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1.
Bioconjug Chem ; 34(1): 181-192, 2023 01 18.
Artículo en Inglés | MEDLINE | ID: mdl-36519843

RESUMEN

Fully synthetic tumor-associated carbohydrate antigen (TACA)-based vaccines are a promising strategy to treat cancer. To overcome the intrinsic low immunogenicity of TACAs, the choice of the antigens' analogues and multivalent presentation have been proved to be successful. Here, we present the preparation, characterization, and in vitro screening of niosomes displaying multiple copies of the mucin antigen TnThr (niosomes-7) or of TnThr mimetic 1 (niosomes-2). Unprecedentedly, structural differences, likely related to the carbohydrate portions, were observed for the two colloidal systems. Both niosomal systems are stable, nontoxic and endowed with promising immunogenic properties.


Asunto(s)
Vacunas contra el Cáncer , Neoplasias , Humanos , Antígenos de Carbohidratos Asociados a Tumores , Liposomas , Neoplasias/terapia , Carbohidratos/química , Vacunas Sintéticas , Sistema Inmunológico
2.
Int J Mol Sci ; 24(5)2023 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-36901712

RESUMEN

Telomeric G-quadruplexes (G4s) are promising targets in the design and development of anticancer drugs. Their actual topology depends on several factors, resulting in structural polymorphism. In this study, we investigate how the fast dynamics of the telomeric sequence AG3(TTAG3)3 (Tel22) depends on the conformation. By using Fourier transform Infrared spectroscopy, we show that, in the hydrated powder state, Tel22 adopts parallel and mixed antiparallel/parallel topologies in the presence of K+ and Na+ ions, respectively. These conformational differences are reflected in the reduced mobility of Tel22 in Na+ environment in the sub-nanosecond timescale, as probed by elastic incoherent neutron scattering. These findings are consistent with the G4 antiparallel conformation being more stable than the parallel one, possibly due to the presence of ordered hydration water networks. In addition, we study the effect of Tel22 complexation with BRACO19 ligand. Despite the quite similar conformation in the complexed and uncomplexed state, the fast dynamics of Tel22-BRACO19 is enhanced compared to that of Tel22 alone, independently of the ions. We ascribe this effect to the preferential binding of water molecules to Tel22 against the ligand. The present results suggest that the effect of polymorphism and complexation on the G4 fast dynamics is mediated by hydration water.


Asunto(s)
Antineoplásicos , G-Cuádruplex , Humanos , Ligandos , Agua , Telómero
3.
J Am Chem Soc ; 144(7): 2968-2979, 2022 02 23.
Artículo en Inglés | MEDLINE | ID: mdl-35157798

RESUMEN

Coronavirus disease-2019 (COVID-19), a potentially lethal respiratory illness caused by the coronavirus SARS-CoV-2, emerged in the end of 2019 and has since spread aggressively across the globe. A thorough understanding of the molecular mechanisms of cellular infection by coronaviruses is therefore of utmost importance. A critical stage in infection is the fusion between viral and host membranes. Here, we present a detailed investigation of the role of selected SARS-CoV-2 Spike fusion peptides, and the influence of calcium and cholesterol, in this fusion process. Structural information from specular neutron reflectometry and small angle neutron scattering, complemented by dynamics information from quasi-elastic and spin-echo neutron spectroscopy, revealed strikingly different functions encoded in the Spike fusion domain. Calcium drives the N-terminal of the Spike fusion domain to fully cross the host plasma membrane. Removing calcium, however, reorients the peptide back to the lipid leaflet closest to the virus, leading to significant changes in lipid fluidity and rigidity. In conjunction with other regions of the fusion domain, which are also positioned to bridge and dehydrate viral and host membranes, the molecular events leading to cell entry by SARS-CoV-2 are proposed.


