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1.
Calcif Tissue Int ; 114(3): 237-245, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38051322

RESUMEN

This study aimed to examine the association between sex hormone-binding globulin (SHBG) and osteoporosis through a cross-sectional study and a two-sample bidirectional Mendelian randomization (MR). We used the National Health and Nutrition Examination Survey (NHANES) 2013-2014 and 2015-2016 data, with exposure as serum SHBG and outcome as osteoporosis and performed multivariate logistic regression to test the correlation between SHBG and osteoporosis. To determine the causal relationship between SHBG and osteoporosis, a two-sample bidirectional MR was employed. The genome-wide association study (GWAS) dataset for SHBG (n = 189,473) was obtained from the IEU database, and the GWAS dataset for osteoporosis (n = 212,778) was obtained from the FinnGen bioBank. The principal MR technique was inverse-variance weighting (IVW). In MR analyses, the MR-Egger intercept and Cochran Q test were used to detect multiple validity and horizontal heterogeneity. 1249 older adult participants (age ≥ 60) were involved in the cross-sectional study, including 113 osteoporosis cases. We identified a significant relationship between circulating SHBG concentration and osteoporosis risk [OR 3.963, 95% CI (2.095-7.495), P < 0.05]. Subgroup analysis indicated that SHBG was closely linked to the risk of osteoporosis in the female population [OR 1.008, 95% CI (1.002-1.013), P = 0.005] but not in males (P = 0.065). In addition, The IVW approach suggested a causal connection between SHBG and increased osteoporosis risk [OR 1.479, 95% CI (1.144-1.912), P = 0.003], and the MR-Egger intercept and the Cochran Q test validated the consistency of the MR results. Finally, the reverse MR analysis declined to identify a causal relation between SHBG and osteoporosis. Our research demonstrates a significant causal connection between circulating SHBG levels and increased osteoporosis risk. These results indicate that high SHBG may be associated with the risk of osteoporosis in postmenopausal women, but more research is needed.


Asunto(s)
Osteoporosis , Globulina de Unión a Hormona Sexual , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Transversales , Estudio de Asociación del Genoma Completo , Análisis de la Aleatorización Mendeliana , Nonoxinol , Encuestas Nutricionales , Osteoporosis/epidemiología , Osteoporosis/genética , Globulina de Unión a Hormona Sexual/genética
2.
Biotechnol Bioeng ; 120(12): 3570-3584, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37707439

RESUMEN

In this study, eight nonconserved residues with exposed surfaces and flexible conformations of the homotetrameric PGUS (ß-glucuronidase from Aspergillus oryzae Li-3) were identified. Single-point mutation into cysteine enabled the thiol-maleimide reaction and site-specific protein assembly using a two-arm polyethylene glycol (PEG)-maleimide crosslinker (Mal2 ). The Mal2 (1k) (with 1 kDa PEG spacer)-crosslinked PGUS assemblies showed low crosslinking efficiency and unimproved thermostability except for G194C-Mal2 (1k). To improve the crosslinking efficiency, a lengthened crosslinker Mal2 (2k) (with 2 kDa PEG spacer) was used to produce PGUS assembly and a highly improved thermostability was achieved with a half-life of 47.2-169.2 min at 70°C, which is 1.04-3.74 times that of wild type PGUS. It is found that the thermostability of PGUS assembly was closely associated with the formation of inter-tetramer assembly and intratetramer crosslinking, rather than the PEGylation of the enzyme. Therefore, the four-arm PEG-maleimide crosslinker Mal4 (2k) (with 2 kDa PEG spacer) was employed to simultaneously increase the inter-tetramer assembly and intratetramer crosslinking, and the resulting PGUS assemblies showed further improved thermostabilities compared with Mal2 (2k)-crosslinked assemblies. Finally, the application of PGUS assemblies with significantly improved thermostability to the bioconversion of GL proved that the PGUS assembly is a strong catalyst for glycyrrhizin (GL) hydrolysis in industrial applications.


