Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 637
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Eur J Med Chem ; 190: 112114, 2020 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-32061962

RESUMO

A series of 1,2,4-triazole derivatives 1-14 was synthesized to investigate their neuroprotective effects and mechanisms of action. Compounds 5-11 noticeably protected PC12 cells from the cytotoxicity of H2O2 or sodium nitroprusside (SNP). Compound 11 was the most effective derivative. Compound 11 chelated Fe (II) iron, scavenged reactive oxygen species (ROS), and restored the mitochondrial membrane potential (MMP). Moreover, it enhanced the activity of the antioxidant defense system by increasing the serum level of superoxide dismutase (SOD) and promoting the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2). Compound 11 caused certain improvements in behavior, the cerebral infarction area, and serum levels of biochemical indicators (TNF-α, IL-1ß, SOD and MDA) in a rat MCAO model. The lethal dose (LD50) of compound 11 in mice receiving intraperitoneal injections was greater than 400 mg/kg. Meanwhile, pharmacokinetic experiments revealed high bioavailability of this compound after both oral and intravenous administration (F = 60.76%, CL = 0.014 mg/kg/h) and a longer half-life (4.26 and 5.11 h after oral and intravenous administration, respectively). Based on these findings, compound 11 may be a promising neuroprotectant for the treatment of ischemic stroke.

2.
J Mater Chem B ; 2020 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-32068202

RESUMO

Cell culture has become an indispensable tool to uncover fundamental biophysical and biomolecular mechanisms of cells assembling into tissues. An important advancement in cell culture techniques was the introduction of three-dimensional (3D) culture systems. In this study, the mutual fusion of chondrocyte pellets was promoted in order to produce large-sized tissue-engineered cartilage by a multiplexed 3D hanging drop culture and agarose mold method to optimize the means of cultivation. Cell proliferation, aggregation, cell morphology maintenance as well as cartilage related gene expression and matrix secretion in vitro and subcutaneous implantation models were evaluated. These results indicated that the multiplexed 3D hanging drop culture involving the fusion of small pellets into a large structure enabled the efficient production of 3D tissue engineered cartilage that was closer to physiological cartilage tissue in comparison to that of the agarose mold method.

3.
Toxicol Lett ; 323: 48-56, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32017980

RESUMO

Traditional Chinese medicine (TCM) has become a crucial cause of drug-induced liver injury (DILI). Differ from chemical medicines, TCM feature more complex and mostly indefinite components. This review aimed to clarify the classification, underlying mechanisms and targets of the risk components in TCM-induced liver injury to further guide the secure application of TCM. Relevant studies or articles published on the PubMed database from January 2008 to December 2019 were searched. Based on the different chemical structures of the risk ingredients in TCM, they are divided into alkaloids, glycosides, toxic proteins, terpenoids and lactones, anthraquinones, and heavy metals. According to whether drug metabolism is activated or hepatocytes are directly attacked during TCM-induced liver injury, the high-risk substances can be classified into metabolic activation, non-metabolic activation, and mixed types. Mechanisms of the hepatotoxic ingredients in TCM-induced hepatotoxicity, including cytochrome P450 (CYP450) induction, mitochondrial dysfunction, oxidative damage, apoptosis, and idiosyncratic reaction, were also summarized. The targets involved in the risk ingredient-induced hepatocellular injury mainly include metabolic enzymes, nuclear receptors, transporters, and signaling pathways. Our periodic review and summary on the risk signals of TCM-induced liver injury must be beneficial to the integrated analysis on the multi-component, multi-target, and multi-effect characteristics of TCM-induced hepatotoxicity.

4.
Arch Pharm (Weinheim) ; : e1900294, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31894862

RESUMO

A series of (3-benzyl-5-hydroxyphenyl)carbamates were evaluated as new antibacterial agents. Several compounds showed potent inhibitory activity against sensitive and drug-resistant Gram-positive bacteria. The compounds are ineffective against all tested Gram-negative bacteria. The structure of the ester group exerted a profound effect on antibacterial activity. 4,4-Dimethylcyclohexanyl carbamate 6h exhibited the most potent inhibitory activity against the standard and clinically isolated Staphylococcus aureus, Staphylococcus epidermidis, and Enterococcus faecalis (minimum inhibitory concentration = 4-8 µg/ml) strains. The preliminary experimental evidence indicated that these carbamates target the bacterial cell wall and share a similar mechanism of action with vancomycin.

