Blood repellent superhydrophobic surfaces constructed from nanoparticle-free and biocompatible materials

Recent Developments in the Fabrication and Application of Superhydrophobic Suraces

A superhydrophobic surface is defined as having a contact angle exceeding 150 °C, indicating a remarkable ability to repel water. Generally, superhydrophobicity originates from the utilization of low-surface-energy materials with unique micro- and nanostructures. Superhydrophobic surfaces have gained considerable recognition and are widely employed in diverse areas for anti-icing, oil-water separation, anticorrosion, self-cleaning, blood-repellent, and antibacterial applications. These surfaces can greatly enhance industrial processes by yielding significant performance improvements. In this review, we introduce the basic theories that provide a foundation for understanding the hydrophobic properties of superhydrophobic surfaces. We then discuss current techniques for fabricating superhydrophobic coatings, critically analyzing their strengths and limitations. Furthermore, we provide an overview of recent progress in the application of superhydrophobic materials. Finally, we summarize the challenges in developing superhydrophobic materials and future trends in this field. The insights provided by this review can help researchers understand the basic knowledge of superhydrophobic surfaces and obtain the latest progress and challenges in the application of superhydrophobic surfaces. It provides help for further research and practical application of superhydrophobic surfaces.

Preparation of Time-Sequential Functionalized ZnS-ZnO Film for Modulation of Interfacial Behavior of Metals in Biological Service Environments

Blood-contact devices are prone to inflammation, endothelial dysfunction, coagulation, and the uncontrolled release of metal ions during implantation and service. Therefore, it is essential to make these multifunctional. Herein, a superhydrophobic DE@ZnS-ZnO@SA film (composed of dabigatran ester, zinc sulfite, zinc oxide, and stearic acid, respectively) is produced. The prepared film has non-adhesion and antibacterial properties, superior mechanical stability, durability, corrosion resistance, and is self-cleaning and blood-repellent. The results of the hemolysis, cytotoxicity, and other anticoagulant experiments revealed that the film had good blood compatibility, no cytotoxicity, and excellent anticoagulant properties. The film displays anticoagulant properties even after being immersed in Phosphate-Buffered Saline (PBS) for 7 days. Furthermore, the film can spontaneously release H2S gas for 90 h after soaking in an acidic environment (pH = 6) for 90 h. This property improves the acidic microenvironment of the lesion and promotes the proliferation of endothelial cells by using H2S gas. In addition, the film can inhibit the uncontrollable release of Zn2+ ions, avoiding its toxicity even when immersed in an acid environment for 35 days. This time-sequential functionalized surface has the potential to typify the future of blood-contacting scaffolds for long-lasting use.

Combining Chitosan, Stearic Acid, and (Cu-, Zn-) MOFs to Prepare Robust Superhydrophobic Coatings with Biomedical Multifunctionalities

There is an urgent need to develop a series of multifunctional materials with good biocompatibility, high mechanical strength, hemostatic properties, antiadhesion, and anti-infection for applications in wound care. However, successfully developing multifunctional materials is challenging. In this study, two superhydrophobic composite coatings with good biocompatibility, high mechanical strength, strong antifouling and blood repellency, fast hemostasis, and good antibacterial activity are prepared on cotton fabric surface by simple, green, and low-cost one-step dip-coating technology. The results discussed in the manuscript reveals that the two superhydrophobic composite coatings can maintain good mechanical stability, strong water repellency, and durability under various types of mechanical damage, high-temperature treatment, and long-term strong light irradiation. The coatings also exhibit good repellency to various solid pollutants, highly viscous liquid pollutants, and blood. In vitro and in vivo hemostatic experiments show that both composite coatings have good hemostatic and anticlot adhesion properties. More importantly, this superhydrophobic coating prevents bacterial adhesion and growth and released Cu2+ and Zn2+ ions and chitosan to achieve bactericidal properties, thereby protecting injured skin from bacterial infection. The two superhydrophobic coatings enhance the antifouling, antiadhesion, hemostatic, and antibacterial functions of blood-repellent dressings and therefore have broad application prospects in medical and textile fields.

Self-cleaning, superhydrophobic, and antibacterial cotton fabrics with chitosan-based composite coatings

The development of cotton fabrics with special properties such as superhydrophobicity, self-cleaning, oil/water separation, anti-bacterial activity and blood repellency without compromising its intrinsic properties such as flexibility, breathability, comfort, and biodegradability is quite challenging task. In this study, a simple and environmentally friendly approach was used to fabricate superhydrophobic cotton fabric by introducing chitosan-based composite coatings over cotton fabric. The surface properties of the cotton samples were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, and Fourier-transform infrared spectroscopy. The prepared cotton fabrics showed excellent superhydrophobicity with a water contact angle of 154.4° and also possess excellent antibacterial activity against Gram positive and negative bacteria with inhibition zone of 16 mm and 22 mm in disk diffusion method and shake flask method results revealed that the chitosan-PAni-ZnO-STA coated cotton effectively inhibits the bacterial growth. Furthermore, the self-cleaning, blood repellency and oil-water separation performance of cotton fabric were also performed to examine the feasibility of as-modified cotton in both environmental and clinical applications.

