Antibacterial and Antibiofilm Effects of Photodynamic Treatment with Curcuma L. and Trans-Cinnamaldehyde against Listeria monocytogenes.

Photodynamic inactivation (PDI) is a highly effective treatment that can eliminate harmful microorganisms in a variety of settings. This study explored the efficacy of a curcumin-rich extract, Curcuma L., (Cur)- and essential oil component, trans-cinnamaldehyde, (Ca)-mediated PDI against Listeria monocytogenes ATCC 15313 (Lm) including planktonic cells and established biofilms on silicone rubber (Si), polytetrafluoroethylene (PTFE), stainless steel 316 (SS), and polyethylene terephthalate (PET). Applying Ca- and Cur-mediated PDI resulted in planktonic cell reductions of 2.7 and 6.4 log CFU/cm2, respectively. Flow cytometric measurements (FCMs) coupled with CFDA/PI and TOTO®-1 staining evidenced that Ca- doubled and Cur-mediated PDI quadrupled the cell damage. Moreover, the enzymatic activity of Lm cells was considerably reduced by Cur-mediated PDI, indicating its superior efficacy. Photosensitization also affected Lm biofilms, but their reduction did not exceed 3.7 log CFU/cm2. Cur-mediated PDI effectively impaired cells on PET and PTFE, while Ca-mediated PDI caused no (TOTO®-1) or only slight (PI) cell damage, sparing the activity of cells. In turn, applying Ca-mediate PDI to Si largely diminished the enzymatic activity in Lm. SS contained 20% dead cells, suggesting that SS itself impacts Lm viability. In addition, the efficacy of Ca-mediated PDI was enhanced on the SS, leading to increased damage to the cells. The weakened viability of Lm on Si and SS could be linked to unfavorable interactions with the surfaces, resulting in a better effect of Ca against Lm. In conclusion, Cur demonstrated excellent photosensitizing properties against Lm in both planktonic and biofilm states. The efficacy of Ca was lower than that of Cur. However, Ca bears potent antibiofilm effects, which vary depending on the surface on which Lm resides. Therefore, this study may help identify more effective plant-based compounds to combat L. monocytogenes in an environmentally sustainable manner.

Comparison of Clinical Results of Crescent-Shaped Expanded Polytetrafluoroethylene (e-PTFE) and Granulated Rib Cartilage for Filling The Nasal Base to correct Midface Depressions.

Objective: The center of the face plays an important role in the fullness of our facial contours, however, sunken center of the face is more common in Asians than in Europeans and Americans. Expanded polytetrafluoroethylene (PTFE) and rib cartilage are commonly used to fill the nasal base to improve the hollowing of the center of the face. This study aimed to compare the efficacy and safety of crescent-shaped expanded polytetrafluoroethylene (e-PTFE) with granulated rib cartilage for nasal base filling to treat midface depressions. Methods: Fifty-one patients with mild to moderate midface depression and normal occlusion admitted to our department from June 2017 to August 2020 were selected. Comprehensive rhinoplasty was performed, which included nasal base filling using crescentic e-PTFE or granulated rib cartilage. They are all women, with an average age of 27.4 years. The e-PTFE group (group A) had 27 cases, while the granulated rib cartilage group (group B) had 24. Changes in two face parameters, the wing ear line and facial convexity, were measured and recorded based on preoperative and postoperative photographs of the patients and using 3D imaging technology. Postoperative complications and satisfaction were assessed by questionnaires to compare the two surgical approaches' differences, advantages, and disadvantages. Results: Postoperative midface depression improved significantly in 51 patients. Most of the patients who underwent both procedures showed significant improvement in the wing ear line and facial convexity. The 3D imaging has also helped us to more objectively assess the changes in midface concavity. Some patients experienced acute discomfort, such as foreign body sensation and stiffness in the surgical area, for the first three months after nasal base filler surgery. Still, these symptoms resolved on their own within six months. Most patients (92.6% in group A and 91.6% in group B) felt that they had natural facial expressions and were satisfied with the filler results. Conclusion: The use of crescentic e-PTFE and granular rib cartilage to fill the nasal base is easy to operate and has a quick postoperative recovery, allowing for good postoperative results. However, after some of the granular rib cartilage filling treatments, the height of the nasal base was lowered, which may be connected to its limited structural support, ease of displacement, and resorption. Crescentic e-PTFE is superior to granular rib cartilage in terms of both morphology and mechanical support. The crescentic e-PTFE filling method provides rapid postoperative recovery and good shape maintenance, but local stiffness is more pronounced than in the granular rib cartilage group. This may help the plastic surgeon's choice of surgical procedure.

