Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 98
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Small ; 20(3): e2303773, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37702145

RESUMEN

Designing suitable nanomaterials is an ideal strategy to enable early diagnosis and effective treatment of diseases. Carbon dots (CDs) are luminescent carbonaceous nanoparticles that have attracted considerable attention. Through facile synthesis, they process properties including tunable light emission, low toxicity, and light energy transformation, leading to diverse applications as optically functional materials in biomedical fields. Recently, their potentials have been further explored, such as enzyme-like activity and ability to promote osteogenic differentiation. Through refined synthesizing strategies carbon dots, a rich treasure trove for new discoveries, stand a chance to guide significant development in biomedical applications. In this review, the authors start with a brief introduction to CDs. By presenting mechanisms and examples, the authors focus on how they can be used in diagnosing and treating diseases, including bioimaging failure of tissues and cells, biosensing various pathogenic factors and biomarkers, tissue defect repair, anti-inflammation, antibacterial and antiviral, and novel oncology treatment. The introduction of the application of integrated diagnosis and treatment follows closely behind. Furthermore, the challenges and future directions of CDs are discussed. The authors hope this review will provide critical perspectives to inspire new discoveries on CDs and prompt their advances in biomedical applications.


Asunto(s)
Nanopartículas , Puntos Cuánticos , Carbono , Medicina de Precisión , Osteogénesis
2.
Neurosurg Rev ; 47(1): 310, 2024 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-38985351

RESUMEN

The relationship between in-hospital hemoglobin (Hb) drift and outcomes in patients undergoing surgical clipping for aneurysmal subarachnoid hemorrhage (aSAH) is not well studied. This study aims to investigate the association between Hb drift and mortality in this patient population. We conducted a cohort study encompassing adult patients diagnosed with aSAH who were admitted to a university hospital. These patients were stratified into distinct groups based on their Hb drift levels. We employed logistic and Cox proportional hazard models to assess the relationship between Hb drift and outcomes. Additionally, propensity score matching (PSM) was utilized to ensure comparability between patient groups. The discriminative performance of different models was evaluated using C-statistics, integrated discrimination improvement (IDI), and net reclassification improvement (NRI). Overall, our cohort comprised 671 patients, of whom 165 (24.6%) demonstrated an in-hospital Hb drift exceeding 25%. The analyses revealed elevated Hb drift was independently associated with higher likelihood of follow-up mortality (aOR: 3.29, 95% CI: 1.65 to 6.56; P = 0.001) and in-hospital mortality (aOR: 3.44, 95% CI: 1.55 to 7.63; P = 0.002). PSM analysis yielded similar results. Additionally, patients with Hb drift exhibited a notable decrease in survival rate compared to those without Hb drift (aHR: 3.99, 95% CI 2.30 to 6.70; P < 0.001). Furthermore, the inclusion of Hb drift significantly improved the C-statistic (P = 0.037), IDI (2.78%; P = 0.004) and NRI metrics (41.86%; P < 0.001) for mortality prediction. In summary, our results highlight that an in-hospital Hb drift exceeding 25% serves as an independent predictor of mortality in patients who have undergone surgical clipping for aSAH.


Asunto(s)
Hemoglobinas , Hemorragia Subaracnoidea , Humanos , Hemorragia Subaracnoidea/cirugía , Masculino , Femenino , Hemoglobinas/análisis , Persona de Mediana Edad , Adulto , Anciano , Mortalidad Hospitalaria , Resultado del Tratamiento , Estudios de Cohortes , Procedimientos Neuroquirúrgicos/métodos
3.
Neurocrit Care ; 2024 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-38565835

