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Molecularly imprinted polymers (MIPs) have been utilized as biorecognition elements in various fields such as separation, sensing and imaging due to their easy accessibility and high binding capacity to target molecular analytes. To expand the application scope of MIPs and widen their range of targets to microorganisms, we have developed a methodology for the synthesis of MIP shells on the surface of polystyrene microparticles (MPs) with a binding affinity towards E. coli OP50 as a bacterial surrogate. Monodisperse MIP-based core–shell microparticles (MIP-MPs) with controllable shell thickness ranging from 0.25 μm to nearly 3.5 μm were produced using a stepwise polymerization method. Optical and fluorescence microscopy as well as scanning electron microscopy were used for characterization of MIP-MPs and MPs coated with non-imprinted polymers (i.e., NIP-MPs) under various timing and temperature settings. E. coli OP50 imprinting and rebinding experiments were conducted using the MIP-MPs with a suitable MIP shell thickness of 2–3 μm. Capturing experiments were carried out with different concentrations of NIP- and MIP-MPs (i.e., 102, 103 and 104 particles/mL) to investigate the uptake ratio of bacteria (104 cells/mL) and its particle dose-dependency. The optimum uptake ratio of E. coli was approximately 74%, which was achieved using 103 MIP-MPs/mL. NIP-MPs had reduced bacteria recovery and results were statistically lower than MIP-MPs, showing the affinity of our MIP shells towards microorganisms. The results reported here provide a new fabrication methodology and binding efficiency of core–shell MIP-MPs to bacteria, and can create the basis for the fabrication of various imprinted coating layers on spherical substrates with potential applications in bioseparation and point-of-care sensing. [Display omitted] • Polystyrene microparticles (MPs) with molecularly imprinted polymer (MIP) shells. • MIPs composed of four monomers for enhanced imprinting of bacteria cells on MPs. • Two-step temperature-dependent polymerization to control MIP shell thicknesses. • Optimum MIP-MPs to bacteria ratio of 1–10, showing high-level MIP imprinting. • MIP-MPs reached 74% bacteria capturing efficacy improving the state of the art. [ABSTRACT FROM AUTHOR]

Abstract: The purpose of this work was to produce and characterize SiO2–CaO–P2O5 bioactive glass nanoparticles with negative zeta potential for possible use in biomedical applications. 63S bioactive glass was obtained using the sol–gel method. X-ray fluorescence (XRF) spectroscopy and dispersive X-ray analysis (EDX) confirmed the preparation of the 63S bioactive glass with 62.17% SiO2, 28.47% CaO and 9.25% P2O5 (in molar percentage). The in vitro apatite forming ability of prepared bioactive glass was evaluated by Fourier transform infrared spectroscopy (FTIR) after immersion in simulated body fluid (SBF). The result showed that high crystalline hydroxyapatite can form on glass particles. By the gas adsorption (BET method), particle specific surface area and theoretical particle size were 223.6±0.5m2/g and ∼24nm, respectively. Laser dynamic light scattering (DLS) indicated particles were mostly agglomerated and had an average diameter between 100 and 500nm. Finally, using laser Doppler electrophoresis (LDE) the zeta potential of bioactive glass nanoparticles suspended in physiological saline was determined. The zeta potential was negative for acidic, neutral and basic pH values and was −16.18±1.8mV at pH 7.4. In summary, the sol–gel derived nanoparticles revealed in vitro bioactivity in SBF and had a negative zeta potential in physiological saline solution. This negative surface charge is due to the amount and kind of the ions in glass structure and according to the literature, promotes cell attachment and facilitates osteogenesis. The nanometric particle size, bioactivity and negative zeta potential make this material a possible candidate for bone tissue engineering. [Copyright &y& Elsevier]

In this paper, we applied a curved-channel microfluidic device to separate DNA from PCR-inhibitor-containing water and simultaneously wash them into clean water for detection using a portable PCR thermocycler. Environmental DNA (eDNA) sampling has become an effective surveying approach for detecting rare organisms. However, low concentration eDNA molecules may be masked by PCR inhibitors during amplification and detection, increasing the risk of false negatives. Therefore, technologies for on-site DNA separation and washing are urgently needed. Our device consisted of a half-circle microchannel with a DNA-inhibitor sample inlet, a clean buffer inlet, and multiple outlets. By using the flow-induced inertial forces, 10 μm DNA-conjugated microparticles were focused at the inner-wall of the curved microchannel while separation from 1 μm inhibitor-conjugated microparticles and DNA washing were achieved simultaneously with the Dean flow. We achieved singleplex focusing, isolation and washing of 10 μm particles at an efficiency of 94.5 ± 2.0%. In duplex experiments with 1 μm and 10 μm particles, larger particles were washed with an efficiency of 92.1 ± 1.6% and a purity of 79 ± 2%. By surface-functionalizing the microparticles with affinity groups against Atlantic salmon DNA and humic acid (HA), and processing samples of various concentrations in our device, we achieved an effective purification and detection of DNA molecules using the portable PCR thermocycler. Our method significantly decreased PCR quantitation cycles from Cq > 38 to Cq = 30.35 ± 0.5, which confirmed enhancement of PCR amplification. The proposed device takes a promising step forward in sample preparation towards an integrated device that can be used for simultaneous purification and solution exchange of DNA in point-of-need environmental monitoring applications. [Display omitted] • Integrated application of a microfluidic sample preparation chip with portable qPCR. • Dean flow microfluidic DNA separation from inhibitor molecules using microparticles. • Simultaneous DNA solution exchange to PCR buffer at continuous high flow rate. • Device performance characterized in various DNA and inhibitor configurations. • The microfluidic sample preparation significantly enhanced the performance of qPCR. [ABSTRACT FROM AUTHOR]

One of the significant challenges in bone tissue engineering is the fabrication of highly porous scaffolds with interconnected pores and appropriate mechanical properties. Artificial scaffolds which used in the field of medicine are usually made of single phase of polymer or ceramic. However, composition of these materials can produce the scaffolds with improve mechanical and biological properties.The aim of this study is to synthesize three-dimensional hardystonite-diopside (HT-Dio) porous scaffolds modified by polycaporolacton fumarate coating for low-load-bearing bone tissue engineering applications. The results showed that hardystonite scaffolds with 15 wt. % diopside and 6 w/v % polymer polycaporolacton fumarate (PCLF) had a significant bioactivity. The cell culture and cell attachment assay results revealed the well spreading of BMS cells on the surface of modified scaffolds which indicates the high biocompatibility of this scaffold. The modified scaffolds had a mean pore size, porosity, compressive strength, modules and toughness of 293.47 ± 5.51 μm, 74% ± 1.01, 3.37 ± 0.6 MPa, 151 ± 1.1 MPa and 31.3 ± 0.32 kJ/m3, respectively, which are in the appropriate range for spongy bone and hence can be a good candidate for bone tissue engineering applications. Image 1 • Highly porous diopside/hardystonite scaffolds were fabricated. • Applying a PCLF polymer coating doubled the compressive strength of the scaffolds. • The strengthening mechanisms were studied. • Bioactivity, biodegradability and cell viability of the scaffolds were improved. [ABSTRACT FROM AUTHOR]

In this research, Li/Sb Co-Doped KNN ferroelectric powders have been successfully prepared and sintered at various temperatures. The effect of sintering temperature on microstructure and ferroelectric properties of this ceramic was investigated. The results indicate that pure KNN-LS piezoceramic synthesized without formation of conventional tungsten bronze phase. After sintering, a broad trident peak (2θ about 45–47°) in XRD pattern was completely observed which can be a substantial evidence for polymorphic phase transition (PPT) at room temperature. In the FESEM images, for all sintering temperatures, the bimodal cube-like morphology of KNN-LS particles remarkably appeared. The values of relative density increase from about 91% to 93%, with increasing temperature from 1115 to 1120 °C. Further increment in temperature up to 1150 °C causes a serious reduction of relative density (~86%). From 1115 to 1120 °C, relative permittivity (ε r) increases due to about 2% increase in relative density then rapidly diminished when temperature reaches to 1150 °C. The maximum ferroelectric properties of Li/Sb Co-Doped KNN ceramic sintered at 1120 °C (the values of 17 and 14 μC/cm2 for the polarization saturation (P S) and polarization remanent (Pr), respectively) can be due to minimum pore volume of this ceramic during sintering process. [ABSTRACT FROM AUTHOR]

This study aimed to improve the biological properties and corrosion resistance of 316 L stainless steel substrate using polydimethylsiloxane (PDMS)‑silver doped Willemite nanocomposite coating. For this purpose, Ag-doped Willemite nanoparticles (NPs) were synthesized by the sol-gel method initially. Then, PDMS-Ag-doped Willemite nanocomposite coatings with various nanoparticles content were coated on the substrates using an immersion technique. The antibacterial results showed that Willemite NPs containing 5 wt% Ag possessed the highest antibacterial activity than the other samples. The examination of microstructure, hydrophobicity, adhesion strength, corrosion resistance, and biological characteristics of the coatings revealed that the addition of NPs up to 3 wt% enhances the surface roughness, hydrophobicity and coating adhesion. However, at concentrations greater than 3 wt% NPs, the coating's corrosion resistance is reduced owing to the formation of larger agglomerates and induced cracks in the coating. The presence of NPs in the coating promotes the adhesion and viability of bovine mesenchymal stem cells (bMSCs). • Fabrication of Ag-doped Willemite nanoparticles using sol-gel method. • Implementing PDMS-Ag-doped Willemite nanocomposite coatings in various concentrations of NPs on the 316 L stainless steel. • Examination of the composite coatings by FE-SEM, EDX, elemental mapping, XRD, FT-IR, hydrophobicity, adhesion strength, EIS and antibacterial analyses. • PDMS-Ag-doped Willemite nanocomposite coating with desirable biological characteristics and corrosion resistance can be regarded as a functional coating for bone-implant interfaces. [ABSTRACT FROM AUTHOR]

[Display omitted] • Advancements in air sampling devices for virus capturing and concentration. • Review and comparison of conventional and microfluidic virus detection methods. • Comparison of bioanalysis methods in conventional and microfluidic platforms. • Capabilities and future trends of microfluidics in virus handling and detection. With the COVID-19 pandemic, the threat of infectious diseases to public health and safety has become much more apparent. Viral, bacterial and fungal diseases have led to the loss of millions of lives, especially in the developing world. Diseases caused by airborne viruses like SARS-CoV-2 are difficult to control, as these viruses are easily transmissible and can circulate in the air for hours. To contain outbreaks of viruses such as SARS-CoV-2 and institute targeted precautions, it is important to detect them in air and understand how they infect their targets. Point-of-care (PoC) diagnostics and point-of-need (PoN) detection methods are necessary to rapidly test patient and environmental samples, so precautions can immediately be applied. Traditional benchtop detection methods such as ELISA, PCR and culture are not suitable for PoC and PoN monitoring, because they can take hours to days and require specialized equipment. Microfluidic devices can be made at low cost to perform such assays rapidly and at the PoN. They can also be integrated with air- and liquid-based sampling technologies to capture and analyze viruses from air and body fluids. Here, conventional and microfluidic virus detection methods are reviewed and compared. The use of air sampling devices to capture and concentrate viruses is discussed first, followed by a review of analysis methods such as immunoassays, RT-PCR and isothermal amplification in conventional and microfluidic platforms. This review provides an overview of the capabilities of microfluidics in virus handling and detection, which will be useful to infectious disease researchers, biomedical engineers, and public health agencies. [ABSTRACT FROM AUTHOR]