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Biofilm formation by the pathobiont Haemophilus influenzae is associated with human nasopharynx colonization, otitis media in children, and chronic respiratory infections in adults suffering from chronic respiratory diseases such as chronic obstructive pulmonary disease (COPD). ß-lactam and quinolone antibiotics are commonly used to treat these infections. However, considering the resistance of biofilm-resident bacteria to antibiotic-mediated killing, the use of antibiotics may be insufficient and require being replaced or complemented with novel strategies. Moreover, unlike the standard minimal inhibitory concentration assay used to assess antibacterial activity against planktonic cells, standardization of methods to evaluate anti-biofilm drug activity is limited. In this work, we detail a panel of protocols for systematic analysis of drug antimicrobial effect on bacterial biofilms, customized to evaluate drug effects against H. influenzae biofilms. Testing of two cinnamaldehyde analogs, (E)-trans-2-nonenal and (E)-3-decen-2-one, demonstrated their effectiveness in both H. influenzae inhibition of biofilm formation and eradication or preformed biofilms. Assay complementarity allowed quantifying the dynamics and extent of the inhibitory effects, also observed for ampicillin resistant clinical strains forming biofilms refractory to this antibiotic. Moreover, cinnamaldehyde analog encapsulation into poly(lactic-co-glycolic acid) (PLGA) polymeric nanoparticles allowed drug vehiculization while maintaining efficacy. Overall, we demonstrate the usefulness of cinnamaldehyde analogs against H. influenzae biofilms, present a test panel that can be easily adapted to a wide range of pathogens and drugs, and highlight the benefits of drug nanoencapsulation towards safe controlled release.
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In this work, a one-step electrospinning technique has been implemented for the design and development of functional surfaces with a desired morphology in terms of wettability and corrosion resistance by using polycaprolactone (PCL) and zinc oxide nanoparticles (ZnO NPs). The surface morphology has been characterized by confocal microscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM) and water contact angle (WCA), whereas the corrosion resistance has been evaluated by Tafel polarization curves. Strict control over the input operational parameters (applied voltage, feeding rate, distance tip to collector), PCL solution concentration and amount of ZnO NPs have been analyzed in depth by showing their key role in the final surface properties. With this goal in mind, a design of experiment (DoE) has been performed in order to evaluate the optimal coating morphology in terms of fiber diameter, surface roughness (Ra), water contact angle (WCA) and corrosion rate. It has been demonstrated that the solution concentration has a significant effect on the resultant electrospun structure obtained on the collector with the formation of beaded fibers with a higher WCA value in comparison with uniform bead-free fibers (dry polymer deposition or fiber-merging aspect). In addition, the presence of ZnO NPs distributed within the electrospun fibers also plays a key role in corrosion resistance, although it also leads to a decrease in the WCA. Finally, this is the first time that an exhaustive analysis by using DoE has been evaluated for PCL/ZnO electrospun fibers with the aim to optimize the surface morphology with the better performance in terms of corrosion resistance and wettability.
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The unique properties of magnetic nanoparticles have led them to be considered materials with significant potential in the biomedical field. Nanometric size, high surface-area ratio, ability to function at molecular level, exceptional magnetic and physicochemical properties, and more importantly, the relatively easy tailoring of all these properties to the specific requirements of the different biomedical applications, are some of the key factors of their success. In this paper, we will provide an overview of the state of the art of different aspects of magnetic nanoparticles, specially focusing on their use in biomedicine. We will explore their magnetic properties, synthetic methods and surface modifications, as well as their most significative physicochemical properties and their impact on the in vivo behaviour of these particles. Furthermore, we will provide a background on different applications of magnetic nanoparticles in biomedicine, such as magnetic drug targeting, magnetic hyperthermia, imaging contrast agents or theranostics. Besides, current limitations and challenges of these materials, as well as their future prospects in the biomedical field will be discussed.
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Hipertermia Inducida , Nanopartículas de Magnetita , Nanopartículas , Medios de Contraste , Sistemas de Liberación de Medicamentos , MagnetismoRESUMEN
BACKGROUND AND OBJECTIVE: The standardization of treatment of older adults with Philadelphia chromosome negative (Ph-) acute lymphoblastic leukemia (ALL) is challenging, especially in the age range of 55-65 years. This study aimed to compare intensive, pediatric-inspired therapy with non-intensive therapy in this population of patients. PATIENTS AND METHODS: The outcomes of 67 patients prospectively included in two consecutive pediatric-inspired intensive protocols (ALL-HR03 and ALL-HR11) from the Spanish PETHEMA Group were compared with those from 44 patients included in a contemporary semi-intensive protocol (ALL-OLD07). RESULTS: Baseline patient and ALL characteristics were similar in both groups, except for a younger median age in the intensive group (medians: 58 vs. 62 years). Patients treated intensively had a higher complete remission rate (85% vs. 64%, pâ¯=â¯0.005), a lower cumulative incidence of relapse (39% [95%CI, 25% to 52%] vs. 60% [95%CI, 38% to 77%], pâ¯=â¯.003), a similar cumulative incidence of treatment-related mortality (28% [95% CI, 18%, 40%] vs. 21% [95% CI, 10%, 34%]) and superior event-free survival at 2 years (37% [95%CI, 25%-49%) vs. 21% [8%-34%], pâ¯=â¯0.002). On multivariable analysis the type of protocol was the only variable with independent significance for event-free survival (HR [95% CI]: 2 [1.3, 3], pâ¯=â¯.002). CONCLUSIONS: Compared with less intensive chemotherapy, pediatric-inspired intensive chemotherapy significantly improves the outcome of older adults with Ph-negative ALL in the age range of 55-65 years.
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Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Trasplante de Células Madre Hematopoyéticas , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Anciano , Niño , Terapia Combinada , Femenino , Humanos , Masculino , Persona de Mediana Edad , Cromosoma Filadelfia , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Supervivencia sin Progresión , Estudios Prospectivos , Inducción de Remisión , Resultado del TratamientoRESUMEN
The modulation of conjugated polyelectrolyte fluorescence response by nonionic surfactants is dependent on the structures of the surfactant and polymer, polymer average molecular weight, and polyelectrolyte-surfactant interactions. In this paper, we study the effect of nonionic n-alkyl polyoxyethylene surfactants (CiEj) with different alkyl chain lengths (CiE5 with i = 6, 8, 10, and 12) and number of oxyethylene groups (C12Ej with j = 5, 7, and 9) on the photophysics and ionic conductivity of poly{[9,9-bis(6'-N,N,N-trimethylammonium)-hexyl]-2,7-fluorene-alt-1,4-phenylene}bromide (HTMA-PFP) in dimethyl sulfoxide-water 4% (v/v). Molecular dynamics simulations show that HTMA-PFP chains tend to approach as the simulation evolves. However, the minimum distance between the polymer centers of mass increases upon addition of the surfactant and grows with both the surfactant alkyl chain length and the number of oxyethylene groups, although there are no specific polymer-surfactant interactions. A significant increase in the polymer emission intensity has been observed at surfactant concentrations around their critical micelle concentrations (cmcs), which is attributed to polymer aggregate disruption. However, an increase in the solution conductivity for concentrations above the C12E5 cmc has only been observed for the HTMA-PFP/C12E5 system. The enhancement of fluorescence emission intensity and conductivity upon surfactant addition increases with polymer average molecular weights and seems to be controlled by the polymer-surfactant proximity, which is maximum for C10E5 and C12E5.
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BACKGROUND AND OBJECTIVE: The prognosis of acute lymphoblastic leukemia (ALL) is poor in older adults and elderly patients, and subtype-oriented prospective trials are scarce in these patients. We present the results of three prospective parallel subtype-oriented protocols in fit patients older than 55 years. PATIENTS AND METHODS: In 2008, three prospective phase II trials in patients older than 55 years were activated: ALLOLD07 for Philadephia (Ph) chromosome-negative ALL, ALLOPH07 for Ph-positive ALL, and BURKIMAB08 for mature B-ALL. Early death (ED), complete remission (CR), disease-free survival (DFS), overall survival (OS) and toxicity were analyzed. RESULTS: 56, 53 and 21 patients from the ALLOLD07, ALLOPH07 and BURKIMAB08 trials, respectively, were evaluable. CR was 74%, 87% and 70%, with an ED rate of 13%, 11% and 15%, respectively. The medians of DFS were 8 and 38 months for ALLOLD07 and ALLOPH07 protocols, not being achieved in the BURKIMAB08 trial (p=0.001), and the median OS was 12, 37 and 25 months, respectively (p=0.030). Neutropenia, thrombocytopenia and infections were less frequent in the ALLOPH07 trial vs. ALLOLD07 and BURKIMAB trials, and renal toxicity and mucositis were more frequent in the BURKIMAB08 trial vs. the ALLOLD07 and ALLOPH07 trials. ECOG score and WBC count had prognostic significance for OS in ALLOPH07 and BURKIMAB08 trials, whereas no prognostic factors were identified in ALLOLD07 protocol. CONCLUSION: Subtype-oriented treatment had an impact in the outcome of older adults with ALL. The poorest outcome was observed in Ph-negative non-Mature B-cell ALL patients, for whom improvements in therapy are clearly needed.
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Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Anciano , Anciano de 80 o más Años , Estudios de Factibilidad , Femenino , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidad , PronósticoRESUMEN
We have studied the effect of head group and alkyl chain length on ß-phase formation in poly(9,9-dioctylfluorene) (PFO) solubilized in phospholipid liposomes. Systems studied have three different alkyl chain lengths (1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine [DMPC], 1,2-didodecanoyl-sn-glycero-3-phosphatidylcholine [DLPC], 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine [DPPC]) and head groups (1,2-dimyristoyl-sn-glycero-3-phosphate monosodium salt [DMPA], 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine [DMPE] and 1,2-dimyristoyl-sn-glycero-3-phospho-l-serine sodium salt [DMPS]). Changes in liposome size upon addition of PFO are followed by dynamic light scattering. All the phospholipids induce the formation of PFO ß-phase, which is followed by the emission intensity and deconvolution of the absorption spectra. Both the head group and alkyl chain length affect the yield of ß-phase. The photophysics of PFO incorporated in liposomes is characterized by stationary and time-resolved fluorescence, whereas the polymer-phospholipid interactions have been studied by the effect of the PFO concentration on the phospholipid phase transitions (differential scanning calorimetry [DSC]).
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Liposomas , Fosfolípidos/químicaAsunto(s)
Cromosoma Filadelfia , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Humanos , Persona de Mediana Edad , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimología , Estudios Prospectivos , Inhibidores de Proteínas Quinasas/administración & dosificaciónRESUMEN
The well-structured ß-phase emission of the neutral poly(9,9-dioctylfluorene) (PFO) is observed in 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) bilayers, either as polydisperse aqueous liposomes or as the lamellar phase in thin films, and has been characterized by absorption, fluorescence (steady-state and time-resolved), and fluorescence anisotropy spectroscopy. Inclusion of PFO in DMPC liposomes provides a way of obtaining the ordered structure of this neutral polymer in aqueous suspensions. Quantification of the increase of the PFO ß-phase in DMPC liposomes with the increase in polymer concentration is followed by deconvolution of the absorption spectra. In solid films, the presence of the phospholipids enhances the ß-phase formation. In addition, the effect of the PFO concentration on the phospholipid phase transitions has been studied by differential scanning calorimetry (in liposome) and polarized light thermal microscopy (in solid film), confirming PFO/DMPC interactions in both liposome and films. The liposome size and structure in the presence and absence of polymer were characterized by dynamic light scattering and transmission electron microscopy, which showed relatively modest changes in liposome shape but a decrease in size upon incorporation of PFO.
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Fluorenos/química , Membrana Dobles de Lípidos/química , Liposomas/química , Rastreo Diferencial de Calorimetría , Dimiristoilfosfatidilcolina/química , Transición de Fase , Espectrometría de FluorescenciaRESUMEN
The competitive interaction has been studied between double-stranded DNA (dsDNA), the cationic conjugated polyelectrolyte (CPE) poly[9,9-bis(6-N,N,N-trimethylamonium)hexyl)-fluorene-phenylene)] bromide (HTMA-PFP) and anionic or neutral surfactants (sodium dodecyl sulfonate, SDSu, and n-dodecyl pentaoxyethylene glycol ether, C(12)E(5)) in 4% (v/v) dimethyl sulfoxide (DMSO)-water using UV/visible absorption and fluorescence spectroscopy. Dramatic changes are observed in the spectroscopic behavior of the system depending on the order of addition of the reagents, the surfactant charge, and concentration range. If the neutral C(12)E(5) is added to the HTMA-PFP/dsDNA complex, no significant spectroscopic changes are observed. However, if SDSu is added to the same complex, a dramatic increase of the absorbance and emission intensity is observed for surfactant concentrations above the critical micelle concentration (cmc). In contrast, if dsDNA is added to HTMA-PFP/surfactant systems (with surfactant concentrations above their cmc) no significant changes are observed with SDSu, while a dramatic quenching of polymer emission is observed with C(12)E(5), which can be explained quantitatively in terms of HTMA-PFP/surfactant/DNA complexation and the subsequent polymer aggregation upon charge neutralization. The results are compared with those for the binary systems (HTMA-PFP/DNA and HTMA-PFP/surfactants) and indicate the importance of electrostatic interactions between HTMA-PFP and oppositely charged species in the aggregation processes.
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ADN/química , Fluorenos/química , Polímeros/química , Compuestos de Amonio Cuaternario/química , Tensoactivos/química , Electrólitos/química , CinéticaRESUMEN
The interaction between three poly(9,9-bis(6-N,N,N-trimethylammonium)hexyl)fluorene phenylene) bromide (HTMA-PFP) samples of different molecular weights (Mn=14.5, 30.1 and 61.3 kg/mol) and both dsDNA and ssDNA secondary structures has been studied using UV-visible absorption and fluorescence spectroscopies (including steady-state, time-resolved, and anisotropy measurements for the latter), viscosity, and electrical conductivity in 4% (v/v) DMSO-water mixtures. At low nucleic acid concentrations, formation of a 1:1 complex in terms of HTMA-PFP repeat units and DNA bases occurs. This interaction results in quenching of polymer emission. For higher molar ratios of DNA to HTMA-PFP, corresponding to charge neutralization, a second process is observed that is attributed to aggregate formation. From the changes in the absorption spectra, the polymer aggregation constant and the aggregate absorption spectra were calculated by applying an iterative method. Polymer aggregation dramatically quenches HTMA-PFP fluorescence in the region of the electroneutrality point. Under these conditions, the ratio of the emission intensity at 412 nm (maximum) to that at 434 nm (I412/I434) reaches a minimum, the electrical conductivity decreases, and the viscosity of the solution remains constant, showing that the DNA concentration can be determined through various HTMA-PFP physicochemical properties. With respect to the photophysical parameters (emission quantum yield, shape and shift of emission spectra), no significant differences were observed between dsDNA and ssDNA or with conjugated polymer or DNA molecular weight. The two short-lived components in the fluorescence decays are attributed to the presence of aggregates. Aggregates are also suggested to be responsible for the decrease in the fluorescence anisotropy through interchain exciton migration.
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ADN/química , Conductividad Eléctrica , Fluorenos/química , Conformación de Ácido Nucleico , Polímeros/química , Compuestos de Amonio Cuaternario/química , Animales , Masculino , Peso Molecular , Salmón , Espectrofotometría , Testículo/química , Termodinámica , ViscosidadRESUMEN
Interaction between beta-carboline-3-carboxylic acid N-methylamide, betaCMAM, and nucleobases, nucleosides and nucleotides is studied in the ground state with UV-visible, (1)H NMR and (31)P NMR spectroscopies and in the first excited state, with steady-state and time-resolved fluorescence spectroscopy. Job plots show a predominant 1:1 interaction in both electronic states. Association constants are estimated from changes in the absorption spectra, and show that the strongest interaction is produced with the nucleosides: 2'-deoxyadenosine (dAdo) and thymidine (Thd), and with the mononucleotides: 2'-deoxycytidine 5'- monophosphate (5'-dCMP) and uridine 5'- monophosphate (5'-UMP). These results are corroborated by the upfield shifts of two (1)H NMR resonances of the betaCMAM indole group. The (31)P NMR resonance of nucleotides is shifted downfield, suggesting the presence of electrostatic or hydrogen bond interaction with betaCMAM. In the first electronic singlet excited state, static and dynamic quenching of betaCMAM emission is achieved upon addition of nucleobases, nucleosides and nucleotides. This has been analysed using Stern-Volmer kinetics.
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Carbolinas/química , ADN/química , Nucleósidos/química , Nucleótidos/química , Análisis Espectral/métodos , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Espectrometría de Fluorescencia , Espectrofotometría UltravioletaRESUMEN
The complexation of beta-carboline-3-carboxylic acid N-methylamide (betaCMAM) with the sodium salts of the nucleotides polyadenylic (Poly A), polycytidylic (Poly C), polyguanylic (Poly G), polythymidylic (Poly T) and polyuridylic (Poly U) acids, and with double stranded (dsDNA) and single stranded deoxyribonucleic acids (ssDNA) was studied at pH 4, 6 and 9. Predominant 1:1 complex formation is indicated from Job plots. Association constants were determined using the Benesi-Hildebrand equation. BetaCMAM-sensitized singlet oxygen quantum yields were determined at pH 4, 6 and 9, and the effects on this of adding oligonucleotides, dsDNA and ssDNA were studied at the three pH values. With dsDNA, the effect on betaCMAM triplet state formation was also determined through triplet-triplet transient absorption spectra. To evaluate possible oxidative damage of DNA following singlet oxygen betaCMAM photosensitization, we used thiobarbituric acid-reactivity assays and electrophoretic separation of DNA assays. The results showed no oxidative damage at the level of DNA degradation or strand break.
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Carbolinas/química , Daño del ADN/genética , Polinucleótidos/química , Polinucleótidos/genética , Oxígeno Singlete/química , Estructura Molecular , Oxidación-Reducción , EspectrofotometríaRESUMEN
The interaction between the cationic HTMA-PFP (Poly-(9,9-bis(6'-N,N,N-trimethylammonium)hexyl-fluorene phenylene) bromide) and oppositely charged sodium n-alkyl sulfonate surfactants of different chain lengths has been studied in DMSO-water solutions (4% v/v) by UV-visible absorption, fluorescence spectroscopy, fluorescence lifetimes, electrical conductivity, and (1)H NMR spectroscopy. Polymer-surfactant interactions lead to complex spectroscopic behaviors which depends on surfactant concentration. At low surfactant concentrations, the observed strong static fluorescence quenching of fluorescence seems to be associated with formation of aggregates between polymer chains neutralized through interaction with surfactants. This is supported by conductivity and by analysis of absorption spectra deconvoluted at each surfactant concentration using an adapted iterative method. In contrast, above the surfactant critical micelle concentration, there is a strong fluorescence enhancement, leading in some cases to higher intensities than in the absence of surfactants. This is attributed to the transformation of the initially formed aggregates into some new aggregate species involving surfactant and polymer. These changes in HTMA-PFP fluorescence as a function of n-alkyl sulfonate concentration are important for the general understanding of polymer-surfactant interactions, and the aggregates formed may be important as novel systems for applications of these conjugated polyelectrolytes.
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Alcanosulfonatos/química , Fluorenos/química , Polímeros/química , Compuestos de Amonio Cuaternario/química , Tensoactivos/química , Espectrometría de Fluorescencia , Espectrofotometría UltravioletaRESUMEN
Sulfur-bridged pregnanes 6,19-epithioprogesterone, 21-hydroxy-6,19-epithioprogesterone, and the corresponding sulfoxides and sulfones were synthesized and tested as blockers of the immunosuppresive activity of dexamethasone in rat thymocytes. A new one-pot procedure is described for the preparation of 6,19-epithioprogesterone and related compounds by iodocyclization of a 19-sulfanylpregn-5-ene. Antiimmunosuppresive activity was evaluated by the ability of the different steroids to block dexamethasone-mediated apoptosis in thymocytes and dexamethasone-mediated inhibition of the NFkappa-B transcription factor activity. DNA fragmentation and annexin V-FITC positive cells were taken as parameters of apoptosis whereas NFkappa-B activity was tested by the expression of the reporter vector kappaB-luciferase by TNF-alpha in Hela cells. 21-Hydroxy-6,19-epithioprogesterone S,S-dioxide had improved activity in both parameters, while 21-hydroxy-6,19-epithioprogesterone had improved activity only in blocking dexamethasone-induced programmed cell death.