RESUMEN

BACKGROUND: There are knowledge gaps regarding the relative efficacy of statins for aneurysmal subarachnoid hemorrhage (aSAH). This study aims to examine the comparative effectiveness and determine the ranking of different statins with network meta­analysis in patients with aSAH. METHODS: MEDLINE, Embase, Pubmed, and Cochrane Central Register of Controlled Trials were searched from database inception until December 15, 2022. Outcomes included delayed cerebral ischemia (DCI), functional recovery, and mortality. Relative risk (RRs) ratios and associated 95% confidence intervals (CIs) were estimated. The values derived from surface under the cumulative ranking curve were obtained to rank the treatment hierarchy in the analysis. RESULTS: We identified 13 trials involving 1,885 patients. Atorvastatin 20 mg (RR 0.68, 95% CI 0.53-0.86), pravastatin 40 mg (RR 0.51, 95% CI 0.31-0.77), and simvastatin 80 mg (RR 0.54, 95% CI 0.40-0.70) were superior to the placebo in preventing DCI. Additionally, simvastatin 80 mg (RR 0.60, 95% CI 0.42-0.84) and pravastatin 40 mg (RR 0.56, 95% CI 0.32-0.93) were associated with a decreased risk of DCI than simvastatin 40 mg. Comparisons across treatment durations suggested that short-term (RR 0.62, 95% CI 0.50-0.76) statin therapy reduced risk of DCI. CONCLUSIONS: Simvastatin 80 mg might be the most effective intervention in reducing DCI. Additionally, short-term therapy might provide more benefits. Further research with longer follow-up is warranted to validate the current findings in patients with aSAH who are at high risk of DCI.

4.
Angew Chem Int Ed Engl ; 62(17): e202218391, 2023 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-36808675

RESUMEN

Represented herein is the first example of N-radical generation direct from N-H bond activation under mild and redox-neutral conditions. The in situ generated N-radical intercepts a reduced heteroarylnitrile/aryl halide for C-N bond formation under visible-light irradiation of quantum dots (QDs). A series of aryl and alkylamines with heteroarylnitriles/aryl halides exhibit high efficiency, site-selectivity and good functional-group tolerance. Moreover, consecutive C-C and C-N bond formation using benzylamines as substrates is also achieved, producing N-aryl-1,2-diamines with H2 evolution. The redox-neutral conditions, broad substrate scope, and efficiency of N-radical formation are advantageous for organic synthesis.

5.
Angew Chem Int Ed Engl ; 62(29): e202305679, 2023 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-37218528

RESUMEN

The activation of the α-C-H bond of ketones typically requires an amine and a directing group to guide the reaction selectivity in amine-catalysis carbonyl chemistry. For an α-C-H bond activation of ketone, directing groups are also required to control the reaction selectivity. Reported herein is the first α-alkylation of cyclic ketones in the absence of an amine catalyst and directing group. 1 H NMR, XPS, EPR studies and DFT calculations indicate that an α-carbon radical intermediate is formed through direct and selective activation of the inert α-C-H bond of ketones chelating on the surface of colloidal quantum dots (QDs). Such an interaction is essential for weakening the C-H bond, as exemplified, using CdSe QDs as the sole photocatalyst to execute α-C-H alkylation of cyclic ketones under visible-light irradiation. Without an amine catalyst and directing group, the high step- and atom-economy transformation under redox-neutral condition opens a new way for α-C-H functionalization of ketones in carbonyl chemistry.

6.
Metab Eng ; 74: 1-10, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36041638

RESUMEN

Endogenous metabolic pathways in microbial cells are usually precisely controlled by sophisticated regulation networks. However, the lack of such regulations when introducing heterologous pathways in microbial hosts often causes unbalanced enzyme expression and carbon flux distribution, hindering the construction of highly efficient microbial biosynthesis systems. Here, using naringenin as the target compound, we developed an Autonomous Cascaded Artificial Dynamic (AutoCAD) regulation system to automatically coordinate the pathway expression and redirect carbon fluxes for enhanced naringenin production. The AutoCAD regulation system, consisting of both intermediate-based feedforward and product-based feedback control genetic circuits, resulted in a 16.5-fold increase in naringenin titer compared with the static control. Fed-batch fermentation using the strain with AutoCAD regulation further enhanced the naringenin titer to 277.2 mg/L. The AutoCAD regulation system, with intermediate-based feedforward control and product-triggered feedback control, provides a new paradigm of developing complicated cascade dynamic control to engineer heterologous pathways.


