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1.
BMC Cancer ; 24(1): 698, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38849760

RESUMO

BACKGROUND: Tumor-associated macrophages (TAMs) constitute a substantial part of human hepatocellular carcinoma (HCC). The present study was devised to explore TAM diversity and their roles in HCC progression. METHODS: Through the integration of multiple 10 × single-cell transcriptomic data derived from HCC samples and the use of consensus nonnegative matrix factorization (an unsupervised clustering algorithm), TAM molecular subtypes and expression programs were evaluated in detail. The roles played by these TAM subtypes in HCC were further probed through pseudotime, enrichment, and intercellular communication analyses. Lastly, vitro experiments were performed to validate the relationship between CD63, which is an inflammatory TAM expression program marker, and tumor cell lines. RESULTS: We found that the inflammatory expression program in TAMs had a more obvious interaction with HCC cells, and CD63, as a marker gene of the inflammatory expression program, was associated with poor prognosis of HCC patients. Both bulk RNA-seq and vitro experiments confirmed that higher TAM CD63 expression was associated with the growth of HCC cells as well as their epithelial-mesenchymal transition, metastasis, invasion, and the reprogramming of lipid metabolism. CONCLUSIONS: These analyses revealed that the TAM inflammatory expression program in HCC is closely associated with malignant tumor cells, with the hub gene CD63 thus representing an ideal target for therapeutic intervention in this cancer type.


Assuntos
Carcinoma Hepatocelular , Progressão da Doença , Transição Epitelial-Mesenquimal , Neoplasias Hepáticas , Tetraspanina 30 , Macrófagos Associados a Tumor , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Humanos , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Transição Epitelial-Mesenquimal/genética , Macrófagos Associados a Tumor/metabolismo , Macrófagos Associados a Tumor/imunologia , Macrófagos Associados a Tumor/patologia , Tetraspanina 30/metabolismo , Tetraspanina 30/genética , Metabolismo dos Lipídeos/genética , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Prognóstico , Reprogramação Celular/genética
2.
BMC Plant Biol ; 23(1): 659, 2023 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-38124039

RESUMO

BACKGROUND: German chamomile (Matricaria chamomilla L.) is an important medicinal plant, and the essential oils in the flowers have various biological activities. Genetic transformation systems are important for plant quality improvement and molecular research. To the best of our knowledge, a genetic transformation system has not yet been reported for German chamomile. RESULTS: In this study, we developed Agrobacterium-mediated transformation protocols for German chamomile callus tissues. This involved optimizing key parameters, such as hygromycin and cefotaxime concentrations, bacterial density, and infection and co-culture durations. We also performed gas chromatography-mass spectrometry analysis to identify volatile compounds in non-transgenic and transgenic callus and hairy root tissues. Furthermore, to compare and verify the callus transformation system of German chamomile, we transferred McFPS to the hairy roots of German chamomile. The results showed that the optimal conditions for Agrobacterium-mediated callus tissue transformation were as follows: explant, petiole; cefotaxime concentration, 300 mg/L; hygromycin concentration, 10 mg/L; and bacterial solution concentration, OD600 = 0.6; callus transformation efficiency was the highest when the co-culture time was 3 days. CONCLUSIONS: Establishment of a high-efficiency callus transformation system will lay the foundation for gene function identification in German chamomile.


Assuntos
Matricaria , Óleos Voláteis , Matricaria/genética , Matricaria/química , Óleos Voláteis/análise , Cinamatos , Cefotaxima , Camomila/genética , Camomila/química
3.
Thromb J ; 21(1): 33, 2023 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-36973680

RESUMO

BACKGROUND: Pulmonary tumor thrombotic microangiopathy (PTTM) is a rare malignancy-related respiratory complication, demonstrating rapid progression of pulmonary hypertension (PH) and respiratory failure. Although a number of treatments have been attempted for patients diagnosed with or suspected of having PTTM, successful-treated cases of PTTM were mainly from imatinib therapy, which was a PDGF receptor inhibitor. Anlotinib was a novel tyrosine kinase inhibitor that targets VEGFR, FGFR, PDGFR, and c-kit. CASE PRESENTATION: We reported a patient of PTTM associated with gastric carcinoma, whom were treated with anlotinib, thereby exhibiting significant improvement of PH and respiratory dysfunction. CONCLUSION: Our case provides a new understanding of therapy to PTTM, with implications for defining anlotinib as candidate drug for PTTM. Clinical diagnosis and prompt initiation of anlotinib might be one of the strategies in patients with unstable PTTM.

