scholarly journals In VitroandIn VivoEvaluation of Sol-Gel Derived TiO2Coatings Based on a Variety of Precursors and Synthesis Conditions

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Krzysztof Marycz ◽  
Justyna Krzak ◽  
Wiktor Urbański ◽  
Celina Pezowicz
Keyword(s):  
Stainless Steel ◽  
Sol Gel ◽  
Biological Response ◽  
Dip Coating ◽  
Elemental Distribution ◽  
Stainless Steel 316L ◽  
Synthesis Conditions ◽  
Cells Cultured

The effect of synthesis way of TiO2coatings on biocompatibility of transplanted materials using anin vitroandin vivorat model was investigated. TiO2layers were synthesized by a nonaqueous sol-gel dip-coating method on stainless steel 316L substrates applying two different precursors and their combination. Morphology and topography of newly formed biomaterials were determined as well as chemical composition and elemental distribution of a surface samples.In vitrotests were conducted by adipose-derived mesenchymal stem cells cultured on TiO2coatings and stainless steel without coatings to assess the bioreactivity of obtained materials. A positive biological effect of TiO2/316L/1 coatings—based on titanium(IV) ethoxide—was found in bothin vitroandin vivomodels. The TiO2/316L/1 exhibited the highest roughness and the lowest titanium concentration in TiO2than TiO2/316L/2—based on titanium(IV) propoxide and TiO2/316L/3—based on both above-mentioned precursors. The proper fibroblast-like morphology and higher proliferation rate of cells cultured on TiO2/316L/1 were observed when compared to the other biomaterials. No inflammatory response in the bone surrounding implant covered by each of the obtained TiO2was present. Our results showed that improvement of routinely used stainless steel 316L with TiO2/316L/1 layer can stimulate beneficial biological response.

Mechanical Properties and Microarchitecture of Nanoporous Hydroxyapatite Bioceramic Nanoparticle Coatings on Ti and TiN

2006 ◽  
Vol 975 ◽  
Author(s):  
Andrei Stanishevsky ◽  
Shafiul Chowdhury ◽  
Nathaniel Greenstein ◽  
Helene Yockell-Lelievre ◽  
Jari Koskinen
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Biological Response ◽  
Dip Coating ◽  
Nano Crystalline ◽  
Ceramic Manufacturing ◽  
Nanoparticle Coatings

ABSTRACTThe hydroxyapatite (HA) based bioceramic materials are usually prepared at high sintering temperatures to attain suitable mechanical properties. The sintering process usually results in a material which is compositionally and morphologically different from nonstoichiometric nano-crystalline HA phase of hard tissue. At the same time, HA particulates used as precursors in ceramic manufacturing are often very similar to the natural HA nanocrystals. It has been shown that synthetic nanoparticle HA (nanoHA) based materials improve the biological response in vitro and in vivo, but the information on mechanical properties of these materials is scarce.In this work we studied the HA nanoparticle (10 – 80 nm mean size) coatings with 30 – 70% porosity prepared by a dip-coating technique on Ti and TiN substrates. It has been found that the mechanical properties of HA nanoparticle coatings are strongly influenced by the initial size, morphology, and surface treatment of nanoparticles. The nanoindentation Young's modulus and hardness of as–deposited nanoHA coatings were in the range of 2.5 – 6.9 GPa and 80 – 230 MPa, respectively. The coatings were stable after annealing up to at least 600 °C, reaching the Young's modulus up to 23 GPa and hardness up to 540 MPa, as well as in simulated body fluids.

