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1.
Front Microbiol ; 15: 1447301, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39171261

RESUMEN

Introduction: This study investigated the interaction with membrane mimetic systems (LUVs), bacterial membranes, the CD spectra, and the bactericidal activity of two designed trematocine mutants, named Trem-HK and Trem-HSK. Mutants were constructed from the scaffold of Trematocine (Trem), a natural 22-amino acid AMP from the Antarctic fish Trematomus bernacchii, aiming to increase their positive charge. Methods: The selectivity of the designed AMPs towards bacterial membranes was improved compared to Trematocine, verified by their interaction with different LUVs and their membranolytic activity. Additionally, their α-helical conformation was not influenced by the amino acid substitutions. Our findings revealed a significant enhancement in antibacterial efficacy against ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacteriaceae family) pathogens for both Trem-HK and Trem-HSK. Results: Firstly, we showed that the selectivity of the two new designed AMPs towards bacterial membranes was greatly improved compared to Trematocine, verifying their interaction with different LUVs and their membranolytic activity. We determined that their α-helical conformation was not influenced by the amino acid substitutions. We characterized the tested bacterial collection for resistance traits to different classes of antibiotics. The minimum inhibitory and bactericidal concentration (MIC and MBC) values of the ESKAPE collection were reduced by up to 80% compared to Trematocine. The bactericidal concentrations of Trematocine mutants showed important membranolytic action, evident by scanning electron microscopy, on all tested species. We further evaluated the cytotoxicity and hemolytic activity of the mutants. At 2.5 µM concentration, both mutants demonstrated low cytotoxicity and hemolysis, indicating selectivity towards bacterial cells. However, these effects increased at higher concentrations. Discussion: Assessment of in vivo toxicity using the Galleria mellonella model revealed no adverse effects in larvae treated with both mutants, even at concentrations up to 20 times higher than the lowest MIC observed for Acinetobacter baumannii, suggesting a high potential safety profile for the mutants. This study highlights the significant improvement in antibacterial efficacy achieved by increasing the positive charge of Trem-HK and Trem-HSK. This improvement was reached at the cost of reduced biocompatibility. Further research is necessary to optimize the balance between efficacy and safety for these promising AMPs.

2.
Biomolecules ; 13(12)2023 12 14.
Artículo en Inglés | MEDLINE | ID: mdl-38136664

RESUMEN

Antibiotic resistance due to bacterial biofilm formation is a major global health concern that makes the search for new therapeutic approaches an urgent need. In this context,, trans-resveratrol (RSV), a polyphenolic natural substance, seems to be a good candidate for preventing and eradicating biofilm-associated infections but its mechanism of action is poorly understood. In addition, RSV suffers from low bioavailability and chemical instability in the biological media that make its encapsulation in delivery systems necessary. In this work, the anti-biofilm activity of free RSV was investigated on Staphylococcus aureus and, to highlight the possible mechanism of action, we studied the anti-adherence activity and also the cell wall damage on a MRSA strain. Free RSV activity was compared to that of RSV loaded in liposomes, specifically neutral liposomes (L = DOPC/Cholesterol) and cationic liposomes (LG = DOPC/Chol/GLT1) characterized by a galactosylated amphiphile (GLT1) that promotes the interaction with bacteria. The results indicate that RSV loaded in LG has anti-adherence and anti-biofilm activity higher than free RSV. On the other side, free RSV has a higher bacterial-growth-inhibiting effect than encapsulated RSV and it can damage cell walls by creating pores; however, this effect can not prevent bacteria from growing again. This RSV ability may underlie its bacteriostatic activity.


Asunto(s)
Staphylococcus aureus Resistente a Meticilina , Infecciones Estafilocócicas , Humanos , Liposomas/química , Resveratrol/farmacología , Resveratrol/uso terapéutico , Staphylococcus aureus , Infecciones Estafilocócicas/tratamiento farmacológico , Pared Celular , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Pruebas de Sensibilidad Microbiana
3.
J Colloid Interface Sci ; 627: 283-298, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35853406

