Pilot-scale Production of Functionalized mcl-PHA from Grape Pomace Supplemented with Fatty Acids

Bioprocess optimization is a prime target to decrease the cost of functionalized medium-chain-length poly(3-hydroxyalkanoate) (mcl-PHA). We have already demonstrated at the laboratory scale that the pomace of white wine grapes is a promising growth substrate for the biosynthesis of mcl-PHA that is both cheap and does not compete with food and land use. Here, we report the scale-up of a 2-step, 100 L bioprocess with Pseudomonas putida KT2440 involving: (1) a batch growth phase on extract of Gewürztraminer grape pomace, and (2) a fed-batch polymer accumulation phase with a linear feed of 50 mol % octanoic acid and 50 mol % 10-undecenoic acid. With this approach, we achieved a cell dry weight of 14.2 ± 0.3 g L–1 containing 41.1 ± 1.3 wt % of poly(3-hydroxyoctanoate-co-3-hydroxy-10-undecenoate) with 53 mol % and 47 mol % of saturated and unsaturated monomers, respectively. The molecular weight (Mw) was 139 000 Da (PDI = 1.97) and DSC analysis showed a Tg of –45.5 °C but no Tm thus indicating a completely amorphous polymer

A novel transflectance near infrared spectroscopy technique for monitoring hot melt extrusion

yesA transflectance near infra red (NIR) spectroscopy approach has been used to simultaneously measure drug and plasticiser content of polymer melts with varying opacity during hot melt extrusion. A high temperature reflectance NIR probe was mounted in the extruder die directly opposed to a highly reflective surface. Carbamazepine (CBZ) was used as a model drug, with polyvinyl pyrollidone-vinyl acetate co-polymer (PVP-VA) as a matrix and polyethylene glycol (PEG) as a plasticiser. The opacity of the molten extrudate varied from transparent at low CBZ loading to opaque at high CBZ loading. Particulate amorphous API and voids formed around these particles were found to cause the opacity. The extrusion process was monitored in real time using transflectance NIR; calibration and validation runs were performed using a wide range of drug and plasticiser loadings. Once calibrated, the technique was used to simultaneously track drug and plasticiser content during applied step changes in feedstock material. Rheological and thermal characterisations were used to help understand the morphology of extruded material. The study has shown that it is possible to use a single NIR spectroscopy technique to monitor opaque and transparent melts during HME, and to simultaneously monitor two distinct components within a formulation

Cancer Cell Invasion Is Enhanced by Applied Mechanical Stimulation

Metastatic cells migrate from the site of the primary tumor, through the stroma, into the blood and lymphatic vessels, finally colonizing various other tissues to form secondary tumors. Numerous studies have been done to identify the stimuli that drive the metastatic cascade. This has led to the identification of multiple biochemical signals that promote metastasis. However, information on the role of mechanical factors in cancer metastasis has been limited to the affect of compliance. Interestingly, the tumor microenvironment is rich in many cell types including highly contractile cells that are responsible for extensive remodeling and production of the dense extracellular matrix surrounding the cancerous tissue. We hypothesize that the mechanical forces produced by remodeling activities of cells in the tumor microenvironment contribute to the invasion efficiency of metastatic cells. We have discovered a significant difference in the extent of invasion in mechanically stimulated verses non-stimulated cell culture environments. Furthermore, this mechanically enhanced invasion is dependent upon substrate protein composition, and influenced by topography. Finally, we have found that the protein cofilin is needed to sense the mechanical stimuli that enhances invasion. We conclude that other types of mechanical signals in the tumor microenvironment, besides the rigidity, can enhance the invasive abilities of cancer cells in vitro. We further propose that in vivo, non-cancerous cells located within the tumor micro-environment may be capable of providing the necessary mechanical stimulus during the remodeling of the extracellular matrix surrounding the tumor

Disruption of Higher Order DNA Structures in Friedreich's Ataxia (GAA)n Repeats by PNA or LNA Targeting

Expansion of (GAA)n repeats in the first intron of the Frataxin gene is associated with reduced mRNA and protein levels and the development of Friedreich’s ataxia. (GAA)n expansions form non-canonical structures, including intramolecular triplex (H-DNA), and R-loops and are associated with epigenetic modifications. With the aim of interfering with higher order H-DNA (like) DNA structures within pathological (GAA)n expansions, we examined sequence-specific interaction of peptide nucleic acid (PNA) with (GAA)n repeats of different lengths (short: n=9, medium: n=75 or long: n=115) by chemical probing of triple helical and single stranded regions. We found that a triplex structure (H-DNA) forms at GAA repeats of different lengths; however, single stranded regions were not detected within the medium size pathological repeat, suggesting the presence of a more complex structure. Furthermore, (GAA)4-PNA binding of the repeat abolished all detectable triplex DNA structures, whereas (CTT)5-PNA did not. We present evidence that (GAA)4-PNA can invade the DNA at the repeat region by binding the DNA CTT strand, thereby preventing non-canonical-DNA formation, and that triplex invasion complexes by (CTT)5-PNA form at the GAA repeats. Locked nucleic acid (LNA) oligonucleotides also inhibited triplex formation at GAA repeat expansions, and atomic force microscopy analysis showed significant relaxation of plasmid morphology in the presence of GAA-LNA. Thus, by inhibiting disease related higher order DNA structures in the Frataxin gene, such PNA and LNA oligomers may have potential for discovery of drugs aiming at recovering Frataxin expression