Asunto(s)
Ingeniería Metabólica , Redes y Vías Metabólicas , Ingeniería Metabólica/métodos , Fermentación
7.
Angew Chem Int Ed Engl ; 61(10): e202116421, 2022 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-34985181

RESUMEN

Site-selective N-1 and C-3 arylation of indole has been sought after because of the prevalent application of arylindoles and the intricate reactivities associated with the multiple sites of the N-unsubstituted indole. Represented herein is the first regioselective heteroarylation of indole via a radical-radical cross-coupling by visible-light irradiation. Steady and time-resolved spectroscopic and computational studies revealed that the hydrogen-bonding interaction of organic base and its conjugated acid, namely with indole and heteroarylnitrile, determined the reaction pathway, which underwent either proton-coupled electron-transfer or energy-transfer for the subsequent radical-radical cross-coupling, leading to the regioselective formation of C-3 and N-1 heteroarylation of indoles, respectively. The parallel methodologies for regioisomeric N-1 and C-3 heteroaryl indoles with good functional group compatibility could be applied to large-scale synthesis and late-stage derivatization of bioactive compounds under extremely mild reaction conditions.

8.
Neuroimage ; 238: 118260, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34118393

RESUMEN

Revealing the structural and functional change of microvasculature is essential to match vascular response with neuronal activities in the investigation of neurovascular coupling. The increasing use of rhesus models in fundamental and clinical studies of neurovascular coupling presents an emerging need for a new imaging modality. Here we report a structural and functional cerebral vascular study of rhesus monkeys using an ultrafast, portable, and high resolution photoacoustic microscopic system with a long working distance and a special scanning mechanism to eliminate the relative displacement between the imaging interface and samples. We derived the structural and functional response of the cerebral vasculature to the alternating normoxic and hypoxic conditions by calculating the vascular diameter and functional connectivity. Both vasodilatation and vasoconstriction were observed in hypoxia. In addition to the change of vascular diameter, the decrease of functional connectivity is also an important phenomenon induced by the reduction of oxygen ventilatory. These results suggest that photoacoustic microscopy is a promising method to study the neurovascular coupling and cerebral vascular diseases due to the advanced features of high spatiotemporal resolution, excellent sensitivity to hemoglobin, and label-free imaging capability of observing hemodynamics.


Asunto(s)
Corteza Cerebral/diagnóstico por imagen , Circulación Cerebrovascular/fisiología , Hemodinámica/fisiología , Microscopía/métodos , Animales , Macaca mulatta , Acoplamiento Neurovascular/fisiología , Técnicas Fotoacústicas , Vasoconstricción/fisiología , Vasodilatación/fisiología
9.
Appl Microbiol Biotechnol ; 105(13): 5449-5460, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34223949

RESUMEN

Genomes of hyperthermophiles are facing a severe challenge due to increased deamination rates of cytosine induced by high temperature, which could be counteracted by base excision repair mediated by uracil DNA glycosylase (UDG) or other repair pathways. Our previous work has shown that the two UDGs (Tba UDG247 and Tba UDG194) encoded by the genome of the hyperthermophilic euryarchaeon Thermococcus barophilus Ch5 can remove uracil from DNA at high temperature. Herein, we provide evidence that Tba UDG247 is a novel bifunctional glycosylase which can excise uracil from DNA and further cleave the phosphodiester bo nd of the generated apurinic/apyrimidinic (AP) site, which has never been described to date. In addition to cleaving uracil-containing DNA, Tba UDG247 can also cleave AP-containing ssDNA although at lower efficiency, thereby suggesting that the enzyme might be involved in repair of AP site in DNA. Kinetic analyses showed that Tba UDG247 displays a faster rate for uracil excision than for AP cleavage, thus suggesting that cleaving AP site by the enzyme is a rate-limiting step for its bifunctionality. Phylogenetic analysis showed that Tba UDG247 is clustered on a separate branch distant from all the reported UDGs. Overall, we designated Tba UDG247 as the prototype of a novel family of bifunctional UDGs. KEY POINTS: We first reported a novel DNA glycosylase with bifunctionality. Tba UDG247 possesses an AP lyase activity.


