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The use of implantable cardiovascular devices has increased in recent years and the need to improve the efficiency of these devices is at its pinnacle. Titanium and its alloys are...

For decades, titanium and its alloys have been established as a biocompatible material for cardiovascular medical devices such as heart valves, stents, vascular grafts, catheters, etc. However, thrombosis is one of the reasons for implant failure, where blood clot forms on the implant surface, thus obstructing the flow of the blood and that leads to some serious complications. Various surface modification techniques such as heparin modification, albumin coating, surface anodization, plasma etching, and hydrothermal treatments have been explored to improve the hemocompatibility of titanium-based materials. However, there are several limitations related to the robustness of the surfaces and long-term efficacy in vivo. In this study, titanium and its alloy Ti–6Al–4V were hydrothermally treated to form nanostructured surfaces with the aim to enhance their hemocompatibility. These modified surfaces were characterized for their wettability, surface morphology, surface chemistry, and crystallinity. The hemocompatibility of these surfaces was characterized by evaluating blood plasma protein adsorption, platelet adhesion and activation, platelet–leukocyte complex formation, and whole blood clotting. The results indicate lower fibrinogen adsorption, cell adhesion, platelet activation, and whole blood clotting on hydrothermally treated surfaces. Thus, these surfaces may be a promising approach to prevent thrombosis for several titanium blood-contacting medical devices.

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Micro/nano scale surface modifications of titanium based orthopedic and cardiovascular implants has shown to augment biocompatibility. However, bacterial infection remains a serious concern for implant failure, aggravated by increasing antibiotic resistance and over usage of antibiotics. Bacteria cell adhesion on implant surface leads to colonization and biofilm formation resulting in morbidity and mortality. Hence, there is a need to develop new implant surfaces with high antibacterial properties. Recent developments have shown that superhydrophobic surfaces prevent protein and bacteria cell adhesion. In this study, a thermochemical treatment was used modify the surface properties for high efficacy antibacterial activity on titanium surface. The modification led to a micro‐nano surface topography and upon modification with polyethylene glycol (PEG) and silane the surfaces were superhydrophilic and superhydrophobic, respectively. The modified surfaces were characterized for morphology, wettability, chemistry, corrosion resistance and surface charge. The antibacterial capability was characterized with Staphylococcus aureus and Escherichia coli by evaluating the bacteria cell inhibition, adhesion kinetics, and biofilm formation. The results indicated that the superhydrophobic micro‐nano structured titanium surface reduced bacteria cell adhesion significantly (>90%) and prevented biofilm formation compared to the unmodified titanium surface after 24 h of incubation.

High-performance energy storage devices (HPEDs) play a critical role in the realization of clean energy and thus enable the overarching pursuit of nonpolluting, green technologies. Supercapacitors are one class of such lucrative HPEDs; however, a serious limiting factor of supercapacitor technology is its sub-par energy density. This report presents hitherto unchartered pathway of physical deformation, chemical dealloying, and microstructure engineering to produce ultrahigh-capacitance, energy-dense NiMn alloy electrodes. The activated electrode delivered an ultrahigh specific-capacitance of 2700 F/cm3 at 0.5 A/cm3. The symmetric device showcased an excellent energy density of 96.94 Wh/L and a remarkable cycle life of 95% retention after 10,000 cycles. Transmission electron microscopy and atom probe tomography studies revealed the evolution of a unique hierarchical microstructure comprising fine Ni/NiMnO3 nanoligaments within MnO2-rich nanoflakes. Theoretical analysis using density functional theory showed semimetallic nature of the nanoscaled oxygen-vacancy-rich NiMnO3 structure, highlighting enhanced carrier concentration and electronic conductivity of the active region. Furthermore, the geometrical model of NiMnO3 crystals revealed relatively large voids, likely providing channels for the ion intercalation/de-intercalation. The current processing approach is highly adaptable and can be applied to a wide range of material systems for designing highly efficient electrodes for energy-storage devices.

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SARS-CoV-2 is a pandemic coronavirus that causes severe respiratory disease (COVID-19) in humans and is responsible for millions of deaths around the world since early 2020. The virus affects the human respiratory cells through its spike (S) proteins located at the outer shell. To monitor the rapid spreading of SARS-CoV-2 and to reduce the deaths from the COVID-19, early detection of SARS-CoV-2 is of utmost necessity. This report describes a flexible colorimetric biosensor capable of detecting the S protein of SARS-CoV-2. The colorimetric biosensor is made of polyurethane (PU)-polydiacetylene (PDA) nanofiber composite that was chemically functionalized to create a binding site for the receptor molecule—nucleocapsid antibody (anti-N) protein of SARS-CoV-2. After the anti-N protein conjugation to the functionalized PDA fibers, the PU-PDA-NHS-anti fiber was able to detect the S protein of SARS-CoV-2 at room temperature via a colorimetric transition from blue to red. The PU-PDA nanofiber-based biosensors are flexible and lightweight and do not require a power supply such as a battery when the colorimetric detection to S protein occurs, suggesting a sensing platform of wearable devices and personal protective equipment such as face masks and medical gowns for real-time monitoring of virus contraction and contamination. The wearable biosensors could significantly power mass surveillance technologies to fight against the COVID-19 pandemic. Graphical abstract Supplementary Information The online version contains supplementary material available at 10.1007/s44164-022-00022-z.