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1.
J Biol Chem ; 298(5): 101780, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35231443

RESUMO

Membrane contact sites are specialized areas where the membranes of two distinct organelles are physically connected and allow for the exchange of molecules and for signaling processes. Understanding the mechanisms whereby proteins localize to and function in these structures is of special interest; however, methods allowing for reconstitution of these contact sites are few and only based on synthetic membranes and recombinant proteins. Here, we devised a strategy to create in situ artificial contact sites between synthetic and endogenous organelle membranes. Liposomes functionalized with a peptide containing a two phenylalanines in an acidic tract (FFAT) motif were added to adherent cells whose plasma membrane was perforated. Confocal and super-resolution microscopy revealed that these liposomes associated with the endoplasmic reticulum via the specific interaction of the FFAT motif with endoplasmic reticulum-resident vesicle-associated membrane protein-associated proteins. This approach allowed for quantification of the attachment properties of peptides corresponding to FFAT motifs derived from distinct proteins and of a protein construct derived from steroidogenic acute regulatory protein-related lipid transfer domain-3. Collectively, these data indicate that the creation of in situ artificial contact sites represents an efficient approach for studying the membrane-tethering activity of proteins and for designing membrane contact site reconstitution assays in cellular contexts.


Assuntos
Retículo Endoplasmático , Lipossomos , Membranas Artificiais , Motivos de Aminoácidos , Retículo Endoplasmático/química , Retículo Endoplasmático/metabolismo , Retículo Endoplasmático/ultraestrutura , Lipossomos/química , Lipossomos/metabolismo , Lipossomos/ultraestrutura , Proteínas de Membrana/química , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Proteínas Recombinantes , Proteínas de Transporte Vesicular/química , Proteínas de Transporte Vesicular/genética , Proteínas de Transporte Vesicular/metabolismo
2.
Int J Mol Sci ; 23(2)2022 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-35054962

RESUMO

Novel monosubstituted pillar[5]arenes containing both amide and carboxyl functional groups were synthesized. Solid lipid nanoparticles based on the synthesized macrocycles were obtained. Formation of spherical particles with an average hydrodynamic diameter of 250 nm was shown for pillar[5]arenes containing N-(amidoalkyl)amide fragments regardless of their concentration. It was established that pillar[5]arene containing N-alkylamide fragments can form spherical particles with two different sizes (88 and 223 nm) depending on its concentration. Mixed solid lipid nanoparticles based on monosubstituted pillar[5]arenes and surfactant (dodecyltrimethylammonium chloride) were obtained for the first time. The surfactant made it possible to level the effect of the macrocycle concentration. It was found that various types of aggregates are formed depending on the macrocycle/surfactant ratio. Changing the macrocycle/surfactant ratio allows to control the charge of the particles surface. This controlled property will lead to the creation of molecular-scale porous materials that selectively interact with various types of substrates, including biopolymers.


Assuntos
Calixarenos/química , Fenômenos Químicos , Lipossomos/química , Nanopartículas/química , Compostos de Amônio Quaternário/química , Tensoativos/química , Tensoativos/farmacologia , Amidas/química , Técnicas de Química Sintética , Lipossomos/ultraestrutura , Estrutura Molecular , Nanopartículas/ultraestrutura , Tamanho da Partícula , Análise Espectral , Tensoativos/síntese química
3.
Cells ; 10(12)2021 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-34943929

RESUMO

Boron neutron capture therapy (BNCT) is a cancer treatment with clinically demonstrated efficacy using boronophenylalanine (BPA) and sodium mercaptododecaborate (BSH). However, tumor tissue selectivity of BSH and retention of BPA in tumor cells is a constant problem. To ensure boron accumulation and retention in tumor tissues, we designed a novel polyethylene glycol (PEG)-based boron-containing lipid (PBL) and examined the potency of delivery of boron using novel PBL-containing liposomes, facilitated by the enhanced permeability and retention (EPR) effect. PBL was synthesized by the reaction of distearoylphosphoethanolamine and BSH linked by PEG with Michael addition while liposomes modified using PBL were prepared from the mixed lipid at a constant molar ratio. In this manner, novel boron liposomes featuring BSH in the liposomal surfaces, instead of being encapsulated in the inner aqueous phase or incorporated in the lipid bilayer membrane, were prepared. These PBL liposomes also carry additional payload capacity for more boron compounds (or anticancer agents) in their inner aqueous phase. The findings demonstrated that PBL liposomes are promising candidates to effect suitable boron accumulation for BNCT.


