Nanoarchitectured air-stable supported lipid bilayer incorporating sucrose–bicelle complex system

Cell-membrane-mimicking supported lipid bilayers (SLBs) provide an ultrathin, self-assembled layer that forms on solid supports and can exhibit antifouling, signaling, and transport properties among various possible functions. While recent material innovations have increased the number of practically useful SLB fabrication methods, typical SLB platforms only work in aqueous environments and are prone to fluidity loss and lipid-bilayer collapse upon air exposure, which limits industrial applicability. To address this issue, herein, we developed sucrose–bicelle complex system to fabricate air-stable SLBs that were laterally mobile upon rehydration. SLBs were fabricated from bicelles in the presence of up to 40 wt% sucrose, which was verified by quartz crystal microbalance-dissipation (QCM-D) and fluorescence recovery after photobleaching (FRAP) experiments. The sucrose fraction in the system was an important factor; while 40 wt% sucrose induced lipid aggregation and defects on SLBs after the dehydration–rehydration process, 20 wt% sucrose yielded SLBs that exhibited fully recovered lateral mobility after these processes. Taken together, these findings demonstrate that sucrose–bicelle complex system can facilitate one-step fabrication of air-stable SLBs that can be useful for a wide range of biointerfacial science applications.

Probing the Lubrication of Shear-Induced Self-Assembled Layer on Amorphous Carbon Films in Methane Atmosphere

Demand for reduction in friction and improvement in wear resistance of moving parts propels exploration in frictional origin for amorphous carbon (a-C) film lubricating properties based on the interfacial states. Methane, as an ideal energy carrier and industrial raw material, is one of active gas. Consequently, the relations between the tribological behaviors of a-C film under methane atmosphere and load or interfacial states were discussed based on experimental and theoretical methods. Experimental results illustrated that, as the load increased, tribological system exhibited various interfacial shear strength at a load of zero and pressure dependence of the shear strength for tribological systems. And then the origin was revealed with theoretical calculation and resulted from the distributions of adsorbates across the sliding interface.

Development of Multiwalled Carbon Nanotube-Based Immunobiosensor for the Detection of Bluetongue Virus

Bluetongue (BT) disease is a noncontagious disease of domestic and wild ruminants (mainly sheep, cattle, deer) caused by the bluetongue virus (BTV) which is an orbivirus of the Reoviridae family and transmitted by vector Culicoides biting midges. It is a reportable disease of considerable socioeconomic concern and of major importance for the international trade of animals and animal products. Conventional diagnostic methods, such as virus propagation and isolation, immunoassays and also various molecular methods have been developed for the detection of the BTV. Here, we present a novel, rapid and pen-side test for the detection of BTV using multiwalled carbon nanotube (MWCNTs) based immunosensor. Though it is not reported yet. The MWCNTs were prepared, characterized and functionalized with carboxyl group. Viral antibodies were conjugated successfully with functionalized MWCNTs and coated on screen printed carbon electrode (SPCE). These SPCE were evaluated by using electrochemical sensor with an antigen specific to BTV antibodies, resulted in the self-assembled layer of antigen–antibody on the surface of SPCE. The approach described in the present study is a prototype for the development of simple and economic diagnostic tool which will provide the routine screening of BT disease at the door of farmers, thereby increasing the income of farmers by decreasing the cost of diagnosis.

Preparation and Antifouling Property of Polyurethane Film Modified by PHMG and HA Using Layer-by-Layer Assembly

To reduce the possibility of bacterial infection and implant-related complications, surface modification on polyurethane (PU) film is an ideal solution to endow hydrophobic PU with antibacterial and antifouling properties. In this work, a variety of polyhexamethylene guanidine/ hyaluronic acid (PHMG/HA) multilayer films were self-assembled layer-by-layer on PU films using polyanions, carboxyl-activated HA, and polycations PHMG by controlling the concentration of these polyelectrolytes as well as the number of layers self-assembled. Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) spectra, water contact angle (WCA), and A Atomic force microscope (AFM) of PU and modified PU films were studied. Protein adsorption and bacterial adhesion as well as the cytotoxicity against L929 of the film on selected PU-(PHMG/HA)5/5-5 were estimated. The results showed that PU-(PHMG/HA)5/5-5 had the best hydrophilicity among all the prepared films, possessing the lowest level of protein adsorption. Meanwhile, this film showed efficient broad-spectrum antibacterial performance as well as significant resistance of bacterial adhesion of more than a 99.9% drop for the selected bacteria. Moreover, almost no influence on cell viability of L929 enhanced the biocompatibility of film. Therefore, the modified PU films with admirable protein absorption resistance, antimicrobial performance, and biocompatibility would have promising applications in biomedical aspect.

Self-Assembled MoS2/ssDNA Nanostructures for the Capacitive Aptasensing of Acetamiprid Insecticide

The aim of this work is to detect acetamiprid using electrochemical capacitance spectroscopy, which is widely used as a pesticide in agriculture and is harmful to humans. We have designed aptasensing platform based on the adsorption of a DNA aptamer on lipoic acid-modified MoS2 nano-sheets. The biosensor takes advantage of the high affinity of single-stranded DNA sequences to MoS2 nano-sheets. The stability of DNA on MoS2 nano-sheets is assured by covalent attachment to lipoic acid that forms self-assembled layer on MoS2 surface. The biosensor exhibits excellent capacitance performances owing to its large effective surface area making it interesting material for capacitive transduction system. The impedance-derived capacitance varies with the increasing concentrations of acetamiprid that can be attributed to the aptamer desorption from the MoS2 nanosheets facilitating ion diffusion into MoS2 interlayers. The developed device showed high analytical performances for acetamiprid detection on electrochemical impedance spectroscopy EIS- derived capacitance variation and high selectivity toward the target in presence of other pesticides. Real sample analysis of food stuff such as tomatoes is demonstrated which open the way to their use for monitoring of food contaminants by tailoring the aptamer.

Engineering Murine Adipocytes and Skeletal Muscle Cells in Meat-like Constructs Using Self-Assembled Layer-by-Layer Biofabrication: A Platform for Development of Cultivated Meat

Global meat consumption has been growing on a per capita basis over the past 20 years resulting in ever-increasing devotion of resources in the form of arable land and potable water to animal husbandry which is unsustainable and inefficient. One approach to meet this insatiable demand is to use biofabrication methods used in tissue engineering in order to make skeletal muscle tissue-like constructs known as cultivated meat to be used as a food source. Here, we demonstrate the use of a scaffold-free biofabrication method that forms cell sheets composed of murine adipocytes and skeletal muscle cells and assembles these sheets in parallel to create a 3D meat-like construct without the use of any exogenous materials. This layer-by-layer self-assembly and stacking process is fast (4 days of culture to form sheets and few hours for assembly) and scalable (stable sheets with diameters >3 cm are formed). Tissues formed with only muscle cells were equivalent to lean meat with comparable protein and fat contents (lean beef had 1.5 and 0.9 times protein and fat, respectively, as our constructs) and incorporating adipocyte cells in different ratios to myoblasts and/or treatment with different media cocktails resulted in a 5% (low fat meat) to 35% (high fat meat) increase in the fat content. Not only such constructs can be used as cultivated meat, they can also be used as skeletal muscle models.

Mimicking the competitive and cooperative behaviors with multi-terminal synaptic memtransistors

The multi-terminal memtransistor is fabricated with a self-assembled layer of APTES to mimic the synaptic competitive and cooperative behaviors.