4.
Int J Mol Sci ; 24(2)2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36675248

RESUMO

The essential oil of German chamomile (Matricaria recutita L.) is widely used in food, cosmetics, and the pharmaceutical industry. α-Bisabolol is the main active substance in German chamomile. Farnesyl diphosphate synthase (FPS) and α-bisabolol synthase (BBS) are key enzymes related to the α-bisabolol biosynthesis pathway. However, little is known about the α-bisabolol biosynthesis pathway in German chamomile, especially the transcription factors (TFs) related to the regulation of α-bisabolol synthesis. In this study, we identified MrFPS and MrBBS and investigated their functions by prokaryotic expression and expression in hairy root cells of German chamomile. The results suggest that MrFPS is the key enzyme in the production of sesquiterpenoids, and MrBBS catalyzes the reaction that produces α-bisabolol. Subcellular localization analysis showed that both MrFPS and MrBBS proteins were located in the cytosol. The expression levels of both MrFPS and MrBBS were highest in the extension period of ray florets. Furthermore, we cloned and analyzed the promoters of MrFPS and MrBBS. A large number of cis-acting elements related to light responsiveness, hormone response elements, and cis-regulatory elements that serve as putative binding sites for specific TFs in response to various biotic and abiotic stresses were identified. We identified and studied TFs related to MrFPS and MrBBS, including WRKY, AP2, and MYB. Our findings reveal the biosynthesis and regulation of α-bisabolol in German chamomile and provide novel insights for the production of α-bisabolol using synthetic biology methods.


Assuntos
Matricaria , Óleos Voláteis , Sesquiterpenos , Geraniltranstransferase/genética , Matricaria/química , Fatores de Transcrição/genética , Óleos Voláteis/química , Sesquiterpenos/química
5.
Financ Res Lett ; 52: 103562, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36471778

RESUMO

This study examines the impact of firms' exposures on COVID-19 sentiment on the stock price crash risk. We show the exposure on COVID-19 sentiment related to the medical, travelling and uncertain aspects significantly increases the stock price crash risk, while the exposure on COVID-19 sentiment related to vaccines significantly decreases the risk of stock price crash. Furthermore, our findings are stronger for non-state-owned firms and firms with low information transparency. Overall, we provide timely policy implication for economic impacts of the COVID-19 on the stock market.

6.
Langmuir ; 38(50): 15839-15847, 2022 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-36475735

RESUMO

A droplet impacting on a rectangular pixel with an offset is prone to cause the liquid to spread out of the pixel and adhere to adjacent pixels in organic light-emitting diode (OLED) inkjet printing. Therefore, the coalescence of a droplet impacting on a rectangular pixel is crucial in understanding the reliable OLED inkjet printing. In this paper, an assumption is established that the rectangular coalescence process is divided into the fusion part and spread part. On this basis, a dynamics model is introduced to analyze the coalescence behavior of a droplet impacting on a rectangular pixel. According to the law of conservation of mass and energy, dynamic equations are developed to obtain the maximum spread length as a function of time. In addition, the volume of the fluid method is used to simulate coalescence dynamics of a droplet impacting on a rectangular pixel by using the software of FLUENT, and the analytical solutions are consistent with the simulation results. Furthermore, the effects of the positioning error and initial velocity on the coalescence dynamics are analyzed. The results show that small initial velocity and positioning error of the droplet are helpful for the reliable OLED inkjet printing.

