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1.
JACS Au ; 4(4): 1458-1470, 2024 Apr 22.
Article in English | MEDLINE | ID: mdl-38665661

ABSTRACT

Our study reveals the underlying principles governing the passive membrane permeability in three large N-methylated macrocyclic peptides (N-MeMPs): cyclosporine A (CycA), Alisporivir (ALI), and cyclosporine H (CycH). We determine a series of conformers required for robust passive membrane diffusion and those relevant to other functions, such as binding to protein targets or intermediates, in the presence of solvent additives. We investigate the conformational interconversions and establish correlations with the membrane permeability. Nuclear magnetic resonance (NMR) and cyclic ion-mobility spectrometry-mass spectrometry (cIMS-MS) are employed to characterize conformational heterogeneity and identify cis-amides relevant for good membrane permeability. In addition, ion mobility selected cIMS-MS and infrared (IR) multiple-photon dissociation (IRMPD) spectroscopy experiments are conducted to evaluate the energy barriers between conformations. We observe that CycA and ALI, both cyclosporines with favorable membrane permeabilities, display multiple stable and well-defined conformers. In contrast, CycH, an epimer of CycA with limited permeability, exhibits fewer and fewer stable conformers. We demonstrate the essential role of the conformational shift from the aqueous cis MeVal11-MeBmt1 state (A1) to the closed conformation featuring cis MeLeu9-MeLeu10 (C1) in facilitating membrane permeation. Additionally, we highlight that the transition from A1 to the all-trans open conformation (O1) is specifically triggered by the presence of CaCl2. We also capture a set of conformers with cis Sar3-MeLeu4, MeLeu9-MeLeu10, denoted as I. Conformationally selected cIMS-MS and IRMPD data of [CycA+Ca]2+ show immediate repopulation of the original population distribution, suggesting that CaCl2 smooths out the energy barriers. Finally, our work presents an improved sampling molecular dynamics approach based on a refined force field that not only consistently and accurately captures established conformers of cyclosporines but also exhibits strong predictive capabilities for novel conformers.

2.
Semergen ; 50(5): 102192, 2024.
Article in English | MEDLINE | ID: mdl-38306821

ABSTRACT

COPD is a disease with a high prevalence that diminishes the quality of life of many patients. Despite this, there are still high rates of under-diagnosis in Spain, partly due to a lack of recognition of the pathology by patients. In this context, the role played by primary care teams becomes fundamental, as they are one of the first lines of entry into the health system. In this paper we explain the different COPD profiles that may be present, and update the tools for diagnosis and treatment, which, together with an attitude of active suspicion of the disease, can help in the correct management of patients, whether they are undiagnosed or have subsequent complications.


Subject(s)
Primary Health Care , Pulmonary Disease, Chronic Obstructive , Quality of Life , Referral and Consultation , Humans , Primary Health Care/standards , Pulmonary Disease, Chronic Obstructive/diagnosis , Pulmonary Disease, Chronic Obstructive/therapy , Pulmonary Disease, Chronic Obstructive/physiopathology , Spain , Prevalence
3.
Cardiovasc Diabetol ; 23(1): 38, 2024 01 20.
Article in English | MEDLINE | ID: mdl-38245716