Assuntos
Terapia por Captura de Nêutron de Boro , Lipídeos/química , Lipossomos/química , Diálise , Lipossomos/ultraestrutura , Polietilenoglicóis/química , Espectroscopia de Prótons por Ressonância Magnética , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Propriedades de Superfície
4.
Comput Math Methods Med ; 2021: 9571286, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34804197

RESUMO

BACKGROUND: With the increasing resistance of antibiotics to bacteria, new and effective methods are needed to transform existing antibiotics to solve the problem of long development cycles for new drugs. The antibiotic nanodelivery system has proven to be a promising strategy. AIM: The purpose of this study is to synthesize penicillin solid lipid nanoparticles (penicillin SLNs) to enhance the antibacterial activity of penicillin against drug-resistant Staphylococcus aureus. MATERIALS AND METHODS: Penicillin SLNs were synthesized. And particle size, the polydispersity index (PI), and zeta potential (ZP) of penicillin SLNs were measured. The surface morphology of penicillin SLNs was observed using a transmission electron microscope. RESULTS: The particle size of penicillin SLNs is 112.3 ± 11.9 nm, the polydispersity index (PI) and zeta potential (ZP) of penicillin SLNs are 0.212 ± 0.03 and -27.6 ± 5.5 mV. The encapsulation efficiency and drug loading were 98.31 ± 1.2% and 4.98 ± 0.05 (%w/w), respectively. Penicillin SLNs had a more significant inhibitory effect on the growth of methicillin-sensitive Staphylococcus aureus (MSSA) after the drug and the bacteria were incubated for 12 hours. The number of MRSA colonies in the penicillin group increased after 12 hours, while the number of MRSA colonies in the penicillin SLNs group did not change significantly. CONCLUSION: Penicillin SLNs enhance the ability of penicillin to enter cells and increase the concentration of penicillin in the cell and also extend the residence time of penicillin in the cell. Our findings indicated that penicillin SLNs enhance the inhibitory effect of penicillin on drug-resistant Staphylococcus aureus.


Assuntos
Lipossomos/administração & dosagem , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Nanopartículas/administração & dosagem , Penicilinas/administração & dosagem , Animais , Biologia Computacional , Portadores de Fármacos/administração & dosagem , Sistemas de Liberação de Medicamentos , Farmacorresistência Bacteriana , Estabilidade de Medicamentos , Humanos , Lipossomos/ultraestrutura , Camundongos , Testes de Sensibilidade Microbiana , Nanopartículas/ultraestrutura , Tamanho da Partícula , Células RAW 264.7
5.
Sci Rep ; 11(1): 16810, 2021 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-34413368

RESUMO

The aim of this study was to evaluate the nature and mechanisms of interaction between HIV peptide/dendrimer complexes (dendriplex) and artificial lipid membranes, such as large unilayered vesicles (LUV) and lipid monolayers in the air-water interface. Dendriplexes were combined as one of three HIV-derived peptides (Gp160, P24 and Nef) and one of two cationic phosphorus dendrimers (CPD-G3 and CPD-G4). LUVs were formed of 1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine (DMPC) or of a mixture of DMPC and dipalmitoyl-phosphatidylglycerol (DPPG). Interactions between dendriplexes and vesicles were characterized by dynamic light scattering (DLS), fluorescence anisotropy, differential scanning calorimetry (DSC) and Langmuir-Blodgett methods. The morphology of formed systems was examined by transmission electron microscopy (TEM). The results suggest that dendriplexes interact with both hydrophobic and hydrophilic regions of lipid bilayers. The interactions between dendriplexes and negatively charged lipids (DMPC-DPPG) were stronger than those between dendriplexes and liposomes composed of zwitterionic lipids (DMPC). The former were primarily of electrostatic nature due to the positive charge of dendriplexes and the negative charge of the membrane, whereas the latter can be attributed to disturbances in the hydrophobic domain of the membrane. Obtained results provide new information about mechanisms of interaction between lipid membranes and nanocomplexes formed with HIV-derived peptides and phosphorus dendrimers. These data could be important for the choosing the appropriate antigen delivery vehicle in the new vaccines against HIV infection.