Treatment of a synthetic decanted oily seawater in a pilot-scale hollow fiber membrane filtration process: Experimental investigation.

This study investigates the performance of a pilot-scale submerged hollow fiber (HF) ultrafiltration (UF) polytetrafluoroethylene (PTFE) membrane filtration system for the treatment of two different types of oily seawater (i.e., seawater contaminated with light and heavy crude oil). The effects of membrane flux and aeration flow rate on membrane performance and the removal efficiency of different fractions of hydrocarbon, including polycyclic aromatic hydrocarbons (PAHs) were examined. The results for both heavy and light crude oil contaminated wastewater reveal that total petroleum hydrocarbon (TPH) removal efficiency of more than 91% was achieved. This research paper determined the optimal operational parameters for an HF membrane filtration system to obtain a good TPH removal efficiency. This system can easily be upscaled and placed on a barge to treat oily wastewater generated from marine oil spills, which can significantly improve the oil spill response capacity.

Is there tea complemented with the appealing flavor of microplastics? A pioneering study on plastic pollution in commercially available tea bags in Bangladesh.

Microplastic pollution is a global concern, mainly due to its adverse effects on organisms and ecosystems. However, our knowledge of its impact on humans, in particular, is still very limited. Thus, while we have not gathered definitive information on their consequences, studies that aim to identify the MP's sources constitute subsidies to better understand the various exposure pathways to these pollutants. Thus, we investigated the possible presence of MP-like particles in teabag samples (of different brands) obtained in Dhaka, Bangladesh. Surprisingly, all analyzed samples (five brands) were contaminated with MPs. Fragments and fibers were identified in a higher percentage, and a wide variety of colors was identified, with a predominance of brown, blue, and red colors. Scanning electron microscope images of teabags exhibited net-like structures of fiber particles with a smooth surface. Furthermore, we observed irregularly shaped MPs and rougher surfaces and fragments in the process of detachment from the main fiber, oxidation flakes, and fracture-like. The average size of these pollutants was between 200.6 and 220.7 µm, and the polymer types identified via Fourier-transform infrared spectroscopy (FT-IR) were polytetrafluoroethylene, high-density polyethylene, polycarbonate, nylon, polyvinyl chloride, polytetrafluoroethylene, ethylene-vinyl acetate, cellulose acetate, and acrylonitrile butadiene styrene, the last three being the most frequent in the analyzed samples. Finally, we noticed that MPs from tea bags in Dhaka could cause an average emission of 10.9 million grams of MPs/year. Although the teabags analyzed in our study are not "complemented with the appealing flavor of MPs", it is very likely that tea ingestion in Dhaka is accompanied by the concomitant ingestion of plastic particles making teabags an important route of human exposure to these micropollutants.

Green Preparation of a Carboxymethyl Cellulose-Coated Membrane for Highly Efficient Separation of Crude Oil-In-Water Emulsions.

Developing high-performance membranes is an extremely significant strategy to combat increasing severe oil pollution. However, most of the previously reported superwettable membranes have been inevitably involved with the use of toxic solvents and complicated preparation processes. In addition, most of them lacked the capacity of separating crude oil-in-water emulsions. Herein, a facile and green strategy is employed to fabricate a polytetrafluoroethylene (PTFE) membrane with a mixed suspension of PDA@ZIF-8 and carboxymethyl cellulose (CMC) using water as a solvent via the vacuum filtration method. Combining hydrophilic property with micro-nano-roughness, the CMC-PDA@ZIF-8-coated PTFE membrane (CPZP membrane) exhibits excellent underwater superoleophobicity. More importantly, the separation efficiency of various surfactant-stabilized oil-in-water emulsions including crude oil/water emulsion is higher than 99.2% with a flux up to 1306.5 L m-2 h-1, and the separation performance remains nearly the same after 10 cycles. Moreover, outstanding underwater superoleophobic and self-cleaning properties are maintained after long-distance sandpaper abrasion and multiple bending tests. Meanwhile, its exceptional separation performance is still maintained in harsh environments (3.5 wt % NaCl, 1 M HCl, 60 °C hot water) even after immersing it for 24 h. Therefore, this green-prepared and high-performance membrane has tremendous application prospects in treating oily wastewater.