5.
Mol Med Rep ; 21(3): 1208-1216, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31894323

RESUMO

Differential expression of microRNA (miR)­335­5p, a key tumor suppressor, has been detected in pre­eclampsia (PE) placentas. However, the role of miR­335­5p in the pathogenesis of PE and the factor modulating its aberrant expression remain unknown. The present study used JEG­3 cells in vitro to investigate these mechanisms. The role of miR­335­5p in proliferation, apoptosis and migration of JEG­3 cells was investigated using MTT, Annexin V­FITC/PI, Transwell migration and wound healing assays, respectively. miR­335­5p expression levels were analyzed using reverse transcription­quantitative PCR. The expression levels of E­cadherin, N­cadherin, Snail, specificity protein 1 (Sp1) and p53 were assessed using western blot analysis. Cell viability analysis was performed using the Cell Counting Kit­8 assay. The intracellular reactive oxygen species (ROS) levels were detected using a 2,7­dichlorodihydrofluorescein diacetate assay. The present results suggested that miR­335­5p did not affect the proliferation or apoptotic rate of JEG­3 cells. Overexpression of miR­335­5p significantly inhibited the migration of JEG­3 cells, decreased the expression levels of Sp1, N­cadherin and Snail, and increased E­cadherin expression. Sp1 silencing produced similar results in JEG­3 cells. H2O2 significantly increased the intracellular ROS levels and miR­335­5p expression, whereas N­acetyl­cysteine pretreatment prior to H2O2 treatment reversed the increases in miR­335­5p expression. Knockdown of p53 significantly decreased the expression levels of miR­335­5p in JEG­3 cells and in H2O2­treated cells. The present results suggested that miR­335­5p expression levels in trophoblast cells could be increased by ROS in a p53­dependent manner, leading to the downregulation of Sp1 and subsequent inhibition of epithelial to mesenchymal transition and cell migration. The present results may provide novel evidence on the etiology of PE.

6.
Artigo em Inglês | MEDLINE | ID: mdl-31975550

RESUMO

Lithium metal anodes are among the most promising candidates for high energy density batteries. However, the long-standing issue of lithium dendrites growth during repeated charge and discharge cycles, which often leads to short circuit by puncturing the porous separator, impedes its practical application. Here, inspired by the defensive armor shield, we provide a morphological design "nano-shield" for separators to resist dendrites. Through both mechanical analysis and experiment, it is revealed that the separator protected by this nano-shield can effectively inhibit the penetration of lithium dendrites by reducing stress intensity and providing high tortuosity , a nd therefore mitigate the short circuit of Li metal batteries. More than 110 h of lithium plating life is achieved in Li/Li cell tests, which is among the longest cycle life of lithium metal anode and five times longer than that of blank separators. This new aspect of morphological and mechanical design combining both theoretical understanding and experimental results not only provides an alternative pathway for extending lifetime of lithium metal anodes, but also sheds a light on the role of separator engineering for various electrochemical energy storage devices .

7.
Genome Biol ; 21(1): 13, 2020 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-31948478

RESUMO

Chromatin interactions are important for gene regulation and cellular specialization. Emerging evidence suggests many-body spatial interactions play important roles in condensing super-enhancer regions into a cohesive transcriptional apparatus. Chromosome conformation studies using Hi-C are limited to pairwise, population-averaged interactions; therefore unsuitable for direct assessment of many-body interactions. We describe a computational model, CHROMATIX, which reconstructs ensembles of single-cell chromatin structures by deconvolving Hi-C data and identifies significant many-body interactions. For a diverse set of highly active transcriptional loci with at least 2 super-enhancers, we detail the many-body functional landscape and show DNase accessibility, POLR2A binding, and decreased H3K27me3 are predictive of interaction-enriched regions.

