RESUMEN
Graphene oxide (GO), derived from graphene, has remarkable chemical-physical properties such as stability, strength, and thermal or electric conductivity and additionally shows antibacterial and anti-inflammatory properties. The present study aimed to evaluate the anti-inflammatory effects of polypropylene suture threads buttons (PPSTBs), enriched with two different concentrations of GO, in the modulation of the inflammatory pathway TLR4/MyD 88/NFκB p65/NLRP3 induced by the Escherichia coli (E. coli) lipopolysaccharide (LPS-E). The gene and the protein expression of inflammatory markers were evaluated in an in vitro model of primary human gingival fibroblasts (hGFs) by real-time PCR, western blotting, and immunofluorescence analysis. Both GO concentrations used in the polypropylene suture threads buttons-GO constructs (PPSTBs-GO) decreased the expression of inflammatory markers in hGFs treated with LPS-E. The hGFs morphology and adhesion on the PPSTBs-GO constructs were also visualized by inverted light microscopy, scanning electron microscopy (SEM), and real-time PCR. Together, these results suggest that enriched PPSTBs-GO modulates the inflammatory process through TLR4/MyD 88/NFκB p65/NLRP3 pathway.
Asunto(s)
Grafito , Lipopolisacáridos , Humanos , Lipopolisacáridos/farmacología , Grafito/farmacología , Grafito/metabolismo , Escherichia coli/metabolismo , Polipropilenos/farmacología , Receptor Toll-Like 4/genética , Receptor Toll-Like 4/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Antiinflamatorios/farmacología , Suturas , Fibroblastos/metabolismoRESUMEN
Innovative non-antibiotic compounds such as graphene oxide (GO) and light-emitting diodes (LEDs) may represent a valid strategy for managing chronic wound infections related to resistant pathogens. This study aimed to evaluate 630 nm LED and 880 nm LED ability to enhance the GO antimicrobial activity against Staphylococcus aureus- and Pseudomonas aeruginosa-resistant strains in a dual-species biofilm in the Lubbock chronic wound biofilm (LCWB) model. The effect of a 630 nm LED, alone or plus 5-aminolevulinic acid (ALAD)-mediated photodynamic therapy (PDT) (ALAD-PDT), or an 880 nm LED on the GO (50 mg/l) action was evaluated by determining the CFU/mg reductions, live/dead analysis, scanning electron microscope observation, and reactive oxygen species assay. Among the LCWBs, the best effect was obtained with GO irradiated with ALAD-PDT, with percentages of CFU/mg reduction up to 78.96% ± 0.21 and 95.17% ± 2.56 for S. aureus and P. aeruginosa, respectively. The microscope images showed a reduction in the cell number and viability when treated with GO + ALAD-PDT. In addition, increased ROS production was detected. No differences were recorded when GO was irradiated with an 880 nm LED versus GO alone. The obtained results suggest that treatment with GO irradiated with ALAD-PDT represents a valid, sustainable strategy to counteract the polymicrobial colonization of chronic wounds.
Asunto(s)
Fotoquimioterapia , Staphylococcus aureus , Ácido Aminolevulínico/farmacología , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Biopelículas , Grafito , Fotoquimioterapia/métodos , Pseudomonas aeruginosaRESUMEN
Curcumin, a yellow polyphenol extracted from the turmeric root is used as a diet supplement. It exhibits anti-inflammatory, antioxidant, and antitumor properties by modulating different intracellular mechanisms. Due to their low solubility in water, the curcumin molecules must be encapsulated into liposomes to improve the bioavailability and biomedical potential. For the periodontal tissue and systemic health, it is essential to regulate the local inflammatory response. In this study, the possible beneficial effect of liposomes loaded with curcumin (CurLIP) in neural crest-derived human periodontal ligament stem cells (hPDLSCs) and in endothelial-differentiated hPDLSCs (e-hPDLSCs) induced with an inflammatory stimulus (lipopolysaccharide obtained from Porphyromonas gingivalis, LPS-G) was evaluated. The CurLIP formulation exhibited a significant anti-inflammatory effect by the downregulation of Toll-like receptor-4 (TLR4)/Myeloid differentiation primary response 88 (MyD88)/nuclear factor kappa light chain enhancer of activated B cells (NFkB)/NLR Family Pyrin Domain Containing 3 (NLRP3)/Caspase-1/Interleukin (IL)-1ß inflammation cascade and reactive oxygen species (ROS) formation. Moreover, the exposure to LPS-G caused significant alterations in the expression of epigenetic modifiers, such as DNA Methyltransferase 1 (DNMT1) and P300, while the CurLIP treatment showed physiological expression. Overall, our in vitro study provides novel mechanistic insights into the intracellular pathway exert by CurLIP in the regulation of inflammation and epigenetic modifications.