Investigation of the effects of biomaterials on proton Bragg peak and secondary neutron production by the Monte Carlo method in the slab head phantom.

Interest in proton therapy has increased in the last decade, as protons are effective to treat deeply located tumors, cause less damage to healthy tissue and allow controlling the energy to be transferred in a target-oriented manner (or energy transfer within target limits). It is known that secondary particles such as neutrons are produced by a result of nuclear interactions of protons with the target. Secondary neutrons can cause an uncontrolled dose increase in healthy tissue near the target site, and because they have a high radiobiological effectiveness, they raise the risk of secondary cancer. There are not enough studies examining the effect of biomaterials on secondary neutron production (SNP) in proton therapy. This study aims to investigate the effect of biomaterials used as implants instead of cranium in the skull on proton depth dose distribution and SNP with Monte Carlo-based PHITS code. Therefore, Bragg peaks and SNPs for 40-140 MeV energy protons were calculated and compared with the literature in a slab head phantom containing stainless steel, CoCrMo (CCM) alloy, alumina, polytetrafluoroethylene, Ti alloy, and NiTi alloy biomaterials used in cranioplasty. It was observed that the most compatible biomaterial compared to cranium for all energies is polytetrafluoroethylene. When polytetrafluoroethylene biomaterial was placed instead of the cranium in the skull, the Bragg peak position of the 100 MeV protons was decreased by 5.04% compared to that in the cranium. In this case, the energy absorbed in the polytetrafluoroethylene biomaterial increased by approximately 28% compared to the cranium, while it decreased by approx. 4% in the brain tissue. It was also observed that while SNP was 0.0501 in the cranium, it increased by almost 18% in PTFE.

Preservation of oil slick samples on adsorbent Teflon fabric: Potential for deployment aboard autonomous surface vessels.

In this communication, we report results of an experiment in which crude oil adsorbed on Teflon fabric is exposed to conditions expected in natural ocean-surface collection vehicle containers over a period of 3 months. Samples were recovered at designated time points and analyzed to determine degree of preservation of molecular signatures. Ratios of saturate hydrocarbons were preferentially preserved compared to those of aromatic compounds. Unsubstituted aromatic compounds such as naphthalene and dibenzothiophene were removed at higher rates relative to methyl-substituted homologues owing to differences in biodegradability and solubility. Ratios of important marker compounds persist over several months with sufficient fidelity for accurate determination of source-rock facies and thermal maturity. Collection and storage of oil samples on small pieces of adsorbent Teflon mesh broadens the opportunity space for collection of organic geochemistry data. Deployment of automated samplers equipped with such Teflon meshes aboard autonomous surface vehicles and human-operated vessels promises cheaper, better coverage of geochemical data in seep, slick, and spill surveys conducted for research, exploration, monitoring, and emergency response efforts.

Does washing medical devices before and after use decrease bacterial contamination?: An in vitro study.

ABSTRACT: Surface treatment of medical devices may be a way of avoiding the need for replacement of these devices and the comorbidities associated with infection. The aim of this study was to evaluate whether pre- and postcontamination washing of 2 prostheses with different textures can decrease bacterial contamination.The following microorganisms were evaluated: Staphylococcus aureus, Staphylococcus epidermidis, Proteus mirabilis and Enterococcus faecalis. Silicone and expanded polytetrafluoroethylene vascular prostheses were used and divided into 3 groups: prostheses contaminated; prostheses contaminated and treated before contamination; and prostheses contaminated and treated after contamination. Treatments were performed with antibiotic solution, chlorhexidine and lidocaine. After one week of incubation, the prostheses were sown in culture medium, which was incubated for 48 hours. The area of colony formation was evaluated by fractal dimension, an image analysis tool.The antibiotic solution inhibited the growth of S epidermidis and chlorhexidine decrease in 53% the colonization density for S aureus in for both prostheses in the pre-washing. In postcontamination washing, the antibiotic solution inhibited the growth of all bacteria evaluated; there was a 60% decrease in the colonization density of S aureus and absence of colonization for E faecalis with chlorhexidine; and lidocaine inhibited the growth of S aureus in both prostheses.Antibiotic solution showed the highest efficiency in inhibiting bacterial growth, especially for S epidermidis, in both washings. Lidocaine was able to reduce colonization by S aureus in post-contamination washing, showing that it can be used as an alternative adjuvant treatment in these cases.