Asunto(s)
Glucuronidasa , Ácido Glicirrínico , Glucuronidasa/química , Ácido Glicirrínico/metabolismo , Hidrólisis , Catálisis , Maleimidas , Polietilenglicoles
3.
Sleep Breath ; 27(6): 2379-2388, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37278870

RESUMEN

PURPOSE: The diagnosis of obstructive sleep apnea (OSA) relies on time-consuming and complicated procedures which are not always readily available and may delay diagnosis. With the widespread use of artificial intelligence, we presumed that the combination of simple clinical information and imaging recognition based on facial photos may be a useful tool to screen for OSA. METHODS: We recruited consecutive subjects suspected of OSA who had received sleep examination and photographing. Sixty-eight points from 2-dimensional facial photos were labelled by automated identification. An optimized model with facial features and basic clinical information was established and tenfold cross-validation was performed. Area under the receiver operating characteristic curve (AUC) indicated the model's performance using sleep monitoring as the reference standard. RESULTS: A total of 653 subjects (77.2% males, 55.3% OSA) were analyzed. CATBOOST was the most suitable algorithm for OSA classification with a sensitivity, specificity, accuracy, and AUC of 0.75, 0.66, 0.71, and 0.76 respectively (P < 0.05), which was better than STOP-Bang questionnaire, NoSAS scores, and Epworth scale. Witnessed apnea by sleep partner was the most powerful variable, followed by body mass index, neck circumference, facial parameters, and hypertension. The model's performance became more robust with a sensitivity of 0.94, for patients with frequent supine sleep apnea. CONCLUSION: The findings suggest that craniofacial features extracted from 2-dimensional frontal photos, especially in the mandibular segment, have the potential to become predictors of OSA in the Chinese population. Machine learning-derived automatic recognition may facilitate the self-help screening for OSA in a quick, radiation-free, and repeatable manner.


Asunto(s)
Inteligencia Artificial , Apnea Obstructiva del Sueño , Masculino , Humanos , Femenino , Reconocimiento Facial Automatizado , Polisomnografía/métodos , Encuestas y Cuestionarios , Aprendizaje Automático , Tamizaje Masivo
4.
J Anat ; 240(4): 669-677, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-34761390

RESUMEN

In 2016, two adult male sperm whales beached off of Yangkou Port in Nantong City, Jiangsu Province, China. The local government planned to preserve them as specimens, one was entrusted to Dalian Hoffen Biological Co., Ltd., and thus became the first sperm whale to be preserved by plastination. The other sperm whale was preserved in Nantong by the traditional stripping method (The skin was preserved, and then the prosthesis was filled into the skin to preserve the specimens. The material of the prosthesis was polyurethane. The outline of the animal was sculpted by suturing the skin like a bag and filling it with polyurethane). Plastination of such a large marine mammal allowed us to view the mutual adaptations of its internal structure to its specific living environment and daily habits. This sperm whale is the largest specimen in the world and this is the first time a sperm whale has been preserved using the plastination method. The plastination process also provides a method for studying the anatomy of large marine mammals for humans to understand deep-sea organisms at close contact and visual level. The plastination of this sperm whale promises to be a world class resource holding tremendous scientific, educational, and artistic value.


Asunto(s)
Plastinación , Cachalote , Animales , China , Masculino , Poliuretanos
5.
Drug Dev Res ; 80(7): 958-969, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31359488

RESUMEN

To minimize the gastric and esophageal injury effect, a system to deliver doxycycline hyclate (DOXY) to the duodenum area is needed. DOXY-containing modified-release oral pellets (DMOP) coated with hydroxypropyl methylcellulose phthalate HP-55 (HPMCP HP-55) and hydroxypropyl methylcellulose E15 (HPMC E15) appear to be a reasonable choice. This coating layer dissolves at pH 5.5, which is the pH of the duodenum, but not at a gastric pH (1.2). The formulation and preparation of DMOP were optimized, and a scale-up test was performed. The results showed that the production reproducibility was acceptable, and the quality of DMOP well met the standards of Chinese Pharmacopeia (Ch.P, 2015 edition). Notably, the accumulated DOXY release was lower than 50% at pH 1.2 (20 min) and higher than 85% at pH 5.5, which met the USP40-NF35 standard for DOXY modified-release formulations. Moreover, the storage stability of DMOP with different packages was investigated by stress testing, accelerated and long-term testings. The stability of DMOP was maintained up to 12 months, in terms of DOXY content and in vitro release behavior. The results seem to suggest that DMOP could be a promising duodenum delivery system.