Upon impact: the fate of adhering <i>Pseudomonas fluorescens</i> cells during Nanofiltration

Nanofiltration (NF) is a high-pressure membrane filtration process increasingly applied in drinking water treatment and water reuse processes. NF typically rejects divalent salts, organic matter, and micropollutants. However, the efficiency of NF is adversely affected by membrane biofouling, during which microorganisms adhere to the membrane and proliferate to create a biofilm. Here we show that adhered Pseudomonas fluorescens cells under high permeate flux conditions are met with high fluid shear and convective fluxes at the membrane-liquid interface, resulting in their structural damage and collapse. These results were confirmed by fluorescent staining, flow cytometry, and scanning electron microscopy. This present study offers a 'first-glimpse' of cell damage and death during the initial phases of bacterial adhesion to NF membranes and raises a key question about the role of this observed phenomena during early-stage biofilm formation under permeate flux and cross-flow conditions.European Research Council (ERC

Symptoms and quality of life at 1-year follow up of patients discharged after an acute COVID-19 episode.

Patients surviving COVID-19 have been described as being at risk of developing sequelae. We aimed to investigate and elicit persistent symptoms, emotional status and quality-of-life in patients discharged after an acute COVID-19 episode. Patient-reported outcome measures were collected during a telephone interview 30 days and 1 year after discharge. Patients' general health status was evaluated using questions based on their symptoms, emotional status was assessed using the items 9 to 12 of the HeartQoL questionnaire and quality of life was assessed at 1 year through the EQ-5D-5L. In patients with a history of cardiovascular disease, all 14 items of the HeartQoL questionnaire were completed to derive the HeartQoL global score. Among 687 patients who survived after being hospitalised for COVID-19 at the University Hospitals of Geneva between 26 February and 26 April 2020, 184 (27%) and 165 (24%), respectively, participated in the follow-up at 30 days and 1 year. Of these 184 participants, 62% were male, median age was 58 years and 21% had a past medical history of cardiovascular disease. At one month after discharge, 61% (113/184) of patients presented fatigue and 28% (52/184) dyspnoea. One year after discharge, the main complaints were persistent fatigue in 27% (45/165) of patients, neurological problems in 17% (28/165) and dyspnoea in 14% (23/165). Eight percent (14/184) of patients declared being significantly worried 1 month after discharge and 5% (9/184) feeling depressed. The number of patients reporting being significantly worried or depressed at 1 year was lower. Regarding the quality of life at 1 year, the median EQ-5D-5L visual analogue scale score was 80 (interquartile range 70-90). Approximately half of patients reported some symptoms 1 year after discharge following an acute episode of COVID-19. The predominant symptom was persistent fatigue both at 1-month and at 1-year follow-up. Emotional status and quality of life appeared satisfactory

Mortality and high risk of major adverse events in patients with COVID-19 and history of cardiovascular disease.

History of cardiovascular diseases (CVDs) may influence the prognosis of patients hospitalised for COVID-19. We investigated whether patients with previous CVD have increased risk of death and major adverse cardiovascular event (MACE) when hospitalised for COVID-19. We included 839 patients with COVID-19 hospitalised at the University Hospitals of Geneva. Demographic characteristics, medical history, laboratory values, ECG at admission and medications at admission were collected based on electronic medical records. The primary outcome was a composite of in-hospital mortality or MACE. Median age was 67 years, 453 (54%) were males and 277 (33%) had history of CVD. In total, 152 (18%) died and 687 (82%) were discharged, including 72 (9%) who survived a MACE. Patients with previous CVD were more at risk of composite outcomes 141/277 (51%) compared with those without CVD 83/562 (15%) (OR=6.0 (95% CI 4.3 to 8.4), p&lt;0.001). Multivariate analyses showed that history of CVD remained an independent risk factor of in-hospital death or MACE (OR=2.4; (95% CI 1.6 to 3.5)), as did age (OR for a 10-year increase=2.2 (95% CI 1.9 to 2.6)), male gender (OR=1.6 (95% CI 1.1 to 2.3)), chronic obstructive pulmonary disease (OR=2.1 (95% CI 1.0 to 4.2)) and lung infiltration associated with COVID-19 at CT scan (OR=1.9 (95% CI 1.2 to 3.0)). History of CVD (OR=2.9 (95% CI 1.7 to 5)), age (OR=2.5 (95% CI 2.0 to 3.2)), male gender (OR=1.6 (95% CI 0.98 to 2.6)) and elevated C reactive protein (CRP) levels on admission (OR for a 10 mg/L increase=1.1 (95% CI 1.1 to 1.2)) were independent risk factors for mortality. History of CVD is associated with higher in-hospital mortality and MACE in hospitalised patients with COVID-19. Other factors associated with higher in-hospital mortality are older age, male sex and elevated CRP on admission

Structure-activity relationship of new NLO organic materials based on push-pull azodyes. 4. Side chain polymers

Several new polymeric materials containing push–pull azobenzene derivatives in the side chains were synthesized by polymer-analogous reactions involving the coupling of the diazonium salts of 4-substituted anilines with a preformed polymer, poly(N-methacryloyl-N′-phenylpiperazine). The second harmonic generation properties of these glassy macromolecular materials were investigated in order to understand the influence of the chromophore chemical structure on dipole orientability and stability of orientation. The results thus obtained were compared with those of analogous guest–host systems and a lack of chromophore mobility was highlighted for the side chain polymers. The use of a short flexible spacer should probably improve the NLO performance