Assuntos
Dendrímeros/química , Sistemas de Liberação de Medicamentos , Bicamadas Lipídicas/química , Nanopartículas/química , Peptídeos/química , Varredura Diferencial de Calorimetria , Polarização de Fluorescência , HIV , Lipossomos/ultraestrutura , Nanopartículas/ultraestrutura , Tamanho da Partícula , Pressão , Eletricidade Estática
6.
Molecules ; 26(16)2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34443296

RESUMO

In recent decades liposomes have been used in different field thanks to their ability to act as a vehicle for a wide range of biomolecules, their great versatility and their easy production. The aim of this study was to evaluate liposomes as a vehicle for the actives present in the HelixComplex (HC) snail mucus for topical delivery. Liposomes composed of a mixture of phosphatidylcholine, cholesterol and octadecylamine were prepared with and without HC (empty liposomes) and their biological efficacy was tested by evaluating cell viability and migration. HC-loaded liposomes (LHC) were stable throughout 60 days of observation, and showed interesting effects on wound healing reconstitution. In particular, we observed that 25 µg/mL LHC were already able to induce a higher cell monolayer reconstitution in comparison to the untreated samples and HC treated samples after only 4 h (28% versus 10% and 7%, p = 0.03 and p= 0.003, respectively). The effect was more evident at 24 h in comparison with the untreated control (54% versus 21.2% and 41.6%, p = 0.006 and p = NS, respectively). These results represent a preliminary, but promising, novelty in the delivery strategy of the actives present in the HelixComplex mucus.


Assuntos
Muco/química , Caramujos/química , Animais , Morte Celular , Linhagem Celular , Fibroblastos/citologia , Técnica de Fratura por Congelamento , Humanos , Lipídeos/análise , Lipossomos/ultraestrutura , Espectrofotometria Infravermelho , Cicatrização/efeitos dos fármacos
7.
Nat Commun ; 12(1): 4174, 2021 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-34234105

RESUMO

The folding of ß-barrel outer membrane proteins (OMPs) in Gram-negative bacteria is catalysed by the ß-barrel assembly machinery (BAM). How lateral opening in the ß-barrel of the major subunit BamA assists in OMP folding, and the contribution of membrane disruption to BAM catalysis remain unresolved. Here, we use an anti-BamA monoclonal antibody fragment (Fab1) and two disulphide-crosslinked BAM variants (lid-locked (LL), and POTRA-5-locked (P5L)) to dissect these roles. Despite being lethal in vivo, we show that all complexes catalyse folding in vitro, albeit less efficiently than wild-type BAM. CryoEM reveals that while Fab1 and BAM-P5L trap an open-barrel state, BAM-LL contains a mixture of closed and contorted, partially-open structures. Finally, all three complexes globally destabilise the lipid bilayer, while BamA does not, revealing that the BAM lipoproteins are required for this function. Together the results provide insights into the role of BAM structure and lipid dynamics in OMP folding.


Assuntos
Proteínas da Membrana Bacteriana Externa/metabolismo , Proteínas de Escherichia coli/metabolismo , Hidrolases/metabolismo , Lipossomos/metabolismo , Dobramento de Proteína , Proteínas da Membrana Bacteriana Externa/genética , Proteínas da Membrana Bacteriana Externa/isolamento & purificação , Proteínas da Membrana Bacteriana Externa/ultraestrutura , Microscopia Crioeletrônica , Difusão Dinâmica da Luz , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/isolamento & purificação , Proteínas de Escherichia coli/ultraestrutura , Hidrolases/genética , Hidrolases/isolamento & purificação , Hidrolases/ultraestrutura , Metabolismo dos Lipídeos , Lipossomos/ultraestrutura , Simulação de Dinâmica Molecular , Conformação Proteica em Folha beta , Proteolipídeos/metabolismo , Proteolipídeos/ultraestrutura , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/ultraestrutura
8.
Nanotechnology ; 32(41)2021 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-34198267