Asunto(s)
Membrana Dobles de Lípidos/metabolismo , Fragmentos de Péptidos/metabolismo , SARS-CoV-2/química , Glicoproteína de la Espiga del Coronavirus/metabolismo , Secuencia de Aminoácidos , Colesterol/química , Membrana Dobles de Lípidos/química , Fluidez de la Membrana , Difracción de Neutrones , Dominios Proteicos , Dispersión del Ángulo Pequeño , Glicoproteína de la Espiga del Coronavirus/química , Liposomas Unilamelares/química , Liposomas Unilamelares/metabolismo
4.
Eur Phys J E Soft Matter ; 39(4): 48, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27112937

RESUMEN

Neutron scattering techniques have been employed to investigate 1,2-dimyristoyl-sn -glycero-3-phosphocholine (DMPC) membranes in the form of multilamellar vesicles (MLVs) and deposited, stacked multilamellar-bilayers (MLBs), covering transitions from the gel to the liquid phase. Neutron diffraction was used to characterise the samples in terms of transition temperatures, whereas elastic incoherent neutron scattering (EINS) demonstrates that the dynamics on the sub-macromolecular length-scale and pico- to nano-second time-scale are correlated with the structural transitions through a discontinuity in the observed elastic intensities and the derived mean square displacements. Molecular dynamics simulations have been performed in parallel focussing on the length-, time- and temperature-scales of the neutron experiments. They correctly reproduce the structural features of the main gel-liquid phase transition. Particular emphasis is placed on the dynamical amplitudes derived from experiment and simulations. Two methods are used to analyse the experimental data and mean square displacements. They agree within a factor of 2 irrespective of the probed time-scale, i.e. the instrument utilized. Mean square displacements computed from simulations show a comparable level of agreement with the experimental values, albeit, the best match with the two methods varies for the two instruments. Consequently, experiments and simulations together give a consistent picture of the structural and dynamical aspects of the main lipid transition and provide a basis for future, theoretical modelling of dynamics and phase behaviour in membranes. The need for more detailed analytical models is pointed out by the remaining variation of the dynamical amplitudes derived in two different ways from experiments on the one hand and simulations on the other.


Asunto(s)
Dimiristoilfosfatidilcolina/química , Elasticidad , Simulación de Dinámica Molecular , Difracción de Neutrones , Transición de Fase , Membrana Dobles de Lípidos/química , Conformación Molecular
5.
Soft Matter ; 11(11): 2183-92, 2015 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-25639345

RESUMEN

The extent and nature of thermal fluctuations in the innovative class of cross-linked polymers called cyclodextrin nanosponges (CDNS) are investigated, on the picosecond time scale, through elastic and quasielastic neutron scattering experiments. Nanosponges are complex 3D polymer networks where covalent bonds connecting different cyclodextrin (CD) units and intra- and inter-molecular hydrogen-bond interactions cooperate to define the molecular architecture and fast dynamics of the polymer. The study presented here aims to clarify the nature of the conformational rearrangements activated by increasing temperature in the nanosponge polymer, and the constraints imposed by intra- and inter-molecular hydrogen-bond patterns on the internal dynamics of the macromolecule. The results suggest a picture, in which conformational rearrangements involving the torsion of the OH groups around the C-O bonds dominate the internal dynamics of the polymer over the picosecond time scale. Moreover, the estimated values of mean square displacements reveal that the motions of the hydrogen atoms in the nanosponges are progressively hampered as the cross-linking degree of the polymer is increased. Finally, the study of the molecular relaxations suggests a dynamical rearrangement of the hydrogen-bond networks, which is characterized by a jump diffusion motion of the more mobile hydrogen atoms belonging to the OH groups of the CD units. All these findings add further contribution to the rational comprehensive view of the dynamics of these macromolecules, which may be particularly beneficial in designing new drug-delivery systems with tuneable inclusion/release properties.

6.
Soft Matter ; 10(3): 519-29, 2014 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-24651633

RESUMEN

The myelin sheath is a tightly packed, multilayered membrane structure wrapped around selected nerve axons in the central and the peripheral nervous system. Because of its electrical insulation of the axons, which allows fast, saltatory nerve impulse conduction, myelin is crucial for the proper functioning of the vertebrate nervous system. A subset of myelin-specific proteins is well-defined, but their influence on membrane dynamics, i.e. myelin stability, has not yet been explored in detail. We investigated the structure and the dynamics of reconstituted myelin membranes on a pico- to nanosecond timescale, influenced by myelin basic protein (MBP) and myelin protein 2 (P2), using neutron diffraction and quasi-elastic neutron scattering. A model for the scattering function describing molecular lipid motions is suggested. Although dynamical properties are not affected significantly by MBP and P2 proteins, they act in a highly synergistic manner influencing the membrane structure.