Asunto(s)
Doxiciclina/administración & dosificación , Sistemas de Liberación de Medicamentos/métodos , Administración Oral , Implantes de Medicamentos/administración & dosificación , Implantes de Medicamentos/química , Liberación de Fármacos , Estabilidad de Medicamentos , Concentración de Iones de Hidrógeno , Derivados de la Hipromelosa/química , Metilcelulosa/análogos & derivados , Metilcelulosa/química , Tamaño de la Partícula , Comprimidos Recubiertos/administración & dosificación , Comprimidos Recubiertos/química
6.
Langmuir ; 31(2): 655-8, 2015 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-25562583

RESUMEN

Silica nanoparticles (SNPs) were sequentially modified with poly(ethylenimine) (PEI) and 2-diethylaminoethyl chloride (DEAE) to prepare a series of positively charged SNPs-PEI and SNPs-PEI-DEAE. The sequential double-modification strategy produced a charge density as high as 1740 µmol/g (4524 µmol/mL), which offered a very high adsorption capacity for bovine serum albumin (314 mg/g). Most importantly, the highly charged SNPs-PEI and SNPs-PEI-DEAE could efficiently facilitate the refolding of like-charged protein at extremely low utilization. For instance, in the refolding of 1 mg/mL lysozyme, the refolding yield reached 75% with only 3.3 µL/mL SNPs-PEI-DEAE. The bead consumption was reduced by nearly 96% as compared to that of the charged microspheres used previously to reach a similar yield. The results proved that the polyelectrolyte-modified SNPs were promising for applications in facilitating like-charged protein refolding, and the research opened up a new way for biotechnology applications of highly charged nanoparticles.


Asunto(s)
Nanopartículas/química , Proteínas/química , Dióxido de Silicio/química , Adsorción , Animales , Bovinos , Polietileneimina/química , Polímeros/química , Replegamiento Proteico
7.
ScientificWorldJournal ; 2014: 483080, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24982959

RESUMEN

This paper proposes a new linear fault-tolerant permanent-magnet (PM) vernier (LFTPMV) machine, which can offer high thrust by using the magnetic gear effect. Both PMs and windings of the proposed machine are on short mover, while the long stator is only manufactured from iron. Hence, the proposed machine is very suitable for long stroke system applications. The key of this machine is that the magnetizer splits the two movers with modular and complementary structures. Hence, the proposed machine offers improved symmetrical and sinusoidal back electromotive force waveform and reduced detent force. Furthermore, owing to the complementary structure, the proposed machine possesses favorable fault-tolerant capability, namely, independent phases. In particular, differing from the existing fault-tolerant machines, the proposed machine offers fault tolerance without sacrificing thrust density. This is because neither fault-tolerant teeth nor the flux-barriers are adopted. The electromagnetic characteristics of the proposed machine are analyzed using the time-stepping finite-element method, which verifies the effectiveness of the theoretical analysis.


Asunto(s)
Algoritmos , Fenómenos Electromagnéticos , Análisis de Falla de Equipo
8.
Food Res Int ; 190: 114581, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38945601

RESUMEN

Microplastics (MPs) pose a significant threat to livestock health. Yet, the roles of polystyrene MPs (PS-MPs) on meat quality and skeletal muscle development in pigs have not been fully determined. To investigate the effect of PS-MPs on skeletal muscle, piglets were given diets supplementation with 0 mg/kg (CON group), 75 mg/kg (75 mg/kg PS-MPs group), and 150 mg/kg PS-MPs (150 mg/kg PS-MPs group), respectively. The results indicated that the average daily gain (ADG) of piglets in the 150 mg/kg PS-MPs group was significantly lower than that in the CON group. No significant differences were observed in the final body weight and ADG between the CON group and the 75 mg/kg PS-MPs group. Piglets in the 150 mg/kg PS-MPs group exhibited decreased meat redness index and type I muscle fiber density. Metabolomic analysis revealed that the contents of meat flavor compounds carnosine, beta-alanine, palmitic acid, and niacinamide in muscle were lower in the 150 mg/kg PS-MPs group than in the CON group. Additionally, piglets subjected to 150 mg/kg PS-MPs exhibited impaired muscle angiogenesis. Further analysis indicated that PS-MPs exposure up-regulated thrombospondin 1 (THBS1) expression by inhibiting THBS1 mRNA and protein degradation, thereby disrupting skeletal muscle angiogenesis. These findings indicate that PS-MPs exposure adversely affects meat quality and hinders skeletal muscle angiogenesis in pigs, providing deeper insights into the detrimental effects of PS-MPs on meat quality and skeletal muscle development.