RESUMO

Polymer-lipid hybrid nanoparticles (PLHNPs) are novel nanoplatforms for the effective delivery of a lipophilic drug in the management of a variety of solid tumors. The present work was designed to develop exemestane (EXE) encapsulated D-alpha-tocopheryl polyethylene glycol succinate (TPGS) based PLHNPs (EXE-TPGS-PLHNPs) for controlled delivery of EXE for breast cancer management. EXE-TPGS-PLHNPs were formulated by single-step nano-precipitation technique and statistically optimized by a 33Box-Behnken design using Design expert®software. The polycaprolactone (PCL;X1), phospholipon 90 G (PL-90G;X2), and surfactant (X3) were selected as independent factors while particles size (PS;Y1), polydispersity index (PDI;Y2), and %entrapment efficiency (%EE;Y3) were chosen as dependent factors. The average PS, PDI, and %EE of the optimized EXE-TPGS-PLHNPs was observed to be 136.37 ± 3.27 nm, 0.110 ± 0.013, and 88.56 ± 2.15% respectively. The physical state of entrapped EXE was further validated by Fourier-transform infrared spectroscopy, differential scanning calorimetry, and powder x-ray diffraction that revealed complete encapsulation of EXE in the hybrid matrix of PLHNPs with no sign of significant interaction between drug and excipients.In vitrorelease study in simulated gastrointestinal fluids revealed initial fast release for 2 h after that controlled release profile up to 24 h of study. Moreover, optimized EXE-TPGS-PLHNPs exhibited excellent stability in gastrointestinal fluids as well as colloidal stability in different storage concentrations. Furthermore, EXE-TPGS-PLHNPs exhibited distinctively higher cellular uptake and time and dose-dependent cytotoxicity against MCF-7 breast tumor cells compared to EXE-PLHNPs without TPGS and free EXE. The obtained results suggested that EXE-TPGS-PLHNPs can be a promising platform for the controlled delivery of EXE for the effective treatment of breast cancer.


Assuntos
Androstadienos/farmacologia , Antineoplásicos/farmacologia , Portadores de Fármacos/síntese química , Composição de Medicamentos/métodos , Lipossomos/química , Nanopartículas/química , Androstadienos/metabolismo , Antineoplásicos/metabolismo , Materiais Biomiméticos/química , Sobrevivência Celular/efeitos dos fármacos , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Análise Fatorial , Corantes Fluorescentes/química , Suco Gástrico/química , Humanos , Cinética , Lipossomos/ultraestrutura , Células MCF-7 , Nanopartículas/ultraestrutura , Fosfatidilcolinas/química , Poliésteres/química , Rodaminas/química , Vitamina E/química
9.
Molecules ; 26(6)2021 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-33805693

RESUMO

Lecithins of different origins and compositions were used for the liposomal encapsulation of carvacrol within the framework of the development of active films for food packaging. Liposomes were incorporated into aqueous polymeric solutions from fully (F) and partially (P) hydrolysed Poly (vinyl alcohol) (PVA) to obtain the films by casting. The particle size distribution and ζ-potential of the liposomal suspensions, as well as their stability over time, were evaluated. Liposomal stability during film formation was analysed through the carvacrol retention in the dried film and the film microstructure. Subtle variations in the size distributions of liposomes from different lecithins were observed. However, the absolute values of the ζ-potential were higher (-52, -57 mV) for soy lecithin (SL) liposomes, followed by those of soy lecithin enriched with phosphatidylcholine (SL-PC) (-43, -50 mV) and sunflower lecithin (SFL) (-33, -38 mV). No significant changes in the liposomal properties were observed during the study period. Lyotropic mesomorphism of lipid associations and carvacrol leakage occurred to differing extents during the film drying step, depending on the membrane lipid composition and surface charge. Liposomes obtained with SL-PC were the most effective at maintaining the stability of carvacrol emulsion during film formation, which led to the greatest carvacrol retention in the films, whereas SFL gave rise to the least stable system and the highest carvacrol losses. P-PVA was less sensitive to the emulsion destabilisation due to its greater bonding capacity with carvacrol. Therefore, P-PVA with carvacrol-loaded SL-PC liposomes has great potential to produce active films for food packaging applications.


Assuntos
Cimenos/administração & dosagem , Embalagem de Alimentos/métodos , Lipossomos/química , Álcool de Polivinil/química , Anti-Infecciosos/administração & dosagem , Antioxidantes/administração & dosagem , Plásticos Biodegradáveis/química , Composição de Medicamentos/métodos , Estabilidade de Medicamentos , Emulsões , Conservação de Alimentos/métodos , Humanos , Lecitinas/química , Lipossomos/ultraestrutura , Microscopia Eletrônica de Varredura , Tamanho da Partícula
10.
Int J Biol Macromol ; 167: 834-844, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33181211