8.
Neuroscience ; 428: 178-191, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31918010

RESUMO

The specific mechanism of migraine chronification remains unclear. We previously demonstrated that synaptic plasticity was associated with migraine chronification. EphB receptors and their ligands, ephrinBs, are considered to be key molecules regulating the synaptic plasticity of the central nervous system. However, whether they can promote the chronification of migraine by regulating synaptic plasticity is unknown. Therefore, we investigated the role of ephrinB/EphB signaling in chronic migraine (CM). Male Sprague-Dawley rats were used to construct a chronic migraine model by dural infusion of an inflammatory soup for 7 days. We used qPCR, western blot, and immunofluorescence to detect the mRNA and protein levels of EphB2 and ephrinB2. The paw withdrawal latency and paw withdrawal threshold were measured after lateral ventricle treatment with EphB1-Fc (an inhibitor of EphB receptor). Changes in synaptic plasticity were explored by examining synaptic-associated proteins by western blot, dendritic spines of neurons by Golgi-Cox staining, and synaptic ultrastructure by transmission electron microscopy. We found that the expression of EphB2 and ephrinB2 increased in CM. The administration of EphB1-Fc relieved hyperalgesia and changes in synaptic plasticity induced by CM. In addition, EphB1-Fc inhibited the upregulation of NR2B phosphorylation. These results indicate that ephrinB/EphB signaling may regulate synaptic plasticity in CM via NR2B phosphorylation, which suggests the novel idea that ephrinB/EphB signaling may be a target for the treatment of migraine chronification.

9.
Chemosphere ; 242: 125261, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31896178

RESUMO

Seedling establishment consists of the former stage (i.e. skotomorphogenesis) and the latter stage (i.e. photomorphogenesis). Due to specific developmental processes in plants, the two stages may have different sensitivities to antibiotics. Tetracycline (TC), for example, is a major-use antibiotic. Radicle length, the relatively sensitive endpoint in plant skotomorphogenesis, is less sensitive than all of the indices of cotyledon colour and pigments in plant photomorphogenesis to TC stress. In conclusion, we suggest that plant photomorphogenesis may be more sensitive than plant skotomorphogenesis to stresses of antibiotics, but which needs further studies.


Assuntos
Antibacterianos/toxicidade , Brassica rapa/efeitos dos fármacos , Desenvolvimento Vegetal/efeitos dos fármacos , Plântula/efeitos dos fármacos , Poluentes do Solo/toxicidade , Tetraciclina/toxicidade , Proteínas de Arabidopsis/genética , Brassica rapa/crescimento & desenvolvimento , Brassica rapa/efeitos da radiação , Cotilédone/efeitos dos fármacos , Cotilédone/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Luz , Pigmentos Biológicos/biossíntese , Plântula/crescimento & desenvolvimento , Plântula/efeitos da radiação
10.
Clin Biochem ; 76: 11-16, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31765637

RESUMO

OBJECTIVE: The clinical and hematologic features of thalassemia are due to different factors, and patients with identical genotypes may regularly exhibit variable severity. In the present work, one homozygous Chinese Gγ+(Aγδß)0-thalassemia case with an asymptomatic phenotype, which is contrary to traditional views, was identified. Analysis of the underlying causes of this rare clinical phenotype involved accurate genetic diagnosis and detection of several genetic modifications. METHODS: Six members of the proband's family were enrolled in the study. Hematological parameters and hemoglobin analysis results were recorded. A suspension-array system, multiplex gap-polymerase chain reaction (gap-PCR) and multiplex ligation-dependent probe amplification (MLPA) were used together to characterize genotypes. Sanger sequencing was utilized to examine the KLF1 gene and four primary fetal hemoglobin (Hb F)-associated single-nucleotide polymorphisms (SNPs). RESULTS: Four family members carried the Chinese Gγ+(Aγδß)0-thalassemia mutation, and a homozygous state was ultimately diagnosed for the proband. All of the Chinese Gγ+(Aγδß)0 mutation-positive cases were coinherited with the Southern Asian α-thalassemia deletion (- - SEA/αα). Two SNP variants, rs7776054 and rs9399137, in the HBS1L-MYB locus were detected in the proband. CONCLUSIONS: Thus far, this is the first study to describe the molecular characterization of a homozygous Chinese Gγ+(Aγδß)0-thalassemia patient who exhibits no clinical symptoms. Our findings suggest that coinheritance of α-thalassemia or HBS1L-MYB locus variants may affect the clinical severity of Chinese Gγ+(Aγδß)0-thalassemia. We conclude that the molecular examination of genetic determinants known to be associated with clinical outcomes in Chinese Gγ+(Aγδß)0-thalassemia should be emphasized.

11.
J Hazard Mater ; 385: 121533, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-31757720

RESUMO

Biochar and compost, two common amendments, were rarely conducted to investigate their combined influence on enzymatic activities and microbial communities in organic-polluted wetlands. This article described the effects of biochar/compost on degradation efficiency of sulfamethoxazole (SMX) and ecosystem responses in polluted wetland soil during the whole remediation process. 1% biochar (SB1) increased degradation efficiency of SMX by 0.067% ascribed to the increase of dehydrogenase and urease. 5% biochar (SB5) decreased degradation efficiency by 0.206% due to the decrease of enzymes especially for dehydrogenase. 2% compost (SC2), 1% biochar & 2% compost (SBC3), both 10% compost (SC10) and 5% biochar & 10% compost (SBC15) enhanced degradation efficiency by 0.033%, 0.015% and 0.222%, respectively, due to the increase of enzymes and biomass. The degradation efficiency was positively related to biomass and enzymatic activities. High-throughput sequencing demonstrated that HCGs (SB5, SC10, SBC15) improved the bacterial diversities but reduced richness through introducing more exogenous predominance strains and annihilated several inferior strains, while LCGs (SB1, SC2, SBC3) exhibited lower diversities but higher richness through enhanced the RAs of autochthonal preponderant species and maintained some inferior species. Additionally, HCGs raised the RAs of amino and lipid metabolism gene but lowered those of carbohydrate compared with LCGs.

12.
Protein Sci ; 29(2): 469-479, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31658402

RESUMO

Free energy of transferring amino acid side-chains from aqueous environment into lipid bilayers, known as transfer free energy (TFE), provides important information on the thermodynamic stability of membrane proteins. In this study, we derived a TFE profile named General Transfer Free Energy Profile (GeTFEP) based on computation of the TFEs of 58 ß-barrel membrane proteins (ßMPs). The GeTFEP agrees well with experimentally measured and computationally derived TFEs. Analysis based on the GeTFEP shows that residues in different regions of the transmembrane (TM) segments of ßMPs have different roles during the membrane insertion process. Results further reveal the importance of the sequence pattern of TM strands in stabilizing ßMPs in the membrane environment. In addition, we show that GeTFEP can be used to predict the positioning and the orientation of ßMPs in the membrane. We also show that GeTFEP can be used to identify structurally or functionally important amino acid residue sites of ßMPs. Furthermore, the TM segments of α-helical membrane proteins can be accurately predicted with GeTFEP, suggesting that the GeTFEP is of general applicability in studying membrane protein.

13.
Biosci Rep ; 40(1)2020 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-31737900

RESUMO

Cervical cancer (CC) is ranked as the fourth most common cancer that occurs in women universally, which normally causes pain in the lower belly. Plenty of studies have stated that the expression of long non-coding RNAs (lncRNAs) is linked to the cellular development of many kinds of cancers. DSCAM-AS1 has been reported to act as an oncogene in other cancer types and the aim of our study was to uncover the function and regulatory mechanism of DSCAM-AS1 in CC. In this research, our findings presented that DSCAM-AS1 expression was up-regulated in CC cells. DSCAM-AS1 led to the development of CC by enhancing cell proliferation, migration and invasion ability. DSCAM-AS1 was verified to combine with miR-877-5p and down-regulate the expression of miR-877-5p. Results also showed that ATXN7L3 was a downstream target gene of miR-877-5p and it was unfavorably modulated by miR-877-5p. Enhanced expression of ATXN7L3 counterbalanced the DSCAM-AS1 knockdown effect on the progression of CC. This was the first time to analyze the underlying regulatory mechanism of the oncogenic DSCAM-AS1. Our findings clarified that DSCAM-AS1 played as an oncogenic lncRNA by targeting miR-877-5p/ATXN7L3 axis to promote CC progression, which may provide insights into the prevention of CC.

14.
Int Wound J ; 17(1): 206-213, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31730274

RESUMO

Geriatric population is increasing rapidly worldwide, and fragility fracture and complication following orthopaedic surgery in elderly people have now become major challenges for surgeons. Further studies are required to identify potentially modifiable factors associated with surgical site infection (SSI) in geriatric patients. This retrospective, multicenter study was conducted at four level I hospitals in China. During the 31-month study period, a total of 2341 patients (65 years or older) underwent orthopaedic surgery and complete data were recorded from September 2015 to April 2018. Demographics information, medications and additional comorbidities, surgery-related variables, and laboratory indexes were extracted and analysed. Receiver-operating characteristic analysis was performed to detect the optimum threshold of continuous variables. Independent risk factors of SSI were identified by univariate and multivariate analyses. Finally, 63 patients suffered from wound infection within the follow-up period, indicating a 2.7% incidence rate of SSI. Statistical results showed that open injury (odds ratio [OR], 9.5; 95% confidence interval [CI], 5.4-16.7), American Society of Anesthesiologists classified III-IV score (OR, 2.2; 95% CI, 1.3-3.8), surgical duration of >132 minutes (OR, 2.9; 95% CI, 1.1-5.0), serum albumin (ALB) of <36.4 mg/L (OR, 2.0; 95% CI, 1.6-3.4), and blood glucose (GLU) of >118 mg/dL (OR, 3.1; 95% CI, 1.1-5.3) were independent risk factors of postoperative SSI. With the application of sensitive and modifiable variables such as surgical duration and the levels of ALB and GLU, more geriatric patients with sub-high risk of postoperative SSI could be identified.

15.
Thromb Res ; 185: 171-179, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31838449

RESUMO

It is important to ascertain platelet responses to blood-contacting medical devices as part of a complete hemocompatibility evaluation. Nevertheless, researchers often face the problem of insufficient quantities of human blood for evaluation of platelet activation by actual medical devices. If animal blood can replace human blood to evaluate platelet activation by medical devices, testing will be smoother and will aid for quality control of related products. Therefore, in this study, we exposed representative biomaterials to human blood, rabbit blood and mouse blood, and evaluated similarities and differences in platelet activation among the three types of blood by measuring various molecular markers. We found that rabbit blood and human blood had considerable similarity in terms of platelet activation, while mouse blood and human blood showed considerable differences. Therefore, rabbit blood may replace human blood for platelet function testing.

16.
IEEE Trans Vis Comput Graph ; 26(1): 1022-1032, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31545731

RESUMO

We propose BarcodeTree (BCT), a novel visualization technique for comparing topological structures and node attribute values of multiple trees. BCT can provide an overview of one hundred shallow and stable trees simultaneously, without aggregating individual nodes. Each BCT is shown within a single row using a style similar to a barcode, allowing trees to be stacked vertically with matching nodes aligned horizontally to ease comparison and maintain space efficiency. We design several visual cues and interactive techniques to help users understand the topological structure and compare trees. In an experiment comparing two variants of BCT with icicle plots, the results suggest that BCTs make it easier to visually compare trees by reducing the vertical distance between different trees. We also present two case studies involving a dataset of hundreds of trees to demonstrate BCT's utility.

17.
Sci Total Environ ; 705: 135979, 2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-31841912

RESUMO

Climate change and eutrophication are both critical environmental issues currently. Climate change induces more critical microplastic pollution and sediment resuspension in eutrophic lakes, and conversely the presence of microplastics and resuspension events would intensify these two environmental effects. Via evaluating the impacts of microplastics and sediment resuspension on climate change and eutrophication, it is favorable to provide recommendations for ecological protection and policy formulation in regard to the nutrient input as well as the production and utilization of plastic. In this review, we explore how climate change and eutrophication interact with microplastic pollution and sediment resuspension in shallow lakes, highlighting that both of the latter two play a significant role in the former two. Furthermore, future prospects are put forward on the further and deeper research on the global warming and eutrophication in shallow lakes with microplastic pollution.

18.
Carbohydr Polym ; 229: 115546, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31826415

RESUMO

The porous antimicrobial starch particles containing N-Halamine functional groups (PST-MBA-Cl particles) were synthesized by a crosslinking polymerization between starch (ST) and N, N'-methylenebisacrylamide (MBA), and then a chlorination of amide groups of MBA. The synthetic process used only water as the solvent and was environmentally friendly. The results showed that under the optimal preparation conditions, the as-synthesized PST-MBA-Cl particles could have a Cl+% of 8.60 %. Antimicrobial tests showed that PST-MBA-Cl particles had very powerful antimicrobial efficacy against both Staphylococcus aureus and Escherichia coli and could completely kill Staphylococcus aureus with a concentration of 2.1 × 106 CFU/mL and Escherichia coli with a concentration of 5.6 × 106 CFU/mL within a contact time of one minute. Furthermore, the N-Halamine functional groups of PST-MBA-Cl particles also showed excellent stability under storage and reproducibility. Therefore, the as-synthesized PST-MBA-Cl particles will have potential applications in water disinfection.

19.
Acta Biomater ; 103: 318-332, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31857257

RESUMO

The host immune response is critical for in situ osteogenesis, but correlations between local inflammatory reactions and biomaterial osteoinduction are still poorly understood. This study used a murine intramuscular implantation model to demonstrate that calcium phosphate ceramics with different phase compositions exhibited divergent osteoinductivities. The osteoinductive potential of each ceramic was closely associated with the immunomodulatory capacity of the material, and especially with the regulation of macrophage polarization and functional status. Biphasic calcium phosphate (BCP) ceramics with superior osteoinductive potential enhanced the fraction of CD206+ M2 macrophages, up-regulated expression of M2 phenotypic markers in vitro, and increased the ARG+ M2 population in vivo. This suggested that BCP ceramics could ameliorate long-term inflammation and build a pro-osteogenic microenvironment. However, ß-tricalcium phosphate (ß-TCP) ceramics with no obvious osteoinductivity increased the fraction of CCR7+ M1 macrophages, promoted the secretion of M1 phenotypic markers in vitro, and maintained a high proportion of iNOS+ M1 macrophages in vivo. It indicated that ß-TCP ceramics could exacerbate inflammation and inhibit ectopic bone formation. Hydroxyapatite ceramics with an intermediate osteoinductivity exhibited a moderate amount of both M1 and M2 macrophages. These findings highlight the critical role of macrophage polarization in biomaterial-dependent osteoinduction, which not only deepens our understanding of osteoinductive mechanisms but also provides a strategy to design bone substitutes by endowing materials with the proper immunomodulatory abilities to achieve the desired clinic performance. STATEMENT OF SIGNIFICANCE: Calcium phosphate (CaP) ceramics with osteoinductive capacities are able to induce ectopic bone formation in non-osseous sites. However, its underlying mechanism is largely unknown. Previous studies have demonstrated an indispensable role of macrophages in osteogenesis, inspiring us that local inflammatory reaction may affect material-dependent osteoinduction. This study indicated that CaP ceramics with different phase composition could present divergent osteoinductive capacities through modulating polarization and functional status of macrophages, as biphasic calcium phosphate with potent osteoinductivity ameliorated long-term inflammation and induced a healing-associated M2 phenotype to initiate bone formation. These findings not only get an insight into the mechanism of CaP-involved osteoinduction, but also help the design of tissue-inducing implants by endowing biomaterials with proper immunomodulatory ability.

20.
J Biomed Mater Res A ; 108(1): 116-126, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31498962

RESUMO

Platelet-rich plasma (PRP) is rich in a variety of growth factors and plays an important role in the proliferation and differentiation of mesenchymal stem cells (MSCs). It has been reported that the preparation of freeze-dried platelets (lyophilized platelets [LyPRP]) from platelets could be an effective strategy to preserve the bioactivity of platelets for a long time. In this study, the osteogenic induction effects of PRP and LyPRP on MSCs were evaluated. The rabbit arterial blood was drawing to preparation of PRP by secondary centrifugation. Whole blood was prepared by lyophilization buffer to prepare LyPRP, which were activated by chloride and their surface morphology was observed. It was observed using a scanning electron microscope that platelets were evenly distributed on the surface of PRP and LyPRP. Growth factors were slowly released from PRP and LyPRP during the first 7 days and detected by the enzyme-linked immunosorbent assay kit. Cell proliferation assays and fluoresceindiacetate/propidium iodide (FDA/PI) staining demonstrated that PRP and LyPRP could promote cell proliferation. PRP and LyPRP were also shown to promote osteogenic differentiation of MSCs in vitro by osteogenesis characteristic staining and qPCR quantitative detection of osteogenic related gene expression. Both PRP and LyPRP could promote the proliferation and osteogenic differentiation of MSCs effectively. Moreover, PRP exhibited a better osteogenic induction effect on MSC than LyPRP.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA