PLOS ONE: [sortOrder=DATE_NEWEST_FIRST, sort=Date, newest first, q=subject:"Membrane technology"]PLOShttps://journals.plos.org/plosone/webmaster@plos.orgaccelerating the publication of peer-reviewed sciencehttps://journals.plos.org/plosone/search/feed/atom?sortOrder=DATE_NEWEST_FIRST&unformattedQuery=subject:%22Membrane+technology%22&sort=Date,+newest+firstAll PLOS articles are Open Access.https://journals.plos.org/plosone/resource/img/favicon.icohttps://journals.plos.org/plosone/resource/img/favicon.ico2024-03-28T13:53:47ZPreparation of pH-sensitive nanogels bioconjugated with shark antibodies (VNAR) for targeted drug delivery with potential applications in colon cancer therapiesLizbeth A. Manzanares-GuevaraJahaziel Gasperin-BulbarelaOlivia Cabanillas-BernalMonserrat Renteria-MacielAngel Licea-ClaverieEugenio R. MéndezAlexei F. Licea-Navarro10.1371/journal.pone.02948742024-01-19T14:00:00Z2024-01-19T14:00:00Z<p>by Lizbeth A. Manzanares-Guevara, Jahaziel Gasperin-Bulbarela, Olivia Cabanillas-Bernal, Monserrat Renteria-Maciel, Angel Licea-Claverie, Eugenio R. Méndez, Alexei F. Licea-Navarro</p>
Cancer is the second leading cause of death worldwide. To combat this disease, novel and specialized therapeutic systems are urgently needed. This is the first study to explore a system that combines shark variable domain (Fv) of new antigen receptor (VNAR) antibodies (hereinafter VNARs), PEGylated nanogels (pH-sensitive poly(<i>N</i>,<i>N</i>-diethylaminoethyl methacrylate, PDEAEM), and the anticancer drug 5-fluorouracil (5-FU) to explore its potential applications in colon cancer therapies. Nanogels were functionalized in a scalable reaction with an <i>N</i>-hydroxysuccinimide (NHS)-terminated polyethylene glycol derivative and bioconjugated with shark antibodies. Dynamic light scattering measurements indicated the presence of monodispersed nanogels (74 to 236 nm). All systems maintained the pH-sensitive capacity to increase in size as pH decreased. This has direct implications for the release kinetics of 5-FU, which was released faster at pH 5 than at pH 7.4. After bioconjugation, the ELISA results indicated VNAR presence and carcinoembryonic antigen (CEA) recognition. <i>In vitro</i> evaluations of HCT-116 colon cancer cells indicated that functionalized empty nanogels are not cytotoxic and when loaded with 5-FU, the cytotoxic effect of the drug is preserved. A 15% reduction in cell viability was observed after two hours of contact with bioconjugated nanogels when compared to what was observed with non-bioconjugated nanogels. The prepared nanogel system shows potential as an effective and site-specific nanocarrier with promising applications in <i>in vivo</i> studies of colon cancer therapies.Effective cell membrane tension protects red blood cells against malaria invasionHaleh AlimohamadiPadmini Rangamani10.1371/journal.pcbi.10116942023-12-04T14:00:00Z2023-12-04T14:00:00Z<p>by Haleh Alimohamadi, Padmini Rangamani</p>
A critical step in how malaria parasites invade red blood cells (RBCs) is the wrapping of the membrane around the egg-shaped merozoites. Recent experiments have revealed that RBCs can be protected from malaria invasion by high membrane tension. While cellular and biochemical aspects of parasite actomyosin motor forces during the malaria invasion have been well studied, the important role of the biophysical forces induced by the RBC membrane-cytoskeleton composite has not yet been fully understood. In this study, we use a theoretical model for lipid bilayer mechanics, cytoskeleton deformation, and membrane-merozoite interactions to systematically investigate the influence of effective RBC membrane tension, which includes contributions from the lipid bilayer tension, spontaneous tension, interfacial tension, and the resistance of cytoskeleton against shear deformation on the progression of membrane wrapping during the process of malaria invasion. Our model reveals that this effective membrane tension creates a wrapping energy barrier for a complete merozoite entry. We calculate the tension threshold required to impede the malaria invasion. We find that the tension threshold is a nonmonotonic