RESUMO

A polylactide composite fracture fixator loaded with vancomycin cationic liposome (PLA@VL) was prepared by reverse evaporation method. The method of cationic liposome encapsulating vancomycin could effectively improve antibacterial property and achieve drug sustained release effect, so as to reduce toxicity of antibiotics in vivo. Scanning electron microscope (SEM) was used to observe morphology and Fourier transform infrared spectroscopy (FTIR) was used to detect the composition of the internal fixator. In vitro drug release model, in vitro degradation model and body fluid osteogenesis model were designed in this study. On the other hand, the experiments of inhibition zone and MC3T3-E1 osteoblasts in mice were conducted to explore antibacterial property, cell activity and adhesion of the PLA@VL composite internal fixator. Alkaline phosphatase (ALP) staining method and alizarin red assay were used to detect the osteogenic induction ability of the composite internal fixator. Finally, mice fracture models were established to verify osteogenic and anti-infection abilities of the composite internal fixator in vivo. The results showed that MC3T3-E1 cells had better adhesion and proliferation abilities on the PLA@VL composite internal fixator than on the PLA fixator, which indicated that the PLA@VL composite internal fixator possessed excellent osteogenic and anti-infection abilities both in vivo and in vitro. Therefore, the above experiments showed that the fracture internal fixator combined with vancomycin cationic liposome had better biocompatibility, antibacterial ability and osteogenic ability, which provides a promising anti-infection material for the clinical field of fracture.


Assuntos
Antibacterianos/administração & dosagem , Fixadores Internos , Lipossomos/química , Poliésteres/análise , Vancomicina/administração & dosagem , Fosfatase Alcalina/metabolismo , Animais , Antibacterianos/química , Materiais Biocompatíveis/química , Biomarcadores , Adesão Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Liberação Controlada de Fármacos , Lipossomos/ultraestrutura , Camundongos , Testes de Sensibilidade Microbiana , Células NIH 3T3 , Osteogênese/efeitos dos fármacos , Solubilidade , Análise Espectral , Engenharia Tecidual , Alicerces Teciduais/química , Vancomicina/química
11.
Int J Mol Sci ; 23(1)2021 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-35008746

RESUMO

Due to growing antimicrobial resistance to antibiotics, novel methods of treatment of infected wounds are being searched for. The aim of this research was to develop a composite wound dressing based on natural polysaccharides, i.e., gellan gum (GG) and a mixture of GG and alginate (GG/Alg), containing lipid nanoparticles loaded with antibacterial peptide-nisin (NSN). NSN-loaded stearic acid-based nanoparticles (NP_NSN) were spherical with an average particle size of around 300 nm and were cytocompatible with L929 fibroblasts for up to 500 µg/mL. GG and GG/Alg sponges containing either free NSN (GG + NSN and GG/Alg + NSN) or NP_NSN (GG + NP_NSN and GG/Alg + NP_NSN) were highly porous with a high swelling capacity (swelling ratio above 2000%). Encapsulation of NSN within lipid nanoparticles significantly slowed down NSN release from GG-based samples for up to 24 h (as compared to GG + NSN). The most effective antimicrobial activity against Gram-positive Streptococcus pyogenes was observed for GG + NP_NSN, while in GG/Alg it was decreased by interactions between NSN and Alg, leading to NSN retention within the hydrogel matrix. All materials, except GG/Alg + NP_NSN, were cytocompatible with L929 fibroblasts and did not cause an observable delay in wound healing. We believe that the developed materials are promising for wound healing application and the treatment of bacterial infections in wounds.


Assuntos
Alginatos/química , Lipossomos/química , Nanopartículas/química , Nisina/uso terapêutico , Polissacarídeos Bacterianos/química , Infecção dos Ferimentos/tratamento farmacológico , Animais , Antibacterianos/farmacologia , Linhagem Celular , Concentração de Íons de Hidrogênio , Lipossomos/ultraestrutura , Camundongos , Testes de Sensibilidade Microbiana , Microscopia de Força Atômica , Nanopartículas/ultraestrutura , Nisina/isolamento & purificação , Infecção dos Ferimentos/patologia
13.
Nanomedicine ; 32: 102323, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33186693

RESUMO

Reconstituted high-density lipoproteins (rHDLs) hold promise as nanocarriers for atherosclerosis-targeted delivery, with biofunctions typified by mediating cholesterol efflux. The paradox is how rHDL offloads the delivered drugs into atherosclerotic foam cells, while simultaneously transferring cholesterol out of cells. Herein, simvastatin-loaded discoidal rHDL (ST-d-rHDL), constructed based on established paradigms, was employed to investigate its basic trafficking mechanism in foam cells. As proved, ST-d-rHDL was resecreted via lysosomal and Golgi apparatus-recycling endosome-mediated pathways following clathrin-mediated endocytosis. And the resecretion ratio reached 60% within 6-h chase with excessive ST-d-rHDLs. During the rHDL resecretion, 39% of cellular cholesterol efflux was detected, accompanied by 85% of the encapsulated cargo released intracellularly. Furthermore, the recycling rate was demonstrated to be promoted by smaller rHDL size and higher cellular lipid contents. Collectively, endocytic recycling confers the synergism in ST-d-rHDL to coordinate cholesterol efflux and intracellular drug release, providing new insights into design of biofunctional rHDL.


Assuntos
Colesterol/metabolismo , Endocitose , Lipoproteínas HDL/química , Preparações Farmacêuticas/metabolismo , Sinvastatina/farmacologia , Animais , Transporte Biológico/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Endocitose/efeitos dos fármacos , Fluorescência , Células Espumosas/citologia , Células Espumosas/efeitos dos fármacos , Espaço Intracelular/metabolismo , Lipossomos/ultraestrutura , Camundongos , Tamanho da Partícula , Células RAW 264.7 , Rodaminas/química
14.
Proc Natl Acad Sci U S A ; 117(50): 31871-31881, 2020 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-33257567

RESUMO

TAT-RasGAP317-326 is a cell-penetrating peptide-based construct with anticancer and antimicrobial activities. This peptide kills a subset of cancer cells in a manner that does not involve known programmed cell death pathways. Here we have elucidated the mode of action allowing TAT-RasGAP317-326 to kill cells. This peptide binds and disrupts artificial membranes containing lipids typically enriched in the inner leaflet of the plasma membrane, such as phosphatidylinositol-bisphosphate (PIP2) and phosphatidylserine (PS). Decreasing the amounts of PIP2 in cells renders them more resistant to TAT-RasGAP317-326, while reducing the ability of cells to repair their plasma membrane makes them more sensitive to the peptide. The W317A TAT-RasGAP317-326 point mutant, known to have impaired killing activities, has reduced abilities to bind and permeabilize PIP2- and PS-containing membranes and to translocate through biomembranes, presumably because of a higher propensity to adopt an α-helical state. This work shows that TAT-RasGAP317-326 kills cells via a form of necrosis that relies on the physical disruption of the plasma membrane once the peptide targets specific phospholipids found on the cytosolic side of the plasma membrane.


Assuntos
Morte Celular/efeitos dos fármacos , Membrana Celular/efeitos dos fármacos , Proteínas Ativadoras de GTPase/farmacologia , Fragmentos de Peptídeos/farmacologia , Fosfatidilinositol 4,5-Difosfato/metabolismo , Fosfatidilserinas/metabolismo , Animais , Células CHO , Membrana Celular/metabolismo , Membrana Celular/ultraestrutura , Cricetulus , Proteínas Ativadoras de GTPase/uso terapêutico , Células HeLa , Humanos , Lipossomos/metabolismo , Lipossomos/ultraestrutura , Microscopia Eletrônica , Simulação de Dinâmica Molecular , Neoplasias/tratamento farmacológico , Ressonância Magnética Nuclear Biomolecular , Fragmentos de Peptídeos/uso terapêutico
16.
Int J Nanomedicine ; 15: 7627-7650, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33116492

RESUMO

The skin is the largest organ in the human body, providing a barrier to the external environment. It is composed of three layers: epidermis, dermis and hypodermis. The most external epidermis is exposed to stress factors that may lead to skin conditions such as photo-aging and skin cancer. Some treatments for skin disease utilize the incorporation of drugs or bioactive compounds into nanocarriers known as liposomes. Liposomes are membranes whose sizes range from nano to micrometers and are composed mostly of phospholipids and cholesterol, forming similar structures to cell membranes. Thus, skin treatments with liposomes have lower toxicity in comparison to traditional treatment routes such as parenteral and oral. Furthermore, addition of edge activators to the liposomes decreases the rigidity of the bilayer structure making it deformable, thereby improving skin permeability. Liposomes are composed of an aqueous core and a lipidic bilayer, which confers their amphiphilic property. Thus, they can carry hydrophobic and hydrophilic compounds, even simultaneously. Current applications of these nanocarriers are mainly in the cosmetic and pharmaceutic industries. Nevertheless, new research has revealed promising results regarding the effectiveness of liposomes for transporting bioactive compounds through the skin. Liposomes have been well studied; however, additional research is needed on the efficacy of liposomes loaded with bioactive peptides for skin delivery. The objective of this review is to provide an up-to-date description of existing techniques for the development of liposomes and their use as transporters of bioactive compounds in skin conditions such as melanoma and skin inflammation. Furthermore, to gain an understanding of the behavior of liposomes during the process of skin delivery of bioactive compounds into skin cells.


Assuntos
Inflamação/patologia , Melanoma/tratamento farmacológico , Neoplasias Cutâneas/tratamento farmacológico , Pele/patologia , Transporte Biológico , Humanos , Lipossomos/ultraestrutura , Absorção Cutânea
17.
Nat Commun ; 11(1): 4502, 2020 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-32908136

RESUMO

Biological tissues, such as muscle, can increase their mechanical strength after swelling due to the existence of many biological membrane barriers that can regulate the transmembrane transport of water molecules and ions. Oppositely, typical synthetic materials show a swelling-weakening behavior, which always suffers from a sharp decline in mechanical strength after swelling, because of the dilution of the network. Here, we describe a swelling-strengthening phenomenon of polymer materials achieved by a bioinspired strategy. Liposomal membrane nanobarriers are covalently embedded in a crosslinked network to regulate transmembrane transport. After swelling, the stretched network deforms the liposomes and subsequently initiates the transmembrane diffusion of the encapsulated molecules that can trigger the formation of a new network from the preloaded precursor. Thanks to the tough nature of the double-network structure, the swelling-strengthening phenomenon is achieved to polymer hydrogels successfully. Swelling-triggered self-strengthening enables the development of various dynamic materials.


Assuntos
Materiais Biomiméticos/química , Hidrogéis/química , Lipossomos/química , Nanoestruturas/química , Força Compressiva , Reagentes de Ligações Cruzadas/química , Lipossomos/ultraestrutura , Teste de Materiais , Microscopia Eletrônica de Transmissão , Nanoestruturas/ultraestrutura , Resistência à Tração
18.
Int J Mol Sci ; 21(15)2020 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-32707876

RESUMO

In this work, we aimed to develop liposomal nanocomposites containing citric-acid-coated iron oxide magnetic nanoparticles (CMNPs) for dual magneto-photothermal cancer therapy induced by alternating magnetic field (AMF) and near-infrared (NIR) lasers. Toward this end, CMNPs were encapsulated in cationic liposomes to form nano-sized magnetic liposomes (MLs) for simultaneous magnetic hyperthermia (MH) in the presence of AMF and photothermia (PT) induced by NIR laser exposure, which amplified the heating efficiency for dual-mode cancer cell killing and tumor therapy. Since the heating capability is directly related to the amount of entrapped CMNPs in MLs, while the liposome size is important to allow internalization by cancer cells, response surface methodology was utilized to optimize the preparation of MLs by simultaneously maximizing the encapsulation efficiency (EE) of CMNPs in MLs and minimizing the size of MLs. The experimental design was performed based on the central composite rotatable design. The accuracy of the model was verified from the validation experiments, providing a simple and effective method for fabricating the best MLs, with an EE of 87% and liposome size of 121 nm. The CMNPs and the optimized MLs were fully characterized from chemical and physical perspectives. In the presence of dual AMF and NIR laser treatment, a suspension of MLs demonstrated amplified heat generation from dual hyperthermia (MH)-photothermia (PT) in comparison with single MH or PT. In vitro cell culture experiments confirmed the efficient cellular uptake of the MLs from confocal laser scanning microscopy due to passive accumulation in human glioblastoma U87 cells originated from the cationic nature of MLs. The inducible thermal effects mediated by MLs after endocytosis also led to enhanced cytotoxicity and cumulative cell death of cancer cells in the presence of AMF-NIR lasers. This functional nanocomposite will be a potential candidate for bimodal MH-PT dual magneto-photothermal cancer therapy.


