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1.
J Cardiovasc Magn Reson ; 26(1): 100007, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38211509

RESUMEN

"Cases of SCMR" is a case series on the SCMR website (https://www.scmr.org) for the purpose of education. The cases reflect the clinical presentation, and the use of cardiovascular magnetic resonance (CMR) in the diagnosis and management of cardiovascular disease. The 2022 digital collection of cases are presented in this manuscript.


Asunto(s)
Enfermedades Cardiovasculares , Valor Predictivo de las Pruebas , Humanos , Enfermedades Cardiovasculares/diagnóstico por imagen , Enfermedades Cardiovasculares/terapia , Persona de Mediana Edad , Femenino , Masculino , Anciano , Imagen por Resonancia Magnética , Adulto , Pronóstico , Adulto Joven
2.
Mol Pharm ; 20(8): 3937-3946, 2023 08 07.
Artículo en Inglés | MEDLINE | ID: mdl-37463151

RESUMEN

Acute myeloid leukemia (AML) kills 75% of patients and represents a major clinical challenge with a need to improve on current treatment approaches. Targeting sphingosine kinase 1 with a novel ATP-competitive-inhibitor, MP-A08, induces cell death in AML. However, limitations in MP-A08's "drug-like properties" (solubility, biodistribution, and potency) hinder its pathway to the clinic. This study demonstrates a liposome-based delivery system of MP-A08 that exhibits enhanced MP-A08 potency against AML cells. MP-A08-liposomes increased MP-A08 efficacy against patient AML cells (>140-fold) and significantly prolonged overall survival of mice with human AML disease (P = 0.03). The significant antileukemic property of MP-A08-liposomes could be attributed to its enhanced specificity, bioaccessibility, and delivery to the bone marrow, as demonstrated in the pharmacokinetic and biodistribution studies. Our findings indicate that MP-A08-liposomes have potential as a novel treatment for AML.


Asunto(s)
Leucemia Mieloide Aguda , Liposomas , Humanos , Ratones , Animales , Liposomas/uso terapéutico , Distribución Tisular , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/metabolismo , Fosfotransferasas (Aceptor de Grupo Alcohol) , Línea Celular Tumoral
3.
Molecules ; 28(9)2023 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-37175059

RESUMEN

Long-time electric field action on perovskite piezoelectric ceramic leads to chemical degradation. A new way to accelerate the degradation is the exposure of the ceramic to DC electric fields under a vacuum. A high-quality commercial piezoelectric material based on PbZr1-xTixO3 is used to study such impacts. To avoid the influence of ferroelectric properties and possible removal of oxygen and lead oxides during the degradation process, the experiments are in the temperature interval of 500 °C > T > TC. Changes in resistance during the electrodegradation process is an electrically-induced deoxidation, transforming the ceramic into a metallic-like material. This occurs with an extremely low concentration of effused oxygen of 1016 oxygen atoms per 1 cm3. Due to this concentration not obeying the Mott criterion for an isolator-metal transition, it is stated that the removal of oxygen mostly occurs along the grain boundaries. It agrees with the first-principle calculations regarding dislocations with oxygen vacancies. The decrease in resistivity during electrodegradation follows a power law and is associated with a decrease in the dislocation dimension. The observed reoxidation process is a lifeline for the reconstructing (self-healing) properties of electro-degraded ceramics in harsh cosmic conditions. Based on all of these investigations, a macroscopic and nanoscopic model of the electrodegradation is presented.

4.
Mol Pharm ; 19(4): 1091-1103, 2022 04 04.
Artículo en Inglés | MEDLINE | ID: mdl-35238208

RESUMEN

SBA-15 mesoporous silica (MPS) has been widely used in oral drug delivery; however, it has not been utilized for solidifying lipid-based formulations, and the impact of their characteristic intrawall microporosity remains largely unexplored. Here, we derive the impact of the MPS microporosity on the in vitro solubilization and in vivo oral pharmacokinetics of the prostate cancer drug abiraterone acetate (AbA) when coencapsulated along with medium chain lipids into the pores. AbA in lipid (at 80% equilibrium solubility) was imbibed within a range of MPS particles (with comparable morphology and mesoporous structure but contrasting microporosity ranging from 0-247 m2/g), and their solid-state properties were characterized. Drug solubilization studies during in vitro lipolysis revealed that microporosity was the key factor in facilitating AbA solubilization by increasing the surface area available for drug-lipid diffusion. Interestingly, microporosity hindered hydrolysis of AbA to its active metabolite, abiraterone (Ab), under simulated intestinal conditions. This unique relationship between microporosity and AbA/Ab aqueous solubilization behavior was hypothesized to have significant implications on the subsequent bioavailability of the active metabolite. In vivo oral pharmacokinetics studies in male Sprague-Dawley rats revealed that MPS with moderate microporosity attained the highest relative bioavailability, while poor in vitro-in vivo correlations (IVIVC) existed between in vitro drug solubilization during lipolysis and in vivo AUC. Despite this, a reasonable IVIVC was established between the in vitro solubilization and in vivoCmax, providing evidence for an association between silica microporosity and oral drug absorption.