Asunto(s)
Thermococcus , Reparación del ADN , Filogenia , Thermococcus/genética , Thermococcus/metabolismo , Uracilo , Uracil-ADN Glicosidasa/genética , Uracil-ADN Glicosidasa/metabolismo
10.
Opt Express ; 28(6): 9002-9013, 2020 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-32225514

RESUMEN

In this study, we evaluate the penetration capability of light in visible, near-infrared-I (NIR-I) and near-infrared-II (NIR-II) optical windows for photoacoustic macroscale imaging inside 9 biological tissues with three typical penetration depths. An acoustic resolution photoacoustic microscopy is designed to guarantee the consistent experiment conditions except excitation wavelength. Experimental results show that short NIR-II (1000-1150 nm) shows the best performance inside kidney, spleen and liver tissues at all depths, while NIR-I (700-1000 nm) works better for muscle, stomach, heart and brain tissues, especially in deep imaging. This study proposes the optimal selection of illumination wavelengths for photoacoustic macroscale imaging in rat organs, which enables the best signal-to-noise ratio (SNR) of the observed target.


Asunto(s)
Imagen Óptica/métodos , Técnicas Fotoacústicas/métodos , Animales , Carbono , Femenino , Rayos Infrarrojos , Tinta , Imagen Óptica/estadística & datos numéricos , Fenómenos Ópticos , Especificidad de Órganos , Técnicas Fotoacústicas/estadística & datos numéricos , Ratas , Ratas Sprague-Dawley , Relación Señal-Ruido
11.
J Nat Prod ; 83(9): 2647-2654, 2020 09 25.
Artículo en Inglés | MEDLINE | ID: mdl-32816473

RESUMEN

Eight new dioxopiperazine alkaloids, penispirozines A-H (1-8), were discovered from the mangrove-derived fungus Penicillium janthinellum HDN13-309. Their structures were elucidated by spectroscopic analysis, TDDFT-ECD calculations, and X-ray diffraction. Compound 1 had an unusual pyrazino[1,2]oxazadecaline coupled with a thiophane ring system, and compound 2 possessed a 6/5/6/5/6 pentacyclic ring system with two rare spirocyclic centers. Interestingly, compounds 3-8 were distinguished by not only the existence of a spiro-thiophane or spiro-furan ring system but also the chirality of the pentacyclic moiety. Compounds 3 and 4 increased the expression of the two relevant phase II detoxifying enzymes SOD2 and HO-1 at 10 µM.


Asunto(s)
Alcaloides/química , Avicennia/microbiología , Penicillium/química , Cristalografía por Rayos X , Inducción Enzimática/efectos de los fármacos , Fermentación , Hemo-Oxigenasa 1/biosíntesis , Espectroscopía de Resonancia Magnética , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Superóxido Dismutasa/biosíntesis , Difracción de Rayos X
12.
J Nat Prod ; 83(10): 2996-3003, 2020 10 23.
Artículo en Inglés | MEDLINE | ID: mdl-32966070

RESUMEN

This project was focused on the discovery of novel compounds that promote endogenous ß-cell regeneration. Screening of extracts identified the fungus Stachybotrys chartarum as a promising candidate. After fermentation and extraction of S. chartarum, we isolated five new prenylated xanthones, namely, staprexanthones A-E (1-5), with staprexanthone A (1) being the first natural xanthone bearing a rare 4,5-dimethyl-1,3-dioxolane moiety. Compounds 1, 2, and 5 significantly increased ß-cell numbers in vivo in a zebrafish model. Further analysis revealed that 2 and 5 promoted ß-cell mass expansion by increasing proliferation of existing ß-cells though promotion of cell-cycle progression at the G1/S transition. These findings indicate that prenylated xanthones are potential new drug leads for antidiabetes therapy by stimulating ß-cell regeneration.