RESUMEN

HYPOTHESIS: The positive charge on liposome surface is known to promote the crossing of the Blood brain barrier (BBB). However, when diastereomeric cationic gemini amphiphiles are among lipid membrane components, also the stereochemistry may affect the permeability of the vesicle across the BBB. EXPERIMENTS: Liposomes featuring cationic diasteromeric gemini amphiphiles were formulated, characterized, and their interaction with cell culture models of BBB investigated. FINDINGS: Liposomes featuring the gemini amphiphiles were internalized in a monolayer of brain microvascular endothelial cells derived from human induced pluripotent stem cells (hiPSC) through an energy dependent transport, internalization involving both clathrin- and caveolae-mediated endocytosis. On the same formulations, the permeability was also evaluated across a human derived in vitro BBB transport model. The permeability of liposomes featuring the gemini amphiphiles was significantly higher compared to that of neutral liposomes (DPPC/Cholesterol), that were not able to cross BBB. Most importantly, the permeability was influenced by the stereochemistry of the gemini and pegylation of these formulations did not result in a drastic reduction of the crossing ability. The in vitro iPSC-derived BBB models used in this work represent an important advancement in the drug discovery research of novel brain delivery strategies and therapeutics for central nervous system diseases.


Asunto(s)
Células Madre Pluripotentes Inducidas , Liposomas , Transporte Biológico , Barrera Hematoencefálica , Cationes , Colesterol , Clatrina , Células Endoteliales , Humanos , Liposomas/química
4.
Front Immunol ; 13: 838331, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35355982

RESUMEN

The C1858T variant of the protein tyrosine phosphatase N22 (PTPN22) gene is associated with pathophysiological phenotypes in several autoimmune conditions, namely, Type 1 diabetes and autoimmune thyroiditis. The R620W variant protein, encoded by C1858T, leads to a gain of function mutation with paradoxical reduced T cell activation. We previously exploited a novel personalized immunotherapeutic approach based on siRNA delivered by liposomes (lipoplexes, LiposiRNA) that selectively inhibit variant allele expression. In this manuscript, we functionalize lipoplexes carrying siRNA for variant C1858T with a high affinity ligand of Siglec-10 (Sig10L) coupled to lipids resulting in lipoplexes (LiposiRNA-Sig10L) that enhance delivery to Siglec-10 expressing immunocytes. LiposiRNA-Sig10L lipoplexes more efficiently downregulated variant C1858T PTPN22 mRNA in PBMC of heterozygous patients than LiposiRNA without Sig10L. Following TCR engagement, LiposiRNA-Sig10L more significantly restored IL-2 secretion, known to be paradoxically reduced than in wild type patients, than unfunctionalized LiposiRNA in PBMC of heterozygous T1D patients.


Asunto(s)
Diabetes Mellitus Tipo 1 , Proteína Tirosina Fosfatasa no Receptora Tipo 22 , Autoinmunidad , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/terapia , Humanos , Factores Inmunológicos , Inmunoterapia , Leucocitos Mononucleares/metabolismo , Ácido N-Acetilneuramínico , Monoéster Fosfórico Hidrolasas , Proteína Tirosina Fosfatasa no Receptora Tipo 22/genética , Proteína Tirosina Fosfatasa no Receptora Tipo 22/metabolismo , ARN Interferente Pequeño/genética , Lectinas Similares a la Inmunoglobulina de Unión a Ácido Siálico
5.
Int J Mol Sci ; 23(4)2022 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-35216297

RESUMEN

The increasing resistance of fungi to antibiotics is a severe challenge in public health, and newly effective drugs are required. Promising potential medications are lipopeptides, linear antimicrobial peptides (AMPs) conjugated to a lipid tail, usually at the N-terminus. In this paper, we investigated the in vitro and in vivo antifungal activity of three short myristoylated and non-myristoylated peptides derived from a mutant of the AMP Chionodracine. We determined their interaction with anionic and zwitterionic membrane-mimicking vesicles and their structure during this interaction. We then investigated their cytotoxic and hemolytic activity against mammalian cells. Lipidated peptides showed a broad spectrum of activity against a relevant panel of pathogen fungi belonging to Candida spp., including the multidrug-resistant C. auris. The antifungal activity was also observed vs. biofilms of C. albicans, C. tropicalis, and C. auris. Finally, a pilot efficacy study was conducted on the in vivo model consisting of Galleria mellonella larvae. Treatment with the most-promising myristoylated peptide was effective in counteracting the infection from C. auris and C. albicans and the death of the larvae. Therefore, this myristoylated peptide is a potential candidate to develop antifungal agents against human fungal pathogens.


Asunto(s)
Antifúngicos , Candida , Animales , Antifúngicos/química , Antifúngicos/farmacología , Biopelículas , Candida albicans , Humanos , Larva , Lipopéptidos/farmacología , Mamíferos , Pruebas de Sensibilidad Microbiana
6.
Chem Phys Lipids ; 243: 105174, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35038451

RESUMEN

Glucosylated liposomes composed of the natural saturated phospholipid 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), cholesterol (Chol) and a cationic amphiphile featuring a glucosyl moiety (GL4), have been developed for delivering the antimicrobial trans-Resveratrol (RSV) to S. epidermidis, characterized by carbohydrate-specific adhesins able to recognize glucose. The cationic derivative of cholesterol, DC-Chol, was also included in liposome formulations, alone or in combination with GL4, in order to explore the role of both cationic charge and sugar moiety in the interaction of liposomes with bacterial cells. RSV was included inside glucosylated cationic liposomes by the thin film method, coupled with either extrusion or sonication; liposome mean diameter, polydispersity index, surface charge, RSV entrapment efficiency and concentration have been measured by DLS, electrophoretic mobility, and HPLC. The antimicrobial activity of RSV-loaded liposomes was evaluated by monitoring the bacterial growth curves of two cell lines of Staphylococcus epidermidis, a slime positive strain (i.e. a strain able to form a biofilm) and a slime negative one. Results point out that, when the glucosylamphiphile GL4 is included in the formulation, only the extrusion protocol allows obtaining monodisperse liposomes with high RSV entrapment efficiency. The mean diameters of empty and resveratrol-loaded liposomes are all around 120-140 nm and size distribution are narrow, except for samples including GL4 at 5 molar percentage. Here the higher polydispersity index may be the indication of the occurrence of a restructuring phenomenon. The microbiological tests put in evidence a different response of the two bacterial cell lines to liposome treatments, in fact, the slime negative bacterial cells, that are not able to produce the extracellular polymeric substances, are more susceptible to the cationic charge of the liposomes and to the detergent effect of GL4. The most interesting results concern DPPC/Chol/GL4 liposomes on the slime positive strain: this formulation, non-toxic in itself, displays an enhanced antibacterial efficacy with respect to free RSV, killing bacteria even at concentration tenfold under the MIC.


Asunto(s)
Liposomas , Staphylococcus epidermidis , Antibacterianos/farmacología , Cationes , Colesterol/farmacología , Liposomas/farmacología , Resveratrol/farmacología
7.
Nanoscale ; 13(27): 11976-11993, 2021 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-34212969

RESUMEN

Though liposome-based drugs are in clinical use, the mechanism of cell internalization of liposomes is yet an object of controversy. The present experimental investigation, carried out on human glioblastoma cells, indicated different internalization routes for two diastereomeric liposomes. Molecular dynamics simulations of the lipid bilayers of the two formulations indicated that the different stereochemistry of a lipid component controls some parameters such as area per lipid molecule and fluidity of lipid membranes, surface potential and water organization at the lipid/water interface, all of which affect the interaction with biomolecules and cell components.


Asunto(s)
Membrana Dobles de Lípidos , Liposomas , Composición de Medicamentos , Humanos , Simulación de Dinámica Molecular , Agua
8.
Methods Mol Biol ; 2275: 27-47, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34118030

RESUMEN

In this chapter we describe: (1) the procedure for the synthesis of four single chain bolaamphiphiles, displaying chains of 12, 16, 20 and 30 methylene units and triphenylphosphonium moieties as headgroups (TPP1-TPP4); (2) the methods used to characterize TPP1-TPP4 spontaneous aggregation in aqueous solution. We illustrate the determination of Krafft point and cac by conductivity measurements and the procedures used to investigate dimensions, morphology, and stability by dynamic and dielectrophoretic laser light scattering, dialysis, transmission electron microscopy, and Raman spectroscopy measurements.