ABSTRACT

BACKGROUND: Legume consumption has been linked to a reduced risk of type 2 diabetes (T2D) and cardiovascular disease (CVD), while the potential association between plasma metabolites associated with legume consumption and the risk of cardiometabolic diseases has never been explored. Therefore, we aimed to identify a metabolite signature of legume consumption, and subsequently investigate its potential association with the incidence of T2D and CVD. METHODS: The current cross-sectional and longitudinal analysis was conducted in 1833 PREDIMED study participants (mean age 67 years, 57.6% women) with available baseline metabolomic data. A subset of these participants with 1-year follow-up metabolomics data (n = 1522) was used for internal validation. Plasma metabolites were assessed through liquid chromatography-tandem mass spectrometry. Cross-sectional associations between 382 different known metabolites and legume consumption were performed using elastic net regression. Associations between the identified metabolite profile and incident T2D and CVD were estimated using multivariable Cox regression models. RESULTS: Specific metabolic signatures of legume consumption were identified, these included amino acids, cortisol, and various classes of lipid metabolites including diacylglycerols, triacylglycerols, plasmalogens, sphingomyelins and other metabolites. Among these identified metabolites, 22 were negatively and 18 were positively associated with legume consumption. After adjustment for recognized risk factors and legume consumption, the identified legume metabolite profile was inversely associated with T2D incidence (hazard ratio (HR) per 1 SD: 0.75, 95% CI 0.61-0.94; p = 0.017), but not with CVD incidence risk (1.01, 95% CI 0.86-1.19; p = 0.817) over the follow-up period. CONCLUSIONS: This study identified a set of 40 metabolites associated with legume consumption and with a reduced risk of T2D development in a Mediterranean population at high risk of cardiovascular disease. TRIAL REGISTRATION: ISRCTN35739639.


Subject(s)
Cardiovascular Diseases , Diabetes Mellitus, Type 2 , Diet, Mediterranean , Fabaceae , Humans , Female , Aged , Male , Diabetes Mellitus, Type 2/diagnosis , Diabetes Mellitus, Type 2/epidemiology , Cardiovascular Diseases/diagnosis , Cardiovascular Diseases/epidemiology , Cardiovascular Diseases/prevention & control , Cross-Sectional Studies , Risk Factors
4.
Sci Adv ; 9(26): eade6308, 2023 06 30.
Article in English | MEDLINE | ID: mdl-37390204

ABSTRACT

Deleterious variants in N-acetylneuraminate pyruvate lyase (NPL) cause skeletal myopathy and cardiac edema in humans and zebrafish, but its physiological role remains unknown. We report generation of mouse models of the disease: NplR63C, carrying the human p.Arg63Cys variant, and Npldel116 with a 116-bp exonic deletion. In both strains, NPL deficiency causes drastic increase in free sialic acid levels, reduction of skeletal muscle force and endurance, slower healing and smaller size of newly formed myofibers after cardiotoxin-induced muscle injury, increased glycolysis, partially impaired mitochondrial function, and aberrant sialylation of dystroglycan and mitochondrial LRP130 protein. NPL-catalyzed degradation of sialic acid in the muscle increases after fasting and injury and in human patient and mouse models with genetic muscle dystrophy, demonstrating that NPL is essential for muscle function and regeneration and serves as a general marker of muscle damage. Oral administration of N-acetylmannosamine rescues skeletal myopathy, as well as mitochondrial and structural abnormalities in NplR63C mice, suggesting a potential treatment for human patients.


Subject(s)
N-Acetylneuraminic Acid , Zebrafish , Animals , Humans , Mice , Disease Models, Animal , Glycoproteins , Muscle, Skeletal , Pyruvates , Regeneration
5.
Nat Commun ; 14(1): 2973, 2023 05 23.
Article in English | MEDLINE | ID: mdl-37221181

ABSTRACT

Single immune checkpoint blockade in advanced neuroendocrine neoplasms (NENs) shows limited efficacy; dual checkpoint blockade may improve treatment activity. Dune (NCT03095274) is a non-randomized controlled multicohort phase II clinical trial evaluating durvalumab plus tremelimumab activity and safety in advanced NENs. This study included 123 patients presenting between 2017 and 2019 with typical/atypical lung carcinoids (Cohort 1), G1/2 gastrointestinal (Cohort 2), G1/2 pancreatic (Cohort 3) and G3 gastroenteropancreatic (GEP) (Cohort 4) NENs; who progressed to standard therapies. Patients received 1500 mg durvalumab and 75 mg tremelimumab for up to 13 and 4 cycles (every 4 weeks), respectively. The primary objective was the 9-month clinical benefit rate (CBR) for cohorts 1-3 and 9-month overall survival (OS) rate for Cohort 4. Secondary endpoints included objective response rate, duration of response, progression-free survival according to irRECIST, overall survival, and safety. Correlation of PD-L1 expression with efficacy was exploratory. The 9-month CBR was 25.9%/35.5%/25% for Cohorts 1, 2, and 3 respectively. The 9-month OS rate for Cohort 4 was 36.1%, surpassing the futility threshold. Benefit in Cohort 4 was observed regardless of differentiation and Ki67 levels. PD-L1 combined scores did not correlate with treatment activity. Safety profile was consistent with that of prior studies. In conclusion, durvalumab plus tremelimumab is safe in NENs and shows modest survival benefit in G3 GEP-NENs; with one-third of these patients experiencing a prolonged OS.