function of spontaneous tension and undergoes a sharp transition from large to small values as the magnitude of interfacial tension increases. We also predict that the physical properties of the RBC cytoskeleton layer—particularly the resting length of the cytoskeleton—play key roles in specifying the degree of the membrane wrapping. We also found that the shear energy of cytoskeleton deformation diverges at the full wrapping state, suggesting the local disassembly of the cytoskeleton is required to complete the merozoite entry. Additionally, using our theoretical framework, we predict the landscape of myosin-mediated forces and the physical properties of the RBC membrane in regulating successful malaria invasion. Our findings on the crucial role of RBC membrane tension in inhibiting malaria invasion can have implications for developing novel antimalarial therapeutic or vaccine-based strategies.Effects of membrane potentials on the electroporation of giant unilamellar vesiclesMd. Abdul WadudMohammad Abu Sayem KaralMd. MoniruzzamanMd. Mamun Or Rashid10.1371/journal.pone.02914962023-09-12T14:00:00Z2023-09-12T14:00:00Z<p>by Md. Abdul Wadud, Mohammad Abu Sayem Karal, Md. Moniruzzaman, Md. Mamun Or Rashid</p>
Living organisms maintain a resting membrane potential, which plays an important role in various biophysical and biological processes. In the context of medical applications, irreversible electroporation (IRE) is a non-thermal and minimally invasive technique that utilizes precisely controlled electric field pulses of micro- to millisecond durations to effectively ablate cancer and tumor cells. Previous studies on IRE-induced rupture of cell-mimetic giant unilamellar vesicles (GUVs) have primarily been conducted in the absence of membrane potentials. In this study, we investigated the electroporation of GUVs, including parameters such as the rate constant of rupture and the probability of rupture, in the presence of various negative membrane potentials. The membranes of GUVs were prepared using lipids and channel forming proteins. As the membrane potential increased from 0 to −90 mV, the rate constant of rupture showed a significant increase from (7.5 ± 1.6)×10<sup>−3</sup> to (35.6 ± 5.5)×10<sup>−3</sup> s<sup>-1</sup>. The corresponding probability of rupture also exhibited a notable increase from 0.40 ± 0.05 to 0.68 ± 0.05. To estimate the pore edge tension, the electric tension-dependent logarithm of the rate constant was fitted with the Arrhenius equation for different membrane potentials. The presence of membrane potential did not lead to any significant changes in the pore edge tension. The increase in electroporation is reasonably explained by the decrease in the prepore free energy barrier. The choice of buffer used in GUVs can significantly influence the kinetics of electroporation. This study provides valuable insights that can contribute to the application of electroporation techniques in the biomedical field.Quantitative determination of lurbinectedin, its unbound fraction and its metabolites in human plasma utilizing ultra-performance LC–MS/MSNicholas KingSoledad Garcia-MartinezEider AlcarazAlba GrisalenaRubin LubomirovRaquel AltaresCarlos Fernandez-TeruelAndrés M. FranceschPablo M. AvilésSalvador Fudio10.1371/journal.pone.02837832023-03-30T14:00:00Z2023-03-30T14:00:00Z<p>by Nicholas King, Soledad Garcia-Martinez, Eider Alcaraz, Alba Grisalena, Rubin Lubomirov, Raquel Altares, Carlos Fernandez-Teruel, Andrés M. Francesch, Pablo M. Avilés, Salvador Fudio</p>