Asunto(s)
Furanos/química , Mitocondrias/efectos de los fármacos , Compuestos Organofosforados/síntesis química , Piridonas/química , Dispersión Dinámica de Luz , Microscopía Electrónica de Transmisión , Estructura Molecular , Compuestos Organofosforados/química , Compuestos Organofosforados/farmacología , Espectrometría Raman , Agua/química
9.
Int J Mol Sci ; 21(4)2020 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-32092980

RESUMEN

Antimicrobial peptides have been identified as one of the alternatives to the extensive use of common antibiotics as they show a broad spectrum of activity against human pathogens. Among these is Chionodracine (Cnd), a host-defense peptide isolated from the Antarctic icefish Chionodraco hamatus, which belongs to the family of Piscidins. Previously, we demonstrated that Cnd and its analogs display high antimicrobial activity against ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter species). Herein, we investigate the interactions with lipid membranes of Cnd and two analogs, Cnd-m3 and Cnd-m3a, showing enhanced potency. Using a combination of Circular Dichroism, fluorescence spectroscopy, and all-atom Molecular Dynamics (MD) simulations, we determined the structural basis for the different activity among these peptides. We show that all peptides are predominantly unstructured in water and fold, preferentially as α-helices, in the presence of lipid vesicles of various compositions. Through a series of MD simulations of 400 ns time scale, we show the effect of mutations on the structure and lipid interactions of Cnd and its analogs. By explaining the structural basis for the activity of these analogs, our findings provide structural templates to design minimalistic peptides for therapeutics.


Asunto(s)
Péptidos Catiónicos Antimicrobianos/química , Membrana Dobles de Lípidos/química , Fosfatidilcolinas/química , Secuencia de Aminoácidos , Animales , Anisotropía , Antibacterianos/química , Antibacterianos/farmacología , Péptidos Catiónicos Antimicrobianos/metabolismo , Péptidos Catiónicos Antimicrobianos/farmacología , Dicroismo Circular , Membranas Artificiales , Simulación de Dinámica Molecular , Perciformes/metabolismo , Conformación Proteica en Hélice alfa , Agua/química
10.
Antibiotics (Basel) ; 9(2)2020 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-32041161

RESUMEN

Antimicrobial peptides (AMPs) are short peptides active against a wide range of pathogens and, therefore, they are considered a useful alternative to conventional antibiotics. We have identified a new AMP in a transcriptome derived from the Antarctic fish Trematomus bernacchii. This peptide, named Trematocine, has been investigated for its expression both at the basal level and after in vivo immunization with an endemic Antarctic bacterium (Psychrobacter sp. TAD1). Results agree with the expected behavior of a fish innate immune component, therefore we decided to synthesize the putative mature sequence of Trematocine to determine the structure, the interaction with biological membranes, and the biological activity. We showed that Trematocine folds into a α-helical structure in the presence of both zwitterionic and anionic charged vesicles. We demonstrated that Trematocine has a highly specific interaction with anionic charged vesicles and that it can kill Gram-negative bacteria, possibly via a carpet like mechanism. Moreover, Trematocine showed minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values against selected Gram-positive and Gram-negative bacteria similar to other AMPs isolated from Antarctic fishes. The peptide is a possible candidate for a new drug as it does not show any haemolytic or cytotoxic activity against mammalian cells at the concentration needed to kill the tested bacteria.

11.
Nanomedicine ; 18: 371-379, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30439564

RESUMEN

In autoimmune diseases as Type 1 diabetes, the actual treatment that provides the missing hormones is not able, however, to interrupt the underlining immunological mechanism. Importantly, novel immunotherapies are exploited to protect and rescue the remaining hormone producing cells. Among probable targets of immunotherapy, the C1858T mutation in the PTPN22 gene, which encodes for the lymphoid tyrosine phosphatase (Lyp) variant R620W, reveals an autoimmunity related pathophysiological role. Our scope was to establish new C1858T PTPN22 siRNA duplexes delivered by liposomal carriers (lipoplexes) to patients' PBMC. Following lipoplexes treatment, CD3+ and CD3- immunotypes were efficiently transfected; cell integrity and viability were preserved. Specific target mRNA down-modulation was observed. After T cell receptor stimulation, in lipoplexes-treated PBMC Lyp function was restored by increased release of IL-2 in cultures. Results set-up the stage for ultimate trials in the treatment of autoimmunity based on the specific inhibitory targeting of C1858T PTPN22 by lipoplexes.