A study of the electrophoretic deposition of polycaprolactone-chitosan-bioglass nanocomposite coating on stainless steel (316L) substrates

2021 ◽  
pp. 088391152110635
Author(s):  
Zahra Sadeghinia ◽  
Rahmatollah Emadi ◽  
Fatemeh Shamoradi
Keyword(s):  
Stainless Steel ◽  
Surface Treatment ◽  
Electrophoretic Deposition ◽  
Deposition Time ◽  
Sol Gel ◽  
Nanocomposite Coating ◽  
Deposition Method ◽  
Stainless Steel 316L ◽  
Gel Method

In this research, bioglass nanoparticles were synthesized via sol-gel method and a polycaprolactone-chitosan-bioglass nanocomposite coating was formed on SS316L substrate using electrophoretic deposition method. Then, the effects of voltage and deposition time on morphology, thickness, roughness, and wettability of final coating were investigated. Finally, biocompatibility and toxicity of the coating were evaluated. The results showed that increase of both time and voltage enhanced the thickness, roughness, and wettability of coating. Also, increase of deposition time increased the agglomeration. Therefore, it can be concluded that voltage of 20 V and time of 10 min are suitable for the formation of a uniform agglomerate-free coating. The presence of bioglass nanoparticles also led to the increase of roughness and improvement of polycaprolactone hydrophobicity. The results also showed higher bioactivity in polycaprolactone-chitosan-1% bioglass nanocomposite coating sample. This sample had a roughness ( Ra) of 1.048 ± 0.037 μm and thickness of 2.54 ± 0.14 μm. In summary, the results indicated that coating of polycaprolactone-chitosan-bioglass nanocomposite on SS316L substrate could be a suitable surface treatment to increase its in vivo bioactivity and biocompatibility.

In Vivo and In Vitro Studies of Biodegradable WE43 Stent

2014 ◽  
Vol 528 ◽  
pp. 70-76 ◽  
Author(s):  
Chun Lan Lu ◽  
He Yan Dong ◽  
Wei Wang ◽  
Gang Yang
Keyword(s):  
Stainless Steel ◽  
Biological Response ◽  
Energy Dispersive Spectrum ◽  
Biodegradable Stent ◽  
Endothelial Surface ◽  
Radial Strength ◽  
Stent Strut ◽  
Immersion Testing

Magnesium alloys are very biocompatible and show promise for use in implant device. The focus of this article lies in the evaluation of the degradation performance and biological response of a paclitaxel-eluting biodegradable stent based on WE43 magnesium alloy by in vivo and in vitro studies. The corrosion characteristics analyzed by immersion testing in phosphate buffered solution (PBS) for 24h. Severe corrosion took place reveal fast degradation, lead to the stent strut easily fracture during expanding. The chemical nature of this conversion in vivo was investigated by scanning electron microscope (SEM) equipped with energy dispersive spectrum (EDS). For the endothelial surface coverage and the microstructure of the stent were also investigated by SEM. The results show that the deployment of the stent in arteries was safe, endothelial coverage occurred above stent struts and between struts after implanted 6 weeks, and more slowly than stainless steel stent and paclitaxel-eluting stainless steel stent. The grains boundaries of the stents are easily corroded in vivo environment, which should strongly affect the radial strength and mechanical integrity of the stent, leading early recoil contribute to restenosis.

scholarly journals Multifactorial Effects of Gelling Conditions on Mechanical Properties of Skin-Like Gelatin Membranes Intended for In Vitro Experimentation and Artificial Skin Models

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1991
Author(s):  
Lilian C. Alarcón-Segovia ◽  
Jorge I. Daza-Agudelo ◽  
Ignacio Rintoul
Keyword(s):  
Mechanical Properties ◽  
Wound Care ◽  
Sol Gel ◽  
Cosmetic Products ◽  
Synthesis Conditions ◽  
Skin Contact ◽  
Alternative Materials ◽  
Different Types

The development of new cosmetic products, skin contact medical devices, skin medicaments, wound care devices, tattooing and piercing has experienced an impressive growth in recent years. In parallel, new restrictions to in vivo experimentation in animals and humans have been widely implemented by regulatory authorities. New knowledge about alternative materials for in vitro skin-related experimentation is required to overcome these severe limitations. This paper presents a set of three 4-D surface response equations describing the mechanical properties of skin-like gelatin membranes intended for use as an alternative biomaterial for in vitro skin-related experimentation. The membranes were obtained by a sol-gel method. The novelty of this contribution is the establishment of the cross-dependency effects of key synthesis conditions on the final mechanical properties of gelatin membranes. The results of this work are useful to produce gelatin membranes with tailored mechanical properties mimicking different types of human skins. In particular, membranes with Young’s modulus of 1 MPa and maximum tensile strength of 0.85 MPa were obtained.

