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An abdominal aortic aneurysm (AAA) is abnormal swelling in the abdominal aorta and a prevalent life-threatening disease. This research introduces a new interdigitated microelectrode (IDME)-sensing surface modified by iron oxide nanoworms (IONWs) for detecting the AAA biomarker insulin-like growth factor-1 (IGF1). A sandwich pattern was formulated with the IGF1 aptamer and IGFBP1 (IGF binding protein-1) on the IONW-constructed IDME hybrid to identify IGF1. The surface morphology of the IONWs revealed a uniform distribution of worm-like structures (80–100 nm) as confirmed by FESEM and FETEM analyses. Further, the presence of the major elements, Fe and O, was confirmed by EDX and XPS studies. The crystal planes that appeared in the IONW reflect cubic magnetite. IONW-modified IDME attained a limit of detection for IGF1 of 1 fM (3σ) with an aptamer-IGF1-IGFBP1 sandwich. This sandwich with IGFBP1 enhanced the current level at all concentrations of IGF1 and displayed linearity in the range 1 fM to 100 pM with a determination coefficient of R2 = 0.9373 [y = 3.38221x – 4.79]. Control experiments with complementary aptamer sequences, IGF2 and IGFBP3 did not show notable signal changes, indicating the specific detection of IGF1. This IONW constructed electrode helps to achieve the detection of low amounts of IGF1 and diagnose AAA at the stage prior to rupture. [ABSTRACT FROM AUTHOR]

To enhance corrosion resistance and hemocompatibility of magnesium alloy (Mg alloy), poly(ethylene glycol) methacrylate (PEGMA) was covalently bonded to micro-arc oxidation treated Mg alloy substrate via thiol-ene photochemistry using self-assembled (3-mercaptopropyl)trimethoxysilane film as spacer. Chemical composition of the modified surfaces was verified by attenuated total reflection Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy analysis and X-ray diffraction. Scanning electronic microscopy was used to show morphologies of the samples at different stages. Results of water contact angle measurement showed that the hydrophilicity of the surface has improved significantly after surface modification. Potentiodynamic polarization, electrochemical impedance spectroscopy and hydrogen evolution test demonstrated that corrosion resistance increased significantly for modified Mg alloy versus unmodified surfaces. In the meantime, the surface bonding of PEGMA imparted anti-platelet adhesion compared to the Mg alloy surface, displaying excellent hemocompatibility. This composite coating technique gives promise in acutely reducing both the corrosion and platelet adhesion, making it attractive for application to blood contacting material, such as vascular stents, made from degradable Mg alloys. [ABSTRACT FROM AUTHOR]

• Abdominal aortic aneurysm (AAA) is the vascular disease forming when aorta swells. • Insulin-like Growth Factor 1 (IGF1) is the circulating biomarker for AAA detected. • Improved ELISA through the aminated silica nanoparticle (SiO 2) mediation. • 400pM of IGF1 detected on amine-SiO 2 modified ELISA & 12.5 nM in conventional ELISA. • Detected in the mixture of IGF1 and relevant proteins (IGF2 and IGFBP3). Abdominal aortic aneurysm (AAA) is the vascular disease forming when aorta in the abdomen swells. AAA with the size of 5.5 and above has possibility to rupture and leads a death. Insulin-like Growth Factor 1 (IGF1) is the circulating biomarker for AAA diagnosis, in this study IGF1 was detected by the improved Enzyme linked Immunoassay (ELISA). The conventional ELISA necessitates the improvement due to the lesser sensitivity than modern sensors. Higher biomolecular immobilization is one of the wise ways to enhance the sensitivity. This study was aimed to capture a higher number of IGF1 on ELISA surface through the aminated silica (SiO 2) nanoparticle with the size measured to be 80−100 nm. On the amine-SiO 2 modified surface, Glutaraldehyde (GLU) complexed IGF1 was chemically bonded. It was found that 400 pM of IGF1 detected on amine-SiO 2 modified ELISA, whereas the conventional ELISA without nanoparticle mediation shows the limit of detection as 12.5 nM with ∼30 times lower detection. The selectivity experiment was carried out with the mixture of IGF1 and relevant proteins (IGF2 and IGFBP3), and it was noticed that anti-IGF1 selectively detected IGF1. This nanoparticle-mediated surface immobilization captured a higher rate of antigen on a larger surface created for high-performance detection. [ABSTRACT FROM AUTHOR]