Subject(s)
Carcinoid Tumor , Neuroendocrine Tumors , Humans , B7-H1 Antigen , Lung
6.
bioRxiv ; 2023 Dec 15.
Article in English | MEDLINE | ID: mdl-36778368

ABSTRACT

Mutations in the microtubule-associated motor protein KIF1A lead to severe neurological conditions known as KIF1A-associated neurological disorders (KAND). Despite insights into its molecular mechanism, high-resolution structures of KIF1A-microtubule complexes remain undefined. Here, we present 2.7-3.4 Å resolution structures of dimeric microtubule-bound KIF1A, including the pathogenic P305L mutant, across various nucleotide states. Our structures reveal that KIF1A binds microtubules in one- and two-heads-bound configurations, with both heads exhibiting distinct conformations with tight inter-head connection. Notably, KIF1A's class-specific loop 12 (K-loop) forms electrostatic interactions with the C-terminal tails of both α- and ß-tubulin. The P305L mutation does not disrupt these interactions but alters loop-12's conformation, impairing strong microtubule-binding. Structure-function analysis reveals the K-loop and head-head coordination as major determinants of KIF1A's superprocessive motility. Our findings advance the understanding of KIF1A's molecular mechanism and provide a basis for developing structure-guided therapeutics against KAND.

7.
Analyst ; 147(13): 3101-3108, 2022 Jun 27.
Article in English | MEDLINE | ID: mdl-35695136

ABSTRACT

LcGg4, a neutral glycosphingolipid (GSL) and cancer antigen, its epimers GalNAc-LcGg4 and GlcNAc-LcGg4, and three lipid forms of GalNAc-LcGg4 were studied by mass spectrometry (MS). It was found that different forms of GalNAc-LcGg4 carrying homologous (d16:1/18:0) and (d18:1/18:0) lipids were easily separated and identified using liquid chromatography (LC)-MS. In addition, like gangliosides, homologous lipid forms of GalNAc-LcGg4 showed the same fragmentation pattern, except for a uniform shift of their glycolipid product ions by a certain m/z number determined by the varied lipid structure. It was also disclosed that LcGg4 and its epimers GalNAc-LcGg4 and GlcNAc-LcGg4, which are different only in the C4-configuration of their non-reducing end sugar residues, gave the same MS/MS product ions in similar relative intensities, as well as the same LC retention time, suggesting the challenge to differentiate epimeric GSLs by LC-MS. However, ion mobility spectrometry (IMS)-MS was able to efficiently separate and distinguish these epimers. This study has demonstrated the promise of IMS-MS for isomeric GSL characterization and the IMS-MS and LC-MS/MS combination for natural GSL analysis.


Subject(s)
Ion Mobility Spectrometry , Neutral Glycosphingolipids , Chromatography, Liquid/methods , Gangliosides , Tandem Mass Spectrometry
8.
Anal Chem ; 94(23): 8441-8448, 2022 06 14.
Article in English | MEDLINE | ID: mdl-35657797

ABSTRACT

The characterization of enantiomers is an important analytical challenge in the chemical and life sciences. Thorough evaluation of the purity of chiral molecules is particularly required in the pharmaceutical industry where safety concerns are paramount. Assessment of the enantiomeric composition is still challenging and time-consuming, meaning that alternative approaches are required. In this study, we exploit the formation of dimers as diastereomeric pairs of enantiomers to affect separation by high resolution cyclic ion mobility-mass spectrometry. Using the example of (R/S)-thalidomide, we show that even though this is not an enantiomer separation, we can determine which enantiomer is in excess and obtain quantitative information on the enantiomer composition without the need for a chiral modifier. Further examples of the approach are presented, including d/l-tryptophan and (R/S)-propanolol, and demonstrate the need for mobility resolving power in excess of 400 (CCS/ΔCCS).


Subject(s)
Ion Mobility Spectrometry , Tryptophan , Mass Spectrometry/methods , Stereoisomerism
9.
ACS Appl Mater Interfaces ; 14(26): 29711-29721, 2022 Jul 06.
Article in English | MEDLINE | ID: mdl-35727222

ABSTRACT

Sodium-ion batteries have emerged as a strong contender among the beyond lithium-ion chemistries due to elemental abundance and the low cost of sodium. Tin (Sn) is a promising alloying electrode with high capacity, redox reversibility, and earth abundance. Tin electrodes, however, undergo a series of intermediate reactions exhibiting multiple voltage plateaus upon sodiation/desodiation. Phase transformations related to incomplete sodiation in tin during cycling, in the presence of a frail solid electrolyte interphase layer, can quickly weaken the structural stability. The structural dynamics and reactivity of the electrode/electrolyte interface, being further dependent on the size and morphology of the active material particle in the presence of different electrolytes, dictate the electrode degradation and survivability during cycling. In this study, we paint a comprehensive picture of the underpinnings of the electrochemical and mechanics coupling and electrode/electrolyte interfacial interactions in alloying Sn electrodes. We elicit the fundamental role of electrode/electrolyte complexations in the Sn electrode structure-property-performance relationship based on multimodal analytics, including electrochemical, microscopy, and tomography analyses.

10.
Front Nutr ; 9: 827307, 2022.
Article in English | MEDLINE | ID: mdl-35284440

ABSTRACT

Background: Current evidence suggests that egg composition might have potential neuroprotective effects. Our aim was to determine the association between egg consumption and the risk of dementia in a Mediterranean population. Methods: This study was carried out in 3 centers from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Spain Dementia Cohort, i.e., 25,015 participants aged 30-70 years, recruited in 1992-1996, and followed up for a mean of 21.5 years. Results: A total of 774 incident dementia cases were diagnosed and validated, of which 518 were Alzheimer's disease (AD). Data on egg consumption were estimated using a validated dietary history questionnaire at recruitment. Cox proportional hazards models, adjusted for confounders, were used in the analyses. No association was observed between egg consumption and either total dementia [hazard ratio between extreme quartiles (HRQ4vs.Q1: 1.05; 95% CI 0.85-1.31; p-trend = 0.93)] or AD (HRQ4vs.Q1 0.93; 95% CI 0.72-1.21; p-trend = 0.50) risks. After dividing the population by adherence to the relative Mediterranean diet (rMED) score, a borderline inverse association was found between egg intake and both total dementia (HRQ4vs.Q1: 0.52; 95% CI 0.30-0.90; p-trend = 0.10) and AD (HRQ4vs.Q1: 0.52; 95% CI 0.27-1.01; p-trend = 0.13) risks within participants with low adherence to rMED score. However, no association was observed in participants with medium and high adherence to rMED score. Conclusion: This prospective study suggests that egg consumption is associated with a reduced risk of dementia, and specifically of AD, in the adult population with low adherence to rMED score; whereas it has no impact in subjects with moderate and high MD adherence.

11.
Med. intensiva (Madr., Ed. impr.) ; 45(5): 298-312, Junio - Julio 2021. tab
Article in Spanish | IBECS | ID: ibc-222311

ABSTRACT

El soporte respiratorio no invasivo (SRNI) comprende 2 modalidades de tratamiento, la ventilación mecá-nica no invasiva (VMNI) y la terapia de alto flujo con cánulas nasales (TAFCN) que se aplican en pacientes adultos, pediátricos y neonatales con insuficiencia respiratoria aguda (IRA). Sin embargo, el grado de acuerdo entre las distintas especialidades sobre el beneficio de estas técnicas en diferentes escenarios clínicos es controvertido. El objetivo del presente consenso fue elaborar una serie de recomendaciones de buena práctica clínica para la aplicación de soporte no invasivo en pacientes con IRA, avaladas por todas las sociedades científicas involucradas en el manejo del paciente adulto y pediátrico/neonatal con IRA. Para ello se contactó con las diferentes sociedades implicadas, quienes designaron a su vez a un grupo de 26 profesionales con suficiente experiencia en su aplicación. Se realizaron 3 reuniones presenciales para consensuar las recomendaciones (hasta un total de 71) fundamentadas en la revisión de la literatura y en la actualización de la evidencia disponible en relación con 3 categorías: indicaciones, monitorización yseguimiento del SRNI. Finalmente, se procedió a votación telemática de cada una de las recomendaciones, por parte de los expertos de cada sociedad científica implicada. Para la clasificación del grado de acuerdo se optó por un sistema analógico de clasificación fácil e intuitivo de usar, y que expresara con claridad si el procedimiento relacionado con el SRNI debía hacerse, podía hacerse o no debía hacerse. (AU)


Non-invasive respiratory support (NIRS) in adult, pediatric, and neonatal patients with acute respiratory failure (ARF) comprises two treatment modalities, non-invasive mechanical ventilation (NIMV) and high-flow nasal cannula (HFNC) therapy. However, experts from different specialties disagree on the benefit of these techniques in different clinical settings. The objective of this consensus was to develop a series of good clinical practice recommendations for the application of non-invasive support in patients with ARF, endorsed by all scientific societies involved in the management of adult and pediatric/neonatal patients with ARF. To this end, the different societies involved were contacted, and they in turn appointed a group of 26 professionals with sufficient experience in the use of these techniques. Three face-to-face meetings were held to agree on recommendations (up to a total of 71) based on a literature review and the latest evidence associated with 3 categories: indications, monitoring and follow-up of NIRS. Finally, the experts from each scientific society involved voted telematically on each of the recommendations. To classify the degree of agreement, an analogue classification system was chosen that was easy and intuitive to use and that clearly stated whether the each NIRS intervention should be applied, could be applied, or should not be applied. (AU)


Subject(s)
Humans , Infant , Child, Preschool , Child , Adult , Noninvasive Ventilation , Respiratory Insufficiency , Cannula , Consensus
12.
Med Intensiva (Engl Ed) ; 45(5): 298-312, 2021.
Article in English | MEDLINE | ID: mdl-34059220

ABSTRACT

Non-invasive respiratory support (NIRS) in adult, pediatric, and neonatal patients with acute respiratory failure (ARF) comprises two treatment modalities, non-invasive mechanical ventilation (NIMV) and high-flow nasal cannula (HFNC) therapy. However, experts from different specialties disagree on the benefit of these techniques in different clinical settings. The objective of this consensus was to develop a series of good clinical practice recommendations for the application of non-invasive support in patients with ARF, endorsed by all scientific societies involved in the management of adult and pediatric/neonatal patients with ARF. To this end, the different societies involved were contacted, and they in turn appointed a group of 26 professionals with sufficient experience in the use of these techniques. Three face-to-face meetings were held to agree on recommendations (up to a total of 71) based on a literature review and the latest evidence associated with 3 categories: indications, monitoring and follow-up of NIRS. Finally, the experts from each scientific society involved voted telematically on each of the recommendations. To classify the degree of agreement, an analogue classification system was chosen that was easy and intuitive to use and that clearly stated whether the each NIRS intervention should be applied, could be applied, or should not be applied.


Subject(s)
Noninvasive Ventilation , Respiratory Insufficiency , Adult , Cannula , Child , Consensus , Humans , Infant, Newborn , Oxygen , Pyruvates , Respiratory Insufficiency/therapy , Societies, Scientific
13.
Med Intensiva (Engl Ed) ; 45(5): 298-312, 2021.
Article in English, Spanish | MEDLINE | ID: mdl-33309463

ABSTRACT

Non-invasive respiratory support (NIRS) in adult, pediatric, and neonatal patients with acute respiratory failure (ARF) comprises two treatment modalities, non-invasive mechanical ventilation (NIMV) and high-flow nasal cannula (HFNC) therapy. However, experts from different specialties disagree on the benefit of these techniques in different clinical settings. The objective of this consensus was to develop a series of good clinical practice recommendations for the application of non-invasive support in patients with ARF, endorsed by all scientific societies involved in the management of adult and pediatric/neonatal patients with ARF. To this end, the different societies involved were contacted, and they in turn appointed a group of 26 professionals with sufficient experience in the use of these techniques. Three face-to-face meetings were held to agree on recommendations (up to a total of 71) based on a literature review and the latest evidence associated with 3 categories: indications, monitoring and follow-up of NIRS. Finally, the experts from each scientific society involved voted telematically on each of the recommendations. To classify the degree of agreement, an analogue classification system was chosen that was easy and intuitive to use and that clearly stated whether the each NIRS intervention should be applied, could be applied, or should not be applied.

15.
Aerosp Med Hum Perform ; 91(4): 311-312, 2020 04 01.
Article in English | MEDLINE | ID: mdl-32493551
16.
Ann Oncol ; 31(10): 1366-1375, 2020 10.
Article in English | MEDLINE | ID: mdl-32569727

ABSTRACT

BACKGROUND: Accumulating evidence has identified Fusobacterium as an important pathogenic gut bacterium associated with colorectal cancer. Nevertheless, only limited data exist about the role of this bacterium in locally advanced rectal cancer (LARC). In this study, we quantified Fusobacterium nucleatum in untreated and post-neoadjuvant chemoradiotherapy (nCRT) samples from LARC patients and investigated its association with therapy response and survival. PATIENTS AND METHODS: A total of 254 samples from 143 patients with rectal adenocarcinomas were analyzed for the presence and abundance of F. nucleatum using RNA in situ hybridization and digital image analysis. Assay accuracy was determined using infected cell lines and tumor samples with available quantitative PCR data. We studied the impact of F. nucleatum load on pathologic complete response and relapse-free survival. Treatment-induced changes were evaluated in paired pre- and post-nCRT samples (n = 71). Finally, tumor microenvironment changes during nCRT were assessed in paired samples (n = 45) by immune contexture analysis. RESULTS: F. nucleatum tissue levels by RNA in situ hybridization strongly correlated with quantitative PCR (r = 0.804, P < 0.001). F. nucleatum abundance was higher in untreated [median, 7.4; 95% confidence interval (3.7-16.2)] compared with treated [median, 1.6; 95% confidence interval (1.3-2.4)] tumors (P <0.001) with 58% (73/126) and 26% (22/85) positive tumors, respectively (P < 0.001). Baseline F. nucleatum levels were not associated with pathologic complete response. F. nucleatum positivity after nCRT, but not baseline status, significantly increased risk of relapse [hazard ratio = 7.5, 95% confidence interval (3.0-19.0); P < 0.001]. Tumors that turned F. nucleatum-negative after nCRT had a strong increase in CD8+ T cells post-nCRT (P < 0.001), while those that persisted F. nucleatum-positive after nCRT lacked CD8+ T cells induction in post-nCRT samples compared with baseline (P = 0.69). CONCLUSION: F. nucleatum persistence post-nCRT is associated with high relapse rates in LARC, potentially linked to suppression of immune cytotoxicity.


