomplish. Finite element (FE) analysis has become a standard tool for modeling mechanical behavior of heart valves; yet, research to date has mostly focused on commercial valves. The purpose of this study has been to evaluate the mechanical behavior of a TEHV material before and after 6 months of implantation in a rat subdermis model. This model allows the recellularization and remodeling potential of the material to be assessed via a simple and inexpensive means prior to more complex ovine orthotropic studies. Biaxial testing was utilized to evaluate the mechanical properties, and subsequently, constitutive model parameters were fit to the data to allow mechanical performance to be evaluated via FE analysis of a full cardiac cycle. Maximum principal stresses and strains from the leaflets and commissures were then analyzed. The results of this study demonstrate that the explanted tissues had reduced mechanical strength compared to the implants but were similar to the native tissues. For the FE models, this trend was continued with similar mechanical behavior in explant and native tissue groups and less compliant behavior in implant tissues. Histology demonstrated recellularization and remodeling although remodeled collagen had no clear directionality. In conclusion, we observed successful recellularization and remodeling of the tissue giving confidence to our TEHV material; however, the mechanical response indicates the additional remodeling would likely occur in the aortic/pulmonary position.

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In Vivo Assessment of Bone Ingrowth Potential of Three-Dimensional E-Beam Produced Implant Surfaces and the Effect of Additional Treatment by Acid Etching and Hydroxyapatite Coating

Journal of Biomaterials Applications ◽

10.1177/0885328210391495 ◽

2011 ◽

Vol 26 (7) ◽

pp. 861-875 ◽

Cited By ~ 7

Author(s):

J. Elizabeth Biemond ◽

Gerjon Hannink ◽

Annemarijn M. G. Jurrius ◽

Nico Verdonschot ◽

Pieter Buma

Keyword(s):

Histological Analysis ◽

Distal Femur ◽

Bone Ingrowth ◽

Three Dimensional ◽

Additional Treatment ◽

Acid Etching ◽

Ha Coating ◽

Beam Surface ◽

Plasma Sprayed

The bone ingrowth potential of three-dimensional E-beam-produced implant surfaces was examined by histology and compared to a porous plasma-sprayed control. The effects of acid etching and a hydroxyapatite (HA) coating were also evaluated by histology. Specimens were implanted in the distal femur of 10 goats. Histological analysis of bone ingrowth was performed 6 weeks after implantation. The E-beam-produced surfaces showed significantly better bone ingrowth compared to the plasma-sprayed control. Additional treatment of the E-beam surface structures with a HA coating, further improved bone ingrowth potential of these structures significantly. Acid etching of the E-beam structures did not influence bone ingrowth significantly. In conclusion, the HA-coated, E-beam-produced structures are promising potential implant surfaces.

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