In this study, micropatterns on polypropylene films were fabricated via plasma pretreatment and UV-initiated graft polymerization. Firstly, radio-frequency plasma, which does not significantly influence bulk attributes of substrates due to limited penetration depth, was utilized to activate polypropylene films. Then, different sizes of micropatterns of poly(hydroxyethyl methacrylate) (PHEMA) were fabricated on the polypropylene films via UV-initiated graft polymerization of hydroxyethyl methacrylate by using photo-masks. Scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, and contact angle (CA) were employed to characterize changes of pristine polypropylene films and modified ones in surface morphology, roughness, hydrophilicity, free energy and the surface chemical composition. All of these confirmed the successful grafting of different sizes of PHEMA micropatterns on the polypropylene surface. Furthermore, the influence of PHEMA micropatterns on cell proliferation and cytotoxicity was evaluated in vitro. Analysis of cell behaviour indicated that PHEMA micropatterns of the appropriate size can promote cellular adhesion and proliferation, and the PHEMA-micropatterned polypropylene films had good biocompatibility. The approach presented here provides an alternative to synthesize on the surface of polypropylene films’ micropatterns with the aim of using them in a diverse array of applications. [ABSTRACT FROM AUTHOR]

Functionalization of magnesium alloy (Mg alloy) with multiple bioactivities is desired to obtain surfaces with improved biocompatibility and antibacterial property. In this article, an anticorrosive and antimicrobial coating was prepared on Mg alloy surface by layer-by-layer (LbL) assembly of polyelectrolytes. A polycationic copolymer (P(DOP- co -DMAEMA + )) bearing dopamine (DOP) and 2-(methacryloxy)ethyl trimethylammonium chloride (DMAEMA + ) was synthesized and deposited on the surface of micro-arc oxidation (MAO) treated Mg alloy substrate as the first layer. The presence of DOP units ensure a strong anchoring on Mg alloy substrate, and the –N + (CH 3 ) 3 groups are sources of positive charge, providing electrostatic interaction with polyanion electrolyte. Negatively charged colloidal silver particles were prepared by using dextran sulfate (DS) as a stabilizer to precede chemical reduction by dextrose and served as a polyanion electrolyte. The functional polyelectrolyte multilayered films were obtained by alternating deposition P(DOP- co -DMAEMA + ) and DS-stabilized silver colloid (DS-Ag) in a spin-assisted LbL assembly manner. The prepared nanosized silver colloids and functionalized Mg alloy were characterized by ultraviolet–visible (UV–vis) spectroscopy, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Potentiodynamic polarization test confirmed that corrosion resistance of modified Mg alloy significantly increased and the fabricated polyelectrolyte multilayer films showed significant antibacterial activity. [ABSTRACT FROM AUTHOR]

To improve corrosion resistance and hemocompatibility of magnesium alloy (Mg alloy), a polymerized 2-methacryloyloxyethyl phosphorycholine (PMPC) coating was fabricated via surface thiol-ene photopolymerization onto Mg alloy treated by cathodic plasma electrolytic deposition (CPED). Surface morphology, chemical composition and phase composition of CPED layer and CPED/PMPC composite coating were investigated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD), respectively. Potentiodynamic polarization test and electrochemical impedance spectroscopy (EIS) illustrated that the corrosion resistane of Mg alloy in simulated body fluid (SBF) was significantly enhanced after the formation of CPED/PMPC composite coating. Platelets adhesion measurement indicated that CPED/PMPC treated Mg alloy possesses promising hemocompatibility. The approach presented here affords an effective alternative for surface modification of Mg alloy to meet the requirements of vascular scaffold materials. [ABSTRACT FROM AUTHOR]

Background: Prior studies reported that 5 ~ 32% COVID-19 patients were critically ill, a situation that poses great challenge for the management of the patients and ICU resources. We aim to identify independent risk factors to serve as prediction markers for critical illness of SARS-CoV-2 infection.Methods: Fifty-two critical and 200 non-critical SARS-CoV-2 nucleic acid positive patients hospitalized in 15 hospitals outside Wuhan from January 19 to March 6, 2020 were enrolled in this study. Multivariable logistic regression and LASSO logistic regression were performed to identify independent risk factors for critical illness.Results: Age older than 60 years, dyspnea, respiratory rate > 24 breaths per min, leukocytosis > 9.5 × 109/L, neutrophilia > 6.3 × 109/L, lymphopenia < 1.1 × 109/L, neutrophil-to-lymphocyte ratio > 3.53, fibrinogen > 4 g/L, d-dimer > 0.55 μg/mL, blood urea nitrogen > 7.1 mM, elevated aspartate transaminase, elevated alanine aminotransferase, total bilirubin > 21 μM, and Sequential Organ Failure Assessment (SOFA) score ≥ 2 were identified as risk factors for critical illness. LASSO logistic regression identified the best combination of risk factors as SOFA score, age, dyspnea, and leukocytosis. The Area Under the Receiver-Operator Curve values for the risk factors in predicting critical illness were 0.921 for SOFA score, 0.776 for age, 0.764 for dyspnea, 0.658 for leukocytosis, and 0.960 for the combination of the four risk factors.Conclusions: Our findings advocate the use of risk factors SOFA score ≥ 2, age > 60, dyspnea and leukocytosis > 9.5 × 109/L on admission, alone or in combination, to determine the optimal management of the patients and health care resources. [ABSTRACT FROM AUTHOR]