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1.
Ann Neurol ; 93(2): 244-256, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36088542

RESUMEN

OBJECTIVE: Despite the increasing number of genes associated with Charcot-Marie-Tooth (CMT) disease, many patients currently still lack appropriate genetic diagnosis for this disease. Autosomal dominant mutations in aminoacyl-tRNA synthetases (ARSs) have been implicated in CMT. Here, we describe causal missense mutations in the gene encoding seryl-tRNA synthetase 1 (SerRS) for 3 families affected with CMT. METHODS: Whole-exome sequencing was performed in 16 patients and 14 unaffected members of 3 unrelated families. The functional impact of the genetic variants identified was investigated using bioinformatic prediction tools and confirmed using cellular and biochemical assays. RESULTS: Combined linkage analysis for the 3 families revealed significant linkage (Zmax LOD = 6.9) between the genomic co-ordinates on chromosome 1: 108681600-110300504. Within the linkage region, heterozygous SerRS missense variants segregated with the clinical phenotype in the 3 families. The mutant SerRS proteins exhibited reduced aminoacylation activity and abnormal SerRS dimerization, which suggests the impairment of total protein synthesis and induction of eIF2α phosphorylation. INTERPRETATION: Our findings suggest the heterozygous SerRS variants identified represent a novel cause for autosomal dominant CMT. Mutant SerRS proteins are known to impact various molecular and cellular functions. Our findings provide significant advances on the current understanding of the molecular mechanisms associated with ARS-related CMT. ANN NEUROL 2023;93:244-256.


Asunto(s)
Enfermedad de Charcot-Marie-Tooth , Serina-ARNt Ligasa , Humanos , Enfermedad de Charcot-Marie-Tooth/genética , Enfermedad de Charcot-Marie-Tooth/metabolismo , Serina-ARNt Ligasa/genética , Mutación , Heterocigoto , Mutación Missense/genética
2.
BMC Oral Health ; 22(1): 602, 2022 12 13.
Artículo en Inglés | MEDLINE | ID: mdl-36514081

RESUMEN

PURPOSE: Oral health is important for general health; nurses are expected to possess good oral health awareness and work together for public oral health promotion. The purpose of this study is to investigate oral health literacy (OHL)and oral health behaviors of nurses, and explore the association between oral health literacy with demographic variables and oral health behaviors. METHODS: A cross-sectional study in a tertiary hospital was conducted using a short-form Health Literacy in Dentistry-14 (HeLD-14) and a 16-items oral health behaviors questionnaire. Information about the subjects' demographic details including age, gender, place of residence, marital status, marital status, education level, monthly household income, working experience, etc. were collected. Independent sample t- test, One- way ANOVA, and multivariable regression were used to identify the association of oral health literacy with demographic variables and oral health behaviors. RESULTS: A total number of 317 nursing nurses participated in the survey, with a mean OHL score of 36.72, SD10.531, 21.8% were categorized as good, 34.1% medium and 44.2% poor oral health literacy; monthly household income, self-rated oral health, brushing time, use of fluoride toothpaste, and regular oral examination were signficantly associated with OHL scores. CONCLUSION: The overall oral health literacy of the nurse population is at a moderate to low level. These findings may help to map and design an oral health education intervention to improve oral health literacy amongst nurses, especially nurses with low monthly household income and poor self-assessed oral health status. Nursing administrators and nursing educators should pay more attention to the oral health status of the nurse population.


Asunto(s)
Alfabetización en Salud , Enfermeras y Enfermeros , Humanos , Salud Bucal , Estudios Transversales , Encuestas y Cuestionarios , China , Conductas Relacionadas con la Salud
3.
Int J Mol Sci ; 22(12)2021 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-34208563

RESUMEN

Bone exhibits piezoelectric properties. Thus, electrical stimulations such as pulsed electromagnetic fields (PEMFs) and stimuli-responsive piezoelectric properties of scaffolds have been investigated separately to evaluate their efficacy in supporting osteogenesis. However, current understanding of cells responding under the combined influence of PEMF and piezoelectric properties in scaffolds is still lacking. Therefore, in this study, we fabricated piezoelectric scaffolds by functionalization of polycaprolactone-tricalcium phosphate (PCL-TCP) films with a polyvinylidene fluoride (PVDF) coating that is self-polarized by a modified breath-figure technique. The osteoinductive properties of these PVDF-coated PCL-TCP films on MC3T3-E1 cells were studied under the stimulation of PEMF. Piezoelectric and ferroelectric characterization demonstrated that scaffolds with piezoelectric coefficient d33 = -1.2 pC/N were obtained at a powder dissolution temperature of 100 °C and coating relative humidity (RH) of 56%. DNA quantification showed that cell proliferation was significantly enhanced by PEMF as low as 0.6 mT and 50 Hz. Hydroxyapatite staining showed that cell mineralization was significantly enhanced by incorporation of PVDF coating. Gene expression study showed that the combination of PEMF and PVDF coating promoted late osteogenic gene expression marker most significantly. Collectively, our results suggest that the synergistic effects of PEMF and piezoelectric scaffolds on osteogenesis provide a promising alternative strategy for electrically augmented osteoinduction. The piezoelectric response of PVDF by PEMF, which could provide mechanical strain, is particularly interesting as it could deliver local mechanical stimulation to osteogenic cells using PEMF.


Asunto(s)
Fosfatos de Calcio , Materiales Biocompatibles Revestidos , Campos Electromagnéticos , Osteogénesis , Poliésteres , Polivinilos , Andamios del Tejido , Regeneración Ósea , Diferenciación Celular , Proliferación Celular , Células Cultivadas , Materiales Biocompatibles Revestidos/química , Expresión Génica , Osteogénesis/efectos de los fármacos , Osteogénesis/genética , Osteogénesis/efectos de la radiación , Poliésteres/química , Poliésteres/farmacología , Polivinilos/química , Solventes , Ingeniería de Tejidos , Difracción de Rayos X
4.
J Cell Mol Med ; 23(6): 4054-4062, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30907490

RESUMEN

Microvesicles (MVs), which are cell-derived membrane vesicles present in body fluids, are closely associated with the development of malignant tumours. Saliva, one of the most versatile body fluids, is an important source of MVs. However, the association between salivary MVs (SMVs) and oral squamous cell carcinoma (OSCC), which is directly immersed in the salivary milieu, remains unclear. SMVs from 65 patients with OSCC, 21 patients with oral ulcer (OU), and 42 healthy donors were purified, quantified and analysed for their correlations with the clinicopathologic features and prognosis of OSCC patients. The results showed that the level of SMVs was significantly elevated in patients with OSCC compared to healthy donors and OU patients. Meanwhile, the level of SMVs showed close correlations with the lymph node status, and the clinical stage of OSCC patients. Additionally, the ratio of apoptotic to non-apoptotic SMVs was significantly decreased in OSCC patients with higher pathological grade. Consistently, poorer overall survival was observed in patients with lower ratio of apoptotic to non-apoptotic SMVs. In conclusion, the elevated level of SMVs is associated with clinicopathologic features and decreased survival in patients with OSCC, suggesting that SMVs are a potential biomarker and/or regulator of the malignant progression of OSCC.


Asunto(s)
Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patología , Micropartículas Derivadas de Células/metabolismo , Micropartículas Derivadas de Células/patología , Neoplasias de la Boca/metabolismo , Neoplasias de la Boca/patología , Saliva/metabolismo , Apoptosis/fisiología , Biomarcadores de Tumor/metabolismo , Progresión de la Enfermedad , Femenino , Humanos , Ganglios Linfáticos/metabolismo , Ganglios Linfáticos/patología , Masculino , Pronóstico
5.
Artif Organs ; 43(5): 515-523, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30229979

RESUMEN

The incidence of peripheral nerve injuries is on the rise and the current gold standard for treatment of such injuries is nerve autografting. Given the severe limitations of nerve autografts which include donor site morbidity and limited supply, neural guide conduits (NGCs) are considered as an effective alternative treatment. Conductivity is a desired property of an ideal NGC. Reduced graphene oxide (rGO) possesses several advantages in addition to its conductive nature such as high surface area to volume ratio due to its nanostructure and has been explored for its use in tissue engineering. However, most of the works reported are on traditional 2D culture with a layer of rGO coating, while the native tissue microenvironment is three-dimensional. In this study, PCL/rGO scaffolds are fabricated using electrohydrodynamic jet (EHD-jet) 3D printing method as a proof of concept study. Mechanical and material characterization of the printed PCL/rGO scaffolds and PCL scaffolds was done. The addition of rGO results in softer scaffolds which is favorable for neural differentiation. In vitro neural differentiation studies using PC12 cells were also performed. Cell proliferation was higher in the PCL/rGO scaffolds than the PCL scaffolds. Reverse transcription polymerase chain reaction and immunocytochemistry results reveal that PCL/rGO scaffolds support neural differentiation of PC12 cells.


Asunto(s)
Grafito/química , Neurogénesis , Traumatismos de los Nervios Periféricos/terapia , Poliésteres/química , Andamios del Tejido/química , Animales , Conductividad Eléctrica , Regeneración Nerviosa , Oxidación-Reducción , Células PC12 , Impresión Tridimensional , Ratas , Ingeniería de Tejidos
6.
J Mater Sci Mater Med ; 29(9): 140, 2018 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-30120625

RESUMEN

Several attempts have been made to fabricate esophageal tissue engineering scaffolds. However, most of these scaffolds possess randomly oriented fibres and uncontrollable pore sizes. In order to mimic the native esophageal tissue structure, electro-hydrodynamic jetting (e-jetting) was used in this study to fabricate scaffolds with aligned fibres and controlled pore size. A hydrophilic additive, Pluronic F127 (F127), was blended with polycaprolactone (PCL) to improve the wettability of the scaffolds and hence the cell adhesion. PCL/F127 composite scaffolds with different weight ratios (0-12%) were fabricated. The wettability, phase composition, and the mechanical properties of the fabricated scaffolds were investigated. The results show that the e-jetted scaffolds have controllable fibres orientated in two perpendicular directions, which are similar to the human esophagus structure and suitable pore size for cell infiltration. In addition, the scaffolds with 8% F127 exhibited better wettability (contact angle of 14°) and an ultimate tensile strength (1.2 MPa) that mimics the native esophageal tissue. Furthermore, primary human esophageal fibroblasts were seeded on the e-jetted scaffolds. PCL/F127 scaffolds showed enhanced cell proliferation and expression of the vascular endothelial growth factor (VEGF) compared to pristine PCL scaffolds (1.5- and 25.8- fold increase, respectively; P < 0.001). An in vitro wound model made using the PCL/F127 scaffolds showed better cell migration than the PCL scaffolds. In summary, the PCL/F127 e-jetted scaffolds offer a promising strategy for the esophagus tissue repair.


Asunto(s)
Esófago , Poloxámero/química , Poliésteres/química , Ingeniería de Tejidos/métodos , Andamios del Tejido , Adhesión Celular , Proliferación Celular , Supervivencia Celular , Fibroblastos/metabolismo , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Imagenología Tridimensional , Ensayo de Materiales , Microscopía Confocal , Porosidad , Estrés Mecánico , Resistencia a la Tracción , Factor A de Crecimiento Endotelial Vascular/metabolismo , Humectabilidad , Cicatrización de Heridas , Difracción de Rayos X
7.
Dis Colon Rectum ; 59(10): 975-83, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27602929

RESUMEN

BACKGROUND: Bowel preparation is burdensome, and less-demanding preparation procedures are needed. Few studies have investigated the effects of low-residue diet and prepackaged low-residue diet in combination with low-volume polyethylene glycol-electrolyte lavage solution during colonoscopy preparation. OBJECTIVE: We compared self-prepared low-residue diets with prepackaged low-residue diets in combination with low-volume polyethylene glycol. DESIGN: This was a single-blinded, 3-arm, multicenter, randomized controlled trial. SETTING: Colonoscopies were conducted in outpatient settings at 3 centers in Taiwan. PATIENTS: The study included 180 patients (age range, 20-75 years) who were scheduled for colonoscopy. INTERVENTIONS: Three groups were compared: group A included self-prepared, 1-day, low-residue diets with a same-day 2.0-L single-dose of polyethylene glycol; group B included prepackaged low-residue diets plus 2.0 L of polyethylene glycol; and group C included prepackaged low-residue diets plus 1.5 L of polyethylene glycol. MAIN OUTCOME MEASURES: The outcome measures were adherence, bowel-cleansing level, and patient satisfaction. RESULTS: One third of the subjects in group A, but none in the prepackaged low-residue diets groups, violated the dietary restrictions. The proportion of right-segment preparation failure was 15.0%, 1.7%, and 6.7% (p = 0.025). Accordingly, treatment B was superior to A (p = 0.008). Among subjects violating the low-residue diets guideline, the right-segment preparation failure rate was 25%. According to a multivariate analysis, low-residue diet compliance (adjusted OR = 6.55 (95% CI, 1.83-23.43)) and BMI were predictors of right-sided preparation adequacy, but the volume of polyethylene glycol ingested was not a predictor. Compared with group A, a greater proportion of subjects in groups B and C reported satisfaction. LIMITATIONS: Patients with high BMI and severe constipation were excluded from this study. This study included only an Asian population. CONCLUSIONS: The prepackaged low-residue diet provides excellent adherence, better bowel cleansing, and a better experience than a self-prepared low-residue diet. With good dietary compliance, 1.5 L of polyethylene glycol provides effective preparation.