Asunto(s)
Microplásticos , Músculo Esquelético , Poliestirenos , Trombospondina 1 , Animales , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/metabolismo , Trombospondina 1/metabolismo , Porcinos , Carne/análisis , Neovascularización Fisiológica/efectos de los fármacos , Carnosina/farmacología , Alimentación Animal , Calidad de los Alimentos , Contaminación de Alimentos/análisis , Masculino , Angiogénesis
9.
Carbohydr Polym ; 301(Pt A): 120300, 2023 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-36436853

RESUMEN

Conductive hydrogels (CHs) have attracted considerable attentions in the fields of wearable electronics, disease diagnosis, and artificial intelligence. However, it is still a great challenge to prepare a single CH system with integrated characteristics of high stretchability, good transparency, and multisensory function through a simple fabrication process. Herein, carboxylic cellulose nanofibers (CCNF) were used to assist the homogeneous distribution of opaque conductive poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate) (PEDOT: PSS) into the crosslinked polyacrylamide network for the fabrication of stretchable and transparent interpenetrating network CH, aiming for a high-performance multisensory system. As expected, the ready formation of hydrogen bonds between the water molecules and a great deal of hydrophilic groups in the hydrogel endow the obtained CH with excellent humidity response behavior in a wide range (0-85%), and the introduction of CCNF and PEDOT: PSS is proved to be an effective strategy to enhance the humidity sensitivity, exhibiting great potential for the noncontact sensing of human respiration and finger movement. Meanwhile, it also displays excellent strain sensing behavior with favorable sensitivity in a broad range (0-837 %), fast response and reliable stability and reproducibility. Importantly, our prepared CH can also detect and discriminate complicated human activities and physiological signals. All these demonstrate the superiority of our prepared CH for the new generation of flexible wearable electronics.


Asunto(s)
Hidrogeles , Nanofibras , Humanos , Hidrogeles/química , Celulosa , Humedad , Reproducibilidad de los Resultados , Inteligencia Artificial
10.
Anim Nutr ; 12: 32-41, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36381066

RESUMEN

We investigated the effects of finely ground wheat bran on the nutrient digestibility, digesta passage rate, and gut microbiota structure in sows. A 3 × 3 Latin square design with 3 test periods and 3 experimental diets was used. Six non-pregnant sows (parity: 5 to 7) were randomly assigned to 3 experimental diets with 2 replicates per treatment in each period. Each period lasted 19 d (12 d for adaptation and 7 d for experiment). The experimental diets included (a) a basal corn and soybean meal diet (CON), (b) a basal diet with 20% coarse wheat bran (CWB; particle size: 605 µm), and (c) a basal diet with 20% fine wheat bran (FWB; particle size: 438 µm). The results demonstrated that the apparent total tract digestibility of neutral detergent fiber, acid detergent fiber and energy were reduced (P < 0.05) in the FWB and CWB groups compared with those in the CON group. Viscosity of digesta increased (P < 0.001) in FWB-fed sows. The passage rate of digesta from the mouth to the ileum decreased (P < 0.001) in FWB-fed sows. Peptide YY (PYY) concentration increased (P = 0.01) in FWB-fed sows after 30 min of feeding. In the FWB group, the relative abundance of Lactobacillaceae at the family level increased (P < 0.05) in the ileal digesta. At the class level, the relative abundance of Clostridia in feces decreased (P < 0.05) in FWB-fed sows. FWB enhanced the concentration of butyrate in feces compared with CON and CWB (P = 0.04). These results suggest that dietary supplementation with finely ground wheat bran reduces the passage rate of digesta, increases the abundance of beneficial microorganisms, and elevates the concentration of short-chain fatty acids and PYY in sows. These findings indicate that the addition of finely-ground wheat bran to the diets of sows is more effective than using coarse wheat bran for improving their satiety and intestinal microbial composition.