Preparation of cultured astrocytes for x-ray microanalysis

1989 ◽  
Vol 47 ◽  
pp. 988-989
Author(s):  
N.K.R. Smith ◽  
K.E. Hunter ◽  
P. Mobley ◽  
L.P. Felpel
Keyword(s):  
Cultured Cells ◽  
Elemental Content ◽  
Elemental Distribution ◽  
Sprague Dawley ◽  
X Ray ◽  
Cultured Astrocytes ◽  
Freeze Dried ◽  
Ultimate Objective

Electron probe energy dispersive x-ray microanalysis (XRMA) offers a powerful tool for the determination of intracellular elemental content of biological tissue. However, preparation of the tissue specimen , particularly excitable central nervous system (CNS) tissue , for XRMA is rather difficult, as dissection of a sample from the intact organism frequently results in artefacts in elemental distribution. To circumvent the problems inherent in the in vivo preparation, we turned to an in vitro preparation of astrocytes grown in tissue culture. However, preparations of in vitro samples offer a new and unique set of problems. Generally, cultured cells, growing in monolayer, must be harvested by either mechanical or enzymatic procedures, resulting in variable degrees of damage to the cells and compromised intracel1ular elemental distribution. The ultimate objective is to process and analyze unperturbed cells. With the objective of sparing others from some of the same efforts, we are reporting the considerable difficulties we have encountered in attempting to prepare astrocytes for XRMA.Tissue cultures of astrocytes from newborn C57 mice or Sprague Dawley rats were prepared and cultured by standard techniques, usually in T25 flasks, except as noted differently on Cytodex beads or on gelatin. After different preparative procedures, all samples were frozen on brass pins in liquid propane, stored in liquid nitrogen, cryosectioned (0.1 μm), freeze dried, and microanalyzed as previously reported.

Tantalum Oxide Nanoparticles as Versatile Contrast Agents for X-ray Computed Tomography

2020 ◽  
Author(s):  
Shatadru Chakravarty ◽  
Jeremy Hix ◽  
Kaitlyn Wieweora ◽  
Maximilian Volk ◽  
Elizabeth Kenyon ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Contrast Agents ◽  
Mesoporous Silica Nanoparticles ◽  
Sol Gel ◽  
Tantalum Oxide ◽  
High Signal ◽  
Drug Delivery Vehicles ◽  
X Ray Computed

Here we describe the synthesis, characterization and in vitro and in vivo performance of a series of tantalum oxide (TaOx) based nanoparticles (NPs) for computed tomography (CT). Five distinct versions of 9-12 nm diameter silane coated TaOx nanocrystals (NCs) were fabricated by a sol-gel method with varying degrees of hydrophilicity and with or without fluorescence, with the highest reported Ta content to date (78%). Highly hydrophilic NCs were left bare and were evaluated in vivo in mice for micro-CT of full body vasculature, where following intravenous injection, TaOx NCs demonstrate high CT contrast, circulation in blood for ~ 3 h, and eventual accumulation in RES organs; and following injection locally in the mammary gland, where the full ductal tree structure can be clearly delineated. Partially hydrophilic NCs were encapsulated within mesoporous silica nanoparticles (MSNPs; TaOx@MSNPs) and hydrophobic NCs were encapsulated within poly(lactic-co-glycolic acid) (PLGA; TaOx@PLGA) NPs, serving as potential CT-imagable drug delivery vehicles. Bolus intramuscular injections of TaOx@PLGA NPs and TaOx@MSNPs to mimic the accumulation of NPs at a tumor site produce high signal enhancement in mice. In vitro studies on bare NCs and formuated NPs demonstrate high cytocompatibility and low dissolution of TaOx. This work solidifies that TaOx-based NPs are versatile contrast agents for CT.