Asunto(s)
Acetato de Abiraterona , Lípidos , Acetato de Abiraterona/química , Administración Oral , Animales , Disponibilidad Biológica , Lípidos/química , Masculino , Ratas , Ratas Sprague-Dawley , Dióxido de Silicio/química , Solubilidad
5.
Pharm Res ; 39(6): 1151-1163, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35318566

RESUMEN

PURPOSE: Cationic polymers have many advantages as vectors for mediated cellular entry and delivery of siRNA. However, toxicity related to their cationic charge has compromised clinical use. It is hypothesized that the siRNA-vector complex composition and properties can be controlled to optimize therapeutic performance. Here we investigate siRNA complexes with branched polyethylenimine (bPEI) versus generation 4 polyamidoamine dendrimers (PAMAM) on interactions with immobilized lipid membranes, and cellular uptake and toxicity. METHODS: A model siRNA was complexed with either PAMAM or bPEI, and their size and zeta-potential characterized. Interaction of the complexes and parent polymers with lipid bilayers was investigated using atomic force microscopy and correlated with the uptake and toxicity in HeLa cells. RESULTS: PAMAM and its siRNA complexes formed circular shaped micron-sized holes in lipid bilayers, while bPEI formed nanoscale holes. Flow cytometry and fluorescence microscopy demonstrated PAMAM-siRNA complexes to have a higher cellular uptake than bPEI-siRNA complexes. bPEI-siRNA complexes did not impact on viability, however PAMAM-siRNA complexes demonstrated increasing cell toxicity as N/P ratio increased. PAMAM-siRNA complexes accumulated around the cell nucleus, while PEI-siRNA complexes were located closer to the cell wall. CONCLUSION: Complexation of PAMAM dendrimer or bPEI with siRNA modified physicochemical properties of the parent polymer, however it did not impact on the mechanism of interaction with model lipid bilayers or how the polymer/siRNA complex interacted and was internalized by HeLa cells. Interaction of siRNA polymer complexes with cells is related to the action of the parent polymer.


Asunto(s)
Dendrímeros , Membrana Dobles de Lípidos , Transporte Biológico , Dendrímeros/química , Células HeLa , Humanos , Polietileneimina , Polímeros , ARN Interferente Pequeño/química
6.
Phys Chem Chem Phys ; 24(7): 4125-4130, 2022 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-35113112

RESUMEN

Advancing the atomistic level understanding of aqueous dissolution of multicomponent materials is essential. We combined ReaxFF and experiments to investigate the dissolution at the Li1+xAlxTi2-x(PO4)3-water interface. We demonstrate that surface dissolution is a sequentially dynamic process. The phosphate dissolution destabilizes the NASICON structure, which triggers a titanium-rich secondary phase formation.

7.
Nanomedicine ; 42: 102536, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35202839

RESUMEN

Bacterial biofilm infections tolerate high concentrations of antibiotics and are insidiously challenging to treat. Liquid crystal nanoparticles (LCNPs) advance the efficacy of tobramycin in biofilm-related infections by increasing the penetration of antibiotics across the biofilm matrix. Herewith, we develop the LCNPs as a platform technology, demonstrating that the LCNPs can increase the efficacy of two antibiotic classes (i.e. aminoglycosides and colistin) in P. aeruginosa biofilm infections. In C. elegans, the LCNPs potentiated the antimicrobial effect and significantly improved the survival of the nematodes. In mice with a full-thickness excisional wound, LCNPs were non-toxic and did not impair wound repair. Compared to the unformulated antibiotic treatment, tobramycin-LCNPs reduced the chronic bacterial load by 100-fold in the wound. This was also emulated in an ex vivo P. aeruginosa porcine wound infection model. The LCNPs represent a versatile platform technology that improves the efficacy of cationic antibiotics against biofilm infections utilizing multiple administration routes.