Asunto(s)
Stachybotrys , Xantonas , Ciclo Celular , Proliferación Celular , Hongos , Estructura Molecular , Prenilación
13.
Appl Microbiol Biotechnol ; 103(9): 3795-3806, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30919103

RESUMEN

DNA ligases are essential enzymes for DNA replication, repair, and recombination processes by catalyzing a nick-joining reaction in double-stranded DNA. The genome of the hyperthermophilic euryarchaeon Thermococcus barophilus Ch5 encodes a putative ATP-dependent DNA ligase (Tba ligase). Herein, we characterized the biochemical properties of the recombinant Tba ligase. The enzyme displays an optimal nick-joining activity at 65-70 °C and retains its DNA ligation activity even after heated at 100 °C for 2 h, suggesting the enzyme is a thermostable DNA ligase. The enzyme joins DNA over a wide pH spectrum ranging from 5.0-10.0, and its optimal pH is 6.0-9.0. Tba ligase activity is dependent on a divalent metal ion: Mn2+, Mg2+, or Ca2+ is an optimal ion for the enzyme activity. The enzyme activity is inhibited by NaCl with high concentrations. Tba ligase is ATP-dependent and can also use UTP as a weak cofactor; however, the enzyme with high concentrations could function without an additional nucleotide cofactor. Mass spectrometric result shows that the residue K250 of Tba ligase is AMPylated, suggesting that the enzyme is bound to AMP. The substitution of K250 of Tba ligase with Ala abolishes the enzyme activity. In addition, the mismatches at the first position 3' to the nick suppress Tba ligase activity more than those at the first position 5' to the nick. The enzyme also discriminates more effectively mismatches at 3' to the nick than those at 5' to the nick in a ligation cycling reaction, suggesting that the enzyme might have potential application in single nucleotide polymorphism.


Asunto(s)
Proteínas Arqueales/química , ADN Ligasas/química , Thermococcus/enzimología , Proteínas Arqueales/genética , Proteínas Arqueales/metabolismo , Clonación Molecular , ADN/genética , ADN/metabolismo , ADN Ligasas/genética , ADN Ligasas/metabolismo , Estabilidad de Enzimas , Calor , Concentración de Iones de Hidrógeno , Especificidad por Sustrato , Thermococcus/química , Thermococcus/genética
14.
Med Sci Monit ; 23: 3240-3246, 2017 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-28671939

RESUMEN

BACKGROUND COL1A2, which encodes collagen type I alpha2, has long been suggested to be a potential positional and functional candidate gene for intracranial aneurysm. We performed a meta-analysis to assess the association between COL1A2 rs42524 polymorphism and the risk of intracranial aneurysm. MATERIAL AND METHODS We conducted a systematic search for relevant literature from the following databases up to 22 July 2016: PubMed, Embase, Web of Science, and China National Knowledge Infrastructure. The strength of association between gene and disease was estimated using odds ratios (ORs) with 95% confidence intervals (CIs) under 5 genetic models. RESULTS A total of 6 qualified studies were enrolled in this meta-analysis. Pooling results indicated a significant association between COL1A2 rs42524 polymorphism and intracranial aneurysm risk under 4 genetic models (C vs. G: OR=1.74, 95%CI=1.34-2.26; GC vs. GG: OR=1.81, 95%CI=1.37-2.41; CC+GC vs. GG: OR=1.74, 95%CI=1.28-2.36; CC vs. GC+GG: OR=1.76, 95%CI=1.02-3.04). This association was still robust when stratified by ethnicity, intracranial aneurysm type, or Hardy-Weinberg Equilibrium, which was stronger in Asian than in Caucasians. No publication bias was observed. CONCLUSIONS This meta-analysis suggests COL1A2 rs42524 is a significant risk factor for IA susceptibility, with an especially strong effect in Asian people. Further larger-scale epidemiological studies among different ethnicities are warranted to confirm our findings.