Aims <p>Ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) methods to quantify total lurbinectedin, its plasma protein binding to derive the unbound fraction and its main metabolites 1′,3′-dihydroxy-lurbinectedin (M4) and <i>N</i>-desmethyl-lurbinectedin (M6) in human plasma, were developed and validated.</p> Materials & methods <p>For lurbinectedin, sample extraction was performed using supported liquid extraction. For metabolites, liquid-liquid extraction with stable isotope–labeled analogue internal standards was used. Plasma protein binding was evaluated using rapid equilibrium dialysis. <i>In vitro</i> investigations at different plasma protein concentrations were carried out to estimate dissociation rate constants to albumin and alpha-1-acid glycoprotein (AAG).</p> Results <p>Calibration curves displayed good linearity over 0.1 to 50 ng/mL for lurbinectedin and 0.5 to 20 ng/mL for the metabolites. Methods were validated in accordance with established guidance.The inter-day precision and accuracy ranged from 5.1% to 10.7%, and from -5% to 6% (lurbinectedin in plasma); from 3.1% to 6.6%, and from 4% to 6% (lurbinectedin in plasma:PBS); from 4.5% to 12.9%, and from 4% to 9% (M4); and from 7.5% to 10.5%, and from 6% to 12% (M6). All methods displayed good linearity (r<sup>2</sup> >0.99). Recovery was evaluated for lurbinectedin in plasma:PBS (66.4% to 86.6%), M4 (7.82% to 13.4%) and M6 (22.2% to 34.3%).The method for lurbinectedin in plasma has been applied in most clinical studies, while the plasma:PBS and metabolites methods were used to evaluate the impact of special conditions on lurbinectedin PK.Lurbinectedin plasma protein binding was 99.6% and highly affected by AAG concentration.</p> Conclusions <p>These UPLC–MS/MS methods enable the rapid and sensitive quantification of lurbinectedin and its main metabolites in clinical samples.</p>Guided-deconvolution for correlative light and electron microscopyFengjiao MaRainer KaufmannJaroslaw SedzickiZoltán CseresnyésChristoph DehioStephanie HoeppenerMarc Thilo FiggeRainer Heintzmann10.1371/journal.pone.02828032023-03-09T14:00:00Z2023-03-09T14:00:00Z<p>by Fengjiao Ma, Rainer Kaufmann, Jaroslaw Sedzicki, Zoltán Cseresnyés, Christoph Dehio, Stephanie Hoeppener, Marc Thilo Figge, Rainer Heintzmann</p>
Correlative light and electron microscopy is a powerful tool to study the internal structure of cells. It combines the mutual benefit of correlating light (LM) and electron (EM) microscopy information. The EM images only contain contrast information. Therefore, some of the detailed structures cannot be specified from these images alone, especially when different cell organelle are contacted. However, the classical approach of overlaying LM onto EM images to assign functional to structural information is hampered by the large discrepancy in structural detail visible in the LM images. This paper aims at investigating an optimized approach which we call EM-guided deconvolution. This applies to living cells structures before fixation as well as previously fixed sample. It attempts to automatically assign fluorescence-labeled structures to structural details visible in the EM image to bridge the gaps in both resolution and specificity between the two imaging modes. We tested our approach on simulations, correlative data of multi-color beads and previously published data of biological samples.Cryo-electron microscopy of adipose tissue extracellular vesicles in obesity and type 2 diabetes mellitusValentina V. MiroshnikovaKseniya V. DrachevaRoman A. KamyshinskyEvgeny V. YastremskyLuiza A. GaraevaIrina A. PobozhevaSergey B. LandaKristina A. AnisimovaStanislav G. BalandovZarina M. HamidDmitriy I. VasilevskySofya N. PchelinaAndrey L. KonevegaTatiana A. Shtam10.1371/journal.pone.02796522023-02-24T14:00:00Z2023-02-24T14:00:00Z<p>by Valentina V. Miroshnikova, Kseniya V. Dracheva, Roman A. Kamyshinsky, Evgeny V. Yastremsky, Luiza A. Garaeva, Irina A. Pobozheva, Sergey B. Landa, Kristina A. Anisimova, Stanislav G. Balandov, Zarina M. Hamid, Dmitriy I. Vasilevsky, Sofya N. Pchelina, Andrey L. Konevega, Tatiana A. Shtam</p>
Extracellular vesicles (EVs) are cell-derived membrane vesicles which play an important role in cell-to-cell communication and physiology. EVs deliver biological information from producing to recipient cells by transport of different cargo such as proteins, mRNAs, microRNAs, non-coding RNAs and lipids. Adipose tissue EVs could regulate metabolic and inflammatory interactions inside adipose tissue depots as well as distal tissues. Thus, adipose tissue EVs are assumed to be implicated in obesity-associated pathologies, notably in insulin resistance and type 2 diabetes mellitus (T2DM). In this study we for the first time characterize EVs secreted by visceral (VAT) and subcutaneous adipose tissue (SAT) of patients with obesity and T2DM with standard methods as well as analyze their morphology with cryo-electron microscopy. Cryo-electron microscopy allowed us to visualize heterogeneous population of EVs of various size and morphology including single EVs and EVs with internal membrane structures in samples from obese patients as well from the control group. Single vesicles prevailed (up to 85% for SAT, up to 75% for VAT) and higher proportion of EVs with internal membrane structures compared to SAT was typical for VAT. Decreased size of single and double SAT EVs compared to VAT EVs, large proportion of multilayered EVs and all EVs with internal membrane structures secreted by VAT distinguished obese patients with/without T2DM from the control group. These findings could support the idea of modified biogenesis of EVs during obesity and T2DM.Remeshing flexible membranes under the control of free energyXinxin WangGaudenz Danuser10.1371/journal.pcbi.10107662022-12-05T14:00:00Z2022-12-05T14:00:00Z<p>by Xinxin Wang, Gaudenz Danuser</p>
Cell membranes are flexible and often undergo large-scale morphological changes during processes like mitosis, protrusion and retraction, or vesicle fusion. Mathematical modeling of cell membranes depends on a representation of the free-form surface by discrete meshes. During morphological changes, these meshes must be adjusted under the minimization of the total free energy. Current methodology for meshing is limited in one of two ways: 1) Free energy-dependent methods have no restriction on the mesh geometry. The resulting irregular meshes cause artifacts in follow-up models of morphodynamics. 2) Geometry-dependent methods maintain mesh quality but violate the physics of free energy minimization. To fill this gap, we regulate mesh geometries via a free-energy-determined remeshing process: adding and removing mesh elements upon morphological changes based on barrier crossings in a double-barrier potential between neighboring vertices in the meshes. We test the method’s robustness by reproducing the morphodynamics of red blood cells and vesicle fusions; and we demonstrate the method’s adaptability by simulating the formation of filopodia, lamellipodia and invaginations. Finally, we use the method to study a mechanical decoupling effect of two connected membrane tethers that has been recently observed experimentally, but has not been mechanistically explained in the context of a complete membrane surface. We propose a biophysical model that strengthens the decoupling effect and broadens the original interpretation of the experiment. The method is developed in C/Matlab and distributed via https://github.com/DanuserLab/biophysicsModels.The effect of levocarnitine supplementation on dialysis-related hypotension: A systematic review, meta-analysis, and trial sequential analysisApi ChewcharatPol ChewcharatWeitao LiuJacqueline CelliniElizabeth A. PhippsJill A. Melendez YoungSagar U. Nigwekar10.1371/journal.pone.02713072022-07-14T14:00:00Z2022-07-14T14:00:00Z<p>by Api Chewcharat, Pol Chewcharat, Weitao Liu, Jacqueline Cellini, Elizabeth A. Phipps, Jill A. Melendez Young, Sagar U. Nigwekar</p>
Background <p>Dialysis patients have been shown to have low serum carnitine due to poor nutrition, deprivation of endogenous synthesis from kidneys, and removal by hemodialysis. Carnitine deficiency leads to impaired cardiac function and dialysis-related hypotension which are associated with increased mortality. Supplementing with levocarnitine among hemodialysis patients may diminish incidence of intradialytic hypotension. Data on this topic, however, lacks consensus.</p> Methods <p>We conducted electronic searches in PubMed, Embase and Cochrane Central Register of Controlled Trials from January 1960 to 19<sup>th</sup> November 2021 to identify randomized controlled studies (RCTs), which examined the effects of oral or intravenous levocarnitine (L-carnitine) on dialysis-related hypotension among hemodialysis patients. The secondary outcome was muscle cramps. Study results were pooled and analyzed utilizing the random-effects model. Trial sequential analysis (TSA) was performed to assess the strength of current evidence.