7.
Cancer Control ; 29: 10732748221145074, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36520061

RESUMO

PURPOSE: Many investigations on prognostic factors in lung cancer have been conducted; however, little is known regarding the outcomes of lung cancer cases complicated by deep vein thrombosis (DVT). This study aimed to determine the risk factors and impact on outcomes of lung cancer patients concurrent with DVT. METHODS: Lung cancer patients who underwent lower-extremity venous ultrasound were enrolled in this study. The patients were divided into a DVT group and a non-DVT group. Demographic information, clinical characteristics, and survival were analyzed by t-test, Wilcoxon test, chi-squared test, and logistic regression analysis. RESULTS: Of the 160 enrolled lung cancer patients, DVT was detected in 30 patients. Among the DVT group, adenocarcinoma was the most common histological type (27/30, 90.00%). Lung cancer complicated with DVT was associated with advanced stage, more severe myocardial injury, and a hypercoagulable state (P < .05). Differences in driver genes between the two groups were not significant. Radiologically, lung cancer patients with DVT were more likely to present with pericardial effusion and pleural effusion than patients without DVT (P < .05). Following multivariable logistic regression analysis, advanced stage (OR 5.368, [95%CI 1.871-18.165], P = .021), NT-proBNP >300 pg/ml (OR 5.575, [95%CI 1.733-3.722], P = .018), D-dimer >5 mg/L (OR 8.449, [95%CI 4.323-18.536], P = .004), CRP >12 mg/L (OR 6.687, [95%CI 1.967-13.617], P = .010), and serum CEA >25 ng/ml (OR 4.755, [95%CI 1.358-3.123], P = .029) were independent risk factors for adenocarcinoma complicated with DVT. Finally, survival analysis revealed that the occurrence of DVT resulted in a poorer prognosis despite anticoagulant therapy (P < .05). CONCLUSION: DVT is a potential complication in patients with lung adenocarcinoma and could represent a prognostic marker for unfavorable outcome. It is essential to screen for DVT in high-risk adenocarcinoma patients.


Assuntos
Adenocarcinoma , Neoplasias Pulmonares , Trombose Venosa , Humanos , Trombose Venosa/complicações , Trombose Venosa/epidemiologia , Fatores de Risco , Neoplasias Pulmonares/complicações , Anticoagulantes , Adenocarcinoma/complicações , Estudos Retrospectivos
8.
Clin Exp Hypertens ; 44(7): 589-594, 2022 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-35766216

RESUMO

OBJECTIVES: We aimed to investigate the differences in clinical features between pulmonary embolism (PE) patients concomitant with lung cancer and without lung cancer (LC) and gain further understanding of the impact of lung cancer on pulmonary embolism. METHODS: This retrospective study sampled 114 patients diagnosed with pulmonary embolism from January 2017 to April 2021 in the First Affiliated Hospital of Soochow University. The patients were categorized into the LC group (n = 22) or non-LC group (n = 92). Myocardial injury, coagulation and blood cell parameters, along with imaging findings, were analyzed for the two groups. The primary outcome measure was the 90-day mortality. RESULTS: Of the 114 patients with pulmonary embolism in the present study, the 90 intermediate-risk patients were enrolled for further investigations. Compared to the non-LC group, patients in the LC group had milder myocardial injury, more severe coagulation function disorder, a higher incidence of central PE and a smaller change in diameter of the main pulmonary artery. We found that the occurrence of pericardial effusion created the risk of lung cancer in patients with pulmonary embolism, but there was no increase in the 90-day mortality for non-LC group versus LC group. CONCLUSION: Intermediate risk PE patients concomitant with lung cancer seem to be more likely to present specific clinical features, accordingly, clinicians must pay great attention to PE patients concomitant with lung cancer and implement effective treatments to simultaneously manage the two conditions.


Assuntos
Neoplasias Pulmonares , Embolia Pulmonar , Humanos , Incidência , Estudos Retrospectivos , Fatores de Risco
9.
Ecotoxicology ; 31(7): 1120-1136, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35864407

RESUMO

The dense vegetation in the wetland could effectively retain microplastic particles, and the distribution of microplastics varied significantly under different planting densities. In addition, microplastics in the soil environment can affect soil properties to a certain extent, which in turn can affect soil functions and biodiversity. In this study, we investigated the distribution of soil microplastics in a mangrove restoration wetland under different planting densities and their effects on wetland soil properties. The results indicated that the average abundance of soil microplastics was 2177.5 n/500 g, of which 70.9% exhibited a diameter ranging from 0.038-0.05 mm, while the remaining soil microplastics accounted for less than 20% of all microplastics, indicating that smaller-diameter microplastics were more likely to accumulate in wetland soil. The microplastic abundance could be ranked based on the planting density as follows: 0.5 × 0.5 m > 1.0 × 0.5 m > 1.0 × 1.0 m > control area. Raman spectroscopy revealed that the predominant microplastic categories in this region included polyethylene terephthalate (PET, 52%), polyethylene (PE, 24%) and polypropylene (PP, 15%). Scanning electron microscopy (SEM) images revealed fractures and tears on the surface of microplastics. EDS energy spectra indicated a large amount of metal elements on the surface of microplastics. Due to the adsorptive features of PET, this substance could influence the soil particle size distribution and thus the soil structure. All physicochemical factors, except for the soil pH, were significantly affected by PET. In addition, the CV analysis results indicated that soils in vegetated areas are more susceptible to PET than are soils in bare ground areas, leading to greater variation in their properties.


