scholarly journals Tuning Nanopore Diameter of Titanium Surfaces to Improve Human Gingival Fibroblast Response

2018 ◽  
Vol 19 (10) ◽  
pp. 2881 ◽  
Author(s):  
Maria Ferrà-Cañellas ◽  
Maria Llopis-Grimalt ◽  
Marta Monjo ◽  
Joana Ramis
Keyword(s):  
Cellular Response ◽  
Human Gingival Fibroblast ◽  
Gingival Fibroblast ◽  
Nanostructured Surfaces ◽  
Force Microscopy ◽  
Interelectrode Spacing ◽  
Tissue Integration ◽  
Atomic Force ◽  
Titanium Surfaces ◽  
Different Diameters

The aim of this study was to determine the optimal nanopore diameter of titanium nanostructured surfaces to improve human gingival fibroblast (hGF) response, with the purpose of promoting gingiva integration to dental implant abutments. Two TiO2 nanoporous groups with different diameters (NP-S ~48 nm and NP-B ~74 nm) were grown on Ti foils using an organic electrolyte containing fluoride by electrochemical oxidation, varying the applied voltage and the interelectrode spacing. The surfaces were characterized by scanning electron microscope (SEM), atomic force microscopy (AFM), and contact angle. The hGF were cultured onto the different surfaces, and metabolic activity, cytotoxicity, cell adhesion, and gene expression were analyzed. Bigger porous diameters (NP-B) were obtained by increasing the voltage used during anodization. To obtain the smallest diameter (NP-S), apart from lowering the voltage, a lower interelectrode spacing was needed. The greatest surface area and number of peaks was found for NP-B, despite these samples not being the roughest as defined by Ra. NP-B had a better cellular response compared to NP-S. However, these effects had a significant dependence on the cell donor. In conclusion, nanoporous groups with a diameter in the range of 74 nm induce a better hGF response, which may be beneficial for an effective soft tissue integration around the implant.

The Influence of the Operating Parameters of Titanium Electropolishing to Obtain Nanostructured Titanium Surfaces

2012 ◽  
Vol 727-728 ◽  
pp. 1638-1642
Author(s):  
Leonardo Marasca Antonini ◽  
Rafael Gomes Mielczarski ◽  
Caroline Pigatto ◽  
Iduvirges Lourdes Müller ◽  
Célia de Fraga Malfatti
Keyword(s):  
Operating Parameters ◽  
Nanostructured Titanium ◽  
Nanostructured Surfaces ◽  
Force Microscopy ◽  
Angle Measurements ◽  
Atomic Force ◽  
Different Temperatures ◽  
Titanium Surfaces

Titanium and Ti alloys have been widely used as biomaterial due to their mechanical properties and high in vitro and in vivo cytocompatibility. Studies have showed that the acceleration of the osseointegration process is associated to the modification of the surface morphology. The aim of this work is to study the influence of the operating parameters of titanium electropolishing to obtain nanostructured titanium surfaces. The titanium electropolishing was carried out with different temperatures (7°C, 18°C and 25°C), current density of 0.19 A/cm2 and electropolishing time of 8 minutes. After the electropolishing process the titanium samples were characterized by Atomic Force Microscopy, profilometry (mechanical profilometer) and contact angle measurements. Preliminary results showed that the Ti nanostructured surfaces formation, strongly depends on the control of operating parameters.

scholarly journals Enhanced Human Gingival Fibroblast Response and Reduced Porphyromonas gingivalis Adhesion with Titania Nanotubes

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Zhiqiang Xu ◽  
Yuqi He ◽  
Xiufeng Zeng ◽  
Xiuxia Zeng ◽  
Junhui Huang ◽  
...  
Keyword(s):  
Dental Implants ◽  
Porphyromonas Gingivalis ◽  
Soft Tissues ◽  
Titania Nanotubes ◽  
Biological Behavior ◽  
Human Gingival Fibroblast ◽  
Gingival Fibroblast ◽  
Related Gene ◽  
Gene Expressions ◽  
Tissue Integration

Successful dental implants rely on stable osseointegration and soft-tissue integration. Titania nanotubes (TNTs) with a diameter of 100 nm could increase the mesenchymal stem cell response and simultaneously decrease Staphylococcus aureus adhesion. However, the interactions between the modified surface and surrounding soft tissues are still unknown. In the present study, we fully investigated the biological behavior of human gingival fibroblasts (HGFs) and the adhesion of Porphyromonas gingivalis (P. gingivalis). TNTs were synthesized on titanium (Ti) surfaces by electrochemical anodization at 10, 30, and 60 V, and the products were denoted as NT10, NT30, and NT60, respectively. NT10 (diameter: 30 nm) and NT30 (diameter: 100 nm) could enhance the HGF functions, such as cell attachment and proliferation and extracellular matrix- (ECM-) related gene expressions, with the latter showing higher enhancement. NT60 (diameter: 200 nm) clearly impaired cell adhesion and proliferation and ECM-related gene expressions. Bacterial adhesion on the TNTs decreased and reached the lowest value on NT30. Therefore, NT30 without pharmaceuticals can be used to substantially enhance the HGF response and reduce P. gingivalis adhesion to the utmost, thus demonstrating significant potential in the transgingival part of dental implants.

scholarly journals Atomic Force Microscopy for the Characterisation of the Effects and Treatment of Infectious Parasites

2013 ◽  
Vol 19 (S4) ◽  
pp. 3-4
Author(s):  
P. Eaton ◽  
J.R.S.A. Leite ◽  
C. Bittencourt ◽  
M. Prudêncio ◽  
M.J. Feio ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Cell Morphology ◽  
Low Income ◽  
Cellular Response ◽  
Parasitophorous Vacuole ◽  
Membrane Integrity ◽  
Liver Cells ◽  
Low Income Countries ◽  
Force Microscopy ◽  
Atomic Force

In this talk the utility of atomic force microscopy (AFM) for research into infectious parasites will be discussed. AFM has grown from relatively recent beginnings to become an extremely powerful technique in the life sciences, coupling high resolution imaging with a range of non-imaging experiments. Importantly, these experiments can be performed in situ, even on individual molecules or on live cells.The two examples discussed relate to the important diseases leishmaniasis and malaria. Leishmaniasis is a disease caused by the protozoan parasite of the Leishmania genera, and causes approximately 60,000 deaths per year. Despite the high death toll, the disease has been the subject of relatively little research and little treatment is available, probably because the most severe cases are confined to developing nations. The most severe form, visceral leishmaniasis is caused by the species known as Leishmania infantum (syn. L. chagasi). A promising new anti-leishmania drug, DS01 has been recently isolated from amphibian secretions and can kill L. infantum in low concentrations. We were able to culture and prepare for microscopy L. infantum promastigotes for the first time, as well as to study the effects of DS01 on cell morphology and membrane integrity. The results from both AFM and SEM are highly complementary and illustrate the possibility of membrane-focussed activity as well as the possibility of attack on the flagella (figure 1).Malaria is one of the most deadly diseases in the world, killing more than 600,000 people per year, mostly in low-income countries. It is caused by Plasmodium parasites, and the most commonly studied stage is that in which the parasite invades the blood. Prior to blood invasion, the parasites infect hepatocytes in the liver, with formation of a parasitophorous vacuole, where they develop into exoerythrocytic forms and multiply to generate thousands of merozoites, later released into the bloodstream and causing disease. However, infection of liver cells, which is clinically silent, is required for disease progression. We studied infection of liver cells by Plasmodium using combined epifluorescence and atomic force microscopy. We observed significant changes in cell morphology as infection progressed (figure 2). Furthermore we made nanoindentation measurements with the AFM, to determine cellular stiffness. We observed stiffening of the cells after 48 hours of infection compared to uninfected cells. This was a cellular response to the Plasmodium infection, rather than a result of the stiffness of the invading parasites themselves. This stiffening may be caused by reinforcement of cytoskeletal structures, and we believe this may reflect a self-defence mechanism by the cell itself.

scholarly journals Thin-film morphologies of block copolymers with nanoparticles

2015 ◽  
Vol 30 (S1) ◽  
pp. S16-S24 ◽  
Author(s):  
Dieter Jehnichen ◽  
Doris Pospiech ◽  
Peter Friedel ◽  
Guping He ◽  
Alessandro Sepe ◽  
...  
Keyword(s):  
Thin Films ◽  
Diblock Copolymers ◽  
Grazing Incidence ◽  
Polymer Surfaces ◽  
Nanostructured Surfaces ◽  
Force Microscopy ◽  
Molar Ratios ◽  
X Ray Scattering ◽  
Atomic Force

Diblock copolymers (BCPs) show phase separation on mesoscopic length scales and form ordered morphologies in both bulk and thin films, the latter resulting in nanostructured surfaces. Morphologies in thin films are strongly influenced by film parameters, the ratio of film thickness and bulk domain spacing. Laterally structured polymer surfaces may serve as templates for controlled assembly of nanoparticles (NPs). We investigated the BCP of poly(n-pentyl methacrylate) and poly(methyl methacrylate) which show bulk morphologies of stacked lamellae or hexagonally packed cylinders. Thin films were investigated by atomic force microscopy and grazing-incidence small-angle X-ray scattering. For film thicknesses f well below dbulk, standing cylinder morphologies were observed in appropriate molar ratios, while film thicknesses around and larger than dbulk resulted in cylinders arranged parallel to surface. To alter and/or improve the morphology also in presence of different NPs (e.g., silica, gold), solvent vapour annealing (SVA) was applied. The BCP morphology usually remains unchanged but periodicities change depending on type and amount of incorporated NPs. It was found that silica clusters enlarge lateral distances of cylinders, whereas Au NPs reduce it. The effect of SVA is weak. The quality of morphology is slightly improved by SVA and lateral distances remain constant or are slightly reduced.

scholarly journals Photoelectrical properties investigated on individual Si nanowires and their size dependence

2020 ◽  
Author(s):  
Xiaofeng Hu ◽  
Shujie Li ◽  
Zuimin Jiang ◽  
Xinju Yang
Keyword(s):  
Barrier Height ◽  
Size Dependence ◽  
Laser Intensity ◽  
Electrostatic Force ◽  
Si Nanowires ◽  
Practical Applications ◽  
Force Microscopy ◽  
Photoelectrical Properties ◽  
Atomic Force ◽  
Different Diameters

Abstract Periodically ordered arrays of vertically aligned Si nanowires (Si NWs) are successfully fabricated with controllable diameters and lengths. Their photoconductive properties are investigated by photoconductive atomic force microscopy (PCAFM) on individual nanowires. The results show that the photocurrent of Si NWs increases significantly with the laser intensity, indicating that Si NWs have good photoconductance and photoresponse capability. This photo-enhanced conductance can be attributed to the photo-induced Schottky barrier change, confirmed by I-V curve analyses. On the other hand, electrostatic force microscopy (EFM) results indicate that a large number of photo-generated charges are trapped in Si NWs under laser irradiation, leading to the lowering of barrier height. Moreover, the size dependence of photoconductive properties is studied on Si NWs with different diameters and lengths. It is found that the increasing magnitude of photocurrent with laser intensity is greatly relevant to the nanowires’ diameter and length. Si NWs with smaller diameters and shorter lengths display better photoconductive properties, which agrees well with the size-dependent barrier height variation induced by photo-generated charges. With optimized diameter and length, great photoelectrical properties are achieved on Si NWs. Overall, in this study the photoelectrical properties of individual Si NWs are systematically investigated by PCAFM and EFM, providing important information for the optimization of nanostructures for practical applications.

scholarly journals Comparison of Cytomorphometry and Early Cell Response of Human Gingival Fibroblast (HGFs) between Zirconium and New Zirconia-Reinforced Lithium Silicate Ceramics (ZLS)

2018 ◽  
Vol 19 (9) ◽  
pp. 2718 ◽  
Author(s):  
María Rizo-Gorrita ◽  
Irene Luna-Oliva ◽  
María-Ángeles Serrera-Figallo ◽  
José-Luis Gutiérrez-Pérez ◽  
Daniel Torres-Lagares
Keyword(s):  
Cellular Response ◽  
Surface Characterization ◽  
Cellular Proliferation ◽  
Lithium Silicate ◽  
Human Gingival Fibroblast ◽  
Gingival Fibroblast ◽  
Gingival Fibroblasts ◽  
Optical Profilometry

New zirconia-reinforced lithium silicate ceramics (ZLS) could be a viable alternative to zirconium (Y-TZP) in the manufacture of implantological abutments—especially in aesthetic cases—due to its good mechanical, optical, and biocompatibility properties. Although there are several studies on the ZLS mechanical properties, there are no studies regarding proliferation, spreading, or cytomorphometry. We designed the present study which compares the surface, cellular proliferation, and cellular morphology between Y-TZP (Vita YZ® T [Vita Zahnfabrik (Postfach, Germany)]) and ZLS (Celtra® Duo [Degudent (Hanau-Wolfgang, Germany)]). The surface characterization was performed with energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), and optical profilometry. Human gingival fibroblasts (HGFs) were subsequently cultured on both materials and early cellular response and cell morphology were compared through nuclear and cytoskeletal measurement parameters using confocal microscopy. The results showed greater proliferation and spreading on the surface of Y-TZP. This could indicate that Y-TZP continues to be a gold standard in terms of transgingival implant material: Nevertheless, more in vitro and in vivo research is necessary to confirm the results obtained in this study.

Dopamine self-polymerized along with hydroxyapatite onto the preactivated titanium percutaneous implants surface to promote human gingival fibroblast behavior and antimicrobial activity for biological sealing

2018 ◽  
Vol 32 (8) ◽  
pp. 1071-1082 ◽  
Author(s):  
Minggang Yang ◽  
Peipei Jiang ◽  
Yang Ge ◽  
Fang Lan ◽  
Xuedong Zhou ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Soft Tissue ◽  
Titanium Surface ◽  
Soft Tissues ◽  
Pure Titanium ◽  
Carboxymethyl Chitosan ◽  
Human Gingival Fibroblast ◽  
Gingival Fibroblast ◽  
Tissue Integration ◽  
Collagen Secretion

The clinical success of dental implants requires not only the optimum osseointegration but also the integration of implant surface with soft tissues to form biological sealing. In this study, alkali-heat treatment was applied to modify the pure titanium surface constructing a unique micro-and nano-structure. Then, poly(dopamine), along and with the additional incorporation of hydroxyapatite and carboxymethyl chitosan have been successfully infiltrated into the preactivated Ti surface during dopamine self-polymerization proceeding. Here, the effects of poly(dopamine)-modified surface coating on the biological behaviors of human gingival fibroblasts (HGFs) and oral pathogens have been systematically studied, which was critical for the early peri-implant soft tissue integration. The results showed that the poly(dopamine)-modified alkali-heat-titanium surface was a superior substrate for human gingival fibroblast adhesion, spread and proliferation. Moreover, further enhancements on cytoskeleton organization, collagen secretion and fibronectin adsorption were generally observed through the additional incorporation of hydroxyapatite. The addition of carboxymethyl chitosan exerted a positive modulation effect on antibacterial activity. Overall, our study demonstrated that combined superior soft tissue integration and antibacterial activity can be achieved by using poly(dopamine)-modified titanium implant, which has great potential in the optimal design of dental implant.

scholarly journals Directed Irradiation Synthesis as an Advanced Plasma Technology for Surface Modification to Activate Porous and “as-received” Titanium Surfaces

Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1349 ◽  
Author(s):  
Ana Civantos ◽  
Jean Paul Allain ◽  
Juan Jose Pavón ◽  
Akshath Shetty ◽  
Osman El-Atwani ◽  
...  
Keyword(s):  
Contact Angle ◽  
Surface Modification ◽  
Titanium Implants ◽  
Lower Percentage ◽  
Force Microscopy ◽  
Atomic Force ◽  
Titanium Surfaces ◽  
Singly Charged ◽  
Biological Performance

For the design of smart titanium implants, it is essential to balance the surface properties without any detrimental effect on the bulk properties of the material. Therefore, in this study, an irradiation-driven surface modification called directed irradiation synthesis (DIS) has been developed to nanopattern porous and “as-received” c.p. Ti surfaces with the aim of improving cellular viability. Nanofeatures were developed using singly-charged argon ions at 0.5 and 1.0 keV energies, incident angles from 0° to 75° degrees, and fluences up to 5.0 × 1017 cm−2. Irradiated surfaces were evaluated by scanning electron microscopy, atomic force microscopy and contact angle, observing an increased hydrophilicity (a contact angle reduction of 73.4% and 49.3%) and a higher roughness on both surfaces except for higher incident angles, which showed the smoothest surface. In-vitro studies demonstrated the biocompatibility of directed irradiation synthesis (DIS) reaching 84% and 87% cell viability levels at 1 and 7 days respectively, and a lower percentage of damaged DNA in tail compared to the control c.p. Ti. All these results confirm the potential of the DIS technique to modify complex surfaces at the nanoscale level promoting their biological performance.

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