Reliable identification of cardiac liability in drug discovery using automated patch clamp: Benchmarking best practices and calibration standards for improved proarrhythmic assessment.

INTRODUCTION: Screening compounds for activity on the hERG channel using patch clamp is a crucial part of safety testing. Automated patch clamp (APC) is becoming widely accepted as an alternative to manual patch clamp in order to increase throughput whilst maintaining data quality. In order to standardize APC experiments, we have investigated the effects on IC50 values under different conditions using several devices across multiple sites. METHODS: APC instruments SyncroPatch 384i, SyncroPatch 384PE and Patchliner, were used to record hERG expressed in HEK or CHO cells. Up to 27 CiPA compounds were used to investigate effects of voltage protocol, incubation time, labware and time between compound preparation and experiment on IC50 values. RESULTS: All IC50 values of 21 compounds recorded on the SyncroPatch 384PE correlated well with IC50 values from the literature (Kramer et al., 2013) regardless of voltage protocol or labware, when compounds were used immediately after preparation, but potency of astemizole decreased if prepared in Teflon or polypropylene (PP) compound plates 2-3 h prior to experiments. Slow acting compounds such as dofetilide, astemizole, and terfenadine required extended incubation times of at least 6 min to reach steady state and therefore, stable IC50 values. DISCUSSION: Assessing the influence of different experimental conditions on hERG assay reliability, we conclude that either the step-ramp protocol recommended by CiPA or a standard 2-s step-pulse protocol can be used to record hERG; a minimum incubation time of 5 min should be used and although glass, Teflon, PP or polystyrene (PS) compound plates can be used for experiments, caution should be taken if using Teflon, PS or PP vessels as some adsorption can occur if experiments are not performed immediately after preparation. Our recommendations are not limited to the APC devices described in this report, but could also be extended to other APC devices.

Closed incisional negative pressure therapy may reduce surgical site infection rate following endophlebectomy with complementary polytetrafluoroethylene arteriovenous fistula of the common femoral vein.

OBJECTIVE: Surgical desobliteration or endophlebectomy of the common femoral vein during deep venous recanalization with complementary polytetrafluoroethylene (PTFE) arteriovenous fistula (AVF), may lead to higher rates of surgical site infection (SSI). It has been reported that closed incisional negative pressure wound therapy (cINPT) may decrease SSI rates after different surgical procedures. The aim of this study was to determine the potential effect of cINPT on the SSI rate of femoral endophlebectomy with a complimentary PTFE AVF. METHODS: Patients with recanalization of the femoral-iliac veins and femoral endophlebectomy with a complementary PTFE AVF and postoperative cINPT were identified. SSI, patency, and complication rates were analyzed. RESULTS: This study included 65 patients with a mean age of 41 ± 14 years. The mean procedure time was 240 ± 11.9 minutes. Primary patency rate was 69.2% and secondary patency rate was 78.4%. SSI classified as Szilagyi I, II, and III occurred in 7.6% (n = 5), 3% (n = 2), and 7.6% (n = 5), respectively, with an overall SSI rate of 18.2%. Surgical wound revision with the application of a vacuum pump was required in 10.7% (n = 7). A multivariate analysis showed that the duration of the surgical procedure (P = .003) as well as lymphatic fistulas (P = .044) to have a significant impact on the SSI rate. CONCLUSIONS: Endophlebectomy with complementary PTFE AVF of the femoral vein is related to an increased rate of lymphatic leakage and SSI. Lymphatic fistula and the duration of surgery could be assessed as relevant influencing factors of SSI. Application of cINPT in this surgical setting may reduce the SSI rate. Despite this potential improvement, SSI rates still limit the clinical success of a deep venous recanalization.

Effectiveness and Safety of Rivaroxaban Compared to Acenocumarol after Infrainguinal Surgical Revascularization.