11.
Carbohydr Polym ; 297: 119967, 2022 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-36184186

RESUMEN

Masks are key to personal protection and their bacteriostatic properties, which are generally overlooked, should be maximized. Towards this goal, a YPS-Pr-Li/BC upconversion antibacterial composite film was prepared by mixing upconversion powder with bacterial cellulose (BC) using a vacuum assisted method. When combined with the low surface energy of stearic acid (STA), the resulting YPS-Pr-Li/BC/STA film had an improved hydrophobic surface. The developed film was characterized by FT-IR, SEM, XRD, and fluorescence spectrophotometry. The results showed that the composite film was successfully prepared and had ultraviolet, visible upconversion luminescence. The bacteriostatic experiments showed that the material had excellent bacteriostatic performance against E. coli and S. aureus under visible light, with a bacteriostatic rate reaching 99 %. The in-vitro cytotoxicity tests showed that YPS-Pr-Li/BC/STA had excellent biocompatibility and could be used in personal protective clothing with close contact with human skin.


Asunto(s)
Celulosa , Staphylococcus aureus , Antibacterianos/química , Antibacterianos/farmacología , Bacterias , Celulosa/química , Celulosa/farmacología , Escherichia coli , Humanos , Máscaras , Polvos , Espectroscopía Infrarroja por Transformada de Fourier
12.
J Med Virol ; 83(4): 616-21, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21328375

RESUMEN

The objectives of the study were to estimate the prevalence of anti-hepatitis C virus (HCV) positivity among blood donors from Chengdu, China, and to determine risk factors associated with infection. In this study, data were collected from volunteer blood donors between July 2006 and June 2007. Anti-HCV test was performed in 119,518 donors. To identify risk factors associated with HCV infections a case-control study was conducted in 305 unique HCV-seropositive blood donors and 610 seronegative donors matched for age and sex. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression. The population attributable risk (PAR) to risk factor was estimated according to the Bruzzi's formula. The prevalence of anti-HCV positivity was 0.53% (95% CI: 0.489-0.572%). The final multivariate model included the following independent HCV risk factors: razor sharing (OR=29.16; 95% CI: 12.89-66.00), blood transfusion (OR=20.84; 95% CI: 3.76-115.45), acupuncture (OR=8.01; 95% CI: 3.16-20.30), a history of hospitalization, injections >10 years earlier, a family history of hepatitis B, dental treatment, and ear piercing. The PAR of risk factors are 68.4%, 6.3%, 14.1%, 23.1%, 29.5%, 29.3%, 38.9%, and 27.8%, respectively, and the total PAR is 98.3%. Infection with HCV among blood donors in Chengdu is associated with iatrogenic risk factors and beauty treatment-related risk. Razor sharing is an important risk factor for HCV infection. These results indicate that infection control measures in healthcare settings may reduce the burden of HCV infection and there is a need for development of effective educational programs to improve HCV knowledge among beauty culture professionals, barber cosmetologists, and the general public to avoid risk behaviors.


Asunto(s)
Donantes de Sangre , Anticuerpos contra la Hepatitis C/sangre , Hepatitis C/epidemiología , Hepatitis C/virología , Adolescente , Adulto , Estudios de Casos y Controles , China/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Estudios Seroepidemiológicos , Adulto Joven
13.
ACS Appl Mater Interfaces ; 13(13): 15572-15583, 2021 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-33760608

RESUMEN

High-performance flexible strain sensors are urgently needed with the rapid development of wearable intelligent electronics. Here, a bifiller of carbon nanotubes (CNTs) and graphene (GR) for filling flexible porous polydimethylsiloxane (CNT-GR/PDMS) nanocomposites is designed and prepared for strain-sensing applications. The typical microporous structure was successfully constructed using the Soxhlet extraction technique, and the connected CNTs and GR constructed a perfect three-dimensional conductive network in the porous skeleton. As a result, the stretchability and sensitivity of the CNT-GR/PDMS-based strain sensors were well regulated based on the porous structure and the typical synergistic conductive network. Based on the destruction effect of the brittle synergistic conductive network located in the outer and inner layers of the cell skeleton and the contact effect between adjacent cells in different strain ranges, the prepared CNTs-GR/PDMS-based strain sensor exhibited superior gauge factors of 182.5, 45.6, 70.2, and 186.5 in the 0-3, 3-57, 57-90, and 90-120% strain regions, respectively. In addition, this material also exhibited an ultralow detection limit (0.5% strain), a fast response time (60 ms), good stability and durability (10,000 cycles), and frequency-/strain-dependent sensing performances, making it active for the detection of various external environments. Finally, the prepared porous CNTs-GR/PDMS-based strain sensor was attached to the skin to detect various human motions, such as wrist bending, finger bending, elbow bending, and knee bending, thereby demonstrating wide application prospects in smart wearable devices.