</p> Results <p>Eight trials with 224 participants were included in our meta-analysis. Compared to control group, L-carnitine reduced the incidence of dialysis-related hypotension among hemodialysis patients (pooled OR = 0.26, 95% CI [0.10–0.72], p = 0.01, I<sup>2</sup> = 76.0%). TSA demonstrated that the evidence was sufficient to conclude the finding. Five studies with 147 participants showed a reduction in the incidence of muscle cramps with L-carnitine group (pooled OR = 0.22, 95% CI [0.06–0.81], p = 0.02, I<sup>2</sup> = 74.7%). However, TSA suggested that further high-quality studies were required. Subgroup analysis on the route of supplementation revealed that only oral but not intravenous L-carnitine significantly reduced dialysis-related hypotension. Regarding dose and duration of L-carnitine supplementation, the dose > 4,200 mg/week and duration of at least 12 weeks appeared to prevent dialysis-related hypotension.</p> Conclusion <p>Supplementing oral L-carnitine for at least three months above 4,200 mg/week helps prevent dialysis-related hypotension. L-carnitine supplementation may ameliorate muscle cramps. Further well-powered studies are required to conclude this benefit.</p>Use of paclitaxel carried in solid lipid nanoparticles to prevent peritoneal fibrosis in ratsFilipe M. O. SilvaPriscila O. CarvalhoElerson C. CostalongaRafael PepineliRaul C. MaranhãoIrene L. Noronha10.1371/journal.pone.02681972022-05-06T14:00:00Z2022-05-06T14:00:00Z<p>by Filipe M. O. Silva, Priscila O. Carvalho, Elerson C. Costalonga, Rafael Pepineli, Raul C. Maranhão, Irene L. Noronha</p>
Background <p>Progressive fibrous thickening of peritoneal membrane (PM) is a major complication of long-term peritoneal dialysis. TGF-β/SMAD pathway activation, inflammation and neoangiogenesis have an important role in PM changes induced by peritoneal dialysis. Here, we investigated the effects of paclitaxel (PTX) carried in lipid core nanoparticles (LDE) on the development of peritoneal fibrosis (PF) in rats.</p> Methods <p>To induce PF, 21 male Wistar rats (300-350g) were injected with chlorhexidine gluconate for 15 consecutive days and randomly assigned to three groups: 1)PF, n = 5: no treatment; 2)LDE, n = 8: treated with LDE only, 3/3 days during 15 days; 3)LDE-PTX, n = 8: treated with PTX (4mg/kg) associated with LDE, 3/3 days during 15 days. A Control group without PF induction (n = 5) was designed, received saline solution, 3/3 days. Peritoneum function tests were performed, and anterior abdominal wall samples of the PM were collected for analyses of peritoneal thickness, immunohistochemitry, and gene expression.</p> Results <p>LDE-PTX treatment preserved the membrane function, maintaining the ultrafiltration rate and mass transfer of glucose at normal levels. LDE-PTX also prevented PM thickening induced by chlorhexidine gluconate injections. LDE-PTX treatment reduced the number of myofibroblasts infiltrating PM and inhibited the cell proliferation. Gene expression of fibronectin, FSP-1, VEGF, TGF-β, and SMAD3 were reduced by LDE-PTX.</p> Conclusions <p>LDE-PTX was effective to prevent development of PF and preserve the PM filtration capacity in this rat model, with clear-cut actions on pro-fibrotic mechanisms. Thus, LDE-PTX can be candidate for future clinical trials as adjuvant to peritoneal dialysis to prevent PF development, since this preparation is devoid of toxicity as shown previously.</p>A role for myosin II clusters and membrane energy in cortex rupture for <i>Dictyostelium discoideum</i>Emmanuel Asante-AsamaniDaniel GrangeDevarshi RawalZully SantiagoJohn LoustauDerrick Brazill10.1371/journal.pone.02653802022-04-25T14:00:00Z2022-04-25T14:00:00Z<p>by Emmanuel Asante-Asamani, Daniel Grange, Devarshi Rawal, Zully Santiago, John Loustau, Derrick Brazill</p>