BACKGROUND: Optimal antithrombotic therapy after lower limb infrainguinal revascularization remains a controversial topic. The use of anticoagulants, alone or in combination with antiplatelet drugs, can potentially improve patency rate and limb salvage, particularly in patients with risk factors for early thrombosis. Bleeding is the main complication of long-term anticoagulant use. New oral anticoagulants can represent an attractive alternative to the standard vitamin K antagonists. The objective of the study is to evaluate the effectiveness (bypass occlusion and major amputation) and safety (major bleeding and all-cause mortality) of rivaroxaban compared to acenocumarol after infrainguinal lower limb surgical revascularization. MATERIAL AND METHODS: Retrospective cohort study of patients with peripheral arterial disease submitted to lower limb infrainguinal bypass revascularization with vein or expanded polytetrafluoroethylene conduit, who were anticoagulated with acenocumarol or rivaroxaban after hospital discharge. Patients with proximal revascularization, revascularization due to any pathology other than peripheral arterial disease, coagulation disorder, stroke or acute myocardial infarction in less than 30 days, glomerular filtration rate <15 mL/min, or on hemodialysis were excluded. RESULTS: One hundred nine patients were included (78.9% male), with a mean age of 64.8 years. After hospital discharge, 40 patients (36.7%) were medicated with rivaroxaban and 69 patients (63.3%) with acenocumarol. At 1 year of follow-up, patients under rivaroxaban and acenocumarol presented comparable major amputation rates (12.5 % vs. 10.1%, P = 0.756), bypass occlusion (22.5% vs. 24.6 %, P = 0.769), and mortality rate (10% vs. 8.7%, P = 0.756). Major bleeding occurred in 13.8% of patients. Patients with renal dysfunction had significantly higher bleeding risk with acenocumarol (45.5% vs. 0%, P = 0.028) compared to rivaroxaban, while patients with normal renal function presented similar bleeding rates with both anticoagulants (6.1% vs. 6.4%, P = 0.953). CONCLUSIONS: Rivaroxaban has equivalent effectiveness to acenocumarol after infrainguinal bypass revascularization, with similar occlusion, major amputation, and mortality rates. Rivaroxaban has an improved safety profile in patients with moderate renal dysfunction due to a significantly lower incidence of major bleeding. In patients with normal renal function, rivaroxaban and acenocumarol present equivalent major bleeding rates.

Fabrication of 3D continuous-flow reverse-transcription polymerase chain reaction microdevice integrated with on-chip fluorescence detection for semi-quantitative assessment of gene expression.

We fabricate a three-dimensional (3D) microdevice operated with minimal peripheral accessories, including a portable pump for semi-automated sample delivery and a single heater for temperature control, for performing reverse transcription polymerase chain reaction (RT-PCR) integrated with a downstream fluorescence detection module for semi-quantitative assessment of gene expression. The microdevice was fabricated by wrapping a polytetrafluoroethylene (PTFE) tube around a pre-designed polycarbonate mold to create a seamless microchannel for both the reverse transcription (RT) of RNA and the amplification of complementary DNA. In addition, a silicone tube, which underwent a two-step surface modification mediated by polyethyleneimine and glutaraldehyde coating, was connected at the outlet to capture amplicons downstream of the PTFE tube for on-site fluorescence detection. This fabrication method enabled continuous-flow RT-PCR (CF RT-PCR) using the 3D CF RT-PCR microdevice as a reactor, a single heater for the temperature control of both RT and PCR processes, and a disposable plastic syringe for semi-automated sample delivery. The microdevice was successfully implemented for the identification of the ß-actin gene, a constitutively expressed gene in all cells, and the sphingosine-1-phosphate lyase 1 gene, a potential pharmacological target gene in the diagnosis of cancer, diabetes, and atherosclerosis. This portable integrated microdevice offers a potential approach towards preliminary studies of gene expression and identification of RNA viruses.

PROPERTIES OF THERMOLUMINESCENT CARDS WITH HIGH SENSITIVE GR-200A LiF:Mg,Cu, P DETECTORS FOR HARSHAW AUTOMATIC READER.

New DML TL cards with GR-200A detectors were developed. The TL sensitivity remains stable and the detectors were sealed firmly during the encapsulation process. The sensitivity, detection threshold, residual signal, reusability, dose response and Teflon capsule resistance of DML cards with two GR-200A detectors with diameter 3.6 mm and thickness 0.38 mm placed in positions 2 and 3 were evaluated. The detection thresholds were 0.61 µSv for the detector at position 2 and 1.15 µSv for the detector at position 3. The residual signals were 0.40% for the detector at position 2 and 0.57% for the detector at position 3. The 10 repeated readings of the same 10 irradiated cards were found within 1% for the two detectors on the cards. The DML cards demonstrate very high sensitivity, low background and good stability and can be used for very low dose ranges in personnel dosimetry and in environmental monitoring.