Asunto(s)
Colágeno Tipo I/genética , Predisposición Genética a la Enfermedad , Aneurisma Intracraneal/genética , Polimorfismo de Nucleótido Simple/genética , Estudios de Asociación Genética , Humanos , Sesgo de Publicación , Factores de Riesgo
15.
J Craniofac Surg ; 28(3): e287-e289, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28468224

RESUMEN

INTRODUCTION: This study reports a rare patient of a rapid spontaneously resolving acute subdural hematoma. In addition, an analysis of potential clues for the phenomenon is presented with a review of the literature. PATIENT PRESENTATION: A 1-year-and-2-month-old boy fell from a height of approximately 2 m. The patient was in a superficial coma with a Glasgow Coma Scale of 8 when he was transferred to the authors' hospital. Computed tomography revealed the presence of an acute subdural hematoma with a midline shift beyond 1 cm. His guardians refused invasive interventions and chose conservative treatment. Repeat imaging after 15 hours showed the evident resolution of the hematoma and midline reversion. Progressive magnetic resonance imaging demonstrated the complete resolution of the hematoma, without redistribution to a remote site. CONCLUSIONS: Even though this phenomenon has a low incidence, the probability of a rapid spontaneously resolving acute subdural hematoma should be considered when patients present with the following characteristics: children or elderly individuals suffering from mild to moderate head trauma; stable or rapidly recovered consciousness; and simple acute subdural hematoma with a moderate thickness and a particularly low-density band in computed tomography scans.


Asunto(s)
Traumatismos Craneocerebrales/complicaciones , Hematoma Subdural Agudo/diagnóstico , Hematoma Subdural Agudo/etiología , Humanos , Lactante , Imagen por Resonancia Magnética , Masculino , Remisión Espontánea , Factores de Tiempo , Tomografía Computarizada por Rayos X
16.
BMC Neurol ; 16: 1, 2016 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-26727957

RESUMEN

BACKGROUND: For cases of severe traumatic brain injury, during primary operation, neurosurgeons usually face a dilemma of whether or not to remove the bone flap after mass lesion evacuation. Decompressive craniectomy, which involves expansion of fixed cranial cavity, is used to treat intra-operative brain swelling and post-operative malignant intracranial hypertension. However, due to indefinite indication, the decision to perform this procedure heavily relies on personal experiences. In addition, decompressive craniectomy is associated with various complications, and the procedure lacks strong evidence of better outcomes. In the present study, we designed a prospective, randomized, controlled trial to clarify the effect of decompressive craniectomy in severe traumatic brain injury patients with mass lesions. METHODS: PRECIS is a prospective, randomized, assessor-blind, single center clinical trial. In this trial, 336 patients with traumatic mass lesions will be randomly allocated to a therapeutic decompressive craniectomy group or a prophylactic decompressive craniectomy group. In the therapeutic decompressive craniectomy group, the bone flap will be removed or replaced depending on the emergence of brain swelling. In the prophylactic decompressive craniectomy group, the bone flap will be removed after mass lesion evacuation. A stepwise management of intracranial pressure will be provided according to the Brain Trauma Foundation guidelines. Salvage decompressive craniectomy will be performed for craniotomy patients once there is evidence of imaging deterioration and post-operative malignant intracranial hypertension. Participants will be assessed at 1, 6 and 12 months after randomization. The primary endpoint is favorable outcome according to the Extended Glasgow Outcome Score (5-8) at 12 months. The secondary endpoints include quality of life measured by EQ-5D, mortality, complications, intracranial pressure and cerebral perfusion pressure control and incidence of salvage craniectomy in craniotomy patients at each investigation time point. DISCUSSION: This study will provide evidence to optimize primary decompressive craniectomy application and assess outcomes and risks for mass lesions in severe traumatic brain injury. TRIAL REGISTRATION: ISRCTN20139421.