scholarly journals A New Antibiotic-Loaded Sol-Gel Can Prevent Bacterial Prosthetic Joint Infection: From in vitro Studies to an in vivo Model

2020 ◽  
Vol 10 ◽  
Author(s):  
John Jairo Aguilera-Correa ◽  
Amaya Garcia-Casas ◽  
Aranzazu Mediero ◽  
David Romera ◽  
Francisca Mulero ◽  
...  
Keyword(s):  
Prosthetic Joint Infection ◽  
Joint Infection ◽  
Sol Gel ◽  
In Vitro Studies ◽  
In Vivo Model ◽  
Prosthetic Joint

scholarly journals Targeting of p38 Mitogen-Activated Protein Kinases to MEF2 Transcription Factors

1999 ◽  
Vol 19 (6) ◽  
pp. 4028-4038 ◽  
Author(s):  
Shen-Hsi Yang ◽  
Alex Galanis ◽  
Andrew D. Sharrocks
Keyword(s):  
Transcription Factors ◽  
Transcriptional Activation ◽  
Cellular Response ◽  
Map Kinases ◽  
Biological Response ◽  
Extracellular Signals ◽  
Extracellular Signal ◽  
Mitogen Activated Protein

ABSTRACT Mitogen-activated protein (MAP) kinase-mediated signalling to the nucleus is an important event in the conversion of extracellular signals into a cellular response. However, the existence of multiple MAP kinases which phosphorylate similar phosphoacceptor motifs poses a problem in maintaining substrate specificity and hence the correct biological response. Both the extracellular signal-regulated kinase (ERK) and c-Jun NH2-terminal kinase (JNK) subfamilies of MAP kinases use a second specificity determinant and require docking to their transcription factor substrates to achieve maximal substrate activation. In this study, we demonstrate that among the different MAP kinases, the MADS-box transcription factors MEF2A and MEF2C are preferentially phosphorylated and activated by the p38 subfamily members p38α and p38β2. The efficiency of phosphorylation in vitro and transcriptional activation in vivo of MEF2A and MEF2C by these p38 subtypes requires the presence of a kinase docking domain (D-domain). Furthermore, the D-domain from MEF2A is sufficient to confer p38 responsiveness on different transcription factors, and reciprocal effects are observed upon the introduction of alternative D-domains into MEF2A. These results therefore contribute to our understanding of signalling to MEF2 transcription factors and demonstrate that the requirement for substrate binding by MAP kinases is an important facet of three different subclasses of MAP kinases (ERK, JNK, and p38).

Vitamin D modulates the expression of HLA-DR and CD38 after in vitro activation of T-cells

2017 ◽  
Vol 29 (3) ◽  
Author(s):  
Simon Villegas-Ospina ◽  
Wbeimar Aguilar-Jimenez ◽  
Sandra M. Gonzalez ◽  
María T. Rugeles
Keyword(s):  
Vitamin D ◽  
Flow Cytometry ◽  
Healthy Subjects ◽  
Mononuclear Cells ◽  
Activation Markers ◽  
Hla Dr ◽  
In Vitro Activation ◽  
Cells Cultured

AbstractObjective:Vitamin D (VitD) is an anti-inflammatory hormone; however, some evidence shows that VitD may induce the expression of activation markers, such as CD38 and HLA-DR. We explored its effect on the expression of these markers on CD4Materials and methods:CD38 and HLA-DR expression was measured by flow cytometry in PHA/IL-2-activated mononuclear cells cultured under VitD precursors: three cholecalciferol (10Results:Cholecalciferol at 10Conclusion:Although no significant correlations were observed in vivo in healthy subjects, VitD treatment in vitro modulated immune activation by increasing the expression of CD38 and decreasing the proliferation of HLA-DR

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