Blebs, pressure driven protrusions of the cell membrane, facilitate the movement of eukaryotic cells such as the soil amoeba <i>Dictyostelium discoideum</i>, white blood cells and cancer cells. Blebs initiate when the cell membrane separates from the underlying cortex. A local rupture of the cortex, has been suggested as a mechanism by which blebs are initiated. However, much clarity is still needed about how cells inherently regulate rupture of the cortex in locations where blebs are expected to form. In this work, we examine the role of membrane energy and the motor protein myosin II (myosin) in facilitating the cell driven rupture of the cortex. We perform under-agarose chemotaxis experiments, using <i>Dictyostelium discoideum</i> cells, to visualize the dynamics of myosin and calculate changes in membrane energy in the blebbing region. To facilitate a rapid detection of blebs and analysis of the energy and myosin distribution at the cell front, we introduce an autonomous bleb detection algorithm that takes in discrete cell boundaries and returns the coordinate location of blebs with its shape characteristics. We are able to identify by microscopy naturally occurring gaps in the cortex prior to membrane detachment at sites of bleb nucleation. These gaps form at positions calculated to have high membrane energy, and are associated with areas of myosin enrichment. Myosin is also shown to accumulate in the cortex prior to bleb initiation and just before the complete disassembly of the cortex. Together our findings provide direct spatial and temporal evidence to support cortex rupture as an intrinsic bleb initiation mechanism and suggests that myosin clusters are associated with regions of high membrane energy where its contractile activity leads to a rupture of the cortex at points of maximal energy.Development of β-cyclodextrin/polyvinypyrrolidone-co-poly (2-acrylamide-2-methylpropane sulphonic acid) hybrid nanogels as nano-drug delivery carriers to enhance the solubility of Rosuvastatin: An in vitro and <i>in vivo</i> evaluationHina ShoukatFahad PervaizMehran KhanSadia RehmanFaizan AkramUsman AbidSobia NoreenMuhammad NadeemRubina QaiserRizwan AhmadIrshad Farooq10.1371/journal.pone.02630262022-01-21T14:00:00Z2022-01-21T14:00:00Z<p>by Hina Shoukat, Fahad Pervaiz, Mehran Khan, Sadia Rehman, Faizan Akram, Usman Abid, Sobia Noreen, Muhammad Nadeem, Rubina Qaiser, Rizwan Ahmad, Irshad Farooq</p>
The present study is aimed at enhancing the solubility of rosuvastatin (RST) by designing betacyclodextrin/polyvinypyrrolidone-co-poly (2-acrylamide-2-methylpropane sulphonic acid) crosslinked hydrophilic nanogels in the presence of crosslinker methylene bisacrylamide through free-radical polymerization method. Various formulations were fabricated by blending different amounts of betacyclodextrin, polyvinylpyrrolidone, 2-acrylamide-2-methylpropane sulphonic acid, and methylene bisacrylamide. The developed chemically crosslinked nanogels were characterized by FTIR, SEM, PXRD, TGA, DSC, sol-gel analysis, zeta size, micromeritics properties, drug loading percentage, swelling, solubility, and release studies. The FTIR spectrum depicts the leading peaks of resultant functional groups of blended constituents while a fluffy and porous structure was observed through SEM images. Remarkable reduction in crystallinity of RST in developed nanogels revealed by PXRD. TGA and DSC demonstrate the good thermal stability of nanogels. The size analysis depicts the particle size of the developed nanogels in the range of 178.5 ±3.14 nm. Drug loading percentage, swelling, solubility, and release studies revealed high drug loading, solubilization, swelling, and drug release patterns at 6.8 pH paralleled to 1.2 pH. <i>In vivo</i> experiments on developed nanogels in comparison to marketed brands were examined and better results regarding pharmacokinetic parameters were observed. The compatibility and non-toxicity of fabricated nanogels to biological systems was supported by a toxicity study that was conducted on rabbits. Efficient fabrication, excellent physicochemical properties, improved dissolution, high solubilization, and nontoxic nanogels might be a capable approach for the oral administration of poorly water-soluble drugs.Inhaled ciprofloxacin-loaded poly(2-ethyl-2-oxazoline) nanoparticles from dry powder inhaler formulation for the potential treatment of lower respiratory tract infectionsMohammad Zaidur Rahman SabujTim R. DargavilleLisa NissenNazrul Islam10.1371/journal.pone.02617202021-12-23T14:00:00Z2021-12-23T14:00:00Z<p>by Mohammad Zaidur Rahman Sabuj, Tim R. Dargaville, Lisa Nissen, Nazrul Islam</p>