Asunto(s)
Diabetes Mellitus Tipo 1/inmunología , Diabetes Mellitus Tipo 1/terapia , Regulación hacia Abajo , Inmunoterapia , Proteína Tirosina Fosfatasa no Receptora Tipo 22/genética , ARN Interferente Pequeño/metabolismo , Linfocitos T/metabolismo , Adolescente , Secuencia de Bases , Cationes , Niño , Preescolar , Diabetes Mellitus Tipo 1/genética , Dispersión Dinámica de Luz , Femenino , Humanos , Lípidos/química , Liposomas , Masculino , Proteína Tirosina Fosfatasa no Receptora Tipo 22/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo
12.
Langmuir ; 34(44): 13288-13295, 2018 11 06.
Artículo en Inglés | MEDLINE | ID: mdl-30350684

RESUMEN

The micellization of chiral enantiopure surfactants, dodecyl- N, N-dimethyl- N-( S)-(1-phenyl)ethylammonium bromide and hexadecyl- N, N-dimethyl- N-( S)-(1-phenyl)ethylammonium bromide, was investigated by circular dichroism spectroscopy and isothermal titration calorimetry. The formation of wormlike micelles (WLMs) upon the addition of sodium salicylate to the aqueous solutions of the surfactant was observed only in the case of hexadecyl- N, N-dimethyl- N-( S)-(1-phenyl)ethylammonium bromide. The presence of WLMs was assessed by cryogenic transmission electron microscopy, rheology, and isothermal titration calorimetry experiments, and their supramolecular chirality was investigated by circular dichroism spectroscopy. Depending on the length of the hydrophobic tail, molecular chirality is transferred into a different chiral supramolecular trait. Our findings demonstrate that hydrophobic interactions by controlling the organization and functions of self-assemblies also control the transcription of the chiral information from molecules to complex supramolecular systems.

13.
J Colloid Interface Sci ; 531: 451-462, 2018 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-30053690

RESUMEN

HYPOTHESIS: Bolaamphiphiles are characterized by wide polymorphism of their aggregates, due to the connection of the headgroups that renders their investigation very intriguing in several technological applications. Some bolaamphiphiles displaying the triphenylphosphonium motif (TPP-bolaamphiphiles) were previously explored for their ability in crossing the mitochondrial membranes but their colloidal features, which are crucial for the potential development of an effective drug delivery system, were never investigated. EXPERIMENTS: Single chain TPP-bolaamphiphiles, featuring chains of 12, 16, 20 and 30 methylene units, were synthesized and their aggregation features (Krafft point, cac, dimensions, morphology, stability) were investigated by conductivity, dialysis, transmission electron microscopy, Raman spectroscopy, dynamic and dielectrophoretic laser light scattering measurements. FINDINGS: All the TPP-bolaamphiphiles spontaneously self-assemble into vesicles, independently of the chain length. The bolaamphipile with the longest chain forms monodispersed vesicles whereas for the other bolaamphiphiles two distinct populations of vesicles are observed. All vesicles are not equilibrium systems, in particular vesicles formed by the bolaamphiphiles featuring 20 and 30 methylene units result notably stable to dilution thanks to both the tightening of molecular packing at increasing chain length and the progressive reduction of the monomer percentage in U-shaped conformation. These features make these TPP-bolaamphiphiles very attractive as minor components for the development of novel mitochondriotropic liposomes.


Asunto(s)
Furanos/química , Compuestos Organofosforados/química , Piridonas/química , Dimerización , Dispersión Dinámica de Luz , Liposomas/química , Tamaño de la Partícula , Espectrometría Raman , Electricidad Estática , Tensoactivos/química , Termodinámica
14.
ChemMedChem ; 13(15): 1597-1607, 2018 08 10.
Artículo en Inglés | MEDLINE | ID: mdl-29873449

RESUMEN

Glaucoma affects millions of people worldwide and causes optic nerve damage and blindness. The elevation of the intraocular pressure (IOP) is the main risk factor associated with this pathology, and decreasing IOP is the key therapeutic target of current pharmacological treatments. As potential ocular hypotensive agents, we studied compounds that act on two receptors (serotonin 2A and adrenergic α1 ) linked to the regulation of aqueous humour dynamics. Herein we describe the design, synthesis, and pharmacological profiling of a series of novel bicyclic and tricyclic N2-alkyl-indazole-amide derivatives. This study identified a 3,4-dihydropyrazino[1,2-b]indazol-1(2H)-one derivative with potent serotonin 2A receptor antagonism, >100-fold selectivity over other serotonin subtype receptors, and high affinity for the α1 receptor. Moreover, upon local administration, this compound showed superior ocular hypotensive action in vivo relative to the clinically used reference compound timolol.


