Mammalian Cell Behavior on Hydrophobic Substrates: Influence of Surface Properties

The influence of different surface properties holding to a modification of the substrate towards hydrophobic or superhydrophobic behavior was reviewed in this paper. Cell adhesion, their communication, and proliferation can be strongly manipulated, acting on interfacial relationship involving stiffness, surface charge, surface chemistry, roughness, or wettability. All these features can play mutual roles in determining the final properties of biomedical applications ranging from fabrics to cell biology devices. The focus of this work is the mammalian cell viability in contact with moderate to highly water repellent coatings or materials and also in combination with hydrophilic areas for more specific application. Few case studies illustrate a range of examples in which these surface properties and design can be fruitfully matched to the specific aim

Regenerable Superhydrophobic Coatings for Biomedical Fabrics

Coatings with high water repellence represent a promising field for biomedical applications. Superhydrophobicity (SH) can be used for preventing adhesion, controlling cell deposition, and spreading by inhibition of adsorption processes at liquid-solid interfaces. The recyclability of medical aids like fabrics can open the way for lower cost and more environmentally-friendly solutions. In this case, two different coatings form recyclable and low global warming potential materials and green solvents have been prepared and characterized based on their wettability properties. The resulting substrates have been used for the adhesion and spreading of representative skin cell lines, both tumoral and non-tumoral, showing a strong decrease in cell viability with values <10%. The coated substrates showed a complete recovery on initial SH properties after rinsing with suitable solvents

Mammalian cell viability on hydrophobic and superhydrophobic fabrics

fecting its growth, survival and also for its communication with other cells on fabrics. The combination of low surface energy and a specific surface morphology (micro/nano-roughness) leads to significantly less wettable surfaces, known as superhydrophobic characterized by high contact angle above 150° and a very small hysteresis. Such high water repellent coatings feature small area available to be exploited in many applications where interactions with aqueous environment are strongly to be avoided. In this work, the authors have investigated the influence of coating polyester fabric at different degree of hydrophobicity by mixed organicinorganic coating with moderated to highly water repellence. Depending on the coating composition and structure, the hydrophobicity of the fabric can be finely modulated by an easy-to-prepare method applicable to commercial, low cost fabric substrates providing advanced performance. In vitro experiments have been performed in order to establish the influence of surface modification on adhesion of representative model mammalian cell lines such as 3T3 fibroblasts, HaCaT keratinocytes and HeLa epithelial carcinoma cells. The obtained results suggested that, in addition to the chemistry and morphology of the coating, the characteristics of the substrate are important parameters on the final cell viabilities

Toxicity study in blood and tumor cells of laser produced medicines for application in fabrics

Phenothiazine derivatives are non-antibiotics with antimicrobial, fungistatic and fungicidal effects. We exposed to a high energy UV laser beam phenothiazines solutions in water at 20mg/mL concentration to increase antibacterial activity of resulting mixtures. Compared to previous results obtained on bacteria, more research is needed about UV laser irradiated phenothiazines applications on cancer cell cultures to evidence possible anticancerous properties. Evaluation of the safety of the newly obtained photoproducts in view of use on humans is also needed. Due to expensive animal testing in toxicology and pressure from general public and governments to develop alternatives to in vivo testing, in vitro cell-based models are attractive for preliminary testing of new materials. Cytotoxicity screening reported here shows that laser irradiated (4h exposure time length) chlorpromazine and promazine are more efficient against some cell cultures. Interaction of laser irradiated phenothiazines with fabrics show that promethazine and chlorpromazine have improved wetting properties. Correlation of these two groups of properties shows that chlorpromazine appears to be more recommended for applications on tissues using fabrics as transport vectors. The reported results concern stability study of phenothiazines water solutions to know the time limits within which they are stable and may be used. Keywords: Culture cells; Fabrics; Hemolysis; In vitro cytotoxicity; Laser; Phenothiazines

Sustainable Materials for Liquid Repellent Coatings

A modern environmental safety approach requires the implementation of green or sustainable strategies, such as banning or significantly lowering the presence of harmful substances on the market or in the industrial environment. To date, the majority of highly performing solutions are still based on fluorine chemistry, even with a growing effort to lower its impact. Economic costs, but also persistence, long-term degradation, and transformation in the environment can raise issues about medium- and long-term effects on human health and wildlife. Coatings with high water and oil repellence are used worldwide in daily life and in industrial and research fields, such as self-cleansing, anti-icing, and anti-biofouling. The combination of a particular geometry or surface structure and low-energy materials results in unique properties related to a range of materials in natural or synthetic categories aiming to build, when possible, a fluorine-free world. This work revises recent and key literature to propose valid alternatives to fluoro compounds in terms of water and oil repellence, as well as stability and resistance to physico-chemical agents. In this paper, natural compounds like fatty acids and waxes are addressed together with more synthetic systems like silicon-based solutions, and polymeric and inorganic nanostructured coatings. Most of the revised papers deal with topics fulfilling environmental requirements but are mainly restricted to highly repellent water and aqueous systems. Nevertheless, new and sustainable strategies for providing suitable, highly oleophobic surfaces to lower fluorine presence have been reported from a small but growing body of literature

Superhydrophobicity and Durability in Recyclable Polymers Coating

Highly hydrophobic and superhydrophobic materials obtained from recycled polymers represent an interesting challenge to recycle and reuse advanced performance materials after their first life. In this article, we present a simple and low-cost method to fabricate a superhydrophobic surface by employing polytetrafluoroethylene (PTFE) powder in polystyrene (PS) dispersion. With respect to the literature, the superhydrophobic surface (SHS) was prepared by utilizing a spray- coating technique at room temperature, a glass substrate without any further modification or thermal treatment, and which can be applied onto a large area and on to any type of material with some degree of fine control over the wettability properties. The prepared surface showed superhydrophobic behavior with a water contact angle (CA) of 170°; furthermore, the coating was characterized with different techniques, such as a 3D confocal profilometer, to measure the average roughness of the coating, and scanning electron microscopy (SEM) to characterize the surface morphology. In addition, the durability of SH coating was investigated by a long-water impact test (raining test), thermal treatment at high temperature, an abrasion test, and in acidic and alkaline environments. The present study may suggest an easy and scalable method to produce SHS PS/PTFE films that may find implementation in various fields

Wetting Properties of Simulated and Commercial Contaminants on High Transmittance Superhydrophobic Coating

The large and necessary diffusion of huge solar plants in extra urban areas implies the adoption of maintenance strategies especially where human intervention would require high costs and logistic problems. Animal dejections like bird droppings and agricultural sprays are environmental agents able to significantly decrease light absorption and, in some cases, cause serious damage to the electric conversion systems in a photovoltaic panel. In this work, the performance of a superhydrophobic (SH) coating in terms of durable self-cleaning properties and transparency has been studied in the presence of commercial and simulated contaminants on glass reference and solar panel surfaces. Wettability studies have been carried out both in static and dynamic conditions in order to compare the compositional effect of commercial liquids used as fertilizers or pesticides and molecules like pancreatin as model substances simulating bird droppings. From these studies, it can be observed that the superhydrophobic coating, independently from the surface where it is applied, is able to repel water and substances used such as fertilizers or pesticides and substances simulating bird droppings, maintaining its properties and transparency. This kind of approach can provide information to design suitable spray formulations without the above-mentioned drawbacks to be used in natural environment areas and agrosolar plants

Superhydrophobic Coatings from Recyclable Materials for Protection in a Real Sea Environment

Recyclable materials can be referred to as both those materials directly recycled from wastes and those derived from any kind of transformation before use. Highly water repellent coatings with wettability properties, known as superhydrophobic (SH), are related to surfaces with contact angles above 150&#176; and a very small hysteresis. The small area available for these surfaces when in contact with water can be exploited in many applications in which interactions with an aqueous environment are usually desirable to be avoided, like for protection and friction reduction in a marine environment. SH coatings under investigation have been prepared starting from recyclable materials with the aim to provide a sustainable and low cost solution, with potential application to large surfaces in a marine environment. Wetting studies, surface characterization, and electrochemical tests show how these surfaces can be used in terms of fouling prevention and the protection of metals in underwater conditions

Regenerable Superhydrophobic Coatings for Biomedical Fabrics

Coatings with high water repellence represent a promising field for biomedical applications. Superhydrophobicity (SH) can be used for preventing adhesion, controlling cell deposition, and spreading by inhibition of adsorption processes at liquid&ndash;solid interfaces. The recyclability of medical aids like fabrics can open the way for lower cost and more environmentally-friendly solutions. In this case, two different coatings form recyclable and low global warming potential materials and green solvents have been prepared and characterized based on their wettability properties. The resulting substrates have been used for the adhesion and spreading of representative skin cell lines, both tumoral and non-tumoral, showing a strong decrease in cell viability with values &lt; 10%. The coated substrates showed a complete recovery on initial SH properties after rinsing with suitable solvents