Asunto(s)
Antiinflamatorios no Esteroideos/farmacología , Curcumina/farmacología , Endotelio Vascular/efectos de los fármacos , Inflamación/tratamiento farmacológico , Lipopolisacáridos/farmacología , Cresta Neural/efectos de los fármacos , Células Madre/efectos de los fármacos , Diferenciación Celular , Endotelio Vascular/citología , Endotelio Vascular/metabolismo , Humanos , Inflamación/metabolismo , Inflamación/patología , Liposomas/administración & dosificación , Liposomas/química , Cresta Neural/citología , Cresta Neural/metabolismo , Ligamento Periodontal/citología , Ligamento Periodontal/efectos de los fármacos , Ligamento Periodontal/metabolismo , Porphyromonas gingivalis/química , Especies Reactivas de Oxígeno , Células Madre/citología , Células Madre/metabolismoRESUMEN
Extracellular vesicles (EVs) are released by shedding during different physiological processes and are increasingly thought to be new potential biomarkers. However, the impact of pre-analytical processing phases on the final measurement is not predictable and for this reason, the translation of basic research into clinical practice has been precluded. Here we have optimized a simple procedure in combination with polychromatic flow cytometry (PFC), to identify, classify, enumerate, and separate circulating EVs from different cell origins. This protocol takes advantage of a lipophilic cationic dye (LCD) able to probe EVs. Moreover, the application of the newly optimized PFC protocol here described allowed the obtainment of repeatable EVs counts. The translation of this PFC protocol to fluorescence-activated cell sorting allowed us to separate EVs from fresh peripheral blood samples. Sorted EVs preparations resulted particularly suitable for proteomic analyses, which we applied to study their protein cargo. Here we show that LCD staining allowed PFC detection and sorting of EVs from fresh body fluids, avoiding pre-analytical steps of enrichment that could impact final results. Therefore, LCD staining is an essential step towards the assessment of EVs clinical significance.
Asunto(s)
Biomarcadores , Vesículas Extracelulares/metabolismo , Citometría de Flujo , Biopsia Líquida , Animales , Citometría de Flujo/métodos , Humanos , Biopsia Líquida/métodos , Tamaño de la Partícula , Plasma , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
Liposomes loaded with drugcyclodextrin complexes are widely used as drug delivery systems, especially for species with low aqueous solubility and stability. Investigation of the intimate interactions of macrocycles with liposomes are essential for formulation of efficient and stable drug-in-cyclodextrin-in-liposome carriers. In this work, we reported the preparation of unilamellar vesicles of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) embedded with native ß-cyclodextrin and two synthetic derivatives: heptakis(2,3,6-tri-O-methyl)-ß-cyclodextrin (TMCD) and heptakis(2,3-di-O-acetyl)-ß-cyclodextrin (DACD). We then studied the effect of these macrocycles on the liposomal size, membrane viscosity, and liposomal stability at different temperatures and concentrations. We observed that TMCD and DACD affected vesicle size and the change of size was related to CD concentration. Irrespective of its nature, the macrocycle established interactions with the phospholipidic head groups, preventing cyclodextrins to diffuse into the lipid bilayer, as confirmed by molecular dynamics simulations. Such supramolecular structuring improves liposome stability making these colloid systems promising carriers for biologically active compounds.