Asunto(s)
Antiinfecciosos , Cristales Líquidos , Nanopartículas , Animales , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Biopelículas , Caenorhabditis elegans , Cationes , Ratones , Pseudomonas aeruginosa , Porcinos , Tobramicina/farmacología
8.
Nano Lett ; 21(8): 3451-3457, 2021 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-33852297

RESUMEN

Molten hydroxides, often used for crystal growth and nanoparticle synthesis, have recently been applied for the single step densification of several inorganic materials under moderate uniaxial pressures and 1000 °C below their usual sintering temperatures. The latter approach, termed cold sintering process (CSP), is a mechanochemically driven process that enables the densification of inorganic materials through a dissolution-precipitation creep mechanism. In this study, we report the main densification mechanisms of BaTiO3 in a NaOH-KOH eutectic mixture. A chemical insight at the atomistic level, investigated by ReaxFF molecular dynamics simulations, offers plausible ionic complex formation scenarios and reactions at the BaTiO3/molten hydroxide interface, enabling the dissolution-precipitation reactions and the subsequent cold sintering of BaTiO3.

9.
Small ; 17(24): e2100531, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33978317

RESUMEN

Pseudomonas aeruginosa biofilms cause persistent and chronic infections, most known clinically in cystic fibrosis (CF). Tobramycin (TOB) is a standard anti-pseudomonal antibiotic; however, in biofilm infections, its efficacy severely decreases due to limited permeability across the biofilm matrix. Herewith, a biomimetic, nanostructured, lipid liquid crystal nanoparticle-(LCNP)-formulation is discovered to significantly enhance the efficacy of TOB and eradicate P. aeruginosa biofilm infections. Using an advanced, biologically-relevant co-culture model of human CF bronchial epithelial cells infected with P. aeruginosa biofilms at an air-liquid interface, nebulized TOB-LCNPs completely eradicated 1 × 109 CFU mL-1 of P. aeruginosa after two doses, a 100-fold improvement over the unformulated antibiotic. The enhanced activity of TOB is not observed with a liposomal formulation of TOB or with ciprofloxacin, an antibiotic that readily penetrates biofilms. It is demonstrated that the unique nanostructure of the LCNPs drives the enhanced penetration of TOB across the biofilm barrier, but not through the healthy lung epithelium barrier, significantly increasing the available antibiotic concentration at the site of infection. The LCNPs are an innovative strategy to improve the performance of TOB as a directed pulmonary therapy, enabling the administration of lower doses, reducing the toxicity, and amplifying the anti-biofilm activity of the anti-pseudomonal antibiotic.


Asunto(s)
Fibrosis Quística , Cristales Líquidos , Nanopartículas , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Biopelículas , Fibrosis Quística/tratamiento farmacológico , Humanos , Pruebas de Sensibilidad Microbiana , Pseudomonas aeruginosa , Tobramicina
10.
Rheumatology (Oxford) ; 60(4): 1882-1890, 2021 04 06.
Artículo en Inglés | MEDLINE | ID: mdl-33150434

RESUMEN

OBJECTIVE: This study explores whether the prognosis of interstitial lung disease in rheumatoid arthritis (RA-ILD) has improved over time and assesses the potential influence of drug therapy in a large multicentre UK network. METHODS: We analysed data from 18 UK centres on patients meeting criteria for both RA and ILD diagnosed over a 25-year period. Data included age, disease duration, outcome and cause of death. We compared all cause and respiratory mortality between RA controls and RA-ILD patients, assessing the influence of specific drugs on mortality in four quartiles based on year of diagnosis. RESULTS: A total of 290 RA-ILD patients were identified. All cause (respiratory) mortality was increased at 30% (18%) compared with controls 21% (7%) (P =0.02). Overall, prognosis improved over quartiles with median age at death rising from 63 years to 78 years (P =0.01). No effect on mortality was detected as a result of DMARD use in RA-ILD. Relative risk (RR) of death from any cause was increased among patients who had received anti-TNF therapy [2.09 (1.1-4.0)] P =0.03, while RR was lower in those treated with rituximab [0.52(0.1-2.1)] or mycophenolate [0.65 (0.2-2.0)]. Patients receiving rituximab as their first biologic had longer three (92%), five (82%) and seven year (80%) survival than those whose first biologic was an anti-TNF agent (82%, 76% and 64%, respectively) (P =0.037). DISCUSSION: This large retrospective multicentre study demonstrates survival of patients with RA-ILD has improved. This may relate to the increasing use of specific immunosuppressive and biologic agents.


Asunto(s)
Artritis Reumatoide/complicaciones , Enfermedades Pulmonares Intersticiales/etiología , Adulto , Anciano , Anciano de 80 o más Años , Antirreumáticos/efectos adversos , Antirreumáticos/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Artritis Reumatoide/mortalidad , Estudios de Casos y Controles , Causas de Muerte , Femenino , Humanos , Inmunosupresores/efectos adversos , Inmunosupresores/uso terapéutico , Enfermedades Pulmonares Intersticiales/diagnóstico , Enfermedades Pulmonares Intersticiales/mortalidad , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos , Riesgo , Reino Unido
11.
Inorg Chem ; 60(17): 13453-13460, 2021 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-34403579

RESUMEN

Cold sintering (CS) is a chemically driven densification technique enabling a substantial decrease in the sintering temperature of oxides, by several hundreds of degrees Celsius. Although the densification process in CS is known to be mainly driven by pressure solution creep, additional fundamental aspects driving the interfacial chemistry reactions are still a subject of debate. Herein, we focus on the aspect of speciation in the densification process. The densification of zinc oxide (ZnO) by CS using zinc acetylacetonate hydrate (Zn(acac)2·xH2O), a versatile ligand often used as a precursor for ZnO synthesis in wet chemistry, is reported. The successful densification of ZnO using H2O and Zn(acac)2·xH2O confirms the importance of speciation in CS, as ZnO has a very low solubility in pure H2O. The evolution of the system at different stages of sintering and the role of the Zn(acac)2·xH2O species were evaluated.

12.
Anal Chem ; 92(18): 12605-12612, 2020 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-32786490

RESUMEN

High- and ultrahigh-throughput label-free sample analysis is required by many applications, extending from environmental monitoring to drug discovery and industrial biotechnology. HTS methods predominantly are based on a targeted workflow, which can limit their scope. Mass spectrometry readily provides chemical identity and abundance for complex mixtures, and here, we use microdroplet generation microfluidics to supply picoliter aliquots for analysis at rates up to and including 33 Hz. This is demonstrated for small molecules, peptides, and proteins up to 66 kDa on three commercially available mass spectrometers from salty solutions to mimic cellular environments. Designs for chip-based interfaces that permit this coupling are presented, and the merits and challenges of these interfaces are discussed. On an Orbitrap platform droplet infusion rates of 6 Hz are used for analysis of cytochrome c, on a DTIMS Q-TOF similar rates were obtained, and on a TWIMS Q-TOF utilizing IM-MS software rates up to 33 Hz are demonstrated. The potential of this approach is demonstrated with proof of concept experiments on crude mixtures including egg white, unpurified recombinant protein, and a biotransformation supernatant.


Asunto(s)
Dispositivos Laboratorio en un Chip , Péptidos/análisis , Proteínas/análisis , Bibliotecas de Moléculas Pequeñas/análisis , Espectrometría de Masas , Tamaño de la Partícula , Programas Informáticos , Propiedades de Superficie
13.
Immunogenetics ; 72(1-2): 9-24, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31741010

RESUMEN

Among the genes with the highest allelic polymorphism and sequence diversity are those encoding the classical class I and class II molecules of the major histocompatibility complex (MHC). Although many thousands of MHC sequences have been deposited in general sequence databases like GenBank, the availability of curated MHC sequences with agreed nomenclature has been enormously beneficial. Along with the Immuno Polymorphism Database-IMunoGeneTics/human leukocyte antigen (IPD-IMGT/HLA) database, a collection of databases for curated sequences of immune importance has been developed. A recent addition is an IPD-MHC database for chickens. For many years, the nomenclature system for chicken MHC genes has been based on a list of standard, presumed to be stable, haplotypes. However, these standard haplotypes give different names to identical sequences. Moreover, the discovery of new recombinants between haplotypes and a rapid increase in newly discovered alleles leaves the old system untenable. In this review, a new nomenclature is considered, for which alleles of different loci are given names based on the system used for other MHCs, and then haplotypes are named according to the alleles present. The new nomenclature system is trialled, first with standard haplotypes and then with validated sequences from the scientific literature. In the trial, some class II B sequences were found in both class II loci, presumably by gene conversion or inversion, so that identical sequences would receive different names. This situation prompts further suggestions to the new nomenclature system. In summary, there has been progress, but also problems, with the new IPD-MHC system for chickens.


Asunto(s)
Pollos/genética , Bases de Datos Factuales , Inmunogenética , Complejo Mayor de Histocompatibilidad/genética , Complejo Mayor de Histocompatibilidad/inmunología , Polimorfismo Genético , Terminología como Asunto , Animales
14.
Langmuir ; 36(13): 3367-3376, 2020 04 07.
Artículo en Inglés | MEDLINE | ID: mdl-32167765

RESUMEN

Understanding lipase-mediated hydrolysis mechanisms within solid-state nanocarriers is fundamental for the rational design of lipid-based formulations. In this study, SBA-15 ordered mesoporous silica (MPS) particles were engineered with well-controlled nanostructural properties to systematically elucidate the role of intrawall microporosity, mesopore size, and particle structure on lipase activity. The microporosity and diffusional path length were shown to be key modulators for lipase-provoked hydrolysis of medium chain triglycerides confined within MPS, with small changes in the pore size, between 9 and 13 nm, showing now a clear correlation to lipase activity. Lipid speciation within MPS after lipolysis, obtained through 1H NMR, indicated that free fatty acids preferentially adsorbed to rod-shaped MPS (RodMPS) particles with high microporosity. MPS that formed aggregated spindle-like structures (AggMPS) had intrinsically reduced microporosity, which was hypothesized to limit lipase/lipid diffusion to and from the MPS pores and thus retard lipolysis kinetics. A linear correlation between the microporosity and the extent of lipase-provoked hydrolysis was observed within both AggMPS and RodMPS, ultimately indicating that the intricate interplay between the microporosity and lipid/lipase diffusion can be harnessed to optimize lipolysis kinetics for silica-lipid hybrid carriers. The new insights derived in this study are integral to the future development of solid-state lipid-based nanocarriers that control the lipase activity for improving the absorption of poorly soluble bio-active compounds.

15.
Pharm Res ; 37(4): 77, 2020 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-32236761

RESUMEN

PURPOSE: Abiraterone acetate (AbA) is a poorly water-soluble drug with an oral bioavailability of <10% and a significant pharmaceutical food effect. We aimed to develop a more efficient oral solid-state lipid-based formulation for AbA using a supersaturated silica-lipid hybrid (super-SLH) approach to achieve high drug loading, improve in vitro solubilization and mitigate the food effect, while gaining a mechanistic insight into how super-SLH are digested and release drug. METHODS: The influence of super-SLH saturation level and lipid type on the physicochemical properties and in vitro solubilization during lipolysis of the formulations was investigated and compared to the commercial product, Zytiga. RESULTS: Super-SLH achieved significantly greater levels of AbA solubilization compared to Zytiga. Solubilization was influenced by the AbA saturation level, which determined the solid state of AbA and the relative amount of lipid, and the lipid utilized, which determined its degree of digestion and the affinity of the lipid and digestion products to the silica. A fine balance existed between achieving high drug loads using supersaturation and improving performance using the lipid-based formulation approach. The non-supersaturated SLH prepared with Capmul PG8 mitigated the 3-fold in vitro food effect. CONCLUSION: SLH and super-SLH improve in vitro solubilization of AbA, remove the food effect and demonstrate potential to improve oral bioavailability in vivo. Graphical Abstract Abiraterone acetate was formulated as silica-lipid hybrids and demonstrated enhanced in vitro solubilization in comparison to pure abiraterone acetate and commercial product, Zytiga.


Asunto(s)
Acetato de Abiraterona/química , Caprilatos/química , Composición de Medicamentos/métodos , Excipientes/química , Glicéridos/química , Dióxido de Silicio/química , Administración Cutánea , Disponibilidad Biológica , Digestión , Liberación de Fármacos , Estabilidad de Medicamentos , Interacciones Alimento-Droga , Humanos , Cinética , Lipólisis , Pancreatina/química , Solubilidad , Propiedades de Superficie
16.
Eur J Nutr ; 59(6): 2729-2737, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31637467