Superhydrophobic modification of cellulosic paper-based materials: Fabrication, properties, and versatile applications

Cellulose is the cheapest and mostly widespread green raw material on earth. Due to the easy and versatile developed modification of cellulose, many cellulosic paper-based sustainable materials and their multifunctional applications have attained increasing interest under the background of the implementation of the "plastic ban" policy. However, intrinsic cellulose paper is hydrophilic and non-water-proof, which highly limited its application, thus becoming a bottleneck for the development of "cellulosic paper-based plastic replacement". Unquestioningly, the superhydrophobic modification of cellulosic paper-based materials and the extension of their high value-added applications are highly desired, which is the main content of this review. More importantly, we presented the comprehensive discussion of the functionalized applications of superhydrophobic cellulosic paper-based materials ranging from conventional products to high value-added functional materials such as paper straw and paper mulch film for the first time, which have great industrialization potential and value. This review would offer the valuable guidance and insightful information for the rational construction of sustainable superhydrophobic cellulosic paper for advanced functional devices.

Construction of Hierarchical Micro/Nanostructured ZnO/Cu-ZnMOFs@SA Superhydrophobic Composite Coatings with Excellent Multifunctionality of Anticorrosion, Blood-Repelling, and Antimicrobial Properties

Naked medical devices are often damaged by blood, bacteria, and other extreme environmental conditions (heat, humidity, acid, alkali, salts, and others), causing device failure and increasing difficulty for the operator. They can also cause inflammation and coagulation resulting in severe complications and even death. In this work, the superhydrophobic ZnO/copper-zinc metal-organic frameworks@stearic acid (ZnO/Cu-ZnMOFs@SA) composite coatings with hierarchical micro/nanostructures were fabricated on Zn substrates via a one-step hydrothermal method. The effects of hierarchical micro/nanostructures on surface wettability, physicochemical stability, and biological properties have been studied in this manuscript. The structure not only provided the coatings with robust waterproofing, abrasive resistance, durability, and thermal and light irradiation stability but also successfully recovered their superhydrophobicity by remodifying the surface with SA, showing excellent repeatability. In addition, the coating demonstrates excellent corrosion resistance and self-cleaning ability and rejects various solid and liquid contaminants. The superhydrophobic ZnO/Cu-ZnMOFs@SA composite coatings also exhibited excellent antibacterial and thrombosis resistance. The findings indicated that the superhydrophobic composite coatings have a strong potential for application in medical instruments for exhibiting multifunctional properties in various extreme environments.

Superhydrophobic Biological Fluid-Repellent Surfaces: Mechanisms and Applications

Superhydrophobic biological fluid-repellent surfaces (SBFRSs) have attracted great attention in the treatment of blood and urine-related diseases because of their unique wettability and compatibility, which creates a new path for the development of medical apparatus and instruments, and are expected to create advances in various fields. Here, this review provides an up-to-date summary of research progress on the repellent mechanism and application of SBFRSs. The underlying physical and chemical principles for designing superhydrophobic surfaces are first introduced. Then, the dialectical influences of solid-liquid interactions between superhydrophobic surfaces and biological fluids on the wettability and compatibility are emphatically expounded. Subsequently, attention is drawn to the recent applications of SBFRSs in biomedical fields, such as surgical medical apparatus, implant materials, extracorporeal circulation devices, and biological fluid detection. Finally, the outlook and challenges in terms of employing SBFRSs are also discussed. This review is expected to provide a comprehensive guidance for the preparation of SBFRSs with compatibility and long-term superhydrophobic stability that is closely related to clinical applications.

Laser-Enabled Surface Treatment of Disposable Endoscope Lens with Superior Antifouling and Optical Properties