Assuntos
Microplásticos , Poluentes Químicos da Água , Monitoramento Ambiental/métodos , Plásticos/análise , Solo , Poluentes Químicos da Água/análise , Áreas Alagadas
10.
Yeast ; 37(7-8): 359-371, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32491201

RESUMO

In the budding yeast Saccharomyces cerevisiae, Svl3 and Pam1 proteins work as functional homologues. Loss of their function causes increased levels of chitin deposition in the cell wall and temperature sensitivity, suggesting their involvement in cell wall formation. We found that the N- and C-termini of these proteins have distinctive and critical functions. They contain an N-terminal part that has a probable 2-dehydropantoate 2-reductase domain. In Svl3, this part can be replaced with the yeast 2-dehydropantoate 2-reductase, Pan5, suggesting that Svl3 and its homologues may be able to mediate 2-dehydropantoate 2-reductase function. On the other hand, Svl3 is recruited to the bud tip and bud neck via multiple localization signals in the C-terminal part. One of such signals is the lysine-rich region located in the C-terminal end. The function and localization of Svl3 are significantly disrupted by the loss of this lysine-rich region; however, its localization is not completely abolished by the mutation because another localization signal enables appropriate transport. Svl3 and Pam1 orthologues are found in cells across fungal species. The Svl3 orthologues of Candida glabrata can complement the loss of Svl3 and Pam1 in S. cerevisiae. C. glabrata cells lacking the SVL3 and PAM1 orthologue genes exhibit phenotypes similar to those observed in svl3∆pam1∆ S. cerevisiae cells. Thus, Svl3 homologues may be generally required for the assembly of the cell wall in fungal cells.


Assuntos
Parede Celular/genética , Parede Celular/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Oxirredutases do Álcool , Candida glabrata , Quitina/metabolismo , Genes Fúngicos/genética , Mutação , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
11.
J Phys Chem A ; 123(1): 371-381, 2019 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-30585491

RESUMO

The fragment-based coupled-cluster (CC) theory utilizing the transferable functional groups through natural localized molecular orbital (NLMO), that is, the natural linear-scaled coupled-cluster (NLSCC) has been further developed to take the extra-fragment interactions into account. The correction to the interaction energies sacrificed during the fragmentation process for the previous NLSCC method is computed by a computationally efficient perturbation theory that maintains the original scaling. The new linear-scaled coupled-cluster for the singles and doubles (CCSD) method is applied to the analysis of relative energies of delicate conformational problems of polypeptides. By adding a perturbation correction, results accurate to less than a kcal/mol are obtained for the alanine tetramer.

13.
J Chem Phys ; 149(6): 064111, 2018 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-30111144

RESUMO

This manuscript presents the first consistent ionization potential (IP) optimized global hybrid functional to accurately estimate the vertical ionization and excitation energies of the inner-shell electrons in molecules. The new method fulfills the IP theorem that the Kohn-Sham eigenvalues of all the occupied orbitals (including the core orbitals) are good approximations to the exact vertical ionization energies. The accuracy of the one-particle spectrum is essential to enabling the one-particle density functional theory (DFT) to provide accurate results. Compared to its precursor, the range-separated hybrid functional CAM-QTP00, the new method is more computationally efficient. The IP theorem enables the new method to provide inner-shell ionization energies measured by X-ray photoelectron spectroscopy, and it can further accurately simulate the X-ray absorption spectrum (XAS, or NEXAFS). The simulated spectra can be compared to the experiment directly without shifting. In addition, the new method reduces the delocalization error (many-electron self-interaction error) which is a severe problem in DFT.