Asunto(s)
Dimetilpolisiloxanos/química , Grafito/química , Nanotubos de Carbono/química , Dispositivos Electrónicos Vestibles , Fenómenos Biomecánicos , Técnicas Biosensibles/instrumentación , Técnicas Biosensibles/métodos , Conductividad Eléctrica , Humanos , Nanotubos de Carbono/ultraestructura , Porosidad , Estrés Mecánico
14.
Mater Sci Eng C Mater Biol Appl ; 118: 111414, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33255016

RESUMEN

An intelligent narrow pH-triggered multilayer film was prepared on magnesium alloys, aiming to solve the implant infections during the implantation period and improve the corrosion resistance of magnesium alloys. The encapsulation of ibuprofen by chitosan (IBU@CS) makes the release of IBU sensitive to narrow pH (pH 6.8-7.4). Positive charged IBU@CS was assembled with heparin (Hep) to fabricate (Hep/IBU@CS)10 film on AZ31 alloys using layer-by-layer method. The microstructure, composition and anticorrosion properties of the film were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and electrochemical experiments. Cellular activity was studied by MTT cell viability assay. The results showed that the Hep/IBU@CS multilayer films improved the corrosion resistance of magnesium alloys. The in vitro test demonstrated that the release of IBU in the film presented narrow pH sensitivity. The films showed no obvious signs of cytotoxicity conformed by the MTT assay and presented antibacterial properties. These preliminary results demonstrate the potential use of the Hep/IBU@CS multilayer films on magnesium-based implants.


Asunto(s)
Ibuprofeno , Magnesio , Aleaciones/farmacología , Materiales Biocompatibles Revestidos , Corrosión , Preparaciones de Acción Retardada , Concentración de Iones de Hidrógeno , Ibuprofeno/farmacología , Espectroscopía Infrarroja por Transformada de Fourier , Propiedades de Superficie
15.
Int J Biol Macromol ; 151: 628-634, 2020 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-32092421

RESUMEN

Polylactic acid (PLA) is a biodegradable and biocompatible polyester derived from renewable resources like corn starch, presenting great potential in clinical applications like tissue engineering, implants and drug delivery systems. However, the intrinsic brittleness restricts its real applications. In this work, PLA nanocomposites were prepared by incorporating a small amount of carboxyl functionalized multi-walled carbon nanotubes (CNTs) and surface compatabilized montmorillonite (MMT) via technologies of freeze-drying and masterbatch-based melt blending. In the resulting nanocomposites, a well-distributed nano-filler network with microstructures of 1-D CNTs/2-D MMT platelets is formed favored by the enhanced interfacial interaction between the organic modified fillers with PLA matrix. Thanks to the well dispersed organic modified nanofillers, a large number of microcracks and extremely stretched PLA matrix are induced during tensile process, dissipating amounts of energy. As a result, the filler networks reinforce PLA with increment of 19% in modulus, remarkably increase by 13.8 times in toughness relative to PLA control without sacrificing strength. Thus, the PLA nanocomposites with excellent properties prepared through the facile and effective route possess broad prospect in biomedical applications.


Asunto(s)
Arcilla/química , Nanocompuestos/química , Nanotubos de Carbono/química , Poliésteres/química , Algoritmos , Materiales Biocompatibles/química , Fenómenos Mecánicos , Modelos Teóricos , Estructura Molecular , Nanocompuestos/ultraestructura , Nanotubos de Carbono/ultraestructura , Difracción de Rayos X
16.
Acta Biomater ; 104: 147-157, 2020 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-31904558

RESUMEN

Synergistic anti-tumor effect of anti-PD-1/L1 antibody (aPD-1/aPD-L1) and 1-methyl-D,L-tryptophan (1-MT) in melanoma has been well demonstrated, while efficient topical delivery systems are still largely unexplored. Here, a highly drug-concentrated hybrid core-shell microneedle (CSMN) system for co-delivery of checkpoint inhibitors was developed. Based on the specific drug-matrix interaction, the system concentrated aPD-L1 in the tips of microneedles through electrostatic interactions, and increased the amount of 1-MT loaded in CSMN by preventing its premature crystallization using PVA, the material used to prepare CSMN core. The prepared CSMN exhibited high transdermal delivery efficiency and long topical retention time of aPD-L1 for 2 days. Drug-loaded CSMN achieved better anti-tumor efficacy than the intra-tumor injection group at the same dose, which was likely because the former recruited more T lymphocytes to the tumor site. These findings suggested that this CSMN system was a promising local delivery system of both aPD-L1 and 1-MT for melanoma immunotherapy, and its unique core-shell structure could be readily adapted as a modular platform for various diseases, where combination therapy of both biomacromolecular drugs and other small-molecular agents were required. STATEMENT OF SIGNIFICANCE: In the present study, a core-shell microneedle (CSMN) system was constructed to achieve targeted co-delivery of checkpoint inhibitors to melanoma, while preventing significant systemic exposure. To overcome the drawback of insufficient drug loading of microneedles and effectively encapsulate two drugs simultaneously, microneedles were divided into two independent functional areas, a charged shell and a hydrophilic core and encapsulated drugs based on respective drug-matrix interaction. The charged shell prepared by chitosan could concentrate aPD-L1 in the tips of microneedles through electrostatic interactions. The core prepared by PVA successfully increased the amount of 1-MT loaded in microneedles by preventing its premature crystallization. The prepared CSMN exhibited high transdermal delivery efficiency and better anti-tumor efficacy than intra-tumor injection at the same dose.


Asunto(s)
Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Inmunoterapia , Melanoma/inmunología , Melanoma/terapia , Agujas , Administración Cutánea , Animales , Antineoplásicos/uso terapéutico , Quitosano/química , Cristalización , Femenino , Melanoma/patología , Ratones Endogámicos C57BL , Polímeros/química , Ratas Sprague-Dawley
17.
Adv Healthc Mater ; 8(21): e1900898, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31583838

RESUMEN

The precise delivery of traditional dissolving microneedles (TDMNs) is often limited by the incomplete insertion due to the skin deformation, and the topical irritation is inevitable after long application, which ultimately results in compromised therapeutic efficacy. The aim of this study is to develop a rapidly separating dissolving microneedles (RSDMNs) system to achieve precise drug delivery. Therapeutic molecules are concentrated in the needle tip, while the blank separating part allows it to counteract skin indentation and rapidly separate from the base part. For rational design of an ideal separating part, and the molecular interactions between polymer and sugar are explored to make a good balance between mechanical performance and disintegration rate. The optimal RSDMNs can rapidly disintegrate in the mimic skin within 30 s, and the generated micropores in the skin reseal quickly. The ex vivo drug permeation of RSDMNs is significantly higher than that of TDMNs due to the complete needle imbed aided by the separating part. Furthermore, RSDMNs exhibit excellent in vivo anti-inflammation effect by remarkably down regulating the expression of TNF-α, IL-1ß, and IL-6. In conclusion, the RSDMNs can reach precise drug delivery in a short time, which are more reliable for the self-administration strategy in the future.


Asunto(s)
Sistemas de Liberación de Medicamentos/métodos , Agujas , Polímeros/química , Animales , Rastreo Diferencial de Calorimetría , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Espectroscopía de Resonancia Magnética , Masculino , Ratones , Células 3T3 NIH , Ratas Sprague-Dawley , Piel/metabolismo , Espectroscopía Infrarroja por Transformada de Fourier , Factor de Necrosis Tumoral alfa/metabolismo
18.
ACS Appl Mater Interfaces ; 11(45): 42594-42606, 2019 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-31618002

RESUMEN

Wearable pressure sensors are in great demand with the rapid development of intelligent electronic devices. However, it is still a huge challenge to obtain high-performance pressure sensors with high sensitivity, wide response range, and low detection limit simultaneously. Here, a polyimide (PI)/carbon nanotube (CNT) composite aerogel with the merits of superelastic, high porosity, robust, and high-temperature resistance was successfully prepared through the freeze drying plus thermal imidization process. Benefiting from the strong chemical interactions between PI and CNT and stable electrical property, the composite aerogel exhibits versatile and superior brilliant sensing performance, which includes wide sensing range (80% strain, 61 kPa), ultrahigh sensitivity (11.28 kPa-1), ultralow detection limit (0.1% strain, <10 Pa), fast response time (50 ms) and recovery time (70 ms), remarkable long-term stability (1000 cycles), and exceptional detection ability toward different deformations (compression, distortion, and bending). Furthermore, the composite aerogel also shows stable sensing performance after annealing under different high temperatures and good thermal insulation property, making it workable in various harsh environments. As a result, the composite aerogel is suitable for the full-range human motion detection (including airflow, pulse, vocal cord vibration, and human movement) and precise detection of the pressure distribution when it is assembled into E-skin, demonstrating its great potential to serve as a high-performance wearable pressure sensor.


Asunto(s)
Electrónica/instrumentación , Nanotubos de Carbono/química , Resinas Sintéticas/química , Geles/química , Humanos , Límite de Detección , Porosidad , Presión
19.
Acta Biomater ; 67: 99-110, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29225151

RESUMEN

Local anesthetics have been widely used for postoperative analgesia. However, multiple injections or local infiltration is required due to the short half-lives of local anesthetics after single injection, which results in poor compliance and increasing medical expense. In this study, an in situ forming gel (ISFG) based on lyotropic liquid crystal was developed to deliver bupivacaine hydrochloride (BUP) for long-acting postoperative analgesia. BUP-ISFG was designed to be administrated as a precursor solution which would spontaneously transform into gel with well-defined internal nanostructures for sustained drug release at the site of administration when exposed to physiological fluid. A lamellar-hexagonal-cubic phase transition occurred during the in situ gelation. The lamellar phase of the precursor solution endows it with low viscosity for good syringeability while the unique nanostructures of hexagonal and cubic phases of the in situ gel provide sustained drug release. Persistent analgesia effect in vivo was achieved with BUP-ISFG, and the plasma BUP concentration was found to be steadier compared to commercially available BUP for injection. In addition, the ISFG displayed acceptable biocompatibility and good biodegradability. The findings are positive about ISFG as a sustained release system for persistent postoperative analgesia. STATEMENT OF SIGNIFICANCE: To address the issue of insufficient postoperative analgesia associated with short half-lives of local anesthetics after single injection, an in situ forming gel (ISFG) based on lyotropic liquid crystal was developed to deliver bupivacaine hydrochloride (BUP) for postoperative analgesia over three days. The results demonstrated that persistent analgesia effect in vivo was achieved with single injection of BUP-ISFG, and the plasma BUP concentration was found to be steadier compared to commercially available BUP injection. The BUP-ISFG possessed a lamellar-hexagonal-cubic phase transition with corresponding crystal change in 3D nanostructure during the in situ gelation. The relationship between crystal nanostructure and carrier function, might provide some insights to the design and clinical applications of the drug delivery systems based on lyotropic liquid crystal.


Asunto(s)
Analgesia , Geles/química , Inyecciones , Cristales Líquidos/química , Cuidados Posoperatorios , Animales , Materiales Biocompatibles/química , Bupivacaína/sangre , Bupivacaína/farmacocinética , Liberación de Fármacos , Masculino , Nanoestructuras/química , Transición de Fase , Conejos , Ratas Sprague-Dawley , Reología , Soluciones
20.
ACS Appl Mater Interfaces ; 10(7): 6124-6136, 2018 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-29356496

RESUMEN

Considerable attention has been devoted to producing antibacterial fabrics due to their very wide applications in medicine, hygiene, hospital, etc. However, the poor antibacterial durability and bad bacterial antiadhesion capacity of most existing antibacterial fabrics limit their applications. In this work, a series of antibacterial and polymeric quaternary ammonium monomers with different alkyl chain length were successfully synthesized to copolymerize with fluorine-containing and other acrylic monomers to generate cationic fluorinated polymer emulsions and durably antibacterial and bacterially antiadhesive cotton fabrics. The relation between antibacterial constituent and its antibacterial activity was investigated. The study indicated that the alkyl chain length and contents of the antibacterial monomers, as well as the add-on percentage of polymer greatly influenced the antibacterial activities of the fabrics. In addition, it was found that incorporation of fluorine component into the polymer greatly enhanced the antibacterial activity and bacterial antiadhesion of the treated fabrics due to the low surface energy induced hydrophobicity. Finally, antibacterial and antiadhesive models of action of the obtained fabrics were illustrated.


Asunto(s)
Polímeros de Fluorocarbono/química , Antibacterianos , Fibra de Algodón , Textiles
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