Asunto(s)
Lesiones Encefálicas/cirugía , Protocolos Clínicos , Craniectomía Descompresiva/métodos , Evaluación de Resultado en la Atención de Salud/métodos , Ensayos Clínicos Controlados Aleatorios como Asunto/métodos , Proyectos de Investigación , Adolescente , Adulto , Anciano , Lesiones Encefálicas/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Índice de Severidad de la Enfermedad , Adulto Joven
17.
J Nanosci Nanotechnol ; 16(6): 5470-9, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27427586

RESUMEN

Delivery of proteins and peptides with excellent bioactivity and controlled release still is a great challenge nowadays. In this study, a pH-responsive delivery system obtained by anchoring 8-nm Fe3O4 nanoparticles (NPs) onto SBA-15 supports with a particle diameter in the range of 0.6-1 µm and a pore size of 6.2 nm was synthesized and investigated. The pH-stimulative response is based on the interaction between the tris(aminomethyl)ethane (TAE) groups anchored onto the pore outlet of mesoporous silica scaffolds and the carboxybenzaldehyde (CBA) groups coated on the Fe3O4 NPs, which can lead to a rapid release under the acid condition (pH = 5) and a zero release with the increase of pH value (pH = 7.4). With BMP-2 as a model protein, this Fe3O4 nanopartilces-capped mesoporous silica showed a rapid response to the change of pH for protein delivery. Furthermore, the released BMP-2 could still maintain its bioactivity and induce the osteoblast differentiation of BMSCs. Besides, the magnetic orientation mainly attributes to the Fe3O4 NPs served as the nanocaps. The excellent bio-compatibility is demonstrated by the MTT assay on BMSCs model cells. These results show that Fe3O4 NPs-capped SBA-15 materials have an effective load for large molecule size proteins, such as BMP-2, and show an excellent applied prospect in pH-responsive controlled release system.


Asunto(s)
Proteína Morfogenética Ósea 2/química , Portadores de Fármacos/química , Nanopartículas de Magnetita/química , Dióxido de Silicio/química , Adamantano/química , Fosfatasa Alcalina/metabolismo , Portadores de Fármacos/farmacología , Liberación de Fármacos , Concentración de Iones de Hidrógeno , Ensayo de Materiales , Porosidad
18.
BMC Surg ; 15: 111, 2015 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-26467905

RESUMEN

BACKGROUND: The risk factors of predicting the need for postoperative decompressive craniectomy due to intracranial hypertension after primary craniotomy remain unclear. This study aimed to investigate the value of intraoperative intracranial pressure (ICP) monitoring in predicting re-operation using salvage decompressive craniectomy (SDC). METHODS: From January 2008 to October 2014, we retrospectively reviewed 284 patients with severe traumatic brain injury (STBI) who underwent craniotomy for mass lesion evacuation without intraoperative brain swelling. Intraoperative ICP was documented at the time of initial craniotomy and then again after the dura was sutured. SDC was used when postoperative ICP was continually higher than 25 mmHg for 1 h without a downward trend. Univariate and multivariate analyses were applied to both initial demographic and radiographic features to identify risk factors of SDC requirement. RESULTS: Of 284, 41 (14.4%) patients who underwent SDC had a higher Initial ICP than those who didn't (38.1 ± 9.2 vs. 29.3 ± 8.1 mmHg, P < 0.001), but there was no difference in ICP after the dura was sutured. The factors which have significant effects on SDC are higher initial ICP [odds ratio (OR): 1.100, 95% confidence interval (CI): 1.052-1.151, P < 0.001], older age (OR: 1.039, 95% CI: 1.002-1.077, P = 0.039), combined lesions (OR: 3.329, 95% CI: 1.199-9.244, P = 0.021) and early hypotension (OR: 2.524, 95% CI: 1.107-5.756, P = 0.028). The area under the curve of multivariate regression model was 0.771. CONCLUSIONS: The incidence of re-operation using SDC after craniotomy was 14.4%. The independent risk factors of SDC requirement are initial ICP, age, early hypotension and combined lesions.


