The global COVID-19 pandemic has attracted considerable attention toward innovative methods and technologies for suppressing the spread of viruses. Transmission via contaminated surfaces has been recognized as an important route for spreading SARS-CoV-2. Although significant efforts have been made to develop antibacterial surface coatings, the literature remains scarce for a systematic study on broad-range antiviral coatings. Here, we aim to provide a comprehensive overview of the antiviral materials and coatings that could be implemented for suppressing the spread of SARS-CoV-2 via contaminated surfaces. We discuss the mechanism of operation and effectivity of several types of inorganic and organic materials, in the bulk and nanomaterial form, and assess the possibility of implementing these as antiviral coatings. Toxicity and environmental concerns are also discussed for the presented approaches. Finally, we present future perspectives with regards to emerging antimicrobial technologies such as omniphobic surfaces and assess their potential in suppressing surface-mediated virus transfer. Although some of these emerging technologies have not yet been tested directly as antiviral coatings, they hold great potential for designing the next generation of antiviral surfaces.

Healthcare acquired infections are a major human health problem, and are becoming increasingly troublesome with the emergence of drug resistant bacteria. Engineered surfaces that reduce the adhesion, proliferation, and spread of bacteria have promise as a mean of preventing infections and reducing the use of antibiotics. To address this need, we created a flexible plastic wrap that combines a hierarchical wrinkled structure with chemical functionalization to reduce bacterial adhesion, biofilm formation, and the transfer of bacteria through an intermediate surface. These hierarchical wraps were effective for reducing biofilm formation of World Health Organization-designated priority pathogens Gram positive methicillin-resistant Staphylococcus aureus (MRSA) and Gram negative Pseudomonas aeruginosa by 87 and 84%, respectively. In addition, these surfaces remain free of bacteria after being touched by a contaminated surface with Gram negative E. coli. We showed that these properties are the result of broad liquid repellency of the engineered surfaces and the presence of reduced anchor points for bacterial adhesion on the hierarchical structure. Such wraps are fabricated using scalable bottom-up techniques and form an effective cover on a variety of complex objects, making them superior to top-down and substrate-specific surface modification methods.

Electrochemical biosensors hold great promise for enabling clinical analysis of biomarkers at the point-of-care. This is particularly of interest for cancer management due to the importance of early diagnostics as well as the critical need for frequent treatment monitoring. We have reviewed clinically-relevant electrochemical biosensors that have been developed over the past five years for the analysis of prostate specific antigen (PSA), a model protein target for prostate cancer management. We have critically evaluated the key performance metrics of these biosensors for clinical translation: limit-of-detection, linear range, and recovery rate in bodily fluids. These PSA electrochemical biosensors can be broadly categorized as sandwich assays, direct detection assays, and indirect detection assays. Among these, indirect detection assays deliver the lowest limit-of-detection. We have identified the development of multiplexed assays for detecting a panel of cancer biomarkers that includes a combination of protein and nucleic acids targets as a key priority for future development.

