Development of a Paper-Based Microfluidic System for a Continuous High-Flow-Rate Fluid Manipulation.

The current study describes the development of a disposable paper-based microfluidic system, which unlike its predecessors that are only capable of processing a small amount of fluid, can continuously process the fluid at a high flow rate of up to 1.5 mL/min. The fabrication procedure was clean-room-free and robust, involving the use of a CO2 laser to engrave the microchannels on a paper substrate, followed by alkenyl ketene dimer treatment to hydrophobize the paper and lamination. The microchannel down to a minimum depth of ∼80 µm with an average roughness of ∼8 µm was engraved on the substrate. As a proof of concept, the applicability of this system to enrich the microparticles based on the inertial focusing mechanism was tested. This new generation of paper-based microfluidic system can be potentially used for the diagnostic applications where the analyte is low in quantity and processing a large volume of fluid sample is required.

Enhanced wound-healing efficacy of electrospun mesoporous hydroxyapatite nanoparticle-loaded chitosan nanofiber developed using pluronic F127.

One of the goals of wound repairing is to mimic the function and architecture of the native extracellular matrix (ECM). To this end, for the first time, we used pluronic F127 and mesoporous rod-like hydroxyapatite nanoparticles (mr-HAP NPs) simultaneously to prepare a novel low-diameter electrospun ECM-mimicking wound dressing based on a mixture of chitosan and polyethylene oxide. F127 is used as a surface tension regulator of the polymer solution. In addition, F127 has the special ability to reduce the size of nanofibers. mr-HAP NPs are used as cell proliferation accelerators which also improve the mechanical properties and water uptake capacity of the as-prepared dressing. The average size of nanofibers in the presence of F127 was about 110 nm which was more than 2.5 times lower than nanofibers prepared without F127. The water uptake capacity was evaluated to investigate the wound exudate absorption capacity of the wound dressing. It was observed that the incorporation of mr-HAP NPs into wound dressing structure increases the water uptake capacity by more than 2.5 times. Alongside the evaluation of cytocompatibility through in vitro cell viability assay, the wound healing efficacy was also determined in full-thickness skin wounds in a rat model for 15 days. The cytocompatible wound dressing showed significantly higher wound closure efficacy than the control group so the wounds healed entirely on the last day of the treatment period. As well, the pathology analysis proved better granulation tissue development and greater re-epithelialization. These findings are by virtue of the improved mechanical properties, accelerated cell migration and proliferation, proper environment for oxygen exchange, and enhanced exudate uptake of the wound dressing. These all are due to the presence of F127 and mr-HAP.

Rapid Detection of Gram-Positive and -Negative Bacteria in Water Samples Using Mannan-Binding Lectin-Based Visual Biosensor.

Waterborne bacterial infection is a health threat worldwide, making accurate and timely bacteria detection crucial to prevent waterborne disease outbreaks. Inspired by the intrinsic capability of mannan-binding lectin (MBL) in recognizing the pathogen-associated molecular patterns (PAMPs), a visual biosensor is developed here for the on-site detection of both Gram-positive and -negative bacteria. The biosensor was synthesized by immobilization of the MBL protein onto the blue carboxyl-functionalized polystyrene microparticles (PSM), which is then used in a two-step assay to detect bacterial cells in water samples. The first step involved a 20 min incubation following the MBL-PSM and calcium chloride solution addition to the samples. The second step was to add ethanol to the resultant blue mixture and observe the color change with the naked eye after 15 min. The biosensor had a binary (all-or-none) response, which in the presence of bacterial cells kept its blue color, while in their absence the color changed from blue to colorless. Testing the water samples spiked with four Gram-negative bacteria including Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa and two Gram-positive bacteria of Enterococcus faecalis and Staphylococcus aureus showed that the biosensor could detect all tested bacteria with a concentration as low as 101.5 CFU/ml. The performance of biosensor using the water samples from a water treatment plant also confirmed its capability to detect the pathogens in real-life water samples without the need for instrumentation.

Non-antibiotic antimicrobial agents to combat biofilm-forming bacteria.

Biofilms can be produced by multiple species or by a single strain of bacteria. The biofilm state enhances the resistance of the resident microorganisms to antimicrobial agents by producing extracellular polymeric substances. Typically, antibiotics are used to stop the growth of bacteria, but emerging resistance has limited their effectiveness. Bacteria in biofilms are less susceptible to antibiotics compared with their free-floating state, as biofilms impair antibiotic penetration. To obviate this challenge, non-antibiotic antimicrobial agents are needed. This review describes two classes of these agents, namely antimicrobial nanoparticles and antimicrobial peptides. Applications of these antimicrobials in the food industry and medical applications are discussed, and the directions for future research are highlighted.

An energy efficient production of high moisture barrier nanocellulose/carboxymethyl cellulose films via spray-deposition technique.

Nanocellulose (NC) films are considered as a prospective alternative to non-sustainable packaging materials, however, their higher embodied energy and limited moisture barrier properties are regarded as a huge constraint regarding their commercialization. This study aims to produce films with relatively low environmental impact and improved barrier performance. For this purpose, carboxymethyl cellulose (CMC) and NC were combined, and this resulted in multidimensional advantages. The mass production of films could be achieved in only 2 h (requiring at least 24 h under ambient conditions) when dried in an oven at 75 °C with enhanced mechanical properties and without compromising their dimensional stability. The moisture barrier properties of the NC/CMC films were improved up to 92 % compared with the NC films alone and the results achieved are comparable with packaging materials such as polyethylene terephthalate (PET), polycarbonates (PC) etc. Finally, the NC/CMC (1:1) films have low environmental impact compared with PET films.

Comparing the Effect of Foot Reflexology Massage, Foot Bath and Their Combination on Quality of Sleep in Patients with Acute Coronary Syndrome.

Introduction: Many patients in coronary care unit (CCU) suffer from decreased sleep quality caused by environmental and mental factors. This study compared the efficacy of foot reflexology massage, foot bath, and a combination of them on the quality of sleep of patients with acute coronary syndrome (ACS). Methods: This quasi-experimental study was implemented on ACS patients in Iran. Random sampling was used to divide the patients into four groups of 35 subjects. The groups were foot reflexology massage, foot bath, a combination of the two and the control group. Sleep quality was measured using the Veran Snyder-Halpern questionnaire. Data were analyzed by SPSS version 13. Results: The mean age of the four groups was 61.22 (11.67) years. The mean sleep disturbance in intervention groups (foot reflexology massage and foot bath groups) during the second and third nights was significantly less than before intervention. The results also showed a greater reduction in sleep disturbance in the combined group than in the other groups when compared to the control group. Conclusion: It can be concluded that the intervention of foot bath and massage are effective in reducing sleep disorders and there was a synergistic effect when used in combination. This complementary care method can be recommended to be implemented by CCU nurses.