Endoscopes are ubiquitous in minimally invasive or keyhole surgeries globally. However, frequent removal of endoscopes from the patient's body due to the lens contaminations results in undesirable consequences. Therefore, a cost-effective process chain to fabricate thermoplastic-based endoscope lenses with superior antifouling and optical properties is proposed in this research. Such multifunctional surface response was achieved by lubricant impregnation of nanostructures. Two types of topographies were produced by femtosecond laser processing of metallic molds, especially to produce single-tier laser-induced periodic surface structures (LIPSS) and two-tier multiscale structures (MS). Then, these two LIPSS and MS masters were used to replicate them onto two thermoplastic substrates, namely polycarbonate and cyclic olefin copolymer, by using hot embossing. Finally, the LIPSS and MS surfaces of the replicas were infiltrated by silicone oils to prepare lubricant-impregnated surfaces (LIS). Droplet sliding tests revealed that the durability of the as-prepared LIS improved with the increase of the lubricant viscosity. Moreover, the single-tier LIPSS replicas exhibited longer-lasting lubricant conservation properties than the MS ones. Also, LIPSS-LIS replicas demonstrated an excellent optical transparency, better than the MS-LIS ones, and almost match the performance of the reference polished ones. Furthermore, the LIPSS-LIS treatment led to superior antifouling characteristics, i.e., regarding fogging, blood adhesion, protein adsorption, and microalgae attachment, and thus demonstrated its high suitability for treating endoscopic lenses. Finally, a proof-of-concept LIPSS-LIS treatment of endoscope lenses was conducted that confirmed their superior multifunctional response.

A versatile "3M" methodology to obtain superhydrophobic PDMS-based materials for antifouling applications

Fouling, including inorganic, organic, bio-, and composite fouling seriously affects our daily life. To reduce these effects, antifouling strategies including fouling resistance, release, and degrading, have been proposed. Superhydrophobicity, the most widely used characteristic for antifouling that relies on surface wettability, can provide surfaces with antifouling abilities owing to its fouling resistance and/or release effects. PDMS shows valuable and wide applications in many fields, and due to the inherent hydrophobicity, superhydrophobicity can be achieved simply by roughening the surface of pure PDMS or its composites. In this review, we propose a versatile "3M" methodology (materials, methods, and morphologies) to guide the fabrication of superhydrophobic PDMS-based materials for antifouling applications. Regarding materials, pure PDMS, PDMS with nanoparticles, and PDMS with other materials were introduced. The available methods are discussed based on the different materials. Materials based on PDMS with nanoparticles (zero-, one-, two-, and three-dimensional nanoparticles) are discussed systematically as typical examples with different morphologies. Carefully selected materials, methods, and morphologies were reviewed in this paper, which is expected to be a helpful reference for future research on superhydrophobic PDMS-based materials for antifouling applications.

One-step Green Fabrication of Antimicrobial Surfaces via In Situ Growth of Copper Oxide Nanoparticles

Microorganisms such as pathogenic bacteria, fungi, and viruses pose a serious threat to human health and society. Surfaces are one of the major pathways for the transmission of infectious diseases. Therefore, imparting antipathogenic properties to these surfaces is significant. Here, we present a rapid, one-step approach for practical fabrication of antimicrobial and antifungal surfaces using an eco-friendly and low-cost reducing agent, the extract of Cedrus libani. Copper oxide nanoparticles were grown in situ on the surface of print paper and fabric in the presence of the copper salt and extract, without the use of any additional chemicals. The morphology and composition of the grown nanoparticles were characterized using field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction techniques. The analysis revealed that the grown particles consist of mainly spherical CuO nanoparticles with an average size of ∼14 nm and its clusters with an average size of ∼700 nm. The in situ growth process enables strong bonding of the nanoparticles to the surface, resulting in enhanced durability against wear and tear. Moreover, the fabricated surface shows excellent growth inhibition ability and bactericidal activity against both gram-negative and gram-positive bacteria, Escherichia coli and Staphylococcus aureus, as well as antifungal activity against Candida albicans, a common pathogenic fungus. The ability to grow copper oxide nanoparticles on different surfaces paves the way for a range of applications in wound dressings, masks, and protective medical equipment.

Nanostructures for the Prevention, Diagnosis, and Treatment of SARS-CoV-2: A Review

Scientists, doctors, engineers, and even entire societies have become aware of the seriousness of the COVID-19 infection and are taking action quickly, using all the tools from protection to treatment against coronavirus SARS-CoV-2. Especially in this sense, scientific approaches and materials using nanotechnology are frequently preferred. In this review, we focus on how nanoscience and nanotechnology approaches can be used for protective equipment, diagnostic and treatment methods, medicine, and vaccine applications to stop the coronavirus SARS-CoV-2 and prevent its spread. SARS-CoV-2, which itself can be considered as a core-shell nanoparticle, can interact with various materials around it and remain bound for variable periods of time while maintaining its bioactivity. These applications are especially critical for the controlled use of disinfection systems. One of the most important processes in the fight against coronavirus is the rapid diagnosis of the virus in humans and the initiation of isolation and treatment processes. The development of nanotechnology-based test and diagnostic kits is another important research thrust. Nanotechnological therapeutics based on antiviral drug design and nanoarchitecture vaccines have been vital. Nanotechnology plays critical roles in the production of protective film surfaces for self-cleaning and antiviral masks, gloves, and laboratory clothes. An overview of literature studies highlighting nanotechnology and nanomaterial-based approaches to combat SARS-CoV-2 is presented.