Subject(s)
Fusobacterium nucleatum , Rectal Neoplasms , Chemoradiotherapy , Humans , Neoadjuvant Therapy , Neoplasm Recurrence, Local , Rectal Neoplasms/therapy , Rectum , Tumor Microenvironment
17.
Rev. patol. respir ; 23(2): 72-74, abr.-jun. 2020. ilus
Article in Spanish | IBECS | ID: ibc-197584

ABSTRACT

Solobacterium moorei es un bacilo grampositivo anaerobio no esporulado colonizador de flora oral y digestiva. Está asociado principalmente con infecciones periodontales aunque también se han descrito casos de infecciones de partes blandas o ginecológicas y casos de bacteriemia en pacientes inmunodeprimidos. Su perfil de sensibilidad es aún controvertido, habiéndose objetivado efectividad frente a betalactámicos, vancomicina, quinolonas y metronidazol. Informamos del caso de un paciente con diagnóstico de neumonía necrotizante por Solobacterium moorei, tratándose de un microorganismo poco común en esta clase de patología


Solobacterium moorei is a non-sporulated anaerobic gram-positive bacillus colonizer of oral and digestive flora. It is mainly associated with periodontal infections although there have also been reports of soft tissue or gynecological infections and cases of bacteremia in immunosuppressed patients. Its sensitivity profile is still controversial, with effectiveness against beta-lactams, vancomycin, quinolones and metronidazole being observed. We report the case of a patient with a diagnosis of necrotizing pneumonia by Solobacterium moorei, being a rare microorganism in this kind of pathology


Subject(s)
Humans , Male , Adult , Gram-Positive Bacterial Infections/diagnostic imaging , Gram-Positive Bacterial Infections/microbiology , Pneumonia, Necrotizing/diagnostic imaging , Pneumonia, Necrotizing/microbiology , Gram-Positive Bacteria/isolation & purification
18.
Pharm Res ; 37(6): 107, 2020 May 27.
Article in English | MEDLINE | ID: mdl-32462273

ABSTRACT

PURPOSE: Desorption electrospray ionization mass spectrometry imaging (DESI-MSI) coupled with gas-phase ion mobility spectrometry was used to characterize the drug distribution in polymeric implants before and after exposure to accelerated in vitro release (IVR) media. DESI-MSI provides definitive chemical identification and localization of formulation components, including 2D chemical mapping of individual components with essentially no sample preparation. METHODS: Polymeric implants containing 40% (w/w) entecavir and poly(D,L-lactide) (PLA) were prepared and then exposed to either acidified PBS (pH 2.5) or MeOH:H2O (50:50, v/v) medias during a 7-day IVR test using continuous flow-through (CFT) cell dissolution. The amount of drug released from the polymer matrix during the 7-day IVR test was monitored by online-ultraviolet spectroscopy (UV) and HPLC-UV. After that period, intact implants and radial sections of implants were analyzed by DESI-MSI with ion mobility spectrometry. The active ingredient along with impurities and contaminants were used to generate chemical maps before and after exposure to the release medias. RESULTS: Bi-phasic release profiles were observed for implants during IVR release using both medias. During the second phase of release, implants exposed to PBS, pH 2.5, released the entecavir faster than the implants exposed to MeOH:H2O (50:50, v/v). Radial images of the polymer interior show that entecavir is localized along the central core of the implant after exposure to MeOH:H2O (50:50, v/v) and that the drug is more uniformly distributed throughout the implant after exposure to acidified PBS (pH 2.5). CONCLUSIONS: DESI-MSI coupled with ion mobility analysis produced chemical images of the drug distribution on the exterior and interior of cylindrical polymeric implants before and after exposure to various release medias. These results demonstrated the utility of this technique for rapid characterization of drug and impurity/degradant distribution within polymeric implants with direct implications for formulation development as well as analytical method development activities for various solid parenteral and oral dosage forms. These results are especially meaningful since samples were analyzed with essentially no preparative procedures.


Subject(s)
Chemistry, Pharmaceutical/methods , Drug Implants/chemistry , Drug Liberation , Polymers/chemistry , Spectrometry, Mass, Electrospray Ionization , Drug Implants/pharmacokinetics
19.
Aerosp Med Hum Perform ; 91(5): 385-386, 2020 May 01.
Article in English | MEDLINE | ID: mdl-32327010
20.
Aerosp Med Hum Perform ; 91(3): 121-122, 2020 Mar 01.
Article in English | MEDLINE | ID: mdl-32164799
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