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1.
J Phys Chem Lett ; 12(20): 5023-5029, 2021 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-34024101

RESUMO

Lipopolysaccharides (LPS) in sea spray aerosol (SSA) particles have recently been shown to undergo heterogeneous reactions with HNO3 in the atmosphere. Here, we integrate theory and experiment to further investigate how the most abundant sea salt cations, Na+, Mg2+, and Ca2+, impact HNO3 reactions with LPS-containing SSA particles. Aerosol reaction flow tube studies show that heterogeneous reactions of SSA particles with divalent cation (Mg2+ and Ca2+) and LPS signatures were less reactive with HNO3 than those dominated by monovalent cations (Na+). All-atom molecular dynamics simulations of model LPS aggregates suggest that divalent cations cross-link the oligosaccharide chains to increase molecular aggregation and rigidity, which changes the particle phase and morphology, decreases water diffusion, and consequently decreases the reactive uptake of HNO3. This study provides new insight into how complex chemical interactions between ocean-derived salts and biogenic organic species can impact the heterogeneous reactivity of SSA particles.


Assuntos
Cálcio/química , Lipopolissacarídeos/química , Magnésio/química , Ácido Nítrico/química , Água do Mar/química , Sódio/química , Aerossóis/química , Cátions/química , Tamanho da Partícula , Sais/química , Propriedades de Superfície
2.
Molecules ; 26(5)2021 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-33800936

RESUMO

Hydrogel beads based on the husk of agarwood fruit (HAF)/sodium alginate (SA), and based on the HAF/chitosan (CS) were developed for the removal of the dyes, crystal violet (CV) and reactive blue 4 (RB4), in aqueous solutions, respectively. The effects of the initial pH (2-10) of the dye solution, the adsorbent dosage (0.5-3.5 g/L), and contact time (0-540 min) were investigated in a batch system. The dynamic adsorption behavior of CV and RB4 can be represented well by the pseudo-second-order model and pseudo-first-order model, respectively. In addition, the adsorption isotherm data can be explained by the Langmuir isotherm model. Both hydrogel beads have acceptable adsorption selectivity and reusability for the study of selective adsorption and regeneration. Based on the effectiveness, selectivity, and reusability of these hydrogel beads, they can be treated as potential adsorbents for the removal of dyes in aqueous solutions.


Assuntos
Ânions/química , Cátions/química , Corantes/isolamento & purificação , Frutas/química , Hidrogéis/química , Poluentes Químicos da Água/isolamento & purificação , Madeira/química , Adsorção , Corantes/análise , Poluentes Químicos da Água/análise , Purificação da Água
3.
Molecules ; 26(8)2021 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-33921656

RESUMO

The solution behavior and physicochemical characteristics of polymer-colloid complexes based on cationic imidazolium amphiphile with a dodecyl tail (IA-12) and polyacrylic acid (PAA) or DNA decamer (oligonucleotide) were evaluated using tensiometry, conductometry, dynamic and electrophoretic light scattering and fluorescent spectroscopy and microscopy. It has been established that PAA addition to the surfactant system resulted in a ca. 200-fold decrease in the aggregation threshold of IA-12, with the hydrodynamic diameter of complexes ranging within 100-150 nm. Electrostatic forces are assumed to be the main driving force in the formation of IA-12/PAA complexes. Factors influencing the efficacy of the complexation of IA-12 with oligonucleotide were determined. The nonconventional mode of binding with the involvement of hydrophobic interactions and the intercalation mechanism is probably responsible for the IA-12/oligonucleotide complexation, and a minor contribution of electrostatic forces occurred. The latter was supported by zeta potential measurements and the gel electrophoresis technique, which demonstrated the low degree of charge neutralization of the complexes. Importantly, cellular uptake of the IA-12/oligonucleotide complex was confirmed by fluorescence microscopy and flow cytometry data on the example of M-HeLa cells. While single IA-12 samples exhibit roughly similar cytotoxicity, IA-12-oligonucleotide complexes show a selective effect toward M-HeLa cells (IC50 1.1 µM) compared to Chang liver cells (IC50 23.1 µM).


Assuntos
Resinas Acrílicas/química , Cátions/química , Coloides/química , DNA/química , Polímeros/química , Linhagem Celular Tumoral , Citometria de Fluxo , Células HeLa , Humanos , Interações Hidrofóbicas e Hidrofílicas , Imidazóis/química , Microscopia de Fluorescência
4.
Molecules ; 26(5)2021 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-33806643

RESUMO

A novel, simple, low-cost, and user-friendly potentiometric surfactant sensor based on the new 1,3-dihexadecyl-1H-benzo[d]imidazol-3-ium-tetraphenylborate (DHBI-TPB) ion-pair for the detection of cationic surfactants in personal care products and disinfectants is presented here. The new cationic surfactant DHBI-Br was successfully synthesized and characterized by nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectrometry, liquid chromatography-mass spectrometry (LC-MS) and elemental analysis and was further employed for DHBI-TPB ion-pair preparation. The sensor gave excellent response characteristics for CTAB, CPC and Hyamine with a Nernstian slope (57.1 to 59.1 mV/decade) whereas the lowest limit of detection (LOD) value was measured for CTAB (0.3 × 10-6 M). The sensor exhibited a fast dynamic response to dodecyl sulfate (DDS) and TPB. High sensor performances stayed intact regardless of the employment of inorganic and organic cations and in a broad pH range (2-11). Titration of cationic and etoxylated (EO)-nonionic surfactant (NSs) (in Ba2+) mixtures with TPB revealed the first inflexion point for a cationic surfactant and the second for an EO-nonionic surfactant. The increased concentration of EO-nonionic surfactants and the number of EO groups had a negative influence on titration curves and signal change. The sensor was successfully applied for the quantification of technical-grade cationic surfactants and in 12 personal care products and disinfectants. The results showed good agreement with the measurements obtained by a commercial surfactant sensor and by a two-phase titration. A good recovery for the standard addition method (98-102%) was observed.


Assuntos
Técnicas Biossensoriais/métodos , Cátions/química , Cosméticos/análise , Desinfetantes/análise , Imidazóis/química , Potenciometria/métodos , Tensoativos/química , Concentração de Íons de Hidrogênio
5.
Int J Mol Sci ; 22(4)2021 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-33669232

RESUMO

Tracer diffusion coefficients obtained from the Taylor dispersion technique at 25.0 °C were measured to study the influence of sodium, ammonium and magnesium salts at 0.01 and 0.1 mol dm-3 on the transport behavior of sodium hyaluronate (NaHy, 0.1%). The selection of these salts was based on their position in Hofmeister series, which describe the specific influence of different ions (cations and anions) on some physicochemical properties of a system that can be interpreted as a salting-in or salting-out effect. In our case, in general, an increase in the ionic strength (i.e., concentrations at 0.01 mol dm-3) led to a significant decrease in the limiting diffusion coefficient of the NaHy 0.1%, indicating, in those circumstances, the presence of salting-in effects. However, the opposite effect (salting-out) was verified with the increase in concentration of some salts, mainly for NH4SCN at 0.1 mol dm-3. In this particular salt, the cation is weakly hydrated and, consequently, its presence does not favor interactions between NaHy and water molecules, promoting, in those circumstances, less resistance to the movement of NaHy and thus to the increase of its diffusion (19%). These data, complemented by viscosity measurements, permit us to have a better understanding about the effect of these salts on the transport behaviour of NaHy.


Assuntos
Ânions/química , Cátions/química , Ácido Hialurônico/química , Água/química , Sulfato de Amônio/química , Transporte Biológico , Difusão , Cloreto de Lítio/química , Sulfato de Magnésio/química , Concentração Osmolar , Sais/química , Cloreto de Sódio/química , Soluções , Sulfatos/química , Temperatura , Tiocianatos/química , Viscosidade
6.
Phys Rev Lett ; 126(4): 046001, 2021 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-33576667

RESUMO

We demonstrate a novel principle of contactless actuation for ionic membranes in salt solution based on solvation. Actuation is driven by differential swelling of the sides of the membrane, due to comigrating water in the solvation shells of mobile ions. We validate our theory through a series of experiments, which unravel a strong dependence of membrane deflection on the hydration numbers of mobile ions in the external solution and membrane. Our study suggests a critical role of solvation in the chemoelectromechanics of natural and artificial selectively permeable membranes.


Assuntos
Membranas/química , Modelos Químicos , Cátions/química , Eletroquímica , Soluções/química
7.
Methods Mol Biol ; 2246: 87-96, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33576984

RESUMO

Oligonucleotides able to hybridize bacterial RNA via in situ hybridization may potentially act as new antimicrobials, replacing antibiotics, and as fast in vivo diagnostic probes, outperforming current clinical methodologies. Nonetheless, oligonucleotides are not able to efficiently permeate the multi-layered bacterial envelope to reach their target RNA in the cytosol. Cationic fusogenic liposomes are here suggested as vehicles to enable the internalization of oligonucleotides in bacteria. Here, we describe the formulation of DOTAP-DOPE liposomes, their complexation with small negatively charged oligonucleotides, and the evaluation of the intracellular delivery of the oligonucleotides in bacteria. This strategy uncovers the potential of performing FISH in vivo for real-time detection and treatment of infections.


Assuntos
Bactérias/metabolismo , Lipossomos/química , Oligonucleotídeos/metabolismo , Cátions/química , Citosol/metabolismo , Ácidos Graxos Monoinsaturados/química , Hibridização in Situ Fluorescente/métodos , Fosfatidiletanolaminas/química , Compostos de Amônio Quaternário/química , RNA Bacteriano/metabolismo
8.
ACS Appl Mater Interfaces ; 13(7): 7913-7923, 2021 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-33573372

RESUMO

Biomimetic biomaterials are being actively explored in the context of cancer immunotherapy because of their ability to directly engage the immune system to generate antitumor responses. Unlike cellular therapies, biomaterial-based immunotherapies can be precisely engineered to exhibit defined characteristics including biodegradability, physical size, and tuned surface presentation of immunomodulatory signals. In particular, modulating the interface between the biomaterial surface and the target biological cell is key to enabling biological functions. Synthetic artificial antigen presenting cells (aAPCs) are promising as a cancer immunotherapy but are limited in clinical translation by the requirement of ex vivo cell manipulation and adoptive transfer of antigen-specific CD8+ T cells. To move toward acellular aAPC technology for in vivo use, we combine poly(lactic-co-glycolic acid) (PLGA) and cationic poly(beta-amino-ester) (PBAE) to form a biodegradable blend based on the hypothesis that therapeutic aAPCs fabricated from a cationic blend may have improved functions. PLGA/PBAE aAPCs demonstrate enhanced surface interactions with antigen-specific CD8+ T cells that increase T cell activation and expansion ex vivo, associated with significantly increased conjugation efficiency of T cell stimulatory signals to the aAPCs. Critically, these PLGA/PBAE aAPCs also expand antigen-specific cytotoxic CD8+ T cells in vivo without the need of adoptive transfer. Treatment with PLGA/PBAE aAPCs in combination with checkpoint therapy decreases tumor growth and extends survival in a B16-F10 melanoma mouse model. These results demonstrate the potential of PLGA/PBAE aAPCs as a biocompatible, directly injectable acellular therapy for cancer immunotherapy.


Assuntos
Células Apresentadoras de Antígenos/imunologia , Células Artificiais/imunologia , Imunoterapia , Melanoma/terapia , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/imunologia , Polímeros/química , Animais , Células Artificiais/química , Linfócitos T CD8-Positivos/imunologia , Cátions/química , Cátions/imunologia , Melanoma/imunologia , Camundongos , Tamanho da Partícula , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Propriedades de Superfície
9.
ACS Appl Mater Interfaces ; 13(2): 2336-2345, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33410653

RESUMO

Lipid nanoparticles of internal cubic symmetry, termed cuboplexes, are potential nonviral delivery vehicles for gene therapy due to their "topologically active" nature, which may enhance endosomal escape and improve delivery outcomes. In this study, we have used cationic cuboplexes, based on monoolein (MO) doped with a cationic lipid, for the encapsulation and delivery of antisense green fluorescent protein (GFP)-small interfering RNA (siRNA) into Chinese Hamster Ovary (CHO)-GFP cells. Agarose gel electrophoresis has confirmed the successful encapsulation of siRNA within cationic cubosomes, while synchrotron small-angle X-ray scattering (SAXS) demonstrated that the underlying cubic nanostructure of the particles was retained following encapsulation. The cationic cubosomes were shown to be reasonably nontoxic against the CHO-GFP cell line. Fluorescence-activated cell sorting (FACS) provided evidence of the successful transfection to CHO-GFP cells. Knockdown efficiency was strongly linked to the type of cationic lipid used, although all cubosomes had essentially the same internal nanostructure. The gene knockdown efficiency for some cationic cubosomes was shown to be higher than lipofectamine, which is a commercially available liposome-based formulation, while the controlled release of the siRNA from the cubosomes over a 72 h period was observed using confocal microscopy. This combination exemplifies the potential of cationic cuboplexes as a novel, nonviral, controlled-release delivery vector for siRNA.


Assuntos
Portadores de Fármacos/química , Glicerídeos/química , Interferência de RNA , RNA Interferente Pequeno/administração & dosagem , Animais , Células CHO , Cátions/química , Cricetulus , Proteínas de Fluorescência Verde/genética , Lipídeos/química , RNA Interferente Pequeno/genética , Transfecção
10.
Ecotoxicol Environ Saf ; 208: 111704, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396035

RESUMO

Clay minerals can adsorb both microorganisms and heavy metals. In this study, typical soil bacterium, Enterobacter sp. was applied to investigate the potential protection of the bacterial cells from Pb2+ stress by clay minerals. The sorption by two representative types of montmorillonite (Mt) were contrasted, i.e., Mts/Mtw with strong/weak CEC. There was no significant difference between the two clay minerals regarding their adsorption of Pb2+ cations in water (i.e., ~55 mg L-1). However, the sorption of bacterial cells on the two clay minerals showed evident contrasts, which resulted in the different capacity of Pb sorption. Mts with high CEC preferentially adsorbed abundant bacterial cells (rather than Pb2+) on its surface. The residual Pb2+ concentration in solution actually raised by 7.5% after the addition of Enterobacter sp. In addition, both the Pb-contaminated cells and "healthy" cells (with low Pb contamination) could be adsorbed onto Mt surface, whereas the latter dominated the adsorbents on Mts. This was due to that the Mts with high CEC could provide more exchangeable cations, building more cation bridging ligands between the microbial cells (whatever the types of cells) and clay surface. Furthermore, the adsorbed "healthy" bacterial cells might escape from clay surface via "self-liberating" mechanism, i.e., increasing electrostatic repulsion between the bacteria and clay during microbial decomposition of the medium. This study hence elucidated the protection of microorganisms from Pb2+ stress by Mt.


Assuntos
Argila/química , Enterobacter/efeitos dos fármacos , Chumbo/toxicidade , Poluentes do Solo/toxicidade , Adsorção , Bentonita/química , Cátions/química , Enterobacter/metabolismo , Chumbo/química , Metais Pesados/química , Minerais/química , Poluentes do Solo/química
11.
Int J Mol Sci ; 22(2)2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33450934

RESUMO

This editorial summarizes the 13 scientific papers published in the Special Issue "Physiology, Biochemistry, and Pharmacology of Transporters for Organic Cations" of the International Journal of Molecular Sciences [...].


Assuntos
Cátions/metabolismo , Proteínas de Membrana Transportadoras/fisiologia , Cátions/química , Fenômenos Químicos , Descoberta de Drogas , Proteínas de Membrana Transportadoras/química
12.
Int J Mol Sci ; 22(1)2021 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-33466417

RESUMO

Liposomes are highly biocompatible and versatile drug carriers with an increasing number of applications in the field of nuclear medicine and diagnostics. So far, only negatively charged liposomes with intercalated radiometals, e.g., 64Cu, 99mTc, have been reported. However, the process of cellular uptake of liposomes by endocytosis is rather slow. Cellular uptake can be accelerated by recently developed cationic liposomes, which exhibit extraordinarily high membrane fusion ability. The aim of the present study was the development of the formulation and the characterization of such cationic fusogenic liposomes with intercalated radioactive [131I]I- for potential use in therapeutic applications. The epithelial human breast cancer cell line MDA-MB-231 was used as a model for invasive cancer cells and cellular uptake of [131I]I- was monitored in vitro. Delivery efficiencies of cationic and neutral liposomes were compared with uptake of free iodide. The best cargo delivery efficiency (~10%) was achieved using cationic fusogenic liposomes due to their special delivery pathway of membrane fusion. Additionally, human blood cells were also incubated with cationic control liposomes and free [131I]I-. In these cases, iodide delivery efficiencies remained below 3%.


Assuntos
Cátions/química , Portadores de Fármacos/química , Radioisótopos do Iodo/administração & dosagem , Radioisótopos do Iodo/química , Lipossomos/química , Nanopartículas/química , Animais , Células CHO , Linhagem Celular , Linhagem Celular Tumoral , Cricetulus , Endocitose/efeitos dos fármacos , Humanos , Fusão de Membrana/efeitos dos fármacos
13.
Eur J Med Chem ; 212: 113152, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33453601

RESUMO

The development of new drugs for musculoskeletal regeneration purposes has attracted much attention in the last decades. In this work, we present three novel vitamin B9 (folic acid)-derivatives bearing divalent cations (ZnFO, MgFO and MnFO), providing their synthesis mechanism and physicochemical characterization. In addition, a strong emphasis has been placed on evaluating their biological properties (along with our previously reported SrFO) using human mesenchymal stem cells (hMSC). In all the cases, pure folate derivatives (MFOs) with a bidentate coordination mode between the metal and the folate anion, and a 1:1 stoichiometry, were obtained in high yields. A non-cytotoxic dose of all the MFOs (50 µg/mL) was demonstrated to modulate by their own the mRNA profiles towards osteogenic-like or fibrocartilaginous-like phenotypes in basal conditions. Moreover, ZnFO increased the alkaline phosphatase activity in basal conditions, while both ZnFO and MnFO increased the matrix mineralization degree in osteoinductive conditions. Thus, we have demonstrated the bioactivity of these novel compounds and the suitability to further studied them in vivo for musculoskeletal regeneration applications.


Assuntos
Materiais Biocompatíveis/química , Ácido Fólico/química , Células-Tronco Mesenquimais/citologia , Sistema Musculoesquelético/citologia , Engenharia Tecidual , Materiais Biocompatíveis/síntese química , Cátions/síntese química , Cátions/química , Células Cultivadas , Portadores de Fármacos/síntese química , Portadores de Fármacos/química , Ácido Fólico/síntese química , Humanos
14.
Int J Biol Macromol ; 171: 234-241, 2021 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-33412203

RESUMO

Despite numerous applications of nanofibrous alginate (Alg) mat, its facile fabrication via electrospinning is still challenging. The low alginate content compared to the carrier polymer and existence of impurities are the main drawbacks of existing approaches. The purpose of this research is both to study and improve alginate electrospinnability by focusing on the effect of inter- and intramolecular hydrogen bonding. Based on hard and soft acids and bases (HSAB) theory, the Na+ cations (carboxylate counter-cation) were substituted with a harder acid, Li+ cation, to increase the strength of ionic interaction and decrease the density of hydrogen bonding. Viscosity and electrical conductivity measurements as well as FTIR and 1H NMR revealed a lower intramolecular hydrogen bonding density in Li-Alg. SEM images showed improvement of alginate electrospinnability for Li-Alg compared to the salts of Na-Alg and K-Alg. This study sheds more light on underlying reasons hindering alginate electrospinning and introduces a simple method for fabrication of nanofibers with high alginate content.


Assuntos
Alginatos/química , Nanofibras/química , Configuração de Carboidratos , Cátions/química , Teoria da Densidade Funcional , Condutividade Elétrica , Ligação de Hidrogênio , Lítio/química , Microscopia Eletrônica de Varredura , Potássio/química , Sódio/química , Espectroscopia de Infravermelho com Transformada de Fourier , Viscosidade
15.
Int J Biol Macromol ; 170: 793-809, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33387544

RESUMO

Paper industry uses cationic polymers for imparting strong bonds with pulp furnish to enhance strength properties. Due to environmental reasons, emphasis is on utilization of biobased polymers in place of synthetic. Sugarcane bagasse, an agro-industrial waste, was processed for extraction of alpha cellulose and preparation of cationic derivative. Reaction conditions were optimized to achieve highly substituted cationic derivative with insertion of 2-hydroxy-3-(trimethylammonium) propyl group. Artificial neural network (ANN) was applied to analyze the experimental data for cationization modeling. Maximum degree of substitution 0.66, was achieved at 5.0 M NaOH/anhydro glucose unit (AGU), 20 °C alkalization temperature, 8 min alkalization time, 3.5 M/AGU etherification agent concentration, 45 min time and 60 °C etherification reaction temperature. The experimental results showed that mean square error values for input parameters were significantly low. The ANN based regression values of the output, and computed values of target were close to unity. ANN based fitting indicates better performance level to predict the degree of substitution. The synthesized cationic cellulose was characterized through FTIR, XRD, NMR, FESEM and TGA. The activity of cationized cellulose as wet-end additive was tested for bagasse, wheat straw and recycled pulps due to their shorten fiber and feeble pulp characters than wood pulp.


Assuntos
Celulose/química , Saccharum/química , Cátions/química , Resíduos Industriais , Polímeros/química , Reciclagem/métodos , Temperatura
16.
Carbohydr Polym ; 256: 117535, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33483051

RESUMO

The high viscosity of ionic liquids, even at relatively high temperatures, can greatly affect the production of cellulose fibers through the wet-spinning process. The high viscosity mainly by due to the hydrogen bond interaction between the cations and anions of ionic liquids. It is possible to reduce the viscosity by modulating the hydrogen bond interaction. In the present work, copper chloride (CuCl2) was dissolved in 1-butyl-3-methylimidazolium chloride ([Bmim]Cl)-cellulose solution, followed by the formation of a complex with the chloride anions by converting it to [CuCl4]2- anion. Through this strategy, the extrusion velocity of the solution improved, and the produced fibers obtained smoother surfaces and shrunken diameters.


Assuntos
Celulose/química , Cloretos/química , Cobre/química , Líquidos Iônicos/química , Íons , Metais/química , Ânions/química , Cátions/química , Hidrogéis , Ligação de Hidrogênio , Imidazóis/química , Microscopia Eletrônica de Varredura , Solventes/química , Temperatura , Elementos de Transição , Viscosidade
17.
Methods Mol Biol ; 2211: 43-55, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33336269

RESUMO

The assessment of the efficient binding between a nucleic acid and its associated nanoparticle is crucial for gene delivery. Emerging from the extensive search for versatile gene carriers, are complexes formed between nucleic acids and nonviral nanocarriers that promise to be viable alternatives to the predominantly viral-based gene delivery vehicles. However, much is still to be known about the exact structure and physico-chemical properties of such nanocomplexes. This chapter will concentrate on cationic lipid, polymer, and functionalized metal nanoparticles and their interaction with nucleic acids by direct conjugation or electrostatic interaction. Methods commonly employed to evaluate the nature and extent of nucleic acid interactions with cationic nanocarriers, such a nucleic acid binding, nuclease protection, and dye displacement assays will be described. In addition, the ultrastructural morphology, size, and zeta potential of these nanocomplexes, which are crucial for their cellular uptake and intracellular trafficking, will be assessed using electron microscopy, fluorescent detection, and nanoparticle tracking analysis (NTA). These assays have the ability to visualize and quantify the interaction and can also be used to complement each other, in addition to providing confirmation of the formation of the relevant nanocomplexes.


Assuntos
Cátions/química , Técnicas de Transferência de Genes , Nanopartículas/química , Ácidos Nucleicos/administração & dosagem , Ácidos Nucleicos/química , Linhagem Celular , Células Cultivadas , Expressão Gênica , Genes Reporter , Humanos
18.
Methods Mol Biol ; 2211: 57-68, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33336270

RESUMO

Catanionic nanovesicles are attractive as a novel class of delivery vehicle because they can increase the stability, adsorption, and cellular uptake of a broad range of drugs. These hybrid lipid nanocarriers consist of solid and liquid lipids, which are biocompatible and biodegradable. Since liquid lipid is added to the nanocarrier, the lipids are present in a crystalline defect or amorphous structure state. As a result, hybrid lipid nanocarriers have a higher drug loading capability and suffer less drug leakage during preparation and storage compared to the pure lipid nanocarriers. Catanionic nanovesicles have been shown to increase stability, adsorption, cellular uptake, apoptosis induction, tumor cell cytotoxicity, and antitumorigenic effect, making it a highly desirable vehicle for drug delivery. For example, the anticancer compound curcumin (CC) have shown great promise to cure cancers such as lung cancer, breast cancer, stomach cancer, and colon cancer. However, like many potential antitumor drugs, CC on its own has poor water solubility, easy photodegradation, chemical instability, low bioavailability, rapid metabolism, and fast systematic clearance, which severely limits its clinical applications. In this chapter, we demonstrate the use of catanionic nanovesicles to improve the bioavailability and efficacy of CC for anticancer applications. This technique can be easily adapted for delivery and evaluation of other bioactive compounds.


Assuntos
Antineoplásicos/administração & dosagem , Antineoplásicos/farmacocinética , Cátions/química , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Lipídeos/química , Nanopartículas/química , Animais , Disponibilidade Biológica , Biomarcadores , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Composição de Medicamentos , Humanos , Neoplasias Pulmonares , Ensaios Antitumorais Modelo de Xenoenxerto
19.
Phys Chem Chem Phys ; 23(2): 1352-1362, 2021 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-33367433

RESUMO

Adsorption processes are central to ionic transport in industrial and biological membrane systems. Multivalent cations modulate the conductive properties of nanofluidic devices through interactions with charged surfaces that depend principally on the ion charge number. Considering that ion channels are specialized valves that demand a sharp specificity in ion discrimination, we investigate the adsorption dynamics of trace amounts of different salts of trivalent cations in biological nanopores. We consider here OmpF from Escherichia coli, an archetypical protein nanopore, to probe the specificity of biological nanopores to multivalent cations. We systematically compare the effect of three trivalent electrolytes on OmpF current-voltage relationships and characterize the degree of rectification induced by each ion. We also analyze the open channel current noise to determine the existence of equilibrium/non-equilibrium mechanisms of ion adsorption and evaluate the extent of charge inversion through selectivity measurements. We show that the interaction of trivalent electrolytes with biological nanopores occurs via ion-specific adsorption yielding differential modulation of ion conduction and selectivity inversion. We also demonstrate the existence of non-equilibrium fluctuations likely related to ion-dependent trapping-detrapping processes. Our study provides fundamental information relevant to different biological and electrochemical systems where transport phenomena involve ion adsorption in charged surfaces under nanoscale confinement.


Assuntos
Complexos de Coordenação/química , Lantânio/química , Nanoporos , Porinas/química , Espermidina/química , Adsorção , Cátions/química , Cobalto/química , Escherichia coli/química
20.
Methods Mol Biol ; 2197: 253-269, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32827142

RESUMO

This chapter describes the synthesis of stealth and cationic liposomes and their complexation with plasmid DNA to generate lipoplexes for gene delivery applications. Two techniques are presented: a top-down approach which requires a second step of processing for downsizing the liposomes (i.e., ethanol injection method) and a microfluidic technique that explores the diffusion of ethanol in water to allow the proper lipid self-assembly. The synthesis of stealth liposomes is also a challenge since the use of poly(ethylene glycol) favors the formation of oblate micelles. In this protocol, the stealth cationic liposome synthesis by exploring the high ionic strength to overcome the formation of secondary structures like micelles is described. Finally, the electrostatic complexation between cationic liposomes and DNA is described, indicating important aspects that guarantee the formation of uniform lipoplexes.


Assuntos
Cátions/química , Técnicas de Química Sintética , Técnicas de Transferência de Genes , Lipossomos/síntese química , Microfluídica , DNA/administração & dosagem , DNA/química , Desenho de Equipamento , Lipídeos/química , Lipossomos/química , Microfluídica/instrumentação , Microfluídica/métodos , Plasmídeos/administração & dosagem , Plasmídeos/química , Plasmídeos/genética , Soluções
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