Asunto(s)
Lesiones Encefálicas/cirugía , Craniectomía Descompresiva/métodos , Hipertensión Intracraneal/cirugía , Presión Intracraneal/fisiología , Monitoreo Intraoperatorio/métodos , Terapia Recuperativa/métodos , Adolescente , Adulto , Anciano , Lesiones Encefálicas/complicaciones , Lesiones Encefálicas/fisiopatología , China/epidemiología , Craneotomía/métodos , Femenino , Humanos , Incidencia , Hipertensión Intracraneal/epidemiología , Hipertensión Intracraneal/etiología , Masculino , Persona de Mediana Edad , Periodo Posoperatorio , Reoperación , Estudios Retrospectivos , Factores de Riesgo , Adulto Joven
19.
RSC Adv ; 14(9): 6462-6469, 2024 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-38384721

RESUMEN

This perspective article describes a new dual carbon fiber battery, where both the cathode and anode are made of carbon fiber. The dual carbon fiber battery combines the advantages of carbon fiber and dual graphite batteries, including a higher working potential compared to lithium-ion batteries, a high areal capacity, and easy access due to the mature manufacturing technology of carbon fibers. In this article, we discuss the mechanism, current status and potential application areas of dual carbon fiber batteries. Additionally, we highlight the challenges and prospects of these batteries.

20.
Aging (Albany NY) ; 16(4): 3231-3240, 2024 02 08.
Artículo en Inglés | MEDLINE | ID: mdl-38334965

RESUMEN

PURPOSE: We studied the functions of sodium tanshinone IIA sulfonate (TSA) in inducing tumor growth in obstructive sleep apnea (OSA)-mimicking intermittent hypoxia (IH) xenograft mice and the underlying potential molecular mechanism. METHODS: RNA sequencing was conducted to screen the differentially expressed microRNAs in cell lines exposed to IH with or without TSA treatment. As part of the 5-week in vivo study, we treated xenograft mice with 8-h IH once daily. TSA and miR-138 inhibitors or mimics were administrated appropriately. In addition, we performed real-time quantitative polymerase chain reaction (RT-PCR), Western blotting, enzyme-linked immunosorbent assay (ELISA), immunohistochemistry (IHC), microvessel density (MVD), and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assays. RESULTS: RNA sequencing and RT-PCR results demonstrated that TSA increased the levels of miR-138 under IH conditions in vitro. TSA reduced the IH-stimulated high levels of hypoxia-induced factor-1α and vascular endothelial growth factor. Furthermore, IH contributed to high tumor migration, invasion, MVD, and low apoptosis. TSA attenuated IH-mediated tumor proliferation, migration, invasion, MVD, and increased apoptosis, whereas miR-138 inhibitor interrupted the effect of TSA on treating IH-induced tumor behaviors. CONCLUSIONS: OSA mimicking IH facilitates tumor growth and reduces miR-138 levels. TSA inhibits IH-induced tumor growth by upregulating the expression of miR-138.


Asunto(s)
MicroARNs , Neoplasias , Fenantrenos , Apnea Obstructiva del Sueño , Humanos , Ratones , Animales , Regulación hacia Arriba , Xenoinjertos , Factor A de Crecimiento Endotelial Vascular/metabolismo , Hipoxia/metabolismo , MicroARNs/genética
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA