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1.
Biomacromolecules ; 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38820501

RESUMO

The development of a natural, additive-free, absorbable sponge with procoagulant activity for noncompressible hemostasis remains a challenging task. In this study, we extracted high molecular weight keratin (HK) from human hair and transformed it into a hemostatic sponge with a well-interconnected pore structure using a foaming technique, freeze-drying, and oxidation cross-linking. By controlling the cross-linking degree, the resulting sponge demonstrated excellent liquid absorption ability, shape recovery characteristics, and robust mechanical properties. The HK10 sponge exhibited rapid liquid absorption, expanding up to 600% within 5 s. Moreover, the HK sponge showed superior platelet activation and blood cell adhesion capabilities. In SD rat liver defect models, the sponges demonstrated excellent hemostatic performance by sealing the wound and expediting coagulation, reducing the hemostatic time from 825 to 297 s. Furthermore, HK sponges have excellent biosafety, positioning them as a promising absorbable sponge with the potential for the treatment of noncompressible hemostasis.

2.
Brain Res ; 1832: 148864, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38484924

RESUMO

AIMS: Lysophosphatidylcholine acyltransferase 3 (LPCAT3) is known to play a pivotal role in lipid metabolism, but its role in the early brain injury (EBI) following subarachnoid hemorrhage (SAH) remains unclear. This study provides insights into LPCAT3 expression alterations and functional implications in EBI following SAH. METHODS: SAH models of adult male Sprague-Dawley (SD) rats were established by intravascular perforation. Lentivirus vectors were administered by intracerebroventricular injection (i.c.v.) to either induce LPCAT3 overexpression or knockdown 14 days before SAH induction. Western blot, immunofluorescence, Nissl staining, MDA detection, ROS detection, iron content detection, and short-term and long-term neurobehavioral tests were performed to investigate the effects of regulated-LPCAT3 after SAH. RESULTS: LPCAT3 levels were found to be significantly elevated in SAH. Suppression of LPCAT3 expression via shRNA improved oxidative stress, reduced brain edema, alleviated behavioral and cognitive deficits following SAH and decreased neuronal death, while upregulating LPCAT3 expression showed opposing effects. CONCLUSION: LPCAT3 is involved in SAH-induced EBI and associated with ferroptosis. Our findings provide a referential basis for potential therapeutic interventions aimed at alleviating EBI following SAH.


Assuntos
Lesões Encefálicas , Ferroptose , Hemorragia Subaracnóidea , Ratos , Masculino , Animais , Ratos Sprague-Dawley , Encéfalo/metabolismo , Hemorragia Subaracnóidea/metabolismo , Lesões Encefálicas/metabolismo , Apoptose
3.
Front Endocrinol (Lausanne) ; 15: 1292458, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38549768

RESUMO

Background: Preeclampsia (PE) is one of the most severe pregnancy-related diseases; however, there is still a lack of reliable biomarkers. In this study, we aimed to develop models for predicting early-onset PE, severe PE, and the gestation duration of patients with PE. Methods: Eligible patients with PE were enrolled and divided into a training (n = 253) and a validation (n = 108) cohort. Multivariate logistic and Cox models were used to identify factors associated with early-onset PE, severe PE, and the gestation duration of patients with PE. Based on significant factors, nomograms were developed and evaluated using the area under the curve (AUC) and a calibration curve. Results: In the training cohort, multiple gravidity experience (p = 0.005), lower albumin (ALB; p < 0.001), and higher lactate dehydrogenase (LDH; p < 0.001) were significantly associated with early-onset PE. Abortion history (p = 0.017), prolonged thrombin time (TT; p < 0.001), and higher aspartate aminotransferase (p = 0.002) and LDH (p = 0.003) were significantly associated with severe PE. Abortion history (p < 0.001), gemellary pregnancy (p < 0.001), prolonged TT (p < 0.001), higher mean platelet volume (p = 0.014) and LDH (p < 0.001), and lower ALB (p < 0.001) were significantly associated with shorter gestation duration. Three nomograms were developed and validated to predict the probability of early-onset PE, severe PE, and delivery time for each patient with PE. The AUC showed good predictive performance, and the calibration curve and decision curve analysis demonstrated clinical practicability. Conclusion: Based on the clinical features and peripheral blood laboratory indicators, we identified significant factors and developed models to predict early-onset PE, severe PE, and the gestation duration of pregnant women with PE, which could help clinicians assess the clinical outcomes early and design appropriate strategies for patients.


Assuntos
Nomogramas , Pré-Eclâmpsia , Gravidez , Humanos , Feminino , Pré-Eclâmpsia/diagnóstico , Primeiro Trimestre da Gravidez , Gravidez de Gêmeos , Biomarcadores
4.
Medicine (Baltimore) ; 102(41): e35426, 2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37832100

RESUMO

RATIONALE: Foreign body (FB) ingestion is a common clinical emergency, although in most cases, the FB can pass safely through the entire gastrointestinal tract without causing any damage. However, ingestion of large dentures is very rare and alarming, as it can threaten the intestinal mucosa and cause perforation of the gastrointestinal tract, among other complications. PATIENT CONCERNS: A 64-year-old Chinese male was referred to our hospital for removal of a FB, which was a large denture. Clinical symptoms included chest and upper abdominal pain. He had no cough or dyspnea. Medical history included a recent cerebral infarction, craniocerebral surgery, and being bedridden for a long term. DIAGNOSES: We initially suspected a single and smooth denture, complicated by pharyngeal and esophageal mucosal injury. Radiographic examination however showed a 70-mm long opaque object located in the middle and upper esophagus, close to the trachea and aorta. INTERVENTIONS: Multiple dentures and metal hooks were removed via endoscopy using a net, grasping forceps, and rubber jacket. OUTCOMES: The patient recovered well and experienced no postoperative complications. The patient was discharged 5 days after endoscopic therapy. LESSONS: Our case showed that endoscopy was effective for the retrieval of an esophageal FB. For sharp FBs, the use of a net and rubber jacket is a good choice. However, we advocate for appropriate surgery in patients in whom endoscopy is not possible after an accurate diagnosis or those with severe complications.


Assuntos
Doenças do Esôfago , Corpos Estranhos , Masculino , Humanos , Adulto , Pessoa de Meia-Idade , Borracha , Endoscopia Gastrointestinal , Doenças do Esôfago/complicações , Corpos Estranhos/diagnóstico por imagem , Corpos Estranhos/cirurgia , Corpos Estranhos/complicações , Ingestão de Alimentos , Dentaduras/efeitos adversos
5.
J Mater Chem B ; 11(42): 10234-10251, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37869993

RESUMO

Uncontrollable hemorrhage and subsequent wound infection pose severe threats to life, especially in the case of deep, non-compressible, massive bleeding. Here, a wool keratin/zeolitic imidazolate framework-8 (WK/ZIF-8) composite shape memory sponge is prepared by incorporating ZIF-8 nanoparticles into wool keratin. The combination of keratin and ZIF-8 particles not only reduces the effect of ZIF-8 particles on cell viability but also bolsters the mechanical properties of the keratin sponge and endows it with antibacterial efficacy. Due to the synergistic effect of the excellent hemostatic performance of keratin and Zn2+ release from ZIF-8 nanoparticles, the porous structure suitable for blood cell adhesion and the shape recovery ability of sponges, the WK/ZIF-8 composite sponge exhibits superior hemostatic performance to commercial medical sponges in SD rat and rabbit hemorrhage models. In addition, in vitro and in vivo antibacterial experiments demonstrate the anti-infection activity of the composite sponge. Overall, the WK/ZIF-8 composite sponge provides a promising approach to rapidly control bleeding and promote wound healing.


Assuntos
Hemostáticos , Zeolitas , Animais , Coelhos , Ratos , Ratos Sprague-Dawley , Hemostáticos/farmacologia , , Queratinas , Hemorragia/tratamento farmacológico , Antibacterianos/farmacologia
6.
BMC Microbiol ; 23(1): 255, 2023 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-37704987

RESUMO

BACKGROUND: Rainbow trout (Oncorhynchus mykiss) is becoming popular with the increased demand for fish protein. However, the limited resources and expense of fish meal and oil have become restrictive factors for the development of the rainbow trout related industry. To solve this problem, plant-derived proteins and vegetable oils have been developed as alternative resources. The present study focuses on evaluating the effects of two experimental diets, FMR (fish meal replaced with plant-derived protein) and FOR (fish oil replaced with rapeseed oil), through the alteration of the gut microbiota in triploid rainbow trout. The commercial diet was used in the control group (FOM). RESULTS: Amplicon sequencing of the 16S and 18S rRNA genes was used to assess the changes in gut bacteria and fungi. Our analysis suggested that the α-diversity of both bacteria and fungi decreased significantly in the FMR and FOR groups, and ß-diversity was distinct between FOM/FMR and FOM/FOR based on principal coordinate analysis (PCoA). The abundance of the Planctomycetota phylum increased significantly in the FMR group, while that of Firmicutes and Bacteroidetes decreased. We also found that the fungal phylum Ascomycota was significantly increased in the FMR and FOR groups. At the genus level, we found that the abundance of Citrobacter was the lowest and that of pathogenic Schlesneria, Brevundimonas, and Mycoplasma was highest in the FMR and FOR groups. Meanwhile, the pathogenic fungal genera Verticillium and Aspergillus were highest in the FMR and FOR groups. Furthermore, canonical correspondence analysis (CCA) and network analysis suggested that the relatively low-abundance genera, including the beneficial bacteria Methylobacterium, Enterococcus, Clostridium, Exiguobacterium, Sphingomonas and Bacteroides and the fungi Papiliotrema, Preussia, and Stachybotrys, were positively correlated with plant protein or rapeseed oil. There were more modules that had the above beneficial genera as the hub nodes in the FMR and FOR groups. CONCLUSIONS: Our study suggested that the FMR and FOR diets could affect the gut microbiome in rainbow trout, which might offset the effects of the dominant and pathogenic microbial genera. This could be the underlying mechanism of explaining why no significant difference was observed in body weight between the different groups.


Assuntos
Microbioma Gastrointestinal , Oncorhynchus mykiss , Animais , Óleo de Brassica napus , Peso Corporal , Bacteroides
7.
J Asian Nat Prod Res ; 25(11): 1076-1084, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37724355

RESUMO

The investigation of chemical constituents from the rhizomes of Ruscus aculeatus resulted in the isolation of two new biphenyl derivatives, aculebiphenyls A and B (1-2), together with two known analogs (3-4). Their chemical structures were elucidated based on extensive spectroscopic interpretation and HR-ESI-MS analysis. Compounds 3-4 were isolated from the Ruscus genus for the first time. The isolated compounds were tested for anti-inflammatory activities and antibacterial activities. Compound 1 exhibited significant inhibitory effects on LPS-induced NO production and COX-2 with IC50 values of 10.8 µM and 0.4 µM. Compound 1 also significantly down-regulated the levels of inflammatory cytokines IL-1ß, IL-6, and TNF-α. Compound 1 showed moderate antibacterial activities.


Assuntos
Ruscus , Ruscus/química , Rizoma , Antibacterianos/farmacologia
8.
Int J Mol Sci ; 24(18)2023 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-37762362

RESUMO

Developing highly efficient and multifunctional epoxy resins (EPs) that overcome the shortcomings of flammability and brittleness is crucial for pursuing sustainable and safe application but remains a huge challenge. In this paper, a novel biomass-containing intumescent flame retardant containing a rigid-flexible and multi-siloxane bridge structure (DPB) was synthesized using siloxane; 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO); and biomass vanillin. DPB could facilitate the formation of a carbon residual with an intumescent structure, which effectively blocked the propagation of heat and oxygen. As a result, the peak heat release rate (pHRR) and total heat release (THR) of DPB/EP-7.5 decreased by 38.8% and 45.0%, respectively. In terms of mechanical properties, the tensile and flexural elongations at break of DPB/EP-7.5 increased by 77.2% and 105.3%, respectively. Impressively, DPB/EP-7.5 had excellent dielectric properties, with a dielectric constant of 2.5-2.9. This was due to the Si-O bonds (multi-siloxane bridges) contained in DPB/EP, which can quench the polarization behavior of the hydroxyl group. This paper provides a facile strategy for the preparation of multifunctional EP, which will pave the way for the promotion and application of EP in the high-end field.


Assuntos
Resinas Epóxi , Siloxanas , Animais , Biomassa , Carbono , Estro
9.
Front Genet ; 14: 1148126, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37284062

RESUMO

Background: Notch receptors (Notch 1/2/3/4), the critical effectors of the Notch pathway, participate in the tumorigenesis and progression of many malignancies. However, the clinical roles of Notch receptors in primary glioblastoma (GBM) have not been fully elucidated. Methods: The genetic alteration-related prognostic values of Notch receptors were determined in the GBM dataset from The Cancer Genome Atlas (TCGA). Two GBM datasets from TCGA and Chinese Glioma Genome Atlas (CGGA) were used to explore the differential expression between Notch receptors and IDH mutation status, and GBM subtypes. The biological functions of Notch Receptors were explored by Gene Ontology and KEGG analysis. The expression and prognostic significance of Notch receptors were determined in the TCGA and CGGA datasets and further validated in a clinical GBM cohort by immunostaining. A Notch3-based nomogram/predictive risk model was constructed in the TCGA dataset and validated in the CGGA dataset. The model performance was evaluated by receiver operating curves, calibration curves, and decision curve analyses. The Notch3-related phenotypes were analyzed via CancerSEA and TIMER. The proliferative role of Notch3 in GBM was validated in U251/U87 glioma cells by Western blot and immunostaining. Results: Notch receptors with genetic alterations were associated with poor survival of GBM patients. Notch receptors were all upregulated in GBM of TCGA and CGGA databases and closely related to the regulation of transcription, protein-lysine N-methyltransferase activity, lysine N-methyltransferase activity, and focal adhesion. Notch receptors were associated with Classical, Mesenchymal, and Proneural subtypes. Notch1 and Notch3 were closely correlated with IDH mutation status and G-CIMP subtype. Notch receptors displayed the differential expression at the protein level and Notch3 showed a prognostic significance in a clinical GBM cohort. Notch3 presented an independent prognostic role for primary GBM (IDH1 mutant/wildtype). A Notch3-based predictive risk model presented favorable accuracy, reliability, and net benefits for predicting the survival of GBM patients (IDH1 mutant/wildtype and IDH1 wildtype). Notch3 was closely related to immune infiltration (macrophages, CD4+ T cells, and dendritic cells) and tumor proliferation. Conclusion: Notch3-based nomogram served as a practical tool for anticipating the survival of GBM patients, which was related to immune-cell infiltration and tumor proliferation.

10.
ACS Biomater Sci Eng ; 9(4): 2001-2013, 2023 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-36930196

RESUMO

It remains a challenge to develop effective hemostatic products in battlefield rescue for noncompressible massive hemorrhage. Some previous research had concentrated on the modification of different materials to improve the hemostasis ability of sponges. Herein, to investigate the relationship between the taper of microchannels and hemostatic performance of porous sponges, gelatin methacryloyl-based sponges with designed conical microchannels and a disordered porous structure were prepared using the 3D printing method and freeze-drying technology. Experiments and theoretical model analysis demonstrated that the taper and distribution of microchannels in the sponge affected the water and blood absorption properties, as well as the expansion ability. In treatment of SD rat liver defect and SD rat liver perforation wound, GS-1 sponge with the taper (1/15) microchannels exhibited an excellent hemostatic effect with blood loss of 0.866 ± 0.093 g and a hemostasis time of 280 ± 10 s. Results showed that the hemostatic capacities of GelMA sponges were increased with the bottom diameter (taper) of conical microchannels. This is a potential strategy to develop designed taper sponges with designed taper microchannels for rapidly controlling hemorrhage.


Assuntos
Gelatina , Hemostáticos , Ratos , Animais , Ratos Sprague-Dawley , Gelatina/farmacologia , Gelatina/química , Hemostáticos/farmacologia , Hemostáticos/uso terapêutico , Hemostáticos/química , Hemorragia/tratamento farmacológico
11.
Fitoterapia ; 166: 105435, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36731607

RESUMO

In order to find potential agents for treating cancer disease in naturally occurring compounds, we conducted a systematic phytochemical investigation on the endemic species of Garcinia nujiangensis. Three new biphenyl derivatives (1-3) and one new polycyclic polyprenylated benzophenone (4), together with four known benzophenone analogues (5-8), have been isolated from the CH2Cl2 extract of the twigs and leaves of G. nujiangensis. Their structures were determined by detailed spectroscopic analyses and comparison with structurally related known analogues. Experimental and calculated ECD method was used to determine the absolute configuration of 1 and 4. Moreover, compounds 5-7 were isolated for the first time from this species. The cytotoxicities of the new compounds were evaluated using HL-60, HepG2, and A549 human cancer cell lines. Compound 4 showed more significant antiproliferative effects against HepG2 cells with an IC50 value of 11.38 ± 0.79 µM than that of three biphenyl derivatives. The morphological features of apoptosis were evaluated in 4-treated HepG2 cells. Compound 4 effectively prevented the cell cycle progression of HepG2 cells in G2 phase. Additionally, western blot analysis indicated that treatment of 4 on HepG2 cells led to decreased expression of anti-apoptotic Bcl-2 and pro-Caspase-3, and increased protein expression of both pro-apoptotic Bax and cleaved PARP with reference to ß-actin. Overall, our results suggested that the active polycyclic polyprenylated benzophenone derivatives in the twigs and leaves of G. nujiangensis can be used as a valuable source of bioactive compounds for the pharmaceutical industry.


Assuntos
Antineoplásicos Fitogênicos , Garcinia , Humanos , Fenóis/farmacologia , Linhagem Celular Tumoral , Estrutura Molecular , Garcinia/química , Antineoplásicos Fitogênicos/farmacologia , Antineoplásicos Fitogênicos/química , Apoptose , Benzofenonas/farmacologia
12.
Life Sci ; 318: 121501, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-36801213

RESUMO

AIMS: Taurohyodeoxycholic acid (THDCA), a natural 6α-hydroxylated bile acid, exhibits intestinal anti-inflammatory effects. This study aimed to explore the efficacy of THDCA on ulcerative colitis and to reveal its mechanisms of action. MAIN METHODS: Colitis was induced by intrarectal administration of trinitrobenzene sulfonic acid (TNBS) to mice. Mice in the treatment group were gavage THDCA (20, 40, and 80 mg/kg/day) or sulfasalazine (500 mg/kg/day) or azathioprine (10 mg/kg/day). The pathologic markers of colitis were comprehensively assessed. The levels of Th1-/Th2-/Th17-/Treg-related inflammatory cytokines and transcription factors were detected by ELISA, RT-PCR, and Western blotting. The balance of Th1/Th2 and Th17/Treg cells was analyzed by Flow cytometry. KEY FINDINGS: THDCA significantly alleviated colitis by improving the body weight, colon length, spleen weight, histological characteristics, and MPO activity of colitis mice. THDCA reduced the secretion of Th1-/Th17-related cytokines (IFN-γ, IL-12p70, IL-6, IL-17A, IL-21, IL-22, and TNF-α) and the expressions of transcription factors (T-bet, STAT4, RORγt, and STAT3), but increase the production of Th2-/Treg-related cytokines (IL-4, IL-10, and TGF-ß1) and the expressions of transcription factors (GATA3, STAT6, Foxp3, and Smad3) in the colon. Meanwhile, THDCA inhibited the expressions of IFN-γ, IL-17A, T-bet, and RORγt, but improved the expression of IL-4, IL-10, GATA3, and Foxp3 in the spleen. Furthermore, THDCA restored the proportion of Th1, Th2, Th17, and Treg cells, and balanced the Th1/Th2 and Th17/Treg immune response of colitis mice. SIGNIFICANCE: THDCA can alleviate TNBS-induced colitis via regulating Th1/Th2 and Th17/Treg balance, which may represent a promising treatment for patients with colitis.


Assuntos
Colite Ulcerativa , Colite , Camundongos , Animais , Colite Ulcerativa/patologia , Linfócitos T Reguladores , Interleucina-17 , Interleucina-10 , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares , Ácido Trinitrobenzenossulfônico , Interleucina-4/farmacologia , Colite/induzido quimicamente , Citocinas/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Células Th17
13.
Front Neurol ; 13: 1009253, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36324387

RESUMO

Introduction: Subarachnoid hemorrhage (SAH) is a severe hemorrhagic stroke with high mortality. However, there is a lack of clinical tools for predicting in-hospital mortality in clinical practice. LAR is a novel clinical marker that has demonstrated prognostic significance in a variety of diseases. Methods: Critically ill patients diagnosed and SAH with their data in the Medical Information Mart for Intensive Care-IV (MIMIC-IV) database and the eICU Collaborative Research Database (eICU-CRD) were included in our study. Multivariate logistic regression was utilized to establish the nomogram. Results: A total of 244 patients with spontaneous SAH in the MIMIC-IV database were eligible for the study as a training set, and 83 patients in eICU-CRD were included for external validation. Data on clinical characteristics, laboratory parameters and outcomes were collected. Univariate and multivariate logistic regression analysis identified age (OR: 1.042, P-value: 0.003), LAR (OR: 2.592, P-value: 0.011), anion gap (OR: 1.134, P-value: 0.036) and APSIII (OR: 1.028, P-value: < 0.001) as independent predictors of in-hospital mortality and we developed a nomogram model based on these factors. The nomogram model incorporated with LAR, APSIII, age and anion gap demonstrated great discrimination and clinical utility both in the training set (accuracy: 77.5%, AUC: 0.811) and validation set (accuracy: 75.9%, AUC: 0.822). Conclusion: LAR is closely associated with increased in-hospital mortality of patients with spontaneous SAH, which could serve as a novel clinical marker. The nomogram model combined with LAR, APSIII, age, and anion gap presents good predictive performance and clinical practicability.

14.
Biomater Adv ; 134: 112698, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35581074

RESUMO

It is still a challenge to develop a sponge that can efficiently control noncompressible bleeding to meet the emergency treatment and clinical demand. Herein, we combined the 3D printing sacrificial template method and freeze-drying technology to prepare polyvinyl alcohol/sodium alginate (PVA/SA) composite sponges with ordered microchannels and disordered porous structure. Compared with conventional sponges, the prepared sponge showed ultra-rapid water/blood absorption capacity and satisfactory mechanical properties. Furthermore, when the sponge was stuffed into a noncompressible wound and contacted with blood, it could accurately guide and quickly absorb a large amount of blood through the microchannels. Moreover, the platelets, red blood cells and coagulation factors would be enriched in the microchannels and microporous structure. In the SD rat liver noncompressible hemorrhage and femoral artery puncture injury model, PVA-SA composite sponge with 3D ordered/disordered porous structure showed enhanced hemostatic performance compared with commercial MPVA sponges. Depend on the special ordered/disordered porous structure, PVA-SA composite sponge could accelerate the blood convergence and promote coagulation. This design of special porous structure opened up a new avenue to develop hemostatic sponges for rapidly controlling noncompressible hemorrhage.


Assuntos
Quitosana , Hemostáticos , Alginatos/farmacologia , Animais , Quitosana/química , Hemorragia/terapia , Hemostáticos/farmacologia , Álcool de Polivinil/química , Porosidade , Ratos , Ratos Sprague-Dawley
15.
Polymers (Basel) ; 14(3)2022 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-35160634

RESUMO

Composite materials composed of polylactide (PLA) and nano-hydroxyapatite (n-HA) have been recognized as excellent candidate material in bone repai The difference in hydrophilicity/hydrophobicity and poor interfacial compatibility between n-HA filler and PLA matrix leads to non-uniform dispersion of n-HA in PLA matrix and consequent poor reinforcement effect. In this study, an HA/PLA nanocomposite was designed based on the surface modification of n-HA with poly(D-lactide) (PDLA), which not only can improve the dispersion of n-HA in the poly(L-lactide) (PLLA) matrix but also could form a stereocomplex crystal with the matrix PLLA at the interface and ultimately lead to greatly enhanced mechanical performance The n-HA/PLA composites were characterized by means of scanning electron microscopy, Fourier transform infrared spectroscopy, X-Ray diffraction, thermal gravity analysis, differential scanning calorimetry, and a mechanical test; in vitro cytotoxicity of the composite material as well as its efficacy in inducing osteogenic differentiation of rat bone marrow stromal cells (rMSCs) were also evaluated. Compared with those of neat PLLA, the tensile strength, Young's modulus, interfacial shear strength, elongation at break and crystallinity of the composites increased by 34%, 53%, 26%, 70%, and 17%, respectively. The adhesion and proliferation as well as the osteogenic differentiation of rMSCs on HA/PLA composites were clearly evidenced. Therefore, the HA/PLA composites have great potential for bone repai.

16.
Virus Genes ; 51(3): 423-9, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26560706

RESUMO

The RNA-dependent RNA polymerase (RdRp) of rice stripe virus (RSV) is critical for both the transcription and replication of the viral genome. Despite its importance, little is known about how it functions in cells. In the present study, RSV RdRp was split into three pieces, since expression of the full protein could not be achieved. Then, the intracellular localization of these three RdRp fragments and their interactions with nucleocapsid protein (NP) were investigated, which is another viral protein required for viral RNA synthesis. The data showed that all three RdRp fragments displayed punctuate staining patterns in the cytoplasm, and the C-terminal fragment co-localized with NP in the perinuclear region. Both bimolecular fluorescence complementation and co-immunoprecipitation experiments demonstrated that of the three RdRp fragments, only the C-terminal fragment could interact with NP. Further analysis using a series of truncated NPs identified the N-terminal 50-amino-acid region within NP as the determinant for its interaction with the C-terminus of RdRp.


Assuntos
Proteínas do Nucleocapsídeo/metabolismo , RNA Polimerase Dependente de RNA/metabolismo , Tenuivirus/metabolismo , Animais , Coinfecção/virologia , Imunoprecipitação/métodos , Mutação , Sinais de Localização Nuclear , Proteínas do Nucleocapsídeo/biossíntese , Proteínas do Nucleocapsídeo/genética , Oryza/virologia , Folhas de Planta/virologia , Ligação Proteica , Mapeamento de Interação de Proteínas , RNA Viral/biossíntese , RNA Viral/metabolismo , RNA Polimerase Dependente de RNA/biossíntese , RNA Polimerase Dependente de RNA/genética , Células Sf9/virologia , Tenuivirus/genética , Proteínas Virais/biossíntese , Proteínas Virais/metabolismo , Replicação Viral
17.
Virus Genes ; 51(2): 276-82, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26250446

RESUMO

The nucleocapsid protein (NP) of rice stripe virus (RSV) encapsidates viral genomic RNAs to form virion. The binding of NP with RNA is essential for the formation of virus particle. In this study, the binding specificity of RSV NP to RNA and the domains within the NP that mediate this interaction were investigated by gel electrophoretic mobility shift assays and Northwestern blot analysis. The results demonstrated that RSV NP was able to bind to all synthetic RNAs and DNAs without sequence specificity. Using a series of truncated NPs expressed in E. coli and synthetic peptides, we mapped the RNA-binding domain of NP to the central region from amino acid residues 201-232. Further alanine substitution analysis revealed that Lys(206), Lys(207), Lys(220), and Tyr(221) in the RNA-binding domain were essential for NP to bind with RNA.


Assuntos
Proteínas do Nucleocapsídeo/genética , Proteínas do Nucleocapsídeo/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , RNA/metabolismo , Tenuivirus/fisiologia , Northern Blotting , DNA/metabolismo , Análise Mutacional de DNA , Ensaio de Desvio de Mobilidade Eletroforética , Escherichia coli/genética , Expressão Gênica , Mutagênese Sítio-Dirigida , Ligação Proteica , Estrutura Terciária de Proteína , Deleção de Sequência , Especificidade por Substrato , Tenuivirus/genética
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