Asunto(s)
Catárticos , Enfermedades del Colon/diagnóstico , Colonoscopía/métodos , Dietoterapia/métodos , Polietilenglicoles , Cuidados Preoperatorios/métodos , Irrigación Terapéutica/métodos , Adulto , Índice de Masa Corporal , Catárticos/administración & dosificación , Catárticos/efectos adversos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Evaluación de Resultado en la Atención de Salud , Cooperación del Paciente , Prioridad del Paciente , Polietilenglicoles/administración & dosificación , Polietilenglicoles/efectos adversos , Tensoactivos/administración & dosificación , Tensoactivos/efectos adversos
8.
J Craniofac Surg ; 27(8): e762-e763, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28005814

RESUMEN

Syngnathia is a rare malformation involving soft tissue and/or bony adhesions between the maxilla and mandible. Less than 40 patients have been reported in the literature. Here the authors report a 6-month-old infant diagnosed as syngnathia of the palate and mouth floor combined with cleft palate and funnel chest in the Department of Oral and Maxillofacial Surgery at Henan Provincial People's Hospital in January 2015. The authors discussed and evaluated the diagnostic and treatment difficulties on surgical and anesthetic procedure. There is no standard treatment protocol, but early treatment is necessary to improve airway functions and infant feeding, and to support proper nutrition for the growth of maxillofacial region.


Asunto(s)
Anomalías Múltiples , Labio Leporino/diagnóstico , Tórax en Embudo/diagnóstico , Anomalías Maxilomandibulares/diagnóstico , Anomalías de la Boca/diagnóstico , Suelo de la Boca/anomalías , Humanos , Lactante , Masculino
9.
Small ; 11(46): 6225-36, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26488923

RESUMEN

For decades, poly(ethylene glycol) (PEG) has been widely incorporated into nanoparticles for evading immune clearance and improving the systematic circulation time. However, recent studies have reported a phenomenon known as "accelerated blood clearance (ABC)" where a second dose of PEGylated nanomaterials is rapidly cleared when given several days after the first dose. Herein, we demonstrate that natural red blood cell (RBC) membrane is a superior alternative to PEG. Biomimetic RBC membrane-coated Fe(3)O(4) nanoparticles (Fe(3)O(4) @RBC NPs) rely on CD47, which is a "don't eat me" marker on the RBC surface, to escape immune clearance through interactions with the signal regulatory protein-alpha (SIRP-α) receptor. Fe(3)O(4) @RBC NPs exhibit extended circulation time and show little change between the first and second doses, with no ABC suffered. In addition, the administration of Fe(3)O(4) @RBC NPs does not elicit immune responses on neither the cellular level (myeloid-derived suppressor cells (MDSCs)) nor the humoral level (immunoglobulin M and G (IgM and IgG)). Finally, the in vivo toxicity of these cell membrane-camouflaged nanoparticles is systematically investigated by blood biochemistry, hematology testing, and histology analysis. These findings are significant advancements toward solving the long-existing clinical challenges of developing biomaterials that are able to resist both immune response and rapid clearance.


Asunto(s)
Materiales Biomiméticos/farmacología , Circulación Sanguínea/efectos de los fármacos , Materiales Biocompatibles Revestidos/farmacología , Membrana Eritrocítica/metabolismo , Nanopartículas/química , Animales , Compuestos Férricos/química , Hidrodinámica , Evasión Inmune , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Ensayo de Materiales , Ratones , Nanopartículas/toxicidad , Nanopartículas/ultraestructura , Polietilenglicoles/química , Células RAW 264.7 , Electricidad Estática , Factores de Tiempo , Distribución Tisular/efectos de los fármacos
10.
Org Biomol Chem ; 13(3): 686-90, 2015 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-25424983

RESUMEN

A miscible tetrahydrofuran-tris buffer mixture has been used to fabricate polydopamine hollow capsules with a size of 200 nm and with a shell thickness of 40 nm. An unusual non-emulsion soft template mechanism has been disclosed to explain the formation of capsules. The results indicate that the capsule structure is highly dependent on the volume fraction of tetrahydrofuran as well as the solvent, and the shell thickness of capsules can be controlled by adjusting the reaction time and dopamine concentration.


Asunto(s)
Dopamina/química , Furanos/química , Indoles/síntesis química , Nanocápsulas/química , Polímeros/síntesis química , Trometamina/química , Microscopía Electrónica de Transmisión , Nanocápsulas/ultraestructura , Tamaño de la Partícula , Propiedades de Superficie , Factores de Tiempo
11.
J Integr Plant Biol ; 57(2): 213-28, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24912543

RESUMEN

In this study, the role of the rice (Oryza sativa L.) histidine kinase OsHK3 in abscisic acid (ABA)-induced antioxidant defense was investigated. Treatments with ABA, H2 O2 , and polyethylene glycol (PEG) induced the expression of OsHK3 in rice leaves, and H2 O2 is required for ABA-induced increase in the expression of OsHK3 under water stress. Subcellular localization analysis showed that OsHK3 is located in the cytoplasm and the plasma membrane. The transient expression analysis and the transient RNA interference test in rice protoplasts showed that OsHK3 is required for ABA-induced upregulation in the expression of antioxidant enzymes genes and the activities of antioxidant enzymes. Further analysis showed that OsHK3 functions upstream of the calcium/calmodulin-dependent protein kinase OsDMI3 and the mitogen-activated protein kinase OsMPK1 to regulate the activities of antioxidant enzymes in ABA signaling. Moreover, OsHK3 was also shown to regulate the expression of nicotinamide adenine dinucleotide phosphate oxidase genes, OsrbohB and OsrbohE, and the production of H2 O2 in ABA signaling. Our data indicate that OsHK3 play an important role in the regulation of ABA-induced antioxidant defense and in the feedback regulation of H2 O2 production in ABA signaling.


Asunto(s)
Ácido Abscísico/metabolismo , Antioxidantes/metabolismo , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Transducción de Señal , Ácido Abscísico/farmacología , Ascorbato Peroxidasas/metabolismo , Catalasa/metabolismo , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Glutatión Reductasa/metabolismo , Peróxido de Hidrógeno/farmacología , Modelos Biológicos , Oryza/efectos de los fármacos , Oryza/enzimología , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/genética , Polietilenglicoles/farmacología , Transporte de Proteínas/efectos de los fármacos , Protoplastos/efectos de los fármacos , Protoplastos/metabolismo , Interferencia de ARN/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genética , Fracciones Subcelulares/efectos de los fármacos , Fracciones Subcelulares/metabolismo , Superóxido Dismutasa/metabolismo , Regulación hacia Arriba/efectos de los fármacos , Regulación hacia Arriba/genética
12.
Int J Biol Macromol ; 273(Pt 1): 132993, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38862049

RESUMEN

Low ionic conductivity and poor interface stability of poly(ethylene oxide) (PEO) restrict the practical application as polymeric electrolyte films to prepare solid-state lithium (Li) metal batteries. In this work, biomass-based carboxymethyl chitosan (CMCS) is designed and developed as organic fillers into PEO matrix to form composite electrolytes (PEO@CMCS). Carboxymethyl groups of CMCS fillers can promote the decomposition of Lithium bis(trifluoromethane sulfonimide) (LiTFSI) to generate more lithium fluoride (LiF) at CMCS/PEO interface, which not only forms ionic conductive network to promote the rapid transfer of Li+ but also effectively enhances the interface stability between polymeric electrolyte and Li metal. The enrichment of carboxyl, hydroxyl, and amidogen functional groups within CMCS fillers can form hydrogen bonds with ethylene oxide (EO) chains to improve the tensile properties of PEO-based electrolyte. In addition, the high hardness of CMCS additives can also strengthen mechanical properties of PEO-based electrolyte to resist penetration of Li dendrites. LiLi symmetric batteries can achieve stable cycle for 2500 h and lithium iron phosphate full batteries can maintain 135.5 mAh g-1 after 400 cycles. This work provides a strategy for the enhancement of ion conductivity and interface stability of PEO-based electrolyte, as well as realizes the resource utilization of biomass-based CMCS.


Asunto(s)
Quitosano , Conductividad Eléctrica , Suministros de Energía Eléctrica , Electrólitos , Litio , Polietilenglicoles , Quitosano/química , Quitosano/análogos & derivados , Polietilenglicoles/química , Litio/química , Electrólitos/química , Iones/química
13.
Genes (Basel) ; 14(5)2023 04 29.
Artículo en Inglés | MEDLINE | ID: mdl-37239375

RESUMEN

WRKY transcription factors (TFs), which are plant-specific TFs, play significant roles in plant defense. Here, a pathogen-induced WRKY gene, named AktWRKY12, which was the homologous gene of AtWRKY12, was isolated from Akebia trifoliata. The AktWRKY12 gene has a total length of 645 nucleotides and an open reading frame (ORF) encoding 214 amino acid polypeptides. The characterizations of AktWRKY12 were subsequently performed with the ExPASy online tool Compute pI/Mw, PSIPRED and SWISS-MODEL softwares. The AktWRKY12 could be classified as a member of WRKY group II-c TFs based on sequence alignment and phylogenetic analysis. The results of tissue-specific expression analysis revealed that the AktWRKY12 gene was expressed in all the tested tissues, and the highest expression level was detected in A. trifoliata leaves. Subcellular localization analysis showed that AktWRKY12 was a nuclear protein. Results showed that the expression level of AktWRKY12 significantly increased in A. trifoliata leaves with pathogen infection. Furthermore, heterologous over-expression of AktWRKY12 in tobacco resulted in suppressed expression of lignin synthesis key enzyme genes. Based on our results, we speculate that AktWRKY12 might play a negative role in A. trifoliata responding to biotic stress by regulating the expression of lignin synthesis key enzyme genes during pathogen infection.


Asunto(s)
Lignina , Factores de Transcripción , Factores de Transcripción/metabolismo , Filogenia , Regulación de la Expresión Génica de las Plantas , Clonación Molecular
14.
Adv Sci (Weinh) ; 10(25): e2301095, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37409439

RESUMEN

The service life of an artificial hip joint is limited to 10-15 years, which is not ideal for young patients. To extend the lifespan of these prostheses, the coefficient of friction and wear resistance of metallic femoral heads must be improved. In this study, a Cu-doped titanium nitride (TiNX -Cu) film with "autoantifriction" properties is deposited on a CoCrMo alloy via magnetron sputtering. When delivered in a protein-containing lubricating medium, the Cu in TiNX -Cu quickly and consistently binds to the protein molecules in the microenvironment, resulting in the formation of a stable protein layer. The proteins adsorbed on the TiNX -Cu surface decompose into hydrocarbon fragments owing to the shear stress between the Al2 O3 /TiNX -Cu tribopair. The synergistic effect of the catalysis of Cu and shear stress between the Al2 O3 /TiNX -Cu tribopair transforms these fragments into graphite-like carbon tribofilms with an antifriction property. These tribofilms can simultaneously reduce the friction coefficient of the Al2 O3 /TiNX -Cu tribopair and enhance the wear resistance of the TiNX -Cu film. Based on these findings, it is believed that the autoantifriction film can drive the generation of antifriction tribofilms for lubricating and increasing the wear resistance of prosthetic devices, thereby prolonging their lifespan.


Asunto(s)
Metales , Humanos , Aleaciones , Articulación de la Cadera
15.
Drug Dev Ind Pharm ; 38(3): 365-71, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21854252

RESUMEN

In order to facilitate the intracellular delivery of therapeutic agents, a new type of liposomes-propylene glycol liposomes (PGL) were prepared, and their cell translocation capability in vitro was examined. PGL was composed of hydrogenated egg yolk lecithin, cholesterol, Tween 80 and propylene glycol. With curcumin as a model drug, characterization of loaded PGL were measured including surface morphology, particle size, elasticity, encapsulation efficiency of curcumin and physical stability. Using curcumin-loaded conventional liposomes as the control, the cell uptake capacity of loaded PGL was evaluated by detection the concentration of curcumin in cytoplasm. Compared with conventional liposomes, PGL exhibited such advantages as high encapsulation efficiency (92.74% ± 3.44%), small particle size (182.4 ± 89.2 nm), high deformability (Elasticity index = 48.6) and high stability both at normal temperature (about 25°C) and low temperature at 4°C. From cell experiment in vitro, PGL exhibited the highest uptake of curcumin compared with that of conventional liposomes and free curcumin solution. Little toxic effect on cellular viability was observed by methyl tetrazolium assay. In conclusion, PGL might be developed as a promising intracellular delivery carrier for therapeutic agents.


Asunto(s)
Curcumina/química , Liposomas/química , Vehículos Farmacéuticos/química , Propilenglicol/química , Animales , Disponibilidad Biológica , Células Cultivadas , Química Farmacéutica , Cricetinae , Portadores de Fármacos/química , Sistemas de Liberación de Medicamentos/métodos , Estabilidad de Medicamentos , Tamaño de la Partícula
16.
Drug Dev Ind Pharm ; 38(9): 1090-8, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22188116

RESUMEN

Experiments in vitro and in vivo were designed to investigate tumor growth inhibition of chemotherapeutics-loaded liposomes enhanced by acoustic cavitation. Doxorubicin-loaded liposomes (DOX liposomes) were used in experiments to investigate acoustic cavitation mediated effects on cell viability and chemotherapeutic function. The influence of lingering sensitive period after acoustic cavitation on tumor inhibition was also investigated. Animal experiment was carried out to verify the practicability of this technique in vivo. From experiment results, blank phospholipid-based microbubbles (PBM) combined with ultrasound (US) at intensity below 0.3 W/cm² could produce acoustic cavitation which maintained cell viability at high level. Compared with DOX solution, DOX liposomes combined with acoustic cavitation exerted effective tumor inhibition in vitro and in vivo. The lingering sensitive period after acoustic cavitation could also enhance the susceptibility of tumor to chemotherapeutic drugs. DOX liposomes could also exert certain tumor inhibition under preliminary acoustic cavitation. Acoustic cavitation could enhance the absorption efficiency of DOX liposomes, which could be used to reduce DOX adverse effect on normal organs in clinical chemotherapy.


Asunto(s)
Antibióticos Antineoplásicos/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Doxorrubicina/uso terapéutico , Vehículos Farmacéuticos/química , Terapia por Ultrasonido/métodos , Animales , Antibióticos Antineoplásicos/administración & dosificación , Antibióticos Antineoplásicos/metabolismo , Antibióticos Antineoplásicos/farmacología , Transporte Biológico , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/terapia , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Terapia Combinada , Doxorrubicina/administración & dosificación , Doxorrubicina/metabolismo , Doxorrubicina/farmacología , Resistencia a Antineoplásicos , Femenino , Lecitinas/química , Liposomas , Masculino , Ratones , Ratones Desnudos , Microburbujas , Sonicación , Ensayos Antitumor por Modelo de Xenoinjerto
17.
Curr Opin Biotechnol ; 74: 92-103, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-34920212

RESUMEN

Collagen is the primary component of the extracellular matrix in humans. Traditionally commercial collagen is confined to bovine and porcine sources which have concerns of pathogenic transfer. Marine wastage accounts up to 85% by weight in the fishing industry. Extraction of collagen from these wastes for economic value and environmental sustainability is clear. Marine collagens have several advantages such as excellent biocompatibility, lower zoonotic risks, less immunological risk for patients allergic to mammalian products, and less religious restrictions. However, the properties of marine collagen-based constructs are highly dependent on the methods of fabrication. This article reviews advances in the design and fabrication of marine collagen-based constructs for medical applications. The potential applications of marine collagen in the regeneration of skin, bone and cartilage were also highlighted.


Asunto(s)
Ingeniería de Tejidos , Andamios del Tejido , Animales , Materiales Biocompatibles , Huesos , Bovinos , Colágeno , Matriz Extracelular , Humanos , Mamíferos , Porcinos
18.
Acta Biomater ; 151: 45-69, 2022 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-35970479

RESUMEN

Three-dimensional (3D) bioprinting is an advanced technology to fabricate artificial 3D tissue constructs containing cells and hydrogels for tissue engineering and regenerative medicine. Nanocomposite reinforcement endows hydrogels with superior properties and tailored functionalities. A broad range of nanomaterials, including silicon-based, ceramic-based, cellulose-based, metal-based, and carbon-based nanomaterials, have been incorporated into hydrogel networks with encapsulated cells for improved performances. This review emphasizes the recent developments of cell-laden nanocomposite bioinks for 3D bioprinting, focusing on their reinforcement effects and mechanisms, including viscosity, shear-thinning property, printability, mechanical properties, structural integrity, and biocompatibility. The cell-material interactions are discussed to elaborate on the underlying mechanisms between the cells and the nanomaterials. The biomedical applications of cell-laden nanocomposite bioinks are summarized with a focus on bone and cartilage tissue engineering. Finally, the limitations and challenges of current cell-laden nanocomposite bioinks are identified. The prospects are concluded in designing multi-component bioinks with multi-functionality for various biomedical applications. STATEMENT OF SIGNIFICANCE: 3D bioprinting, an emerging technology of additive manufacturing, has been one of the most innovative tools for tissue engineering and regenerative medicine. Recent developments of cell-laden nanocomposite bioinks for 3D bioprinting, and cell-materials interactions are the subject of this review paper. The reinforcement effects and mechanisms of nanocomposites on viscosity, printability and biocompatibility of bioinks and 3D printed scaffolds are addressed mainly for bone and cartilage tissue engineering. It provides detailed information for further designing and optimizing multi-component bioinks with multi-functionality for specialized biomedical applications.


Asunto(s)
Bioimpresión , Nanocompuestos , Bioimpresión/métodos , Carbono , Celulosa , Hidrogeles/química , Impresión Tridimensional , Silicio , Ingeniería de Tejidos , Andamios del Tejido/química
19.
Inorg Chem ; 50(24): 12387-9, 2011 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-22074312

RESUMEN

A 1D anionic polyoxometalate, [Mn(4)(H(2)O)(18)WZnMn(2)(H(2)O)(2)(ZnW(9)O(34))(2)](4-), undergoes 1D to 3D single-crystal-to-single-crystal structural transformations that are induced by transition-metal cations (Co(2+) and Cu(2+)) and solvent molecules. These solid materials present interesting catalytic activity for the oxidative aromatization of Hantzsch 1,4-dihydropyridines that is dependent on the inserted heterogeneous metal cations.


Asunto(s)
Dihidropiridinas/química , Polímeros/química , Compuestos de Tungsteno/química , Catálisis , Cationes , Cobalto/química , Cobre/química , Cristalización , Cristalografía por Rayos X , Modelos Moleculares , Oxidación-Reducción , Polielectrolitos
20.
J Nanosci Nanotechnol ; 11(6): 5018-23, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21770137

RESUMEN

A series of nanocomposites containing multi-walled carbon nanotubes (MWNTs) and terephthaloyl-di-p-oxybenzoyl chloride-triethylene glycol copolyester (T-T) were prepared by in-situ high-temperature solution polycondensation. The liquid crystalline properties and thermal stability of the resulted MWNTs/T-T nanocomposites were investigated by wide-angle X-ray diffraction (WAXD), polarized optical microscopy (POM), differential scanning calorimetry (DSC), and thermogravimetric analyzer (TGA), respectively. The results showed that MWNT doping at a low concentration improved the thermal stability of T-T matrix and expanded the nematic temperature range without largely changing its conformation, making it more suitable for processing. The dispersion of MWNTs and interfacial interactions between the thermotropic liquid crystalline polymer (TLCP) molecules and the carbon nanotubes (CNTs) were investigated by scanning electron microscopy (SEM) and optical spectroscopies. The UV-vis spectroscopy and fluorescence spectra supported a strong pi-pi* interaction between the polymer and the nanotube.


Asunto(s)
Cristales Líquidos/química , Nanocompuestos/química , Nanotubos de Carbono/química , Poliésteres/química , Rastreo Diferencial de Calorimetría , Microscopía Electrónica de Rastreo , Nanocompuestos/ultraestructura , Termogravimetría , Difracción de Rayos X
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