Assuntos
Glioblastoma/tratamento farmacológico , Hipertermia Induzida/métodos , Lipossomos/química , Nanopartículas de Magnetita/química , Nanocompostos/química , Fototerapia/métodos , Células 3T3 , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Ácido Cítrico/química , Endocitose/efeitos dos fármacos , Glioblastoma/radioterapia , Humanos , Hipertermia , Hipertermia Induzida/instrumentação , Lasers , Lipossomos/síntese química , Lipossomos/ultraestrutura , Campos Magnéticos , Nanopartículas de Magnetita/efeitos da radiação , Nanopartículas de Magnetita/ultraestrutura , Camundongos , Microscopia Eletrônica de Transmissão , Nanocompostos/efeitos da radiação , Tamanho da Partícula
19.
Biochem Biophys Res Commun ; 529(2): 362-365, 2020 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-32703436

RESUMO

Army Liposome Formulations (ALF) are potent adjuvants, of which there are two primary forms, lyophilized ALF (ALFlyo) containing monophosphoryl lipid A (MPLA) and ALF containing MPLA and QS21 (ALFQ). ALFlyo and ALFQ adjuvants are essential constituents of candidate vaccines for bacterial, viral, and parasitic diseases. They have been widely used in preclinical immunogenicity studies in small animals and non-human primates and are progressing to phase I/IIa clinical trials. ALFQ was prepared by adding saponin QS21 to small unilamellar liposome vesicles (SUVs) of ALF55 that contain 55 mol% cholesterol, whereas ALFlyo was created by reconstituting lyophilized SUVs of ALF43, consisting of 43 mol% cholesterol, in aqueous buffer solution. These formulations display heterogenous particle size distribution. Since biophysical characteristics of liposomes may impact their adjuvant potential, we characterized the particle size distribution and lamellarity of the individual liposome particles in ALFlyo and ALFQ formulations using cryo-electron microscopy and a newly developed MANTA technology. ALFlyo and ALFQ exhibited similar particle size distributions with liposomes ranging from 50 nm to several µm. However, fundamental differences were observed in the lamellar structures of the liposomes. ALFlyo displayed a greater number of multilamellar and multivesicular liposome particles, as compared to that in ALFQ, which was predominately unilamellar.


Assuntos
Adjuvantes Imunológicos/química , Lipídeo A/análogos & derivados , Lipossomos/química , Saponinas/química , Colesterol/química , Microscopia Crioeletrônica , Liofilização , Lipídeo A/química , Lipossomos/ultraestrutura , Tamanho da Partícula
20.
Int J Nanomedicine ; 15: 4079-4090, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32606665

RESUMO

PURPOSE: The aim of this study is to develop efficient localized therapy of sertaconazole nitrate for the treatment of vaginal candidiasis. METHODS: Sertaconazole nitrate-loaded cationic liposomes were prepared by thin-film hydration method and coated with different concentrations of pectin (0.05%, 0.1% and 0.2%) to develop mucoadhesive liposomes. The formulated mucoadhesive vesicles were characterized in terms of morphology, entrapment efficiency, particle size, zeta value, mucoadhesive properties and drug release. The selected formula was incorporated into a gel base and further characterized by an ex vivo permeation study in comparison with conventional sertaconazole gel. Also, the in vivo study was performed to assess the efficacy of sertaconazole mucoadhesive liposomal gel in treating rats with vaginal candidiasis. RESULTS: The mucoadhesive liposomes were spherical. Coating liposomes with pectin results in increased entrapment efficiency and particle size compared with uncoated vesicles. On the contrary, zeta values were reduced upon coating liposomes with pectin indicating efficient coating of liposomes with pectin. Mucoadhesive liposomes showed a more prolonged and sustained drug release compared with uncoated liposomes. Ex vivo study results showed that mucoadhesive liposomal gel increased sertaconazole tissue retention and reduced drug tissue penetration. In the invivo study, the mucoadhesive liposomal gel showed a significant reduction in the microbial count with a subsequent reduction in inflammatory responses with the lowest histopathological change compared with conventional gel. CONCLUSION: The study confirmed the potentiality of employing mucoadhesive liposomes as a successful carrier for the vaginal delivery of antifungal drugs.


Assuntos
Antifúngicos/uso terapêutico , Candidíase Vulvovaginal/tratamento farmacológico , Imidazóis/uso terapêutico , Muco/química , Tiofenos/uso terapêutico , Adesividade , Animais , Anti-Infecciosos/farmacologia , Biomarcadores/metabolismo , Preparações de Ação Retardada , Liberação Controlada de Fármacos , Feminino , Géis , Humanos , Imidazóis/farmacologia , Imunoglobulina G/metabolismo , Imunoglobulina M/metabolismo , Mediadores da Inflamação/metabolismo , Lipossomos/ultraestrutura , Mucinas/metabolismo , Tamanho da Partícula , Ratos Sprague-Dawley , Ovinos , Eletricidade Estática , Tiofenos/farmacologia , Vagina/patologia , beta-Glucanas/metabolismo
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