RESUMEN

PURPOSE: Application of intelligent formulation design has the ability to address the poor bioavailability and improve the fasted state bioavailability of fish oils. In this study we assessed the ability of a self-emulsifying drug delivery system (SEDDS), AquaCelle®, as an additive to enhance the oral absorption of Omega-3 ethyl esters (EE) in healthy subjects under low-fat diet conditions. METHODS: Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) EE were formulated with AquaCelle®. A single dose (680 mg dose of oil containing 272 mg of EPA EE and 204 mg of DHA EE), randomized, double-blind, study measured uptake of EPA and DHA over 24 h in healthy adults. Participants were randomized into two groups, receiving either the SEDDS AquaCelle® fish oil formulation or the unformulated fish oil EE as control. RESULTS: The AquaCelle® fish oil EE formulation demonstrated instant and complete emulsification on addition to water to produce an emulsion with an average diameter of 43 µm, compared to the oil alone which did not emulsify. The study revealed a significant difference in absorption (Cmax and AUC0-24h) between the AquaCelle® group and the control group. The AquaCelle® group was capable of increasing maximum plasma concentrations and absorption (AUC0-24h) of total Omega-3 (EPA + DHA) 3.7- and 7.1-fold, respectively, compared to the control. CONCLUSION: Formulating Omega-3 EE with a SEDSS concentrate (AquaCelle®) demonstrated a significant improvement in the oral absorption of Omega-3 fatty acids without requiring a high-fat meal.


Asunto(s)
Ácidos Docosahexaenoicos , Ácidos Grasos Omega-3 , Adulto , Disponibilidad Biológica , Ácido Eicosapentaenoico , Ésteres , Aceites de Pescado , Humanos
17.
J Pharmacol Exp Ther ; 370(3): 742-750, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-30552294

RESUMEN

Supersaturated silica-lipid hybrid (super-SLH) drug carriers are a recent strategy to improve the drug loading of oral solid lipid based formulations, however they are yet to be studied in vivo. This study investigated the in vivo pharmacokinetics (PK) of super-SLH containing ibuprofen (IBU), as a model Biopharmaceutics Classification Scheme (BCS) class II drug, analyzing the influence of supersaturated drug loading on oral bioavailability and assessing in vitro-in vivo correlation (IVIVC). In addition, super-SLH was directly compared with spray-dried SLH and Nurofen to explore its potential advantages over the well-established and commercial formulations. Fasted male Sprague-Dawley rats were administered formulation suspensions (10 mg/kg IBU) via oral gavage, and blood samples were acquired and plasma was analyzed for IBU concentrations over 24 hours. In vivo, super-SLH with drug loads of 9.5 (99.5% saturated) and 19.3% w/w (227% saturated) achieved bioavailabilities equal to spray-dried SLH and 2.2-fold greater than Nurofen. This effect diminished for super-SLH with a drug load of 29.1% w/w (389% saturated), which exhibited a bioavailability of less than Nurofen due to its greater extent of supersaturation and larger content of crystalline IBU. The super-SLH containing 19.3% w/w IBU provided the greatest PK performance, achieving the same degree of bioavailability enhancement as spray-dried SLH and requiring 63% less formulation. A significant positive IVIVC was observed between the performances of the formulations. These findings indicate the potential of super-SLH as an improved oral solid lipid based formulation strategy for enhancing oral bioavailability of other BCS class II drugs.


Asunto(s)
Sistemas de Liberación de Medicamentos/métodos , Lípidos/química , Dióxido de Silicio/química , Administración Oral , Animales , Antiinflamatorios no Esteroideos/administración & dosificación , Antiinflamatorios no Esteroideos/farmacocinética , Área Bajo la Curva , Biofarmacia , Composición de Medicamentos , Ibuprofeno/administración & dosificación , Ibuprofeno/farmacocinética , Masculino , Ratas , Ratas Sprague-Dawley , Solubilidad
18.
Analyst ; 144(3): 872-891, 2019 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-30601490

RESUMEN

High throughput screening (HTS) of molecular analytes is in high demand from and implemented in many areas of chemistry, medicine and industrial biotechnology including the discovery of biomarkers and the development of new chemical entities. Despite its prevalence, technical challenges remain in many of the new application areas of HTS which require rapid results from complex mixtures, for example in: screening biotransformations; targeted metabolomics; and in locating drugs and/or metabolites in biological matrices. Common to all of these are lengthy and costly sample preparation stages, involving recovery from cell cultures, extractions followed by low throughput LC-MS/MS methods or specific fluorescence measurements. In the latter the target molecules need to be inherently fluorescent or to include a fluorescent label or tag which can adversely influence a cellular system. Direct infusion mass spectrometry coupled with robotic sample infusion is a viable contender for information rich HTS with sub-second analysis times, and recent developments in ambient ionisation have heralded a new era where screening can be performed on crude cell lysates or even from live cells. Besides commercially available technologies such as RapidFire, Acoustic Mist Ionisation, and the TriVersa ChipMate there are promising new developments from academic groups. Novel applications using desorption electrospray ionisation, microfluidics, rapid LC-separation and 'one cell' direct infusion methods offer much potential for increasing throughput from 'messy' complex samples and for significantly reducing the amount of material that needs to be analysed. Here we review recent advances in HTS coupled with MS with an emphasis on methods that reduce or remove all sample preparation and will facilitate single cell screening approaches.


Asunto(s)
Ensayos Analíticos de Alto Rendimiento/métodos , Sustancias Macromoleculares/análisis , Espectrometría de Masas/métodos , Análisis de la Célula Individual/métodos , Humanos
19.
Proc Natl Acad Sci U S A ; 113(3): 692-7, 2016 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-26699458

RESUMEN

The chicken major histocompatibility complex (MHC) has strong genetic associations with resistance and susceptibility to certain infectious pathogens. The cell surface expression level of MHC class I molecules varies as much as 10-fold between chicken haplotypes and is inversely correlated with diversity of peptide repertoire and with resistance to Marek's disease caused by an oncogenic herpesvirus. Here we show that the average thermostability of class I molecules isolated from cells also varies, being higher for high-expressing MHC haplotypes. However, we find roughly the same amount of class I protein synthesized by high- and low-expressing MHC haplotypes, with movement to the cell surface responsible for the difference in expression. Previous data show that chicken TAP genes have high allelic polymorphism, with peptide translocation specific for each MHC haplotype. Here we use assembly assays with peptide libraries to show that high-expressing B15 class I molecules can bind a much wider variety of peptides than are found on the cell surface, with the B15 TAPs restricting the peptides available. In contrast, the translocation specificity of TAPs from the low-expressing B21 haplotype is even more permissive than the promiscuous binding shown by the dominantly expressed class I molecule. B15/B21 heterozygote cells show much greater expression of B15 class I molecules than B15/B15 homozygote cells, presumably as a result of receiving additional peptides from the B21 TAPs. Thus, chicken MHC haplotypes vary in several correlated attributes, with the most obvious candidate linking all these properties being molecular interactions within the peptide-loading complex (PLC).


Asunto(s)
Membrana Celular/metabolismo , Antígenos de Histocompatibilidad Clase I/metabolismo , Proteínas de Transporte de Membrana/metabolismo , Péptidos/metabolismo , Temperatura , Secuencia de Aminoácidos , Animales , Transporte Biológico , Pollos , Epítopos/metabolismo , Eritrocitos/metabolismo , Haplotipos , Heterocigoto , Homocigoto , Datos de Secuencia Molecular , Péptidos/química , Estabilidad Proteica , Especificidad por Sustrato , Microglobulina beta-2/metabolismo
20.
Drug Dev Ind Pharm ; 45(3): 349-358, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30411991

RESUMEN

Porous silica-based drug delivery systems have shown considerable promise for improving the oral delivery of poorly water-soluble drugs. More specifically, micro- and meso-porous silica carriers have high surface areas with associated ability to physically adsorb high-drug loads in a molecular or amorphous form; this allows molecular state drug release in aqueous gastrointestinal environments, potential for supersaturation, and hence facilitates enhanced absorption and increased bioavailability. This review focuses primarily on the ability of porous silica materials to modulate in vitro drug release and enhance in vivo biopharmaceutical performance. The key considerations identified and addressed are the physicochemical properties of the porous silica materials (e.g. the particle and pore size, shape, and surface chemistry), drug specific properties (e.g. pKa, solubility, and nature of interactions with the silica carrier), potential for both immediate and controlled release, drug release mechanisms, potential for surface functionalization and inclusion of precipitation inhibitors, and importance of utilizing relevant and effective in vitro dissolution methods with discriminating dissolution media that provides guidance for in vivo outcomes (i.e. IVIVC).


Asunto(s)
Preparaciones Farmacéuticas/química , Dióxido de Silicio/química , Solubilidad/efectos de los fármacos , Administración Oral , Animales , Disponibilidad Biológica , Sistemas de Liberación de Medicamentos/métodos , Humanos , Tamaño de la Partícula
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