agents, [7-12] or changing the surface charge, wettability, chemical affinity, and hydrophilicity. [13-17] Anticoagulants such as heparin have been widely used as coatings on biomedical devices to overcome these adverse effects. [18] Heparin-coated surfaces typically operate through either the release of heparin into the bloodstream for inhibiting clotting in the vicinity of the device surface or reducing coagulation via immobilized heparin on the surface of the device. Anticoagulant coatings fail over time due to leaching and the loss of anticoagulant activity. Furthermore, the administration of anticoagulants (e.g., heparin) both as a coating and a chronic medication, enters the bloodstream, elevating the risk of life-threatening heparin-induced thrombocytopenia, reported to occur in 1-5% of surgical patients. [19] Recently, omniphobic coatings have been introduced on the surface of biomedical devices for reducing biofouling and the resultant blood coagulation, [20-29] while minimizing the administration of anticoagulants. [30] Liquid-infused surfaces are one of the recent classes of omniphobic surfaces which have shown to significantly suppress biofouling and thrombosis with their performances surpassing previous anticoagulant based strategies in terms of longevity under blood flow and anti-biofouling ability. [20-25,27-30] However, in order for these surfaces to sustain their omniphobic and repellent properties, the lubricant layer must be stable on the surfaces, making them difficult to use in open-air applications where the lubricant is susceptible to evaporation. [31] Another class of omniphobic surfaces is those with structural modifications wherein the micro-and nano-scale topography of the surface provides omniphobic properties. Through the formation of micro, nano, and hierarchical structures, air pockets are trapped within the features, leading to the formation of a Cassie wetting state, which reduces the apparent surface energy seen by liquids, [32] resulting in elevated contact angles (CA) and low sliding angles (SA) which lead to omniphobicity. [32] Additionally, the formation of the Cassie state reduces the effective surface area to which platelets and proteins in the blood can bind to, and decreases shear stress at the surfaces reducing platelet adhesion. These two effects reduce the number of nucleation sights for thrombin generation. [33] Hydrophilic polymer surfaces Liquid repellant surfaces have been shown to play a vital role for eliminating thrombosis on medical devices, minimizing blood contamination on common surfaces as well as preventing non-specific adhesion. Herein, an all solution-based, easily scalable method for producing liquid repellant flexible films, fabricated through nanoparticle deposition and heat-induced thin film wrinkling that suppress blood adhesion, and clot formation is reported. Furthermore, superhydrophobic and hydrophilic surfaces are combined onto the same substrate using a facile streamlined process. The patterned superhydrophobic/hydrophilic surfaces show select...

Rapid and reagent-free pathogen tests … …a re urgently needed. In their Research Article (e202204252), Leyla Soleymani, Yingfu Li and co-workers developed adual-electrode electrochemical chip (DEE-Chip) and ab arcode-releasing electroactive aptamer for rapid on-farm detection of porcine epidemic diarrhea viruses (PEDv). In contrast to current biosecurity surveillance with turnaround times of 2-4 days,this technology identifies infection with PEDv in pig saliva in one hour with adiagnostic sensitivity of 100 %and specificity of 83 %.

Amidst the COVID-19 pandemic, it is evident that viral spread is mediated through several different transmission pathways. Reduction of these transmission pathways is urgently needed to control the spread of viruses between infected and susceptible individuals. Herein, we report the use of pathogen-repellent plastic wraps (RepelWrap) with engineered surface structures at multiple length scales (nanoscale to microscale) as a means of reducing the indirect contact transmission of viruses through fomites. To quantify viral repellency, we developed a touch-based viral quantification assay to mimic the interaction of a contaminated human touch with a surface through the modification of traditional viral quantification methods (viral plaque and TCID50 assays). These studies demonstrate that RepelWrap reduced contamination with an enveloped DNA virus as well as the human coronavirus 229E (HuCoV-229E) by more than 4 log 10 (>99.99%) compared to a standard commercially available polyethylene plastic wrap. In addition, RepelWrap maintained its repellent properties after repeated 300 touches and did not show an accumulation in viral titer after multiple contacts with contaminated surfaces, while increases were seen on other commonly used surfaces. These findings show the potential use of repellent surfaces in reducing viral contamination on surfaces, which could, in turn, reduce the surface-based spread and transmission.

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The surface fouling of biomedical devices has been an ongoing issue in healthcare. Bacterial and blood adhesion in particular, severely impede the performance of such tools, leading to poor patient outcomes. Various structural and chemical modifications have been shown to reduce fouling, but all existing strategies lack the combination of physical, chemical, and economic traits necessary for widespread use. Herein, a lubricant infused, hierarchically micro‐ and nanostructured polydimethylsiloxane surface is presented. The surface is easy to produce and exhibits the high flexibility and optical transparency necessary for incorporation into various biomedical tools. Tests involving two clinically relevant, priority pathogens show up to a 98.5% reduction in the biofilm formation of methicillin‐resistant Staphylococcus aureus and Pseudomonas aeruginosa. With blood, the surface reduces staining by 95% and suppresses thrombin generation to background levels. Furthermore, the surface shows applicability within applications such as catheters, extracorporeal circuits, and microfluidic devices, through its effectiveness in dynamic conditions. The perfusion of bacterial media shows up to 96.5% reduction in bacterial adhesion. Similarly, a 95.8% reduction in fibrin networks is observed following whole blood perfusion. This substrate stands to hold high applicability within biomedical systems as a means to prevent fouling, thus improving performance.