Asunto(s)
Proteína Básica de Mielina/química , Vaina de Mielina/química , Humanos , Membrana Dobles de Lípidos/química , Membrana Dobles de Lípidos/metabolismo , Proteína Básica de Mielina/genética , Proteína Básica de Mielina/metabolismo , Difracción de Neutrones , Estructura Terciaria de Proteína , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Dispersión del Ángulo Pequeño , Electricidad Estática , Temperatura
7.
Arch Gynecol Obstet ; 289(3): 671-6, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24026089

RESUMEN

PURPOSE: Our aim is to determine if the reproductive performance after hysteroscopic resection of partial uterine septum was related to septum size. METHODS: The retrospective and comparative cohort study was conducted in a University-affiliated Hospital. A cohort of 112 non-parous patients was treated for a partial uterine septum. The septum size was evaluated by hysteroscopy and transvaginal 3-dimensional ultrasound. The patients were stratified into two groups: group 1 (85 women) with small partial uterine septum (≤2.5 cm) and group 2 (27 women) with large partial uterine septum (>2.5 cm). They were also divided according to their obstetrics history: 39 infertile women and 73 aborters. All underwent hysteroscopic metroplasty with a resectoscope with an equatorial semicircular loop cutting 0° with monopolar energy. All septa were almost completely removed and no complications occurred. RESULTS: The two groups of patients with small (group 1) and large (group 2) partial uterine septum were compared in the terms of reproductive history and performance before and after surgery. In the overall population the reproductive performance after surgery is greatly improved. No significant differences in reproductive performance were evident between patients with small and large partial uterine septa. The reproductive performance was also similar in infertile patients and in aborters. CONCLUSIONS: This study demonstrates that hysteroscopic metroplasty in cases of partial uterine septum and infertility significantly improves the reproductive performance irrespectively of septum size and that reproductive performance is independent from previous obstetrics history.


Asunto(s)
Histeroscopía/métodos , Útero/anomalías , Útero/cirugía , Aborto Habitual/etiología , Aborto Habitual/cirugía , Adulto , Femenino , Humanos , Infertilidad Femenina/etiología , Infertilidad Femenina/cirugía , Embarazo , Pronóstico , Estudios Retrospectivos
8.
Chem Sci ; 15(24): 9249-9257, 2024 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-38903230

RESUMEN

The protein dynamical transition marks an increase in atomic mobility and the onset of anharmonic motions at a critical temperature (T d), which is considered relevant for protein functionality. This phenomenon is ubiquitous, regardless of protein composition, structure and biological function and typically occurs at large protein content, to avoid water crystallization. Recently, a dynamical transition has also been reported in non-biological macromolecules, such as poly(N-isopropyl acrylamide) (PNIPAM) microgels, bearing many similarities to proteins. While the generality of this phenomenon is well-established, the role of water in the transition remains a subject of debate. In this study, we use atomistic molecular dynamics (MD) simulations and elastic incoherent neutron scattering (EINS) experiments with selective deuteration to investigate the microscopic origin of the dynamical transition and distinguish water and PNIPAM roles. While a standard analysis of EINS experiments would suggest that the dynamical transition occurs in PNIPAM and water at a similar temperature, simulations reveal a different perspective, also qualitatively supported by experiments. From room temperature down to about 180 K, PNIPAM exhibits only modest changes of dynamics, while water, being mainly hydration water under the probed extreme confinement, significantly slows down and undergoes a mode-coupling transition from diffusive to activated. Our findings therefore challenge the traditional view of the dynamical transition, demonstrating that it occurs in proximity of the water mode-coupling transition, shedding light on the intricate interplay between polymer and water dynamics.

9.
J Phys Chem Lett ; 15(20): 5543-5548, 2024 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-38752860

RESUMEN

Protein dynamics display distinct traits that are linked to their specific biological function. However, the interplay between intrinsic dynamics and the molecular environment on protein stability remains poorly understood. In this study, we investigate, by incoherent neutron scattering, the subnanosecond time scale dynamics of three model proteins: the mesophilic lysozyme, the thermophilic thermolysin, and the intrinsically disordered ß-casein. Moreover, we address the influence of water, glycerol, and glucose, which create progressively more viscous matrices around the protein surface. By comparing the protein thermal fluctuations, we find that the internal dynamics of thermolysin are less affected by the environment compared to lysozyme and ß-casein. We ascribe this behavior to the protein dynamic personality, i.e., to the stiffer dynamics of the thermophilic protein that contrasts the influence of the environment. Remarkably, lysozyme and thermolysin in all molecular environments reach a critical common flexibility when approaching the calorimetric melting temperature.


Asunto(s)
Caseínas , Muramidasa , Termolisina , Muramidasa/química , Muramidasa/metabolismo , Termolisina/química , Termolisina/metabolismo , Caseínas/química , Glicerol/química , Agua/química , Glucosa/química , Difracción de Neutrones , Simulación de Dinámica Molecular
10.
Eur Phys J E Soft Matter ; 36(7): 80, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23884625

RESUMEN

Neutron spectroscopy provides experimental data on time-dependent trajectories, which can be directly compared to molecular dynamics simulations. Its importance in helping us to understand biological macromolecules at a molecular level is demonstrated by the results of a literature survey over the last two to three decades. Around 300 articles in refereed journals relate to neutron scattering studies of biological macromolecular dynamics, and the results of the survey are presented here. The scope of the publications ranges from the general physics of protein and solvent dynamics, to the biologically relevant dynamics-function relationships in live cells. As a result of the survey we are currently setting up a neutron Dynamics Data Bank (nDDB) with the aim to make the neutron data on biological systems widely available. This will benefit, in particular, the MD simulation community to validate and improve their force fields. The aim of the database is to expose and give easy access to a body of experimental data to the scientific community. The database will be populated with as much of the existing data as possible. In the future it will give value, as part of a bigger whole, to high throughput data, as well as more detailed studies. A range and volume of experimental data will be of interest in determining how quantitatively MD simulations can reproduce trends across a range of systems and to what extent such trends may depend on sample preparation and data reduction and analysis methods. In this context, we strongly encourage researchers in the field to deposit their data in the nDDB.


Asunto(s)
Bases de Datos de Compuestos Químicos , Simulación de Dinámica Molecular , Difracción de Neutrones , Biofisica/métodos , Biofisica/organización & administración , Biofisica/tendencias , Carbohidratos/química , Ácidos Nucleicos/química , Proteínas/química
11.
Macromolecules ; 56(5): 2149-2163, 2023 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-36938513

RESUMEN

We have combined X-ray diffraction, neutron diffraction with polarization analysis, small-angle neutron scattering (SANS), neutron elastic fixed window scans (EFWS), and differential scanning calorimetry (DSC) to investigate polymeric blends of industrial interest composed by isotopically labeled styrene-butadiene rubber (SBR) and polystyrene (PS) oligomers of size smaller than the Kuhn length. The EFWS are sensitive to the onset of liquid-like motions across the calorimetric glass transition, allowing the selective determination of the "microscopic" effective glass transitions of the components. These are compared with the "macroscopic" counterparts disentangled by the analysis of the DSC results in terms of a model based on the effects of thermally driven concentration fluctuations and self-concentration. At the microscopic level, the mixtures are dynamically heterogeneous for blends with intermediate concentrations or rich in PS, while the sample with highest content of the fast SBR component looks as dynamically homogeneous. Moreover, the combination of SANS and DSC has allowed determining the relevant length scale for the α-relaxation through its loss of equilibrium to be ≈30 Å. This is compared with the different characteristic length scales that can be identified in these complex mixtures from structural, thermodynamical, and dynamical points of view because of the combined approach followed. We also discuss the sources of the non-Gaussian effects observed for the atomic displacements and the applicability of a Lindemann-like criterion in these materials.

12.
Expert Opin Drug Saf ; 22(12): 1271-1281, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36681385

RESUMEN

BACKGROUND: Observational studies highlighted high rates of psychotropic medication in persons with autistic spectrum disorder (ASD) with or without intellectual disability, which seems to be associated with the management of problem behaviors more than co-occurrent psychiatric disorders. The purpose of the study is to investigate psychopharmacology use and diagnoses of co-occurrent psychiatric disorder (PD) in persons with ASD attending a public mental health service in Emilia Romagna, Italy. METHODS: The present study is a multicenter, cross-sectional study. RESULTS: 275 persons out of 486 (56.5%) resulted to receive at least one psychotropic drug, compared to 74 persons (15.2%) that were diagnosed with a PD. 63.6% were on poly-pharmacotherapy (2-10 compounds), with 37.8% receiving 3 or more medications. Antipsychotics were the most frequently prescribed class of psychotropic drugs (89%), followed by antiepileptics/mood stabilizers/lithium (42.1%) and anxiolytics (BDZ) (38.5%). Most common psychiatric disorders were psychotic disorders (29.7%), followed by anxiety disorders (17.5%), bipolar disorders (12.2%), and depressive disorders (9.4%). CONCLUSIONS: Our findings support earlier research showing that many individuals with ASD receive pharmacotherapy without being diagnosed with a co-occurring psychiatric disorder, indicating that the main reasons for prescription and the type of compound frequently have little to no link with specific psychopathology.


Asunto(s)
Trastorno del Espectro Autista , Trastorno Bipolar , Discapacidad Intelectual , Humanos , Estudios Transversales , Trastorno del Espectro Autista/tratamiento farmacológico , Trastorno del Espectro Autista/psicología , Discapacidad Intelectual/tratamiento farmacológico , Psicotrópicos/uso terapéutico , Trastorno Bipolar/tratamiento farmacológico , Anticonvulsivantes/uso terapéutico
13.
Int J Nanomedicine ; 18: 7695-7710, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38111847

RESUMEN

Background: Clay minerals are nanomaterials that have recently been recognized as enabling excipients that can promote cell adhesion, proliferation, and differentiation. When nanoclays are loaded in a 3D polymeric nanostructure, the cell-substrate interaction is enhanced, and other bioactive properties are optimized. Purpose: In this study, hectorite (HEC)- and montmorillonite (MMT)-doped polymeric scaffolds were explored for the treatment of deep and chronic skin lesions. Methods: Scaffolds were manufactured by means of electrospinning and then crosslinked by heating. Physicochemical analyses were correlated with in vitro biopharmaceutical characterization to predict the in vivo fate of the clay-doped scaffolds. Results and Discussion: The addition of MMT or HEC to the polymeric scaffold framework modifies the surface arrangement and, consequently, the potential of the scaffolds to interact with biological proteins. The presence of nanoclays alters the nanofiber morphology and size, and MMT doping increases wettability and protein adhesion. This has an impact on fibroblast behavior in a shorter time since scaffold stiffness facilitates cell adhesion and cell proliferation. Conclusion: MMT proved to perform better than HEC, and this could be related to its higher hydrophilicity and protein adhesion.


Asunto(s)
Nanofibras , Ingeniería de Tejidos , Ingeniería de Tejidos/métodos , Andamios del Tejido/química , Nanofibras/química , Arcilla , Adhesión Celular , Proliferación Celular , Poliésteres/química
14.
Clin Transl Allergy ; 13(2): e12209, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36825519

RESUMEN

BACKGROUND: Allergic rhinitis (AR) is a major non-communicable disease that affects the health-related quality of life (HRQoL) of patients. However, data on HRQoL and symptom control in AR patients with comorbid asthma (AR + asthma) are lacking. METHODS: In this multicentre, cross-sectional study, patients with AR were screened and administered questionnaires of demographic characteristics and health conditions (symptoms/diagnosis of AR and asthma, disease severity level, and allergic conditions). HRQoL was assessed using a modified version of the RHINASTHMA questionnaire (30, 'not at all bothered' - 150 'very much bothered') and symptom control was evaluated by a modified version of the Control of Allergic Rhinitis/Asthma Test (CARAT) (0, 'no control' - 30, 'very high control'). RESULTS: Out of 643 patients with AR, 500 (78%) had asthma as a comorbidity, and 54% had moderate-severe intermittent AR, followed by moderate-severe persistent AR (34%). Compared to the patients with AR alone, patients with AR + asthma had significantly higher RHINASTHMA (e.g., median RHINASTHMA-total score 48.5 vs. 84, respectively) and a significantly lower CARAT score (median CARAT-total score 23 vs. 16.5, respectively). Upon stratifying asthma based on severity, AR patients with severe persistent asthma had worse HRQoL and control than those with mild persistent asthma. The association was significantly higher among non-obese participants compared to obese ones, with RHINASTHMA-upper symptoms score but not with CARAT. CONCLUSIONS: Our observation of poorer HRQoL and symptoms control in AR patients with comorbid asthma supports the importance of a comprehensive approach for the management of AR in case of a comorbid allergic condition.

15.
Phys Rev Lett ; 109(12): 128102, 2012 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-23005991

RESUMEN

Neutron scattering reveals a complex dynamics in polypeptide chains, with two main onsets of anharmonicity whose physical origin and biological role are still debated. In this study the dynamics of strategically selected homomeric polypeptides is investigated with elastic neutron scattering using different energy resolutions and compared with that of a real protein. Our data spotlight the dependence of anharmonic transition temperatures and fluctuation amplitudes on energy resolution, which we quantitatively explain in terms of a two-site model for the protein-hydration water energy landscape. Experimental data strongly suggest that the protein dynamical transition is not a mere resolution effect but is due to a real physical effect. Activation barriers and free energy values obtained for the protein dynamical transition allow us to make a connection with the two-well interaction potential of supercooled-confined water proposed to explain a low-density→high-density liquid-liquid transition.


Asunto(s)
Modelos Químicos , Péptidos/química , Proteínas/química , Difracción de Neutrones , Transición de Fase
16.
Biochim Biophys Acta Biomembr ; 1864(9): 183950, 2022 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-35525301

RESUMEN

Biological membranes are generally formed by lipids and proteins. Often, the membrane properties are studied through model membranes formed by phospholipids only. They are molecules composed by a hydrophilic head group and hydrophobic tails, which can present a panoply of various motions, including small localized movements of a few atoms up to the diffusion of the whole lipid or collective motions of many of them. In the past, efforts were made to measure these motions experimentally by incoherent neutron scattering and to quantify them, but with upcoming modern neutron sources and instruments, such models can now be improved. In the present work, we expose a quantitative and exhaustive study of lipid dynamics on DMPC and DMPG membranes, using the Matryoshka model recently developed by our group. The model is confronted here to experimental data collected on two different membrane samples, at three temperatures and two instruments. Despite such complexity, the model describes reliably the data and permits to extract a series of parameters. The results compare also very well to other values found in the literature.


Asunto(s)
Difracción de Neutrones , Fosfolípidos , Membrana Celular , Difusión , Membranas/química , Difracción de Neutrones/métodos , Fosfolípidos/química
17.
Biochim Biophys Acta Biomembr ; 1864(9): 183949, 2022 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-35508224

RESUMEN

In accompanying papers [Bicout et al., BioRxiv https://doi.org/10.1101/2021.09.21.461198 (2021); Cissé et al., BioRxiv https://doi.org/10.1101/2022.03.30.486370 (2022)], a new model called Matryoshka model has been proposed to describe the geometry of atomic motions in phospholipid molecules in bilayers and multilamellar vesicles based on their quasielastic neutron scattering (QENS) spectra. Here, in order to characterize the relaxational aspects of this model, the energy widths of the QENS spectra of the samples were analyzed first in a model-free way. The spectra were decomposed into three Lorentzian functions, which are classified as slow, intermediate, and fast motions depending on their widths. The analysis provides the diffusion coefficients, residence times, and geometrical parameters for the three classes of motions. The results corroborate the parameter values such as the amplitudes and the mobile fractions of atomic motions obtained by the application of the Matryoshka model to the same samples. Since the current analysis was carried out independently of the development of the Matryoshka model, the present results enhance the validity of the model. The model will serve as a powerful tool to decipher the dynamics of lipid molecules not only in model systems, but also in more complex systems such as mixtures of different kinds of lipids or natural cell membranes.


Asunto(s)
Difracción de Neutrones , Neutrones , Difusión , Movimiento (Física) , Difracción de Neutrones/métodos , Fosfolípidos
18.
J Colloid Interface Sci ; 605: 110-119, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34311305

RESUMEN

Synthetic plastic oligomers can interact with the cells of living organisms by different ways. They can be intentionally administered to the human body as part of nanosized biomedical devices. They can be inhaled by exposed workers, during the production of multicomponent, polymer-based nanocomposites. They can leak out of food packaging. Most importantly, they can result from the degradation of plastic waste, and enter the food chain. A physicochemical characterization of the effects of synthetic polymers on the structure and dynamics of cell components is still lacking. Here, we combine a wide spectrum of experimental techniques (calorimetry, x-ray, and neutron scattering) with atomistic Molecular Dynamics simulations to study the interactions between short chains of polystyrene (25 monomers) and model lipid membranes (DPPC, in both gel and fluid phase). We find that doping doses of polystyrene oligomers alter the thermal properties of DPPC, stabilizing the fluid lipid phase. They perturb the membrane structure and dynamics, in a concentration-dependent fashion. Eventually, they modify the mechanical properties of DPPC, reducing its bending modulus in the fluid phase. Our results call for a systematic, interdisciplinary assessment of the mechanisms of interaction of synthetic, everyday use polymers with cell membranes.


Asunto(s)
1,2-Dipalmitoilfosfatidilcolina , Membrana Dobles de Lípidos , Rastreo Diferencial de Calorimetría , Membrana Celular , Humanos , Simulación de Dinámica Molecular , Poliestirenos
19.
J Minim Invasive Gynecol ; 18(4): 449-54, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21621483

RESUMEN

STUDY OBJECTIVE: To determine the reproductive outcome after hysteroscopic metroplasty in women with septate uterus. DESIGN: Retrospective comparative single-center study (Canadian Task Force classification II-3). SETTING: University-affiliated hospital. PATIENTS: Two hundred forty-six patients with septate uterus undergoing hysteroscopic metroplasty between January 1998 and December 2007. The diagnosis was based on hysteroscopy and 3-dimensional ultrasonography. In the most cases laparoscopy was also available. The subjects were divided into 2 age-matched groups. Group 1 consisted of 108 women with unexplained infertility, and group 2 consisted of 138 women suffering from recurrent abortion. INTERVENTIONS: Patients underwent hysteroscopic metroplasty by use of resectoscopy with an equatorial semicircular loop cutting at 0 degree with monopolar energy. All septa were completely removed without complications of bleeding, infection, risk of perforation, visceral injury, or uterine dehiscence during pregnancy. MEASUREMENT AND MAIN RESULTS: The 2 groups were compared in terms of reproductive performance in mean ± SD follow-up of 37 ± 18 months. In group 1, 61 (56.5%) patients achieved pregnancy. Seventy-one pregnancies ensued, including 1 twin gestation. Fourteen of the 71 pregnancies (19.7%) ended in miscarriage. In group 2, 90 (65.3%) patients achieved pregnancy. One hundred twenty-nine pregnancies ensued, including 2 twin gestations. Forty-four of the 129 pregnancies (34.1%) ended in miscarriage. The 2 groups have no significant differences in terms of reproductive outcome after surgery, except for the number of abortions, which was higher in group 2 (p <.05). CONCLUSION: This study confirms that hysteroscopic metroplasty is a simple, safe, and rapid surgical procedure with no complications for achieving normal uterine architecture, which is peculiar to a good reproductive outcome. The use of an equatorial semicircular loop may give satisfactory and similar results to those obtained with Collin's loop.


Asunto(s)
Histeroscopía , Útero/anomalías , Útero/cirugía , Aborto Habitual/etiología , Aborto Habitual/cirugía , Adulto , Diseño de Equipo , Femenino , Humanos , Histeroscopía/instrumentación , Infertilidad Femenina/etiología , Infertilidad Femenina/cirugía , Estudios Retrospectivos
20.
Pharmaceutics ; 13(12)2021 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-34959280

RESUMEN

The spontaneous healing of a tendon laceration results in the formation of scar tissue, which has lower functionality than the original tissue. Moreover, chronic non-healing tendon injuries frequently require surgical treatment. Several types of scaffolds have been developed using the tissue engineering approach, to complement surgical procedures and to enhance the healing process at the injured site. In this work, an electrospun hybrid tubular scaffold was designed to mimic tissue fibrous arrangement and extracellular matrix (ECM) composition, and to be extemporaneously loaded into the inner cavity with human platelet lysate (PL), with the aim of leading to complete post-surgery functional regeneration of the tissue for functional regeneration of the osteo-tendon interface. For this purpose, pullulan (P)/chitosan (CH) based polymer solutions were enriched with hydroxyapatite nanoparticles (HP) and electrospun. The nanofibers were collected vertically along the length of the scaffold to mimic the fascicle direction of the tendon tissue. The scaffold obtained showed tendon-like mechanical performance, depending on HP content and tube size. The PL proteins were able to cross the scaffold wall, and in vitro studies have demonstrated that tenocytes and osteoblasts are able to adhere to and proliferate onto the scaffold in the presence of PL; moreover, they were also able to produce either collagen or sialoproteins, respectively-important components of ECM. These results suggest that HP and PL have a synergic effect, endorsing PL-loaded HP-doped aligned tubular scaffolds as an effective strategy to support new tissue formation in tendon-to-bone interface regeneration.

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