Asunto(s)
Indazoles/uso terapéutico , Hipertensión Ocular/tratamiento farmacológico , Pirazinas/uso terapéutico , Receptor de Serotonina 5-HT2A/efectos de los fármacos , Receptores Adrenérgicos alfa 1/efectos de los fármacos , Animales , Descubrimiento de Drogas , Indazoles/química , Indazoles/farmacología , Presión Intraocular/efectos de los fármacos , Pirazinas/química , Pirazinas/farmacología , Ratas , Relación Estructura-Actividad
15.
RSC Adv ; 8(72): 41331-41346, 2018 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-35559296

RESUMEN

Starting from the sequence of the amphipathic α-helix of chionodracine (Cnd, 22 amino acids), we designed a series of mutants to increase Cnd's antimicrobial activity and selectivity toward prokaryotic cells and drug-resistant bacterial pathogens. We characterized these new Cnd-derived peptides using fluorescence, CD spectroscopy, and transmission electron microscopy, studying their interactions with synthetic lipid vesicles and assaying their biological function against E. faecium, S. aureus, K. pneumoniae, A. baumannii, P. aeruginosa, and Enterobacter sp. Upon interaction with model membranes, these new peptides with higher net charges and hydrophobic moments adopt a helical conformation similar to Cnd. Notably, they display a low cytotoxic activity against human primary cells, a low hemolytic activity, but a significantly high bactericidal activity against drug-resistant bacterial pathogens. The low values of micromolar minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) make these Cnd-derived peptides potential templates to develop antimicrobial agents against drug-resistant human pathogens.

16.
Colloids Surf B Biointerfaces ; 159: 557-563, 2017 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-28850920

RESUMEN

The presence of carbohydrate-binding proteins (i.e. lectins) on the surface of various bacterial strains and their overexpression in some tumor tissues makes the use of glycosylated liposomes a promising approach for the specific drug delivery in antibacterial and anti-cancer therapies. However, the functionalization of liposome surface with sugar moieties by glycosylated amphiphiles does not ensure the binding of sugar-coated vesicles with lectins. In fact, the composition and properties of lipid bilayer play a pivotal role in the exposure of sugar residues and in the interaction with lectins. The influence of the length of the hydrophilic spacer that links the sugar to liposome surface and of the presence of saturated or unsaturated phospholipids in the lipid bilayer on the ability of glucosylated liposomes to interact with a model lectin, Concanavalin A, was investigated. Our results demonstrate that both the chain length and the prensece of unsaturation, parameters that strongly affect the fluidity of the lipid bilayer, affect agglutination. In particular, agglutination is favored when liposomes are in the gel phase within a defined range of temperature. Moreover, the obtained results confirm that the length of the PEG spacer, that influences both lipid organization and the exposure of sugar moieties to the bulk, plays a crucial role in liposome/lectin interaction.


Asunto(s)
Glucosa/química , Membrana Dobles de Lípidos/química , Liposomas/química , Concanavalina A/química , Sistemas de Liberación de Medicamentos/métodos , Interacciones Hidrofóbicas e Hidrofílicas , Fosfolípidos/química , Temperatura
17.
Sci Rep ; 7(1): 2510, 2017 05 31.
Artículo en Inglés | MEDLINE | ID: mdl-28566747

RESUMEN

Estrogen deprivation is associated with delayed healing, while estrogen replacement therapy (ERT) accelerates acute wound healing and protects against development of chronic wounds. However, current estrogenic molecules have undesired systemic effects, thus the aim of our studies is to generate new molecules for topic administration that are devoid of systemic effects. Following a preliminary study, the new 17ß-estradiol derivatives 1 were synthesized. The estrogenic activity of these novel compounds was evaluated in vitro using the cell line ERE-Luc B17 stably transfected with an ERE-Luc reporter. Among the 17ß-estradiol derivatives synthesized, compounds 1e and 1f showed the highest transactivation potency and were therefore selected for the study of their systemic estrogenic activity. The study of these compounds in the ERE-Luc mouse model demonstrated that both compounds lack systemic effects when administered in the wound area. Furthermore, wound-healing experiments showed that 1e displays a significant regenerative and anti-inflammatory activity. It is therefore confirmed that this class of compounds are suitable for topical administration and have a clear beneficial effect on wound healing.


Asunto(s)
Estradiol/administración & dosificación , Terapia de Reemplazo de Estrógeno , Piel/efectos de los fármacos , Cicatrización de Heridas/efectos de los fármacos , Administración Tópica , Animales , Células Cultivadas , Estradiol/análogos & derivados , Estradiol/síntesis química , Receptor alfa de Estrógeno/genética , Receptor alfa de Estrógeno/metabolismo , Estrógenos/metabolismo , Estrona/metabolismo , Femenino , Humanos , Ratones , Ovariectomía , Piel/lesiones , Piel/patología , Cicatrización de Heridas/fisiología
18.
PLoS One ; 12(4): e0175784, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28437437

RESUMEN

Type 1 diabetes and thyroid disease are T cell-dependent autoimmune endocrinopathies. The standard substitutive administration of the deficient hormones does not halt the autoimmune process; therefore, development of immunotherapies aiming to preserve the residual hormonal cells, is of crucial importance. PTPN22 C1858T mutation encoding for the R620W lymphoid tyrosine phosphatase variant, plays a potential pathophysiological role in autoimmunity. The PTPN22 encoded protein Lyp is a negative regulator of T cell antigen receptor signaling; R620W variant, leading to a gain of function with paradoxical reduced T cell activation, may represent a valid therapeutic target. We aimed to develop novel wild type PTPN22 short interfering RNA duplexes (siRNA) and optimize their delivery into Jurkat T cells and PBMC by using liposomal carriers. Conformational stability, size and polydispersion of siRNA in lipoplexes was measured by CD spectroscopy and DLS. Lipoplexes internalization and toxicity evaluation was assessed by confocal microscopy and flow cytometry analysis. Their effect on Lyp expression was evaluated by means of Western Blot and confocal microscopy. Functional assays through engagement of TCR signaling were established to evaluate biological consequences of down-modulation. Both Jurkat T cells and PBMC were efficiently transfected by stable custom lipoplexes. Jurkat T cell morphology and proliferation was not affected. Lipoplexes incorporation was visualized in CD3+ but also in CD3- peripheral blood immunotypes without signs of toxicity, damage or apoptosis. Efficacy in affecting Lyp protein expression was demonstrated in both transfected Jurkat T cells and PBMC. Moreover, impairment of Lyp inhibitory activity was revealed by increase of IL-2 secretion in culture supernatants of PBMC following anti-CD3/CD28 T cell receptor-driven stimulation. The results of our study open the pathway to future trials for the treatment of autoimmune diseases based on the selective inhibition of variant PTPN22 allele using lipoplexes of siRNA antisense oligomers.


Asunto(s)
Regulación hacia Abajo/efectos de los fármacos , Proteína Tirosina Fosfatasa no Receptora Tipo 22/genética , ARN Interferente Pequeño/administración & dosificación , Linfocitos T/efectos de los fármacos , Silenciador del Gen , Humanos , Células Jurkat , Liposomas , Activación de Linfocitos , Proteína Tirosina Fosfatasa no Receptora Tipo 22/metabolismo , Linfocitos T/metabolismo
19.
J Nat Prod ; 79(4): 1155-9, 2016 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-26938881

RESUMEN

The first synthesis of (+)-19-acetoxystemodan-12-ol (1), a stemodane diterpenoid isolated from Stemodia chilensis, is described. The structure was supported by an X-ray crystallographic analysis of intermediate (+)-9a, which confirmed the proposed structure and excluded the structure of (-)-19-hydroxystemod-12-ene as a possible candidate for the Chilean Calceolaria diterpenoid to which the (-)-19-hydroxystemar-13-ene structure (9b) had been erroneously assigned.


Asunto(s)
Abietanos/química , Plantaginaceae/química , Chile , Cristalografía por Rayos X , Diterpenos , Pruebas de Sensibilidad Microbiana , Conformación Molecular , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Estereoisomerismo
20.
Chirality ; 28(1): 22-8, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26480828

RESUMEN

An investigation, based on absorption and circular dichroism spectroscopy, was carried out on assemblies formed in water upon the interaction of heteroaggregates, composed of dyes (Congo Red or Evans Blue) and cetyltrimethylammonium bromide (CTAB), with four enantiopure phopshocholines (DMPC, DPPC, DOPC, and POPC) characterized by the same polar head and different hydrophobic tails. The results show that the nature of the lipid as well as the concentration ratios influence sensitively the absorption and chiroptical properties of the supramolecular structure. Intriguingly, the transfer of chirality from the lipid to the assembly may be triggered or not, depending on the nature of the lipid hydrophobic chain. These findings confirm the fundamental role of hydrophobic interactions in the transcription of chirality from molecules to complex architectures.

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