Non-stick properties of thin-film coatings on dental-restorative instruments.

The non-stick properties of thin-film coatings on dental-restorative instruments were investigated by static contact-angle measurement using dental filler resin as well as by scanning electron microscopy of the amount of sticking dental restorative material. Furthermore, using a customized dipping measurement set-up, non-stick properties were evaluated by measuring force-by-time when the instrument was pulled out of restorative material. Minor improvements in non-stick properties were obtained with commercial diamond-like carbon and commercial polytetrafluoroethylene-based coatings. Major improvements were obtained with an in-house fabricated superhydrophobic coating prepared by a multistep process consisting of surface microstructuring by etching in hydrogen fluoride (HF): hydrogen peroxide (H2 O2 ) (1:1; vol/vol), atomic layer deposition of a 7 nm coating of aluminium oxide and titanium oxide, and a self-assembled monolayer of fluorinated organosilicon. Superhydrophobic coatings provide a possible future solution to prevent unwanted adnerence of composite restorative material to dental instruments.

Protective effect of Tremella fuciformis Berk extract on LPS-induced acute inflammation via inhibition of the NF-κB and MAPK pathways.

Tremella fuciformis Berk (TFB) has long been used as a traditional medicine in Asia. Although TFB exhibits antioxidant and anti-inflammatory effects, the mechanisms of action responsible have remained unknown. We confirmed the anti-inflammatory effects of Tremella fuciformis Berk extract (TFE) in RAW 264.7 cells and observed significantly suppressed LPS-induced iNOS/NO and COX-2/PGE2 production. TFE also suppressed LPS-induced IKK, IkB, and p65 phosphorylation, as well as LPS-induced translocation of p65 from the cytosol. Additionally, TFE inhibited LPS-induced phosphorylation of MAPKs. In an acute inflammation study, oral administration of TFE significantly inhibited LPS-induced IL-1ß, IL-6 and TNF-α production and iNOS and COX-2 expression. The major bioactive compounds from TFB extract were identified as gentisic acid, protocatechuic acid, 4-hydroxybenzoic acid, and coumaric acid. Among these compounds, protocatechuic acid showed the strongest inhibitory effects on LPS-induced NO production in RAW 264.7 cells. Overall, these results suggest that TFE is a promising anti-inflammatory agent that suppresses iNOS/NO and COX-2/PGE2 expression, as well as the NF-κB and MAPK signaling pathways.

Use of array of conducting polymers for differentiation of coconut oil products.

An array of chemiresistors based on conducting polymers was assembled for the differentiation of coconut oil products. The chemiresistor sensors were fabricated through the potentiostatic electrodeposition of polyaniline (PANi), polypyrrole (PPy) and poly(3-methylthiophene) (P-3MTp) on the gap separating two planar gold electrodes set on a Teflon substrate. The change in electrical resistance of the sensors was measured and observed after exposing the array to the headspace of oil samples. The sensor response was found rapid, reversible and reproducible. Different signals were obtained for each coconut oil sample and pattern recognition techniques were employed for the analysis of the data. The developed system was able to distinguish virgin coconut oil (VCO) from refined, bleached & deodorised coconut oil (RBDCO), flavoured VCO, homemade VCO, and rancid VCO.

Selective isolation of hydrophobin SC3 by solid-phase extraction with polytetrafluoroethylene microparticles and subsequent mass spectrometric analysis.

Hydrophobins are small proteins that play a role in a number of processes during the filamentous fungi growth and development. These proteins are characterized by the self-assembly of their molecules into an amphipathic membrane at hydrophilic-hydrophobic interfaces. Isolation and purification of hydrophobins generally present a challenge in their analysis. Hydrophobin SC3 from Schizophyllum commune was selected as a representative of class I hydrophobins in this work. A novel procedure for selective and effective isolation of hydrophobin SC3 based on solid-phase extraction with polytetrafluoroethylene microparticles loaded in a small self-made microcolumn is reported. The tailored binding of hydrophobins to polytetrafluoroethylene followed by harsh elution conditions resulted in a highly specific isolation of hydrophobin SC3 from the model mixture of ten proteins. The presented isolation protocol can have a positive impact on the analysis and utilization of these proteins including all class I hydrophobins. Hydrophobin SC3 was further subjected to reduction of its highly stable disulfide bonds and to chymotryptic digestion followed by mass spectrometric analysis. The isolation and digestion protocols presented in this work make the analysis of these highly hydrophobic and compact proteins possible.