Lower respiratory tract infections (LRTIs) are one of the fatal diseases of the lungs that have severe impacts on public health and the global economy. The currently available antibiotics administered orally for the treatment of LRTIs need high doses with frequent administration and cause dose-related adverse effects. To overcome this problem, we investigated the development of ciprofloxacin (CIP) loaded poly(2-ethyl-2-oxazoline) (PEtOx) nanoparticles (NPs) for potential pulmonary delivery from dry powder inhaler (DPI) formulations against LRTIs. NPs were prepared using a straightforward co-assembly reaction carried out by the intermolecular hydrogen bonding among PEtOx, tannic acid (TA), and CIP. The prepared NPs were characterized by scanning electron microscopy (SEM), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction analysis (PXRD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The CIP was determined by validated HPLC and UV spectrophotometry methods. The CIP loading into the PEtOx was between 21–67% and increased loading was observed with the increasing concentration of CIP. The NP sizes of PEtOx with or without drug loading were between 196–350 nm and increased with increasing drug loading. The <i>in vitro</i> CIP release showed the maximum cumulative release of about 78% in 168 h with a burst release of 50% in the first 12 h. The kinetics of CIP release from NPs followed non-Fickian or anomalous transport thus suggesting the drug release was regulated by both diffusion and polymer degradation. The <i>in vitro</i> aerosolization study carried out using a Twin Stage Impinger (TSI) at 60 L/min air flow showed the fine particle fraction (FPF) between 34.4% and 40.8%. The FPF was increased with increased drug loading. The outcome of this study revealed the potential of the polymer PEtOx as a carrier for developing CIP-loaded PEtOx NPs as DPI formulation for pulmonary delivery against LRTIs.3D fluorescence microscopy data synthesis for segmentation and benchmarkingDennis EschweilerMalte RethwischMareike JarchowSimon KoppersJohannes Stegmaier10.1371/journal.pone.02605092021-12-02T14:00:00Z2021-12-02T14:00:00Z<p>by Dennis Eschweiler, Malte Rethwisch, Mareike Jarchow, Simon Koppers, Johannes Stegmaier</p>
Automated image processing approaches are indispensable for many biomedical experiments and help to cope with the increasing amount of microscopy image data in a fast and reproducible way. Especially state-of-the-art deep learning-based approaches most often require large amounts of annotated training data to produce accurate and generalist outputs, but they are often compromised by the general lack of those annotated data sets. In this work, we propose how conditional generative adversarial networks can be utilized to generate realistic image data for 3D fluorescence microscopy from annotation masks of 3D cellular structures. In combination with mask simulation approaches, we demonstrate the generation of fully-annotated 3D microscopy data sets that we make publicly available for training or benchmarking. An additional positional conditioning of the cellular structures enables the reconstruction of position-dependent intensity characteristics and allows to generate image data of different quality levels. A patch-wise working principle and a subsequent full-size reassemble strategy is used to generate image data of arbitrary size and different organisms. We present this as a proof-of-concept for the automated generation of fully-annotated training data sets requiring only a minimum of manual interaction to alleviate the need of manual annotations.Association between hepatic oxygenation on near-infrared spectroscopy and clinical factors in patients undergoing hemodialysisYuichiro UedaSusumu OokawaraKiyonori ItoYusuke SasabuchiHideyuki HayasakaMasaya KofujiTakayuki UchidaSojiro ImaiSatoshi KiryuSaori MinatoHaruhisa MiyazawaHidenori SanayamaKeiji HiraiKaoru TabeiYoshiyuki Morishita10.1371/journal.pone.02590642021-10-21T14:00:00Z2021-10-21T14:00:00Z<p>by Yuichiro Ueda, Susumu Ookawara, Kiyonori Ito, Yusuke Sasabuchi, Hideyuki Hayasaka, Masaya Kofuji, Takayuki Uchida, Sojiro Imai, Satoshi Kiryu, Saori Minato, Haruhisa Miyazawa, Hidenori Sanayama, Keiji Hirai, Kaoru Tabei, Yoshiyuki Morishita</p>