Asunto(s)
Membrana Dobles de Lípidos/química , Fosfatidilcolinas/química , Liposomas Unilamelares/química , beta-Ciclodextrinas/químicaRESUMEN
Chronic wounds represent an increasing problem worldwide. Graphene oxide (GO) has been reported to exhibit strong antibacterial activity toward both Gram-positive and Gram-negative bacteria. The aim of this work was to investigate the in vitro antimicrobial and antibiofilm efficacy of GO against wound pathogens. Staphylococcus aureus PECHA 10, Pseudomonas aeruginosa PECHA 4, and Candida albicans X3 clinical isolates were incubated with 50 mg/liter of GO for 2 and 24 h to evaluate the antimicrobial effect. Optical and atomic force microscopy images were performed to visualize the effect of GO on microbial cells. Moreover, the antibiofilm effect of GO was tested on biofilms, both in formation and mature. Compared to the respective time controls, GO significantly reduced the S. aureus growth both at 2 and 24 h in a time-dependent way, and it displayed a bacteriostatic effect in respect to the GO t = 0; an immediate (after 2 h) slowdown of bacterial growth was detected for P. aeruginosa, whereas a tardive effect (after 24 h) was recorded for C. albicans Atomic force microscopy images showed the complete wrapping of S. aureus and C. albicans with GO sheets, which explains its antimicrobial activity. Moreover, significant inhibition of biofilm formation and a reduction of mature biofilm were recorded for each detected microorganism. The antibacterial and antibiofilm properties of GO against chronic wound microorganisms make it an interesting candidate to incorporate into wound bandages to treat and/or prevent microbial infections.
Asunto(s)
Antibacterianos/farmacología , Biopelículas/efectos de los fármacos , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Grafito/farmacología , Pruebas de Sensibilidad Microbiana , Pseudomonas aeruginosa/efectos de los fármacosRESUMEN
Carbonic anhydrases (CAs) are implicated in a wide range of diseases, including the upregulation of isoforms CAâ IX and XII in many aggressive cancers. However, effective inhibition of disease-implicated CAs should minimally affect the ubiquitously expressed isoforms, including CAâ I and II, to improve directed distribution of the inhibitors to the cancer-associated isoforms and reduce side effects. Four benzenesulfonamide-based inhibitors were synthesized by using the tail approach and displayed nanomolar affinities for several CA isoforms. The crystal structures of the inhibitors bound to a CAâ IX mimic and CAâ II are presented. Further in silico modeling was performed with the inhibitors docked into CAâ I and XII to identify residues that contributed to or hindered their binding interactions. These structural studies demonstrated that active-site residues lining the hydrophobic pocket, especially positions 92 and 131, dictate the positional binding and affinity of inhibitors, whereas the tail groups modulate CA isoform specificity. Geometry optimizations were performed on each ligand in the crystal structures and showed that the energetic penalties of the inhibitor conformations were negligible compared to the gains from active-site interactions. These studies further our understanding of obtaining isoform specificity when designing small molecule CA inhibitors.
Asunto(s)
Inhibidores de Anhidrasa Carbónica/metabolismo , Anhidrasas Carbónicas/metabolismo , Sulfonamidas/metabolismo , Sitios de Unión , Inhibidores de Anhidrasa Carbónica/síntesis química , Inhibidores de Anhidrasa Carbónica/química , Anhidrasas Carbónicas/química , Dominio Catalítico , Cristalografía por Rayos X , Diseño de Fármacos , Simulación del Acoplamiento Molecular , Unión Proteica , Isoformas de Proteínas/antagonistas & inhibidores , Isoformas de Proteínas/metabolismo , Relación Estructura-Actividad , Sulfonamidas/síntesis química , Sulfonamidas/química , BencenosulfonamidasRESUMEN
We have previously reported the enhancement of the antiproliferative and apoptotic activities of cis-diamminedichloroplatinum(II) (DDP) when it is coadministered with a class I antiarrhythmic drug procainamide hydrochloride (PA). Here, we determined the antiproliferative activity of DDP, either in solution or loaded in liposomes, in the presence of PA, in the bulk solution, or directly embedded in liposomes together with DDP. Our results show that PA potentiates the activity of DDP-liposomes and that this effect is maintained at least in some of the investigated cell types when both drugs were mixed and loaded together into liposomes.