Merging drops in a Teflon tube, and transferring fluid between them, illustrated by protein crystallization and drug screening.

The ability to manipulate drops with small volumes has many practical applications. Current microfluidic devices generally exploit channel geometry and/or active external equipment to control drops. Here we use a Teflon tube attached to a syringe pump and exploit the properties of interfaces between three immiscible liquids to create particular fluidic architectures. We then go on to merge any number of drops (with volumes of micro- to nano-liters) at predefined points in time and space in the tube; for example, 51 drops were merged in a defined order to yield one large drop. Using a different architecture, specified amounts of fluid were transferred between 2 nl drops at specified rates; for example, 2.5 pl aliquots were transferred (at rates of ~500 fl s(-1)) between two drops through inter-connecting nano-channels (width ~40 nm). One proof-of-principle experiment involved screening conditions required to crystallize a protein (using a concentration gradient created using such nano-channels). Another demonstrated biocompatibility; drugs were mixed with human cells grown in suspension or on surfaces, and the treated cells responded like those grown conventionally. Although most experiments were performed manually, moderate high-throughput potential was demonstrated by mixing ~1000 different pairs of 50 nl drops in ~15 min using a robot. We suggest this reusable, low-cost, and versatile methodology could facilitate the introduction of microfluidics into workflows of many experimental laboratories.

On the potential for fibronectin/phosphorylcholine coatings on PTFE substrates to jointly modulate endothelial cell adhesion and hemocompatibility properties.

The use of biomolecules as coatings on biomaterials is recognized to constitute a promising approach to modulate the biological response of the host. In this work, we propose a coating composed by 2 biomolecules susceptible to provide complementary properties for cardiovascular applications: fibronectin (FN) to enhance endothelialization, and phosphorylcholine (PRC) for its non thrombogenic properties. Polytetrafluoroethylene (PTFE) was selected as model substrate mainly because it is largely used in cardiovascular applications. Two approaches were investigated: 1) a sequential adsorption of the 2 biomolecules and 2) an adsorption of the protein followed by the grafting of phosphorylcholine via chemical activation. All coatings were characterized by immunofluorescence staining, X-Ray Photoelectron Spectroscopy and Scanning Electron Microscopy analyses. Assays with endothelial cells showed improvement on cell adhesion, spreading and metabolic activity on FN-PRC coatings compared with the uncoated PTFE. Platelets adhesion and activation were both reduced on the coated surfaces when compared with uncoated PTFE. Moreover, clotting time tests exhibited better hemocompatibility properties of the surfaces after a sequential adsorption of FN and PRC. In conclusion, FN-PRC coating improves cell adhesion and non-thrombogenic properties, thus revealing a certain potential for the development of this combined deposition strategy in cardiovascular applications.

Membrane distillation combined with an anaerobic moving bed biofilm reactor for treating municipal wastewater.

A fermentative strategy with an anaerobic moving bed biofilm reactor (AMBBR) was used for the treatment of domestic wastewater. The feasibility of using a membrane separation technique for post-treatment of anaerobic bio-effluent was evaluated with emphasis on employing a membrane distillation (MD). Three different hydrophobic 0.2 µm membranes made of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), and polypropylene (PP) were examined in this study. The initial permeate flux of the membranes ranged from 2.5 to 6.3 L m(-2) h(-1) when treating AMBBR effluent at a temperature difference between the feed and permeate streams of 20 °C, with the permeate flux increasing in the order PP < PVDF < PTFE. The permeate flux of the PTFE membrane gradually decreased to 84% of the initial flux after the 45 h run for distillation, while a flux decline in MD with either the PVDF or PP membrane was not found under the identical distillation conditions. During long-term distillation with the PVDF membrane, total phosphorus was completely rejected and >98% rejection of dissolved organic carbon was also achieved. The characterization of wastewater effluent organic matter (EfOM) using an innovative suite of analytical tools verified that almost all of the EfOM was rejected via the PVDF MD treatment.