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1.
Int J Nanomedicine ; 16: 2373-2388, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33790555

RESUMEN

Aim: The metastasis of breast cancer is an important cause of tumor recurrence. This study highlights that tyrosine kinase inhibitors dasatinib (DAS) and rosiglitazone (ROZ) inhibit tumor growth and reduce the occurrence of tumor cell metastasis. Due to the poor water solubility, short half-time in the body of DAS and ROZ, which increases the difficulty of tumor treatment, as well as the demand for nano-drug delivery systems for organ-specific therapies. Methods: Hyaluronic acid (HA) and DAS are bonded by a pH-sensitive ester bond to form an HA-DAS polymer. Then, ROZ was added as the core, D-A-tocopherol polydiethylene glycol isosuccinate (TPGS) and HA-DAS were used as carriers to form HA-DAS and TPGS mixed micelle system loaded with ROZ (THDR-NPs). The size and structure of THDR-NPs were characterized, the drug release, stability and biosafety of THDR-NPs were studied. In vitro, the cytotoxicity, targeting effect and tumor metastasis inhibition of THDR-NPs were evaluated in human breast cancer cell lines. In addition, the selective potency of designed THDR-NPs in depleting was further verified in vivo in the tumor-bearing nude mice model. Results: The designed THDR-NPs have a particle size of less than 100 nm, good stability, biological safety and sustained release, and showed strong therapeutic effects on breast cancer models in vitro and in vivo. Moreover, it has been proved that THDR-NPs have the ability to inhibit tumor metastasis. Conclusion: DAS and ROZ were designed into micelles, the efficacy of THDR-NPs was higher than that of free drugs. These results indicate that nanoparticles have a good application prospect in the treatment of tumor metastasis.


Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Sistemas de Liberación de Medicamentos , Animales , Peso Corporal/efectos de los fármacos , Neoplasias de la Mama/patología , Muerte Celular/efectos de los fármacos , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Dasatinib/administración & dosificación , Dasatinib/farmacocinética , Dasatinib/farmacología , Dasatinib/uso terapéutico , Portadores de Fármacos/química , Liberación de Fármacos , Endocitosis/efectos de los fármacos , Femenino , Hemólisis/efectos de los fármacos , Humanos , Ácido Hialurónico/química , Ratones Endogámicos BALB C , Ratones Desnudos , Micelas , Nanopartículas/química , Nanopartículas/ultraestructura , Tamaño de la Partícula , Espectroscopía de Protones por Resonancia Magnética , Ratas Sprague-Dawley , Rosiglitazona/farmacocinética , Rosiglitazona/farmacología , Rosiglitazona/uso terapéutico , Electricidad Estática , Distribución Tisular/efectos de los fármacos , Carga Tumoral/efectos de los fármacos
2.
Int J Nanomedicine ; 16: 2405-2417, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33814907

RESUMEN

Purpose: Ciprofloxacin (CIP) has poor lung targeting after oral inhalation. This study developed optimized inhalable nanostructured lipid carriers (NLCs) for CIP to enhance deposition and accumulation in deeper parts of the lungs for treatment of noncystic fibrosis bronchiectasis (NCFB). Methods: NLC formulations based on stearic acid and oleic acid were successfully prepared by hot homogenization and in vitro-characterized. CIP-NLCs were formulated into nanocomposite micro particles (NCMPs) for administration in dry powder inhalation (DPI) formulations by spray-drying (SD) using different ratios of chitosan (CH) as a carrier. DPI formulations were evaluated for drug content and in vitro deposition, and their mass median aerodynamic diameter (MMAD), fine particle fraction (FPF), fine particle dose (FPD), and emitted dose (ED) were determined. Results: The CIP-NLCs were in the nanometric size range (102.3 ± 4.6 nm), had a low polydispersity index (0.267 ± 0.12), and efficient CIP encapsulation (98.75% ± 0.048%), in addition to a spherical and smooth shape with superior antibacterial activity. The in vitro drug release profile of CIP from CIP-NLCs showed 80% release in 10 h. SD of CIP-NLCs with different ratios of CH generated NCMPs with good yield (>65%). The NCMPs had a corrugated surface, but with increasing lipid:CH ratios, more spherical, smooth, and homogenous NCMPs were obtained. In addition, there was a significant change in the FPF with increasing lipid:CH ratios (P ˂ 0.05). NCMP-1 (lipid:CH = 1:0.5) had the highest FPD (45.0 µg) and FPF (49.2%), while NCMP-3 (lipid:CH = 1:1.5) had the lowest FPF (37.4%). All NCMP powders had an MMAD in the optimum size range of 3.9-5.1 µm. Conclusion: Novel inhalable CIP NCMP powders are a potential new approach to improved target ability and delivery of CIP for NCFB treatment.


Asunto(s)
Bronquiectasia/tratamiento farmacológico , Ciprofloxacino/uso terapéutico , Portadores de Fármacos/química , Lípidos/química , Nanoestructuras/química , Administración por Inhalación , Antibacterianos/administración & dosificación , Antibacterianos/farmacología , Quitosano/química , Ciprofloxacino/administración & dosificación , Portadores de Fármacos/administración & dosificación , Liberación de Fármacos , Inhaladores de Polvo Seco , Fibrosis , Cinética , Liposomas , Pulmón , Pruebas de Sensibilidad Microbiana , Nanoestructuras/ultraestructura , Tamaño de la Partícula , Electricidad Estática
3.
Int J Nanomedicine ; 16: 2533-2553, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33824590

RESUMEN

Purpose: The present study was intended to fabricate chitosan (Ch)-tamarind gum polysaccharide (TGP) polyelectrolyte complex stabilized cubic nanoparticles of simvastatin and evaluate their potential against human breast cancer cell lines. Materials and Methods: The antisolvent precipitation method was used for formulation of nanoparticles. Factorial design (32) was utilized as a tool to analyze the effect of Ch and TGP concentration on particle size and entrapment efficiency of nanoparticles. Results: Formulated nanoparticles showed high entrapment efficiency (67.19±0.42-83.36±0.23%) and small size (53.3-383.1 nm). The present investigation involved utilization of two biological membranes (egg and tomato) as biological barriers for drug release. The study revealed that drug release from tomato membranes was retarded (as compared to egg membranes) but the release pattern matched that of egg membranes. All formulations followed the Baker-Lansdale model of drug release irrespective of the two different biological barriers. Stability studies were carried out for 45 days and exhibited less variation in particle size as well as a reduction in entrapment efficiency. Simvastatin loaded PEC stabilized nanoparticles exhibited better control on growth of human breast cancer cell lines than simple simvastatin. An unusual anticancer effect of simvastatin nanoparticles is also supported by several other research studies. Conclusion: The present study involves first-time synthesis of Ch-TGP polyelectrolyte complex stabilized nanoparticles of simvastatin against MCF-7 cells. It recommends that, in future, theoretical modeling and IVIVC should be carried out for perfect designing of delivery systems.


Asunto(s)
Quitosano/química , Nanopartículas/química , Gomas de Plantas/química , Polielectrolitos/química , Polisacáridos/química , Simvastatina/farmacología , Tamarindus/química , Antineoplásicos/farmacología , Muerte Celular/efectos de los fármacos , Portadores de Fármacos , Sistemas de Liberación de Medicamentos , Liberación de Fármacos , Humanos , Células MCF-7 , Nanopartículas/ultraestructura , Tamaño de la Partícula , Espectrofotometría Infrarroja , Electricidad Estática
4.
Nat Commun ; 12(1): 2333, 2021 04 20.
Artículo en Inglés | MEDLINE | ID: mdl-33879791

RESUMEN

Acaryochloris marina is one of the cyanobacterial species that can use far-red light to drive photochemical reactions for oxygenic photosynthesis. Here, we report the structure of A. marina photosystem I (PSI) reaction center, determined by cryo-electron microscopy at 2.58 Å resolution. The structure reveals an arrangement of electron carriers and light-harvesting pigments distinct from other type I reaction centers. The paired chlorophyll, or special pair (also referred to as P740 in this case), is a dimer of chlorophyll d and its epimer chlorophyll d'. The primary electron acceptor is pheophytin a, a metal-less chlorin. We show the architecture of this PSI reaction center is composed of 11 subunits and we identify key components that help explain how the low energy yield from far-red light is efficiently utilized for driving oxygenic photosynthesis.


Asunto(s)
Proteínas Bacterianas/química , Cianobacterias/química , Complejo de Proteína del Fotosistema I/química , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Clorofila/química , Clorofila/metabolismo , Microscopía por Crioelectrón , Cianobacterias/genética , Cianobacterias/metabolismo , Transporte de Electrón , Luz , Modelos Moleculares , Oxígeno/metabolismo , Fotosíntesis , Complejo de Proteína del Fotosistema I/genética , Complejo de Proteína del Fotosistema I/metabolismo , Estructura Cuaternaria de Proteína , Subunidades de Proteína , Electricidad Estática
5.
Int J Mol Sci ; 22(6)2021 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-33799606

RESUMEN

The interactions at the atomic level between small molecules and the main components of cellular plasma membranes are crucial for elucidating the mechanisms allowing for the entrance of such small species inside the cell. We have performed molecular dynamics and metadynamics simulations of tryptophan, serotonin, and melatonin at the interface of zwitterionic phospholipid bilayers. In this work, we will review recent computer simulation developments and report microscopic properties, such as the area per lipid and thickness of the membranes, atomic radial distribution functions, angular orientations, and free energy landscapes of small molecule binding to the membrane. Cholesterol affects the behaviour of the small molecules, which are mainly buried in the interfacial regions. We have observed a competition between the binding of small molecules to phospholipids and cholesterol through lipidic hydrogen-bonds. Free energy barriers that are associated to translational and orientational changes of melatonin have been found to be between 10-20 kJ/mol for distances of 1 nm between melatonin and the center of the membrane. Corresponding barriers for tryptophan and serotonin that are obtained from reversible work methods are of the order of 10 kJ/mol and reveal strong hydrogen bonding between such species and specific phospholipid sites. The diffusion of tryptophan and melatonin is of the order of 10-7 cm2/s for the cholesterol-free and cholesterol-rich setups.


Asunto(s)
1,2-Dipalmitoilfosfatidilcolina/química , Colesterol/química , Dimiristoilfosfatidilcolina/química , Melatonina/química , Serotonina/química , Triptófano/química , 1,2-Dipalmitoilfosfatidilcolina/metabolismo , Colesterol/metabolismo , Dimiristoilfosfatidilcolina/metabolismo , Enlace de Hidrógeno , Membrana Dobles de Lípidos/química , Membrana Dobles de Lípidos/metabolismo , Melatonina/metabolismo , Simulación de Dinámica Molecular , Serotonina/metabolismo , Soluciones , Electricidad Estática , Termodinámica , Triptófano/metabolismo , Agua/química
6.
Int J Nanomedicine ; 16: 2667-2687, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33854314

RESUMEN

Purpose: The goal was to directly deliver curcumin, a natural polyphenolic anticancer and anti-inflammatory compound, to the lung tissues with minimal systemic exposure through the fabrication of proliposomes, overcoming its poor aqueous solubility and oral bioavailability. Methods: Nano-spray drying was employed to prepare proliposomes using hydroxypropyl beta-cyclodextrin as a carrier. Lecithin and cholesterol were used as lipids, stearylamine and Poloxamer 188 were added as positive charge inducer and a surfactant, respectively. Different characterization parameters were evaluated like percentage yield, entrapment efficiency, drug loading, aerodynamic particle size, in vitro release besides morphological examination. Cytotoxicity studies on cell line A549 lung tumor cells as well as in vivo lung pharmacokinetic studies were also carried. Results: The optimized formulations showed superior aerosolization properties coupled their enhanced ability to reach deep lung tissues with a high % of fine particle fraction. Cytotoxicity studies using MTT assay demonstrated enhanced growth inhibitory effect on lung tumor cells A549 and significant reduction of proinflammatory cytokines such as tumor necrosis factor-α, interleukin-6 and interleukin-10 compared to the pure drug. Results of lung pharmacokinetic tests confirmed the superiority of proliposomal curcumin over curcumin powder in both, the rate and extent of lung tissue absorption, as well as the mean residence time within the lung tissues. Conclusion: The pulmonary delivery of curcumin-loaded proliposomes as dry powder provides a direct approach to lung tissues targeting while avoiding the limitations of the oral route and offering a non-invasive alternative to the parenteral one.


Asunto(s)
Curcumina/administración & dosificación , Curcumina/farmacología , Sistemas de Liberación de Medicamentos , Pulmón/efectos de los fármacos , Células A549 , Animales , Disponibilidad Biológica , Rastreo Diferencial de Calorimetría , Muerte Celular/efectos de los fármacos , Curcumina/farmacocinética , Liberación de Fármacos , Humanos , Liposomas , Masculino , Tamaño de la Partícula , Poloxámero/química , Polvos , Ratas , Solubilidad , Espectroscopía Infrarroja por Transformada de Fourier , Electricidad Estática
7.
Int J Mol Sci ; 22(6)2021 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-33809708

RESUMEN

A typical feature of proteins from the rhodopsin family is the sensitivity of their absorption band maximum to protein amino acid composition. For this reason, studies of these proteins often require methodologies that determine spectral shift caused by amino acid substitutions. Generally, quantum mechanics/molecular mechanics models allow for the calculation of a substitution-induced spectral shift with high accuracy, but their application is not always easy and requires special knowledge. In the present study, we propose simple models that allow us to estimate the direct effect of a charged or polar residue substitution without extensive calculations using only rhodopsin three-dimensional structure and plots or tables that are provided in this article. The models are based on absorption maximum values calculated at the SORCI+Q level of theory for cis- and trans-forms of retinal protonated Schiff base in an external electrostatic field of charges and dipoles. Each value corresponds to a certain position of a charged or polar residue relative to the retinal chromophore. The proposed approach was evaluated against an example set consisting of twelve bovine rhodopsin and sodium pumping rhodopsin mutants. The limits of the applicability of the models are also discussed. The results of our study can be useful for the interpretation of experimental data and for the rational design of rhodopsins with required spectral properties.


Asunto(s)
Aminoácidos/química , Proteínas Bacterianas/química , Modelos Moleculares , Rodopsina/química , Análisis Espectral , Electricidad Estática , Sustitución de Aminoácidos , Animales , Bovinos , Mutación/genética , Protones , Rodopsina/genética , Bases de Schiff/química
8.
Int J Mol Sci ; 22(5)2021 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-33800824

RESUMEN

A new copper complex, trans-diaqua-trans-bis [1-hydroxy-1,2-di (methoxycarbonyl) ethenato] copper (abbreviation Cu(II) complex), was synthesized and its plant growth regulation properties were investigated. The results show a sharp dependence of growth regulation activity of the Cu(II) complex on the type of culture and its concentration. New plant growth regulator accelerated the development of the corn root system (the increase in both length and weight) but showed a smaller effect on the development of the wheat and barley root systems. Stimulation of corn growth decreased with increasing Cu(II) complex concentration from 0.0001% to 0.01% (inhibition at high concentrations-0.01%). The development of corn stems was also accelerated but to a lesser extent. Chitosan-coated calcium alginate microcapsules suitable for delivery of Cu(II) complex to plants were prepared and characterized. Analysis of the FTIR spectrum showed that complex molecular interactions between functional groups of microcapsule constituents include mainly electrostatic interactions and hydrogen bonds. Microcapsules surface exhibits a soft granular surface structure with substructures consisting of abundant smaller particles with reduced surface roughness. Release profile analysis showed Fickian diffusion is the rate-controlling mechanism of Cu(II) complex releasing. The obtained results give new insights into the complexity of the interaction between the Cu(II) complex and microcapsule formulation constituents, which can be of great help in accelerating product development for the application in agriculture.


Asunto(s)
Alginatos/administración & dosificación , Quitosano/administración & dosificación , Portadores de Fármacos/administración & dosificación , Composición de Medicamentos/métodos , Reguladores del Crecimiento de las Plantas/síntesis química , Rastreo Diferencial de Calorimetría , Cápsulas , Difusión , Portadores de Fármacos/química , Germinación/efectos de los fármacos , Enlace de Hidrógeno , Microscopía Electrónica de Rastreo , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/crecimiento & desarrollo , Tallos de la Planta/efectos de los fármacos , Tallos de la Planta/crecimiento & desarrollo , Poaceae/efectos de los fármacos , Poaceae/crecimiento & desarrollo , Espectrometría por Rayos X , Espectroscopía Infrarroja por Transformada de Fourier , Electricidad Estática , Propiedades de Superficie
9.
Int J Mol Sci ; 22(5)2021 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-33800923

RESUMEN

A homo-dimeric enzyme, thymidylate synthase (TS), has been a long-standing molecular target in chemotherapy. To further elucidate properties and interactions with ligands of wild-type mouse thymidylate synthase (mTS) and its two single mutants, H190A and W103G, spectroscopic and theoretical investigations have been employed. In these mutants, histidine at position 190 and tryptophan at position 103 are substituted with alanine and glycine, respectively. Several emission-based spectroscopy methods used in the paper demonstrate an especially important role for Trp 103 in TS ligands binding. In addition, the Advanced Poisson-Boltzmann Solver (APBS) results show considerable differences in the distribution of electrostatic potential around Trp 103, as compared to distributions observed for all remaining Trp residues in the mTS family of structures. Together, spectroscopic and APBS results reveal a possible interplay between Trp 103 and His190, which contributes to a reduction in enzymatic activity in the case of H190A mutation. Comparison of electrostatic potential for mTS complexes, and their mutants, with the substrate, dUMP, and inhibitors, FdUMP and N4-OH-dCMP, suggests its weaker influence on the enzyme-ligand interactions in N4OH-dCMP-mTS compared to dUMP-mTS and FdUMP-mTS complexes. This difference may be crucial for the explanation of the "abortive reaction" inhibitory mechanism of N4OH-dCMP towards TS. In addition, based on structural analyses and the H190A mutant capacity to form a denaturation-resistant complex with N4-OH-dCMP in the mTHF-dependent reaction, His190 is apparently responsible for a strong preference of the enzyme active center for the anti rotamer of the imino inhibitor form.


Asunto(s)
Nucleótidos de Desoxiuracil/metabolismo , Modelos Teóricos , Espectrometría de Fluorescencia/métodos , Electricidad Estática , Timidilato Sintasa/metabolismo , Sustitución de Aminoácidos , Animales , Desoxicitidina Monofosfato/análogos & derivados , Desoxicitidina Monofosfato/metabolismo , Nucleótidos de Desoxiuracil/química , Fluorodesoxiuridilato/metabolismo , Ratones , Modelos Moleculares , Análisis Multivariante , Conformación Proteica , Timidilato Sintasa/química
10.
Phys Chem Chem Phys ; 23(10): 5852-5863, 2021 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-33688867

RESUMEN

COVID-19 has recently caused a global health crisis and an effective interventional therapy is urgently needed. Remdesivir is one effective inhibitor for SARS-CoV-2 viral RNA replication. It supersedes other NTP analogues because it not only terminates the polymerization activity of RNA-dependent RNA polymerase (RdRp), but also inhibits the proofreading activity of intrinsic exoribonuclease (ExoN). Even though the static structure of Remdesivir binding to RdRp has been solved and biochemical experiments have suggested it to be a "delayed chain terminator", the underlying molecular mechanisms is not fully understood. Here, we performed all-atom molecular dynamics (MD) simulations with an accumulated simulation time of 24 microseconds to elucidate the inhibitory mechanism of Remdesivir on nucleotide addition and proofreading. We found that when Remdesivir locates at an upstream site in RdRp, the 1'-cyano group experiences electrostatic interactions with a salt bridge (Asp865-Lys593), which subsequently halts translocation. Our findings can supplement the current understanding of the delayed chain termination exerted by Remdesivir and provide an alternative molecular explanation about Remdesivir's inhibitory mechanism. Such inhibition also reduces the likelihood of Remdesivir to be cleaved by ExoN acting on 3'-terminal nucleotides. Furthermore, our study also suggests that Remdesivir's 1'-cyano group can disrupt the cleavage site of ExoN via steric interactions, leading to a further reduction in the cleavage efficiency. Our work provides plausible and novel mechanisms at the molecular level of how Remdesivir inhibits viral RNA replication, and our findings may guide rational design for new treatments of COVID-19 targeting viral replication.


Asunto(s)
Adenosina Monofosfato/análogos & derivados , Alanina/análogos & derivados , Cianuros/química , Nucleótidos/metabolismo , /fisiología , Adenosina Monofosfato/química , Adenosina Monofosfato/metabolismo , Adenosina Monofosfato/farmacología , Adenosina Monofosfato/uso terapéutico , Alanina/química , Alanina/metabolismo , Alanina/farmacología , Alanina/uso terapéutico , /patología , Dominio Catalítico , Humanos , Simulación de Dinámica Molecular , Ribosa/química , /metabolismo , Electricidad Estática , Replicación Viral/efectos de los fármacos
11.
Int J Nanomedicine ; 16: 1977-1992, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33727810

RESUMEN

Background: Phytostanols are naturally occurring compounds that reduce blood cholesterol levels significantly. However, their aqueous insolubility poses formulation challenges. Aim: To formulate and characterize solid lipid nanoparticle carriers for phytostanol esters to enhance the bioavailability of phytostanols. Methods: Phytostanol ester solid lipid nanoparticles were formulated by the microemulsion method. They were characterized for particle size distribution, polydispersity index, shape, surface charge, entrapment efficiency, stability, chemical structure, and thermal properties. The uptake of the formulation by cell lines, HepG2 and HT-29, and its effect on cell viability were evaluated. Results: The formulation of solid lipid nanoparticles was successfully optimised by varying the type of lipids and their concentration relative to that of surfactants in the present study. The optimised formulation had an average diameter of (171 ± 9) nm, a negative surface charge of (-23.0 ± 0.8) mV and was generally spherical in shape. We report high levels of drug entrapment at (89 ± 5)% in amorphous form, drug loading of (9.1 ± 0.5)%, nanoparticle yield of (67 ± 4)% and drug excipient compatibility. The biological safety and uptake of the formulations were demonstrated on hepatic and intestinal cell lines. Conclusion: Phytostanol ester solid lipid nanoparticles were successfully formulated and characterized. The formulation has the potential to provide an innovative drug delivery system for phytostanols which reduce cholesterol and have a potentially ideal safety profile. This can contribute to better management of one of the main risk factors of cardiovascular diseases.


Asunto(s)
Composición de Medicamentos , Ésteres/química , Hipercolesterolemia/tratamiento farmacológico , Lípidos/química , Nanopartículas/química , Fitosteroles/uso terapéutico , Muerte Celular , Emulsiones/química , Endocitosis , Citometría de Flujo , Células HT29 , Células Hep G2 , Humanos , Tamaño de la Partícula , Polvos , Espectroscopía Infrarroja por Transformada de Fourier , Electricidad Estática , Temperatura
12.
Int J Mol Sci ; 22(5)2021 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-33668791

RESUMEN

Interactions between phospholipid membranes and selected drugs affecting the central nervous system (CNS) were investigated. Small, unilamellar liposomes were used as biomimetic cell membrane models. Microelectrophoretic experiments on two-component liposomes were performed using the electrophoretic light scattering technique (ELS). The effect of both positively (perphenazine, PF) and negatively (barbituric acid, BA) charged drugs on zwitterionic L-α-phosphatidylcholine (PC) membranes were analyzed. Experimental membrane surface charge density (δ) data were determined as a function of pH. Quantitative descriptions of the adsorption equilibria formed due to the binding of solution ions to analyzed two-component membranes are presented. Binding constants of the solution ions with perphenazine and barbituric acid-modified membranes were determined. The results of our research show that both charged drugs change surface charge density values of phosphatidylcholine membranes. It can be concluded that perphenazine and barbituric acid are located near the membrane surface, interacting electrostatically with phosphatidylcholine polar heads.


Asunto(s)
Barbitúricos/farmacología , Sistema Nervioso Central/fisiología , Electricidad , Perfenazina/farmacología , Fosfatidilcolinas/metabolismo , Animales , Aniones , Cationes , Sistema Nervioso Central/efectos de los fármacos , Pollos , Punto Isoeléctrico , Liposomas , Membranas Artificiales , Modelos Biológicos , Dispersión de Radiación , Soluciones , Electricidad Estática
13.
Methods Mol Biol ; 2266: 39-72, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33759120

RESUMEN

The interaction between a protein and its ligands is one of the basic and most important processes in biological chemistry. Docking methods aim to predict the molecular 3D structure of protein-ligand complexes starting from coordinates of the protein and the ligand separately. They are widely used in both industry and academia, especially in the context of drug development projects. AutoDock4 is one of the most popular docking tools and, as for any docking method, its performance is highly system dependent. Knowledge about specific protein-ligand interactions on a particular target can be used to successfully overcome this limitation. Here, we describe how to apply the AutoDock Bias protocol, a simple and elegant strategy that allows users to incorporate target-specific information through a modified scoring function that biases the ligand structure towards those poses (or conformations) that establish selected interactions. We discuss two examples using different bias sources. In the first, we show how to steer dockings towards interactions derived from crystal structures of the receptor with different ligands; in the second example, we define and apply hydrophobic biases derived from Molecular Dynamics simulations in mixed solvents. Finally, we discuss general concepts of biased docking, its performance in pose prediction, and virtual screening campaigns as well as other potential applications.


Asunto(s)
Simulación del Acoplamiento Molecular/métodos , Proteínas/química , Solventes/química , Sitios de Unión , Cristalografía por Rayos X , Quinasa 2 Dependiente de la Ciclina/química , Interacciones Hidrofóbicas e Hidrofílicas , Ligandos , Conformación Molecular , Simulación de Dinámica Molecular , Unión Proteica , Programas Informáticos , Electricidad Estática
14.
Methods Mol Biol ; 2266: 125-140, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33759124

RESUMEN

Rational drug discovery relies heavily on molecular docking-based virtual screening, which samples flexibly the ligand binding poses against the target protein's structure. The upside of flexible docking is that the geometries of the generated docking poses are adjusted to match the residue alignment inside the target protein's ligand-binding pocket. The downside is that the flexible docking requires plenty of computing resources and, regardless, acquiring a decent level of enrichment typically demands further rescoring or post-processing. Negative image-based screening is a rigid docking technique that is ultrafast and computationally light but also effective as proven by vast benchmarking and screening experiments. In the NIB screening, the target protein cavity's shape/electrostatics is aligned and compared against ab initio-generated ligand 3D conformers. In this chapter, the NIB methodology is explained at the practical level and both its weaknesses and strengths are discussed candidly.


Asunto(s)
Descubrimiento de Drogas/métodos , Simulación del Acoplamiento Molecular/métodos , Proteínas/química , Algoritmos , Sitios de Unión , Cristalografía por Rayos X , Ciclooxigenasa 2/química , Bases de Datos de Proteínas , Ligandos , Modelos Moleculares , Conformación Molecular , Unión Proteica , Curva ROC , Bibliotecas de Moléculas Pequeñas/química , Programas Informáticos , Electricidad Estática , Interfaz Usuario-Computador
15.
Methods Mol Biol ; 2266: 141-154, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33759125

RESUMEN

Molecular docking produces often lackluster results in real-life virtual screening assays that aim to discover novel drug candidates or hit compounds. The problem lies in the inability of the default docking scoring to properly estimate the Gibbs free energy of binding, which impairs the recognition of the best binding poses and the separation of active ligands from inactive compounds. Negative image-based rescoring (R-NiB) provides both effective and efficient way for re-ranking the outputted flexible docking poses to improve the virtual screening yield. Importantly, R-NiB has been shown to work with multiple genuine drug targets and six popular docking algorithms using demanding benchmark test sets. The effectiveness of the R-NiB methodology relies on the shape/electrostatics similarity between the target protein's ligand-binding cavity and the docked ligand poses. In this chapter, the R-NiB method is described with practical usability in mind.


Asunto(s)
Descubrimiento de Drogas/métodos , Simulación del Acoplamiento Molecular/métodos , Proteínas/química , Algoritmos , Área Bajo la Curva , Sitios de Unión , Cristalografía por Rayos X , Ciclooxigenasa 2/química , Bases de Datos de Proteínas , Ligandos , Conformación Molecular , Neuraminidasa/química , Unión Proteica , Programas Informáticos , Electricidad Estática
16.
Drug Des Devel Ther ; 15: 1111-1133, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33737804

RESUMEN

Purpose: SARS-CoV-2 engages human ACE2 through its spike (S) protein receptor binding domain (RBD) to enter the host cell. Recent computational studies have reported that withanone and withaferin A, phytochemicals found in Withania somnifera, target viral main protease (MPro) and host transmembrane TMPRSS2, and glucose related protein 78 (GRP78), respectively, implicating their potential as viral entry inhibitors. Absence of specific treatment against SARS-CoV-2 infection has encouraged exploration of phytochemicals as potential antivirals. Aim: This study aimed at in silico exploration, along with in vitro and in vivo validation of antiviral efficacy of the phytochemical withanone. Methods: Through molecular docking, molecular dynamic (MD) simulation and electrostatic energy calculation the plausible biochemical interactions between withanone and the ACE2-RBD complex were investigated. These in silico observations were biochemically validated by ELISA-based assays. Withanone-enriched extract from W. somnifera was tested for its ability to ameliorate clinically relevant pathological features, modelled in humanized zebrafish through SARS-CoV-2 recombinant spike (S) protein induction. Results: Withanone bound efficiently at the interacting interface of the ACE2-RBD complex and destabilized it energetically. The electrostatic component of binding free energies of the complex was significantly decreased. The two intrachain salt bridge interactions (K31-E35) and the interchain long-range ion-pair (K31-E484), at the ACE2-RBD interface were completely abolished by withanone, in the 50 ns simulation. In vitro binding assay experimentally validated that withanone efficiently inhibited (IC50=0.33 ng/mL) the interaction between ACE2 and RBD, in a dose-dependent manner. A withanone-enriched extract, without any co-extracted withaferin A, was prepared from W. somnifera leaves. This enriched extract was found to be efficient in ameliorating human-like pathological responses induced in humanized zebrafish by SARS-CoV-2 recombinant spike (S) protein. Conclusion: In conclusion, this study provided experimental validation for computational insight into the potential of withanone as a potent inhibitor of SARS-CoV-2 coronavirus entry into the host cells.


Asunto(s)
/metabolismo , Antivirales/farmacología , /efectos de los fármacos , Glicoproteína de la Espiga del Coronavirus/metabolismo , Withania , Witanólidos/farmacología , Células A549 , Animales , Antivirales/química , Antivirales/aislamiento & purificación , /virología , Modelos Animales de Enfermedad , Femenino , Interacciones Huésped-Patógeno , Humanos , Masculino , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Dominios y Motivos de Interacción de Proteínas , /patogenicidad , Glicoproteína de la Espiga del Coronavirus/química , Electricidad Estática , Relación Estructura-Actividad , Internalización del Virus/efectos de los fármacos , Withania/química , Witanólidos/química , Witanólidos/aislamiento & purificación , Pez Cebra
17.
Int J Nanomedicine ; 16: 1377-1390, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33658778

RESUMEN

Background: Vascular drug delivery becomes a promising direction in the development of novel therapeutic strategies in the treatment of cardiovascular pathologies, such as hypertension. However, targeted delivery of hydrophobic substances, with poor bioavailability, remains a challenge. Here, we described the hypotensive effects of a low dose of curcumin delivered to the vascular wall using hyaluronic acid-based nanocapsules. Methods: The group of hypertensive TGR(m-Ren2)27 rats, was administrated respectively with the vehicle, curcumin solution or curcumin delivered using hyaluronic acid-based nanocapsules (HyC12-Cur), for 7 days each, maintaining the wash-out period between treatments. Arterial blood pressure (systolic - SBP, diastolic - DBP) and heart rate (HR) were monitored continuously using a telemetry system (Data Science International), and Mean Arterial Pressure (MAP) was calculated from SBP and DBP. Results: In hypertensive rats, a low dose of curcumin (4.5 mg/kg) administrated in HyC12-Cur for 7 days resulted in a gradual inhibition of SBP, DBP and MAP increase without an effect on HR. At the end of HyC12-Cur - based treatment changes in SBP, DBP and MAP amounted to -2.0±0.8 mmHg, -3.9±0.7 mmHg and -3.3±0.7 mmHg, respectively. In contrast, the administration of a curcumin solution (4.5 mg/kg) did not result in a significant hypotensive effect and the animals constantly developed hypertension. Vascular delivery of capsules with curcumin was confirmed using newly developed fluorine-rich nanocapsules (HyFC10-PFOB) with a shell based on a HA derivative and similar size as HyC12-Cur. HyFC10-PFOB gave fluorine signals in rat aortas analyzed ex vivo with a 19F NMR technique after a single intragastric administration. Conclusion: These results suggest that nanocapsules based on hyaluronic acid, the ubiquitous glycosaminoglycan of the extracellular matrix and an integral part of endothelial glycocalyx, may represent a suitable approach to deliver hydrophobic, poorly bioavailable compounds, to the vascular wall.


Asunto(s)
Curcumina/administración & dosificación , Curcumina/uso terapéutico , Ácido Hialurónico/química , Hipertensión/tratamiento farmacológico , Nanocápsulas/química , Administración Oral , Animales , Aorta/efectos de los fármacos , Aorta/patología , Presión Sanguínea/efectos de los fármacos , Curcumina/farmacología , Diástole/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Flúor/química , Frecuencia Cardíaca/efectos de los fármacos , Hidrodinámica , Interacciones Hidrofóbicas e Hidrofílicas , Hipertensión/fisiopatología , Espectroscopía de Resonancia Magnética , Masculino , Tamaño de la Partícula , Ratas , Electricidad Estática , Sístole/efectos de los fármacos
18.
Int J Nanomedicine ; 16: 1601-1616, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33688181

RESUMEN

Introduction: Cancer is the second leading cause of death globally and is responsible, where about 1 in 6 deaths in the world. Therefore, there is a need to develop effective antitumor agents that are targeted only to the specific site of the tumor to improve the efficiency of cancer diagnosis and treatment and, consequently, limit the unwanted systemic side effects currently obtained by the use of chemotherapeutic agents. In this context, due to its unique physical and chemical properties of graphene oxide (GO), it has attracted interest in biomedicine for cancer therapy. Methods: In this study, we report the in vivo application of nanocomposites based on Graphene Oxide (nc-GO) with surface modified with PEG-folic acid, Rhodamine B and Indocyanine Green. In addition to displaying red fluorescence spectra Rhodamine B as the fluorescent label), in vivo experiments were performed using nc-GO to apply Photodynamic Therapy (PDT) and Photothermal Therapy (PTT) in the treatment of Ehrlich tumors in mice using NIR light (808 nm 1.8 W/cm2). Results: This study based on fluorescence images was performed in the tumor in order to obtain the highest concentration of nc-GO in the tumor as a function of time (time after intraperitoneal injection). The time obtained was used for the efficient treatment of the tumor by PDT/PTT. Discussion: The current study shows an example of successful using nc-GO nanocomposites as a theranostic nanomedicine to perform simultaneously in vivo fluorescence diagnostic as well as combined PDT-PTT effects for cancer treatments.


Asunto(s)
Grafito/química , Fotoquimioterapia , Nanomedicina Teranóstica , Adsorción , Animales , Benzofuranos/química , Carcinoma de Ehrlich/patología , Carcinoma de Ehrlich/terapia , Humanos , Verde de Indocianina/farmacología , Masculino , Ratones , Nanocompuestos/química , Tamaño de la Partícula , Rodaminas/farmacología , Espectrometría de Fluorescencia , Espectrometría Raman , Electricidad Estática , Carga Tumoral
19.
Int J Nanomedicine ; 16: 1757-1773, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33688190

RESUMEN

Background: NiO nanoparticles have attracted much attention due to their unique properties. They have been synthesized using chemical and physical techniques that often need toxic chemicals. These toxic chemicals cannot easily be removed from the nanoparticle's surface, make them less biocompatible, and limit their biological applications. Instead, plants based green synthesis of nanoparticles uses phytomolecules as reducing and capping agents. These phytomolecules are biologically active with no or less toxic effects. Materials and Methods: Phytomolecules-coated NiO nanoparticles were synthesized employing a green route using Abutilon indicum leaf extract. For comparative study, we also have synthesized NiO nanoparticles using the co-precipitation method. Synthesized nanoparticles were successfully characterized using different spectroscopic techniques. The synthesized nanoparticles were evaluated for antibacterial activity with agar well diffusion assay against different bacteria compared to standard drug and plant extract. They are also examined for anticancer potential using MTT assay against HeLa cancer cells, and further, their antioxidant potential was determined using DPPH assay. Biocompatibility of the synthesized nanoparticles was assessed against fibroblast cells. Results: Phytomolecules-coated NiO nanoparticles were demonstrated superior antibacterial and anticancer performance against bacteria (E. coli, B. bronchiseptica, B. subtilis, and S. aureus) by presenting highest zone of inhibitions (18 ± 0.58 mm, 21 ± 0.45 mm, 22 ± 0.32 mm, and 23 ± 0.77 mm) and HeLa cancer cells by exhibiting the least cell viability percentage (51.74 ± 0.35%) compared to plant extract and chemically synthesized NiO nanoparticles but were comparable to standard antibiotic and anticancer drugs, respectively. Phytomolecules-coated NiO nanoparticles were also demonstrated excellent antioxidant activity (79.87 ± 0.43% DPPH inhibition) and biocompatibility (> 90% cell viability) with fibroblast cells. Conclusion: Nanoparticle synthesis using the Abutilon indicum leaf extract is an efficient and economical method, produces biocompatible and more biologically active nanoparticles, which can be an excellent candidate for therapeutic applications.


Asunto(s)
Antiinfecciosos/farmacología , Antineoplásicos/farmacología , Antioxidantes/farmacología , Malvaceae/química , Nanopartículas del Metal/química , Fitoquímicos/química , Extractos Vegetales/química , Hojas de la Planta/química , Bacterias/efectos de los fármacos , Compuestos de Bifenilo/química , Fibroblastos/efectos de los fármacos , Tecnología Química Verde , Células HeLa , Humanos , Peroxidación de Lípido/efectos de los fármacos , Masculino , Nanopartículas del Metal/ultraestructura , Pruebas de Sensibilidad Microbiana , Picratos/química , Espectrometría por Rayos X , Espectrofotometría Ultravioleta , Espectroscopía Infrarroja por Transformada de Fourier , Electricidad Estática , Difracción de Rayos X
20.
J Vis Exp ; (168)2021 02 10.
Artículo en Inglés | MEDLINE | ID: mdl-33645576

RESUMEN

Estimations of soil organic carbon are dependent on soil processing methods including removal of undecomposed plant material. Inadequate separation of roots and plant material from soil can result in highly variable carbon measurements. Methods to remove the plant material are often limited to the largest, most visible plant materials. In this manuscript we describe how electrostatic attraction can be used to remove plant material from a soil sample. An electrostatically charged surface passed close to dry soil naturally attracts both undecomposed and partially decomposed plant particles, along with a small quantity of mineral and aggregated soil. The soil sample is spread in a thin layer on a flat surface or a soil sieve. A plastic or glass Petri dish is electrostatically charged by rubbing with polystyrene foam or nylon or cotton cloth. The charged dish is passed repeatedly over the soil. The dish is then brushed clean and recharged. Re-spreading the soil and repeating the procedure eventually results in a diminishing yield of particulates. The process removes about 1 to 5% of the soil sample, and about 2 to 3 times that proportion in organic carbon. Like other particulate removal methods, the endpoint is arbitrary and not all free particulates are removed. The process takes approximately 5 min and does not require a chemical process as do density flotation methods. Electrostatic attraction consistently removes material with higher than average C concentration and C:N ratio, and much of the material can be visually identified as plant or faunal material under a microscope.


Asunto(s)
Compuestos Orgánicos/química , Material Particulado/análisis , Suelo/química , Electricidad Estática , Carbono/análisis , Plantas/química , Plásticos/química
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