The hepato-splanchnic circulation directly influences oxygenation of the abdominal organs and plays an important role in compensating for the blood volume reduction that occurs in the central circulation during hemodialysis (HD) with ultrafiltration. However, the hepato-splanchnic circulation and oxygenation cannot be easily evaluated in the clinical setting of HD therapy. We included 185 HD patients and 15 healthy volunteers as the control group in this study. Before HD, hepatic regional oxygen saturation (rSO<sub>2</sub>), a marker of hepatic oxygenation reflecting the hepato-splanchnic circulation and oxygenation, was monitored using an INVOS 5100c oxygen saturation monitor. Hepatic rSO<sub>2</sub> was significantly lower in patients undergoing HD than in healthy controls (56.4 ± 14.9% vs. 76.2 ± 9.6%, p < 0.001). Multivariable regression analysis showed that hepatic rSO<sub>2</sub> was independently associated with body mass index (BMI; standardized coefficient: 0.294), hemoglobin (Hb) level (standardized coefficient: 0.294), a history of cardiovascular disease (standardized coefficient: -0.157), mean blood pressure (BP; standardized coefficient: 0.154), and serum albumin concentration (standardized coefficient: 0.150) in Model 1 via a simple linear regression analysis. In Model 2 using the colloid osmotic pressure (COP) in place of serum albumin concentration, the COP (standardized coefficient: 0.134) was also identified as affecting hepatic rSO<sub>2</sub>. Basal hepatic oxygenation before HD might be affected by BMI, Hb levels, a history of cardiovascular disease, mean BP, serum albumin concentration, and the COP. Further prospective studies are needed to clarify whether changes in these parameters, including during HD, affect the hepato-splanchnic circulation and oxygenation in HD patients.Peritoneal dialysis modality transition and impact on phosphate and potassium serum levelsDaniela PeruzzoMurilo GuedesJohn W. LarkinGuilherme YokoyamaTaynara Lopes dos SantosRoberto Pecoits-FilhoSilvia Carreira RibeiroAlfonso RamosPasqual BarrettiThyago Proença de Moraeson behalf of the BRAZPD Investigators10.1371/journal.pone.02571402021-10-15T14:00:00Z2021-10-15T14:00:00Z<p>by Daniela Peruzzo, Murilo Guedes, John W. Larkin, Guilherme Yokoyama, Taynara Lopes dos Santos, Roberto Pecoits-Filho, Silvia Carreira Ribeiro, Alfonso Ramos, Pasqual Barretti, Thyago Proença de Moraes, on behalf of the BRAZPD Investigators </p>
Peritoneal dialysis (PD) modalities affect solute removal differently. However, the impacts of switching PD modalities on serum levels of biomarkers of different sizes are not known. Our objective was to analyze whether a change in the PD modality associates with the levels of two routine biochemical laboratories. In this multicentric prospective cohort study. we selected all patients who remained on a PD modality for at least 6 months and switched PD modality. Patients were also required to be treated with the same PD modality for at least 3 months before and after the modality change. The primary outcome was change in potassium and phosphate serum levels. We identified 737 eligible patients who switched their PD modality during the study. We found mean serum phosphate levels increased during the 3 months after switching from CAPD to APD and conversely decreased after switching to from APD to CAPD. In contrast, for potassium the difference in the mean serum levels was comparable between groups switching from CAPD to APD, and vice versa. In conclusion, CAPD seems to be as efficient as APD for the control of potassium serum levels, but more effective for the control of phosphate serum levels. The effect of a higher removal of middle size molecules as result of PD modalities in terms of clinical and patient-reported outcomes should be further explored.