Asunto(s)
Cisplatino/farmacología , Liposomas/química , Procainamida/farmacología , Células A549 , Animales , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Sinergismo Farmacológico , Concentración 50 Inhibidora , Liposomas/síntesis químicaRESUMEN
Surfactants are amphiphilic molecules active at the surface/interface and able to self-assemble. Because of these properties, surfactants have been extensively used as detergents, emulsifiers, foaming agents, and wetting agents. New perspectives have been opened by the exploitation of surfactants for their capacity to interact as well with simple molecules or surfaces. This feature article gives an overview of significant contributions in the panorama of the current research on surfactants, partly accomplished as well by our research group. We look at several recent applications (e.g., adsorption to graphitic surfaces and interactions with hydrate crystals) with the eye of physical organic chemists. We demonstrate that, from the detailed investigation of the forces involved in the interactions with hydrophobic surfaces, it is possible to optimize the design of the surfactant that is able to form a stable and unbundled carbon nanotube dispersion as well as the best exfoliating agent for graphitic surfaces. By studying the effect of different surfactants on the capacity to favor or disfavor the formation of a gas hydrate, it is possible to highlight the main features that a surfactant should possess in order to be devoted to that specific application.
RESUMEN
A comparative thermodynamic investigation of the keto-enol interconversion reaction has been performed in several organic solvents and room-temperature ionic liquids (RTILs) to evaluate the role of the solvent and the effect of the ionic composition of RTILs. The tautomeric constant (KT) values at different temperatures have been analyzed in terms of the van't Hoff relationship to give the relevant thermodynamic parameters. The ΔG° values are the results of quite different combinations of the ΔH° and ΔS° values depending on the nature of the solvent. As expected, in conventional solvents, the tautomeric equilibrium is enthalpically disfavored and entropically favored by the increase in solvent polarity. In ionic liquids, the nature of the anion seems to play a primary role in the thermodynamics of the reaction that is endothermic and enthalpically driven in PF6- and TF2N-based RTILs and exothermic but entropically driven in BF4-based RTILs. The cation effect on the thermodynamics of the reaction is more complex and is consistent with a prevalence of the alkyl side chain segregation in the organization of the ILs.
RESUMEN
With the aim to improve the features of surfactant solutions in terms of sustainability and renewability we propose the use of hydrogenated natural and sustainable plant-derived cardanol as an additive to commercial surfactants. In the present study we demonstrated that its addition, in amounts as high as 10%, to commercial surfactants of different charge does not significantly affect surfactant properties. Conversely, the presence of hydrogenated cardanol can strongly affect spectrophotometric determination of CMC if preferential interactions with the dyes used take place. This latter evidence may be profitably exploited in surfactant manufacturing by considering that the concurrent presence of a rigid organic molecule such as Orange OT and 10% hydrogenated cardanol decreases the CMC of CTAB up to 65 times.
Asunto(s)
Micelas , Fenoles/química , Tensoactivos/química , Cetrimonio , Compuestos de Cetrimonio/química , Agua/químicaRESUMEN
The mechanism of the TiCl4-promoted condensation of methyl acetoacetate, isobutyraldehyde, and indole was studied by a combination of theoretical and experimental techniques. The energy profile of plausible reaction paths was evaluated by DFT calculations, and various reaction intermediates were isolated or observed in solution by NMR spectroscopy. Theoretical and experimental results indicate that the reaction proceeds in three steps, all promoted by titanium: (1) formation of the enolate ion of methyl acetoacetate, (2) Knoevenagel condensation of the enolate ion and aldehyde, and (3) Michael addition of indole to the Knoevenagel adduct. The study sheds light on the role of titanium in the reaction, providing a mechanistic model for analogous reactions.
Asunto(s)
Acetoacetatos/química , Aldehídos/química , Indoles/química , Modelos Teóricos , Titanio/química , Espectroscopía de Resonancia Magnética , Soluciones , TermodinámicaRESUMEN
The three-component reaction of indole, isobutyraldehyde, and methyl acetoacetate affords methyl 2-(acetyl)-3-(1H-indol-3-yl)-4-methylpentanoate as a single diastereomer. To investigate the origin of the observed diastereoselectivity, the thermodynamics and kinetics of interconversion of diastereomers 1 and 2 in solution were studied by a combination of (1)H nuclear magnetic resonance (NMR) spectroscopy, high-performance liquid chromatography (HPLC), mass spectrometry, and deuteration experiments. The results indicate that interconversion is both acid- and base-catalyzed, and that the alpha carbon is the only stereolabile center in the molecule. The evidence points to an enolization mechanism for the interconversion process. The selective precipitation of 1 in the presence of the equilibrium 1â2 eventually results in the exclusive formation of 1 (crystallization-induced asymmetric transformation).
Asunto(s)
Acetoacetatos/química , Aldehídos/química , Indoles/química , Cromatografía Líquida de Alta Presión , Cristalografía por Rayos X , Espectroscopía de Protones por Resonancia Magnética , Espectrometría de Masa por Ionización de Electrospray , EstereoisomerismoRESUMEN
OBJECTIVE: The aim of this study was to evaluate in vitro the behavior and the biocompatibility of primary human osteoblasts (HOs) grown onto different implant surface. METHODS AND MATERIALS: HOs were cultured onto sandblasted/acid-etched (control group) and sandblasted/acid-etched followed by coating with inorganic ions (test group) experimental titanium discs. At established times, SEM analysis, LDH assay, MTT assay, and enzyme-linked immunosorbent assay for type 1 collagen, interleukin (IL)-6, and PGE2 secretion were performed. RESULTS: Both surfaces promote HOs adhesion and proliferation. After 21 days, cells on test surfaces are well spread, flattened, and attached by cellular extensions, whereas cells on control discs appear mainly elongated. Lower LDH levels and higher values of MTT assay are recorded for cells on test respect to control surfaces at each experimental time. Type 1 collagen release increases until 14 days, significantly decreasing at day 21 in cells grown on both surfaces. IL-6 and PGE2 secretion shows a peak in control group samples at day 7, whereas their levels do not significantly modify in both groups at days 14 and 21. CONCLUSION: Results indicate that the test group surface is more biocompatible, well tolerated, and suitable for supporting osteoblasts growth and proliferation.
Asunto(s)
Implantación Dental Endoósea/métodos , Implantes Dentales , Oseointegración/fisiología , Osteoblastos/citología , Propiedades de Superficie , Fosfatasa Alcalina/biosíntesis , Materiales Biocompatibles , Adhesión Celular , Diferenciación Celular , Proliferación Celular , Células Cultivadas , Colágeno Tipo I/biosíntesis , Dinoprostona/metabolismo , Humanos , Interleucina-6/biosíntesis , Titanio/químicaRESUMEN
We have developed a simple artificial photoresponsive ion-gating device by inserting molecular switches in the membrane of liposomes. A controlled and directed proton transport across the bilayer membrane can lower the internal pH of the liposomes from neutral to around 4 under combined light and chemical stimulation.
Asunto(s)
Luz , Membrana Dobles de Lípidos/química , Liposomas/química , Fosfatidilcolinas/química , Protones , Concentración de Iones de Hidrógeno , Estructura MolecularRESUMEN
Starting from previous evidence on the crucial role of imidazolium ions, long alkyl chains, and aromatic rings in favoring the adsorption of surfactants onto carbon nanotube (CNT) walls, we have synthesized novel gemini surfactants with the aim to optimize and identify a reference structure for CNT dispersants. The efficiency of the novel surfactants has been evaluated, discussed, and compared with already well-investigated dispersants. The good affinity of the surfactants for the CNT sidewalls is highlighted by the presence of resonant van Hove absorption and highly resolved Raman and fluorescence spectra, while the strong hydrophobic interactions and favorable packing between the two alkyl chains of the investigated gemini surfactants and the CNT sidewalls ensure good CNT dispersion. Our results show no selectivity toward specific diameters/chiralities, confirming the twin heads of imidazolium surfactants are pointed toward the bulk water, while the alkyl chains are arranged on the CNT walls, improving water solubility at the expense of potential selectivity.
Asunto(s)
Imidazoles/química , Nanotubos de Carbono/química , Tensoactivos/química , Adsorción , Estructura Molecular , Tamaño de la Partícula , Propiedades de SuperficieRESUMEN
Carcinoma ex pleomorphic adenoma is a rare tumor arising from the salivary glands that spreads through direct extension, through the lymphatic vessels, and, rarely, hematogenously. When distant metastases have been found, they have been reported mainly in the lung. We present an unusual case of carcinoma ex pleomorphic adenoma of the parotid gland with splenic metastases. The patient presented with a primary carcinoma ex pleomorphic adenoma of the parotid gland and he underwent a total parotidectomy with laterocervical lymphadenectomy ipsilateral and adjuvant radiation therapy to the right parotid area. One year later, the patient showed an ipsilateral supraclavicular lymph node recurrence, treated with surgery and radiation therapy. Two more years later, the patient developed lung and splenic lesions, detected through CT and PET. He underwent splenectomy and pathologic assessment of the specimen showed metastatic carcinoma ex pleomorphic adenoma. To our knowledge, there is no reported case of a carcinoma ex pleomorphic adenoma metastasizing to the spleen. Patients treated for carcinoma ex pleomorphic adenoma should be investigated for distant metastases with a long-term follow-up examination for local and distant metastases and new splenic lesions in these patients should be investigated.
Asunto(s)
Adenocarcinoma/patología , Adenoma Pleomórfico/patología , Neoplasias de la Parótida/patología , Neoplasias del Bazo/secundario , Adenocarcinoma/cirugía , Adenoma Pleomórfico/cirugía , Anciano , Humanos , Masculino , Neoplasias de la Parótida/cirugía , Pronóstico , Neoplasias del Bazo/cirugíaRESUMEN
PURPOSE: The Re-irradiation and the Breast Cancer Working Groups of the Italian Association of Radiotherapy and Clinical Oncology (AIRO) conducted a survey to provide an overview of the policies for breast cancer (BC) re-irradiation (re-RT) among the Italian radiotherapy (RT) centers. METHODS: In October 2021, 183 RT centers were invited to answer a survey: after an initial section about general aspects, the questionnaire focused on radiation oncologists' (ROs) attitude toward re-RT in three different scenarios: ipsilateral breast tumor recurrence (IBTR) treated with second conservative surgery, IBTR treated with mastectomy and inoperable IBTR. Surveyed ROs were also asked to express their interest in being involved in a prospective trials. RESULTS: Seventy-seven/183 (42.0%) centers answered the Survey, only one RO per center was requested to answer. In particular, 86.5% ROs declared to have performed "curative" re-RT for IBTR during the previous two years (2019-2020): 76.7% respondents administered re-RT after second BCS, 50.9% after mastectomy, and 48.1% for inoperable IBTR. Re-RT practice varied widely among centers in terms of treatment volumes, dose and fractionation schedules, techniques and dose-volume constraints for organs at risks (OARs). Forty-six participants (59.7%) expressed their interest in participating in a prospective study investigating BC re-RT. CONCLUSIONS: About one out of three RT centers in Italy delivered re-RT for IBTR. Nevertheless, practice of re-RT varied widely among centers highlighting the needs for prospective studies to improve knowledge in this field.
Asunto(s)
Neoplasias de la Mama , Reirradiación , Humanos , Femenino , Neoplasias de la Mama/radioterapia , Neoplasias de la Mama/cirugía , Neoplasias de la Mama/tratamiento farmacológico , Estudios Prospectivos , Recurrencia Local de Neoplasia/radioterapia , Recurrencia Local de Neoplasia/cirugía , Recurrencia Local de Neoplasia/patología , Especies Reactivas de Oxígeno , Mastectomía , Oncología Médica , Encuestas y Cuestionarios , Mastectomía Segmentaria/métodosRESUMEN
Responsiveness of liposomes to external stimuli, such as light, should allow a precise spatial and temporal control of release of therapeutic agents or ion transmembrane transport. Here, some aryl-azo derivatives of thymol are synthesized and embedded into liposomes from 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine to obtain light-sensitive membranes whose photo-responsiveness, release behaviour, and permeability towards Cl- ions are investigated. The hybrid systems are in-depth characterized by dynamic light scattering, atomic force microscopy and Raman spectroscopy. In liposomal bilayer the selected guests undergo reversible photoinduced isomerization upon irradiation with UV and visible light, alternately. Non-irradiated hybrid liposomes retain entrapped 5(6)-carboxyfluorescein (CF), slowing its spontaneous leakage, whereas UV-irradiation promotes CF release, due to guest trans-to-cis isomerization. Photoisomerization also influences membrane permeability towards Cl- ions. Data processing, according to first-order kinetics, demonstrates that Cl- transmembrane transport is enhanced by switching the guest from trans to cis but restored by back-switching the guest from cis to trans upon illumination with blue light. Finally, the passage of Cl- ions across the bilayer can be fine-tuned by irradiation with light of longer λ and different light-exposure times. Fine-tuning the photo-induced structural response of the liposomal membrane upon isomerization is a promising step towards effective photo-dynamic therapy.
Asunto(s)
Liposomas , Nanopartículas , Timol , Timol/química , Isomerismo , Liposomas/química , Nanopartículas/química , Fosfatidilcolinas/química , Luz , Membrana Dobles de Lípidos/química , Rayos Ultravioleta , Procesos Fotoquímicos , Permeabilidad de la Membrana Celular , Cloruros/química , Fluoresceínas/química , PermeabilidadRESUMEN
The aim of this study was the evaluation of suitability of novel mucoadhesive hydrogel platforms for the delivery of therapeutics useful for the management of disorders related to the gastrointestinal tract (GI). At this purpose, here we describe the preparation, the physicochemical characterization and drug delivery behaviour of novel hydrogels, based on self-assembling lipopeptides (MPD02-09), obtained by covalently conjugating lauric acid (LA) to SNA's peptide derivatives gotten by variously combining D- and L- amino acid residues. LA conjugation was aimed at improving the stability of the precursor peptides, obtaining amphiphilic structures, and triggering the hydrogels formation through the self-assembling. Budesonide (BUD), an anti-inflammatory drug, was selected as model because of its use in the treatment in GI disorders. Preliminary studies were performed to correlate the chemical structure of the conjugates with the key physicochemical properties of the materials for drug delivery. Two lipopeptides, MPD03 and MPD08, were found to form hydrogels (MPD03h and MPD08h, respectively) with characteristics suitable for drug delivery. These materials showed mucoadhesiveness of about 60 %. In vitro studies carried out with BUD loaded hydrogels showed about 70 % drug release within 6 h. Wound healing assessed in Caco-2 and HaCaT cells, showed reduction of cell-free area to values lower than 10 %. Taking together these results MPD03h and MPD08h have been shown to be excellent candidates for BUD delivery.