scholarly journals A Bacteria and Cell Repellent Zwitterionic Polymer Coating on Titanium Base Substrates towards Smart Implant Devices

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2472
Author(s):  
Mona Es-Souni ◽  
Martha Es-Souni ◽  
Hamzah Bakhti ◽  
Aydin Gülses ◽  
Helge Fischer-Brandies ◽  
...  
Keyword(s):  
Adhesion Strength ◽  
Biofilm Formation ◽  
Human Fibroblasts ◽  
Healing Process ◽  
Strength Properties ◽  
Polymeric Coating ◽  
Smart Devices ◽  
Flat Punch ◽  
Water Contact ◽  
Inflammatory Reactions

Biofouling and biofilm formation on implant surfaces are serious issues that more than often lead to inflammatory reactions and the necessity of lengthy post-operation treatments or the removal of the implant, thus entailing a protracted healing process. This issue may be tackled with a biocompatible polymeric coating that at the same time prevents biofouling. In this work, oxygen plasma-activated silanized titanium substrates are coated with poly(sulfobetaine methacrylate), a zwitterionic antibiofouling polymer, using photopolymerization. The characterization of polymer films includes FT-IR, AFM, and adhesion strength measurements, where adhesion strength is analyzed using a cylindrical flat punch indenter and water contact angle (WCA) measurements. Both cytotoxicity analysis with primary human fibroblasts and fluorescence microscopy with fibroblasts and plaque bacteria are also performed is this work, with each procedure including seeding on coated and control surfaces. The film morphology obtained by the AFM shows a fine structure akin to nanoropes. The coatings can resist ultrasonic and sterilization treatments. The adhesion strength properties substantially increase when the films are soaked in 0.51 M of NaCl prior to testing when compared to deionized water. The coatings are superhydrophilic with a WCA of 10° that increases to 15° after dry aging. The viability of fibroblasts in the presence of coated substrates is comparable to that of bare titanium. When in direct contact with fibroblasts or bacteria, marginal adhesion for both species occurs on coating imperfections. Because photopolymerization can easily be adapted to surface patterning, smart devices that promote both osseointegration (in non-coated areas) and prevent cell overgrowth and biofilm formation (in coated areas) demonstrate practical potential.

Causes of gear pump fails and methods for their elimination

2020 ◽  
pp. 98-107
Author(s):  
Vitaliy A. Zuyevskiy ◽  
Daniil O. Klimyuk ◽  
Ivan A. Shemberev
Keyword(s):  
Adhesion Strength ◽  
Production Systems ◽  
Low Cost ◽  
High Strength ◽  
Strength Properties ◽  
Research Purpose ◽  
Working Fluid ◽  
Gear Pump ◽  
Repair Service ◽  
Recovery Method

Gear pumps are an important element of many production systems and their replacement in case of failure can be quite expensive, so it is important to have a modern and well-tuned technology for their recovery. There are many methods for restoring the pump's performance, depending on the reason that led to its failure. (Research purpose) The research purpose is in determining what causes most often lead to loss of pump performance, and developing a recovery method that provides the greatest post-repair service life of the pump and low cost of repair. (Materials and methods) Authors took into account that the applied coatings must have sufficient adhesion strength and resistance to mechanical, thermal and corrosion loads during operation. It was found that most often significant leaks of the working fluid, leading to failure, occur due to an increase in the gap between the inner surface of the housing and the gears due to active wear of the housing wells. Authors determined that the method of electric spark treatment of worn-out housing wells is best suited to perform the task (a large post-repair resource and low costs). (Results and discussion) It was found by laboratory studies of the adhesion strength of electric spark coatings with various electrodes that the best transfer of the material to the substrate is provided by bronze electrodes BrMKts3-1. It was noted that the coatings applied using the BrMKts3-1 electrode have high strength properties. (Conclusions) Research conducted in the center for collective use "Nano-Center" VIM confirmed the possibility of effective recovery of the gear pump by electric spark treatment.

scholarly journals Bonding of Selected Hardwoods with PVAc Adhesive

2020 ◽  
Vol 11 (1) ◽  
pp. 67
Author(s):  
Ján Iždinský ◽  
Ladislav Reinprecht ◽  
Ján Sedliačik ◽  
Jozef Kúdela ◽  
Viera Kučerová
Keyword(s):  
Adhesion Strength ◽  
Cold Water ◽  
Ph Value ◽  
Water Extract ◽  
Solid Wood ◽  
Contact Angles ◽  
Water Contact ◽  
Ph Values ◽  
Positive Tendency ◽  
The Impact

The bonding of wood with assembly adhesives is crucial for manufacturing wood composites, such as solid wood panels, glulam, furniture parts, and sport and musical instruments. This work investigates 13 hardwoods—bangkirai, beech, black locust, bubinga, ipé, iroko, maçaranduba, meranti, oak, palisander, sapelli, wengé and zebrano—and analyzes the impact of their selected structural and physical characteristics (e.g., the density, cold water extract, pH value, roughness, and wettability) on the adhesion strength with the polyvinyl acetate (PVAc) adhesive Multibond SK8. The adhesion strength of the bonded hardwoods, determined by the standard EN 205, ranged in the dry state from 9.5 MPa to 17.2 MPa, from 0.6 MPa to 2.6 MPa in the wet state, and from 8.5 MPa to 19.2 MPa in the reconditioned state. The adhesion strength in the dry state of the bonded hardwoods was not influenced by their cold water extracts, pH values, or roughness parallel with the grain. On the contrary, the adhesion strength was significantly with positive tendency influenced by their higher densities, lower roughness parameters perpendicular to the grain, and lower water contact angles.

scholarly journals Photobiomodulation of Human Fibroblasts and Keratinocytes with Blue Light: Implications in Wound Healing

2020 ◽  
Author(s):  
Francesca Rossi ◽  
Giada Magni ◽  
Francesca Tatini ◽  
Martina Banchelli ◽  
Federica Cherchi ◽  
...  
Keyword(s):  
Wound Healing ◽  
Blue Light ◽  
Chronic Wounds ◽  
Human Fibroblasts ◽  
Healing Process ◽  
Research Area ◽  
Wound Management ◽  
Blue Led ◽  
Led Light ◽  
New Research

In recent years, photobiomodulation (PBM) has been recognized as a physical therapy in wound management. Despite several published research papers, the mechanism underlying photobiomodulation is still not completely understood. The investigation about application of blue light to improve wound healing is a relatively new research area. Tests in selected patients evidenced a stimulation of the healing process in superficial and chronic wounds treated with a blue LED light emitting at 420 nm; a study in animal model pointed out a faster healing process in superficial wound, with an important role of fibroblasts and myofibroblasts. Here we present a study aiming at evidencing the effects of blue light on the proliferation and metabolism in fibroblasts and keratinocytes. Different light doses were used to treat the cells, evidencing inhibitory and stimulatory effects. Electrophysiology was used to investigate the effects on membrane currents, while Raman spectroscopy revealed the mitochondrial Cytochrome C (Cyt C) oxidase dependence on blue light irradiation. In conclusion, we observed that the blue LED light can be used to modulate the activity of human fibroblasts, and the effects in wound healing are particularly evident when studying the fibroblasts and keratinocytes co-cultures.

Molecular and cellular mechanisms of ultraviolet corneal crosslinking

2021 ◽  
pp. 48-54
Author(s):  
M.M. Bikbov ◽  
◽  
A.R. Khalimov ◽  
Keyword(s):  
Strength Properties ◽  
Short Term ◽  
Cellular Mechanisms ◽  
Inflammatory Reactions ◽  
Corneal Crosslinking ◽  
Ultraviolet Exposure ◽  
Uv Crosslinking ◽  
Radical Processes ◽  
Irreversible Nature ◽  
Ultrastructural Transformation

In the presented mainly experimental work, the regularities and mechanisms of ultrastructural transformation and changes in corneal metabolism under ultraviolet exposure are established. High-quality saturation of the stroma with riboflavin is necessary to perform safe and effective UV crosslinking of the cornea, which can be achieved mainly due to a sufficient area of de-epithelization (at least 8-9 mm). It was found that UV crosslinking of the cornea with the use of developed riboflavin solutions (Dextralink, Ribolink and Khitolink) as photosensitizers increases its strength properties associated with changes in the structural state of collagen fibrils. It is proved that the riboflavin-UV effect on the optical shell of the eyeball is caused by a short-term local increase in free radical processes, a decrease in the overall antioxidant status, and the absence of necrotic and significant inflammatory reactions. It is shown that the lack of riboflavin in the stroma forms a cascade of pathomorphological events of an irreversible nature, leading to the loss of the native structure of the cornea. On the basis of the conducted studies, the necessity of a differentiated approach to the use of riboflavin-containing solutions during ultraviolet crosslinking of the cornea is justified. Key words: ultraviolet corneal crosslinking, molecular-cellular mechanisms, photosensitizers, riboflavin.

scholarly journals One-Step Preparation of Durable Super-Hydrophobic MSR/SiO2 Coatings by Suspension Air Spraying

Micromachines ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 677 ◽  
Author(s):  
Zhengyong Huang ◽  
Wenjie Xu ◽  
Yu Wang ◽  
Haohuan Wang ◽  
Ruiqi Zhang ◽  
...  
Keyword(s):  
Contact Angle ◽  
Adhesion Strength ◽  
Contact Angle Hysteresis ◽  
Surface Hardness ◽  
Hierarchical Structures ◽  
Hydrophobic Surface ◽  
Water Contact ◽  
Hydrophobic Coating ◽  
Mechanical Durability ◽  
One Step

In this study, we develop a facial one-step approach to prepare durable super-hydrophobic coatings on glass surfaces. The hydrophobic characteristics, corrosive liquid resistance, and mechanical durability of the super-hydrophobic surface are presented. The as-prepared super-hydrophobic surface exhibits a water contact angle (WCA) of 157.2° and contact angle hysteresis of 2.3°. Mico/nano hierarchical structures and elements of silicon and fluorine is observed on super-hydrophobic surfaces. The adhesion strength and hardness of the surface are determined to be 1st level and 4H, respectively. The coating is, thus, capable of maintaining super-hydrophobic state after sand grinding with a load of 200 g and wear distances of 700 mm. The rough surface retained after severe mechanical abrasion observed by atomic force microscope (AFM) microscopically proves the durable origin of the super-hydrophobic coating. Results demonstrate the feasibility of production of the durable super-hydrophobic coating via enhancing its adhesion strength and surface hardness.

Global gene expression profiles in fibroblasts from synovial, skin and lymphoid tissue reveals distinct cytokine and chemokine expression patterns

2003 ◽  
Vol 90 (10) ◽  
pp. 688-697 ◽  
Author(s):  
Andrew Filer ◽  
Ewan Ross ◽  
Margarita Bofill ◽  
Stuart Martin ◽  
Mike Salmon ◽  
...  
Keyword(s):  
Gene Expression ◽  
Expression Profiles ◽  
Human Fibroblasts ◽  
Expression Patterns ◽  
Gene Expression Profiles ◽  
Global Gene Expression ◽  
Synovial Fibroblasts ◽  
Skin Fibroblasts ◽  
Inflammatory Reactions ◽  
Tnf Α

SummaryWe investigated the extent to which fibroblasts isolated from diverse tissues differ in their capacity to modulate inflammation by comparing the global gene expression profiles of cultured human fibroblasts from skin, acute and chronically inflamed synovium, lymph node and tonsil. The responses of these fibroblasts to TNF-α, IFN-γ and IL-4 stimulation were markedly different, as revealed by hierarchical cluster analysis and principal component analysis. In the absence of exogenous cytokine, syn-ovial and skin fibroblasts exhibited similar patterns of gene expression. However their transcriptional profiles diverged upon treatment with TNF-α.This proved to be biologically relevant, as TNF-α induced the secretion of different patterns and amounts of IL-6, IL-8 and CCL2 (MCP-1) in the two fibroblast types. Co-culture of skin or synovial fibroblasts with synovial fluid-derived mononuclear cells provided further evidence that these transcriptional differences were functionally significant in an ex vivo setting. Interestingly, the transcriptional response of skin fibroblasts to IL-4 converged with that of TNF-α-treated synovial fibroblasts, suggesting resident tissue fibroblasts and their blood-borne precursors may be imprinted by inflammatory cytokines that are characteristic of different tissues. Our data supports the concept that fibroblasts are heterogeneous, and that they contribute to the tissue-specificity of inflammatory reactions. Fibroblasts are therefore likely to play an active role in the persistence of chronic inflammatory reactions.This publication was partially financed by Serono Foundation for the Advancement of Medical Science.Part of this paper was originally presented at the 2nd International Workshop on New Therapeutic Targets in Vascular Biology from February 6-9, 2003 in Geneva, Switzerland.

scholarly journals The Relative Importance of Shear Forces and Surface Hydrophobicity on Biofilm Formation by Coccoid Cyanobacteria

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 653 ◽  
Author(s):  
Sara I. Faria ◽  
Rita Teixeira-Santos ◽  
Maria J. Romeu ◽  
João Morais ◽  
Vitor Vasconcelos ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Hydrophobic Surface ◽  
Surface Hydrophobicity ◽  
Polymeric Coating ◽  
Relative Importance ◽  
Hydrodynamic Conditions ◽  
Shear Forces ◽  
Lower Shear ◽  
Biofilm Development ◽  
The Impact

Understanding the conditions affecting cyanobacterial biofilm development is crucial to develop new antibiofouling strategies and decrease the economic and environmental impact of biofilms in marine settings. In this study, we investigated the relative importance of shear forces and surface hydrophobicity on biofilm development by two coccoid cyanobacteria with different biofilm formation capacities. The strong biofilm-forming Synechocystis salina was used along with the weaker biofilm-forming Cyanobium sp. Biofilms were developed in defined hydrodynamic conditions using glass (a model hydrophilic surface) and a polymeric epoxy coating (a hydrophobic surface) as substrates. Biofilms developed in both surfaces at lower shear conditions contained a higher number of cells and presented higher values for wet weight, thickness, and chlorophyll a content. The impact of hydrodynamics on biofilm development was generally stronger than the impact of surface hydrophobicity, but a combined effect of these two parameters strongly affected biofilm formation for the weaker biofilm-producing organism. The antibiofilm performance of the polymeric coating was confirmed at the hydrodynamic conditions prevailing in ports. Shear forces were shown to have a profound impact on biofilm development in marine settings regardless of the fouling capacity of the existing flora and the hydrophobicity of the surface.

Biofilm formation capacity of S. aureus under diabetic environments

2020 ◽  
Author(s):  
María Fernández Grajera ◽  
María Coronada Fernández Calderón ◽  
Miguel A. Pacha Olivenza ◽  
Ciro Pérez Giraldo ◽  
Amparo M. Gallardo Moreno ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Ketone Bodies ◽  
The Body ◽  
Inflammatory Reactions ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Combined Action ◽  
High Concentrations ◽  
The Individual ◽  
Clustering Behavior

<p>Diabetes increases the blood glucose levels above those of healthy individuals and poorly controlled diabetes is associated to ketoacidosis. Different authors have shown evidences that diabetes is linked to a higher risk of developing infections in different parts of the body. Although the reasons why diabetes enhances infection episodes are not entirely clear, different undesired physiological responses under diabetic environments are pointed out as the main causes, for example, inflammatory reactions, poor vascularization, neutrophilic chemotaxis or phagocytosis. However, it has so far not been quantified how high concentrations of glucose and ketone bodies can affect the beginning of the infectious process, i.e. the formation of biofilms.</p> <p>In this sense, this research will address how the presence of glucose and ketone bodies can alter the biofilm formation capacity of Staphylococcus aureus. The research will be carried out with six different diabetic conditions, including the individual action of both components (glucose and ketone bodies) and the combined action.</p> <p>The main conclusion of this work is that any studied diabetic condition is able to increase the slime index of S. aureus with respect to control (bacteria grown without diabetic supplements), so the biofilm formation capacity of this bacterium would rise in diabetic people. In addition to the change that can be as high as 400% in glucose concentrations of 1.9 mg/ml, the clustering behavior among the bacteria is also modified at all condition differently.</p>

Adhesion Strength of Human Ligament Fibroblasts

1994 ◽  
Vol 116 (3) ◽  
pp. 237-242 ◽  
Author(s):  
K.-L. Paul Sung ◽  
Michael K. Kwan ◽  
Fausto Maldonado ◽  
Wayne H. Akeson
Keyword(s):  
Adhesion Strength ◽  
Cell Function ◽  
Adhesion Force ◽  
Cruciate Ligament ◽  
Healing Process ◽  
Matrix Proteins ◽  
Functional Relationships ◽  
Seeding Time ◽  
Adhesive Interactions ◽  
Anterior Cruciate

The adhesive interactions of cells with other cells and the extracellular matrix (ECM) play a fundamental role in the organization of cells in differentiated organs, cell motility, and the healing process. The adhesion characteristics of ligament fibroblasts depend on the expression of cell surface molecules and their interaction with the ECM. Although many receptors mediating the effects of ECM components on ligament cell function remain poorly defined, it is known that fibronectin (FN) allows ligament cells to adhere through the VLA-5 receptor (α5β1). A direct measurement of the adhesion between anterior cruciate ligament (ACL) or medial collateral ligament (MCL) fibroblasts and fibronectin matrix proteins was achieved by using a micromanipulation technique to determine the force required to detach an ACL or MCL cell from fibronectin-coated glass. We have found that the adhesion strength is not random, but has well-defined functional relationships with the FN concentration and the seeding time (time allowed for the cell to establish attachment). The adhesion strength (i.e., force required to detach) of ACL cells shows a stronger dependence on FN concentration (1, 2, and 5 μg/ml) for short seeding times (15-30 min) than for long seeding times (38-75 min). For MCL cells, the effect of the seeding time on adhesion strength was apparent for all concentrations. For all the seeding times studied and FN concentrations used, MCL cells had higher adhesion strength than ACL cells. The adhesion strengths of ACL and MCL fibroblasts to FN are correlated to cell adhesion area. The normalized adhesion strength (adhesion force/adhesion area) of MCL fibroblasts is approximately 0.025 mdynes/μm2, which is the same as ACL cells for a seeding time from 18 to 50 minutes.

scholarly journals Healing Process Of Burns Using Ambarella Leaf (Spondias dulcis F.) and Vaselin in Rats (Rattus norvegicus)

2014 ◽  
Vol 8 (1) ◽  
Author(s):  
Ummu Balqis ◽  
Dian Masyitha ◽  
Fera Febrina
Keyword(s):  
Blood Vessels ◽  
Rattus Norvegicus ◽  
Healing Process ◽  
Inflammatory Cells ◽  
Distilled Water ◽  
Inflammatory Reactions ◽  
Treatment Groups ◽  
Degree Burn ◽  
Speed Up ◽  
Collagen Tissue

The aims of this research was to find out the healing process of second degree burn in rats (Rattus norvegicus) using ambarella leaf (Spondias dulcis F.) and vaselin on histopathologically. The research consisted of 4 treatment groups and 3 rats each, P1(double distilled water), P2 (ambarella leaf + double distilled water), P3 (vaselin), and P4 (ambarella leaf + vaselin). Treatment was done twice a day for 21 days. The research parameters are inflammatory reactions and distribution of collagen tissue. Data were analyzed descriptively. The results showed that on day 7, P1 and P3 many infiltration of inflammatory cells, hemorrhage and edema, on P2 and P4 here more infiltration of inflammatory cells, hemorrhage and edema. On the day 14th of many inflammatory cell infiltration, collagen tissue diffuse very thin on were described P1 and P3, and visible presence of new blood vessels was found on P4. On day 21th infiltration of inflammatory cells still present on (P1), there were a lot of new blood vessels on P2, there has been a process of epithelialization (P3), epidermis formed and collagen tissue spread very densely on P4. Based on the results of this study it can be concluded that administration of ambarella leaf and vaselin can speed up the healing process of burns in rats compared with other treatments.Key words: ambarella leaf, burn, vaselin

Sign in / Sign up

Export Citation Format

Share Document