Low-Cost Multifunctional Vacuum Chamber for Manufacturing PDMS Based Composites

Polydimethylsiloxane (PDMS) is one of the best known elastomers and has been used in several areas of activity, due to its excellent characteristics and properties, such as biocompatibility, flexibility, optical transparency and chemical stability. Furthermore, PDMS modified with other materials promotes the desired changes to broaden its range of applications in various fields of science. However, the heating, mixing and degassing steps of the manufacturing process have not received much attention in recent years when it comes to blending with solid materials. For instance, PDMS has been extensively studied in combination with waxes, which are frequently in a solid state at room temperature and as a result the interaction and manufacturing process are extremely complex and can compromise the desired material. Thus, in this work it is proposed a multifunctional vacuum chamber (MVC) with the aim to improve and accelerate the manufacturing process of PDMS composites combined with additives, blends and different kinds of solid materials. The MVC developed in this work allows to control the mixing speed parameters, temperature control and internal pressure. In addition, it is a low cost equipment and can be used for other possible modifications with different materials and processes with the ability to control those parameters. As a result, samples fabricated by using the MVC can achieve a time improvement over 133% at the heating and mixing step and approximately 200% at the last degassing step. Regarding the complete manufacturing process, it is possible to achieve an improvement over 150%, when compared with the conventional manufacturing process. When compared to maximum tensile strength, specimens manufactured using the MVC have shown a 39% and 65% improvement in maximum strain. The samples have also shown a 9% improvement in transparency at room temperature and 12% at a temperature of about 75 °C. It should be noted that the proposed MVC can be used for other blends and manufacturing processes where it is desirable to control the temperature, agitation speed and pressure.

Polydimethylsiloxane Composites Characterization and Its Applications: A Review

Polydimethylsiloxane (PDMS) is one of the most promising elastomers due its remarkable proprieties such as good thermal stability, biocompatibility, corrosion resistance, flexibility, low cost, ease of use, chemically inertia, hyperplastic characteristics, and gas permeability. Thus, it can be used in areas such as microfluidic systems, biomedical devices, electronic components, membranes for filtering and pervaporation, sensors, and coatings. Although pure PDMS has low mechanical properties, such as low modulus of elasticity and strength, it can be improved by mixing the PDMS with other polymers and by adding particles or reinforcements. Fiber-reinforced PDMS has proved to be a good alternative to manufacturing flexible displays, batteries, wearable devices, tactile sensors, and energy harvesting systems. PDMS and particulates are often used in the separation of liquids from wastewater by means of porosity followed by hydrophobicity. Waxes such as beeswax and paraffin have proved to be materials capable of improving properties such as the hydrophobic, corrosion-resistant, thermal, and optical properties of PDMS. Finally, when blended with polymers such as poly (vinyl chloride-co-vinyl acetate), PDMS becomes a highly efficient alternative for membrane separation applications. However, to the best of our knowledge there are few works dedicated to the review and comparison of different PDMS composites. Hence, this review will be focused on PDMS composites, their respective applications, and properties. Generally, the combination of elastomer with fibers, particles, waxes, polymers, and others it will be discussed, with the aim of producing a review that demonstrates the wide applications of this material and how tailored characteristics can be reached for custom applications.

Micro/Nanopatterned Superhydrophobic Surfaces Fabrication for Biomolecules and Biomaterials Manipulation and Analysis

Superhydrophobic surfaces display an extraordinary repulsion to water and water-based solutions. This effect emerges from the interplay of intrinsic hydrophobicity of the surface and its morphology. These surfaces have been established for a long time and have been studied for decades. The increasing interest in recent years has been focused towards applications in many different fields and, in particular, biomedical applications. In this paper, we review the progress achieved in the last years in the fabrication of regularly patterned superhydrophobic surfaces in many different materials and their exploitation for the manipulation and characterization of biomaterial, with particular emphasis on the issues affecting the yields of the fabrication processes and the quality of the manufactured devices.

Development of a Simple Spheroid Production Method Using Fluoropolymers with Reduced Chemical and Physical Damage

Establishing an in vitro–based cell culture system that can realistically simulate in vivo cell dynamics is desirable. It is thus necessary to develop a method for producing a large amount of cell aggregates (i.e., spheroids) that are uniform in size and quality. Various methods have been proposed for the preparation of spheroids; however, none of them satisfy all requirements, such as cost, size uniformity, and throughput. Herein, we successfully developed a new cell culture method by combining fluoropolymers and dot patterned extracellular matrix substrates to achieve size-controlled spheroids. First, the spheroids were spontaneously formed by culturing them two-dimensionally, after which the cells were detached with a weak liquid flow and cultured in suspension without enzyme treatment. Stable quality spheroids were easily produced, and it is expected that the introduction and running costs of the technique will be low; therefore, this method shows potential for application in the field of regenerative medicine.