14.
J Chem Phys ; 148(17): 174309, 2018 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-29739206

RESUMO

Accurate optical characterization of the closo-Si12C12 molecule is important to guide experimental efforts toward the synthesis of nano-wires, cyclic nano-arrays, and related array structures, which are anticipated to be robust and efficient exciton materials for opto-electronic devices. Working toward calibrated methods for the description of closo-Si12C12 oligomers, various electronic structure approaches are evaluated for their ability to reproduce measured optical transitions of the SiC2, Si2Cn (n = 1-3), and Si3Cn (n = 1, 2) clusters reported earlier by Steglich and Maier [Astrophys. J. 801, 119 (2015)]. Complete-basis-limit equation-of-motion coupled-cluster (EOMCC) results are presented and a comparison is made between perturbative and renormalized non-iterative triples corrections. The effect of adding a renormalized correction for quadruples is also tested. Benchmark test sets derived from both measurement and high-level EOMCC calculations are then used to evaluate the performance of a variety of density functionals within the time-dependent density functional theory (TD-DFT) framework. The best-performing functionals are subsequently applied to predict valence TD-DFT excitation energies for the lowest-energy isomers of SinC and Sin-1C7-n (n = 4-6). TD-DFT approaches are then applied to the SinCn (n = 4-12) clusters and unique spectroscopic signatures of closo-Si12C12 are discussed. Finally, various long-range corrected density functionals, including those from the CAM-QTP family, are applied to a charge-transfer excitation in a cyclic (Si4C4)4 oligomer. Approaches for gauging the extent of charge-transfer character are also tested and EOMCC results are used to benchmark functionals and make recommendations.

16.
J Bone Miner Metab ; 35(5): 497-503, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27714461

RESUMO

Osteoporotic patients have a high risk of dental and orthopedic implant failure. Lithium chloride (LiCl) has been reported to enhance bone formation. However, the role of LiCl in the success rate of dental and orthopedic implants in osteoporotic conditions is still unknown. We investigated whether LiCl enhances implant osseointegration, implant fixation, and bone formation in osteoporotic conditions. Sprague-Dawley female rats (n = 18) were ovariectomized (OVX) to induce osteoporosis, and another nine rats underwent sham surgery. Three months after surgery, titanium implants were implanted in the tibia of the OVX and sham group rats. After implantation, the OVX rats were gavaged with 150 mg/kg/2 days of LiCl (OVX + LiCl group) or saline (OVX group), and sham group rats were gavaged with saline for 3 months. Implant osseointegration and bone formation were analyzed using histology, biomechanical testing, and micro computed tomography (micro-CT). More bone loss was observed in the OVX group compared to the control, and LiCl treatment enhanced bone formation and implant fixation in osteoporotic rats. In the OVX group, bone-implant contact (BIC) was decreased by 81.2 % compared to the sham group. Interestingly, the OVX + LiCl group showed 4.4-fold higher BIC compared to the OVX group. Micro-CT data of tibia from the OVX + LiCl group showed higher bone volume, trabecular thickness, trabecular number, and osseointegration compared to the OVX group. Maximum push-out force and implant-bone interface shear strength were 2.9-fold stronger in the OVX + LiCl group compared to the OVX group. In conclusion, LiCl enhanced implant osseointegration, implant fixation, and bone formation in osteoporotic conditions, suggesting LiCl as a promising therapeutic agent to prevent implant failure and bone loss in osteoporotic conditions.

17.
J Chem Phys ; 146(3): 034102, 2017 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-28109216

RESUMO

Though contrary to conventional wisdom, the interpretation of all occupied Kohn-Sham eigenvalues as vertical ionization potentials is justified by several formal and numerical arguments. Similarly, the performance of density functional approximations (DFAs) for fractionally charged systems has been extensively studied as a measure of one- and many-electron self-interaction errors (MSIEs). These complementary perspectives (initially recognized in ab initio dft) are shown to lead to the unifying concept that satisfying Bartlett's IP theorem in DFA's mitigates self-interaction errors. In this contribution, we show that the IP-optimized QTP functionals (reparameterization of CAM-B3LYP where all eigenvalues are approximately equal to vertical IPs) display reduced self-interaction errors in a variety of tests including the He2+ potential curve. Conversely, the MSIE-optimized rCAM-B3LYP functional also displays accurate orbital eigenvalues. It is shown that the CAM-QTP and rCAM-B3LYP functionals show improved dissociation limits, fundamental gaps and thermochemical accuracy compared to their parent functional CAM-B3LYP.

18.
J Chem Phys ; 145(3): 034107, 2016 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-27448874

RESUMO

This manuscript presents the second, consistent density functional in the QTP (Quantum Theory Project) family, that is, the CAM-QTP(01). It is a new range-separated exchange-correlation functional in which the non-local exchange contribution is 100% at large separation. It follows the same basic principles of this family that the Kohn-Sham eigenvalues of the occupied orbitals approximately equal the vertical ionization energies, which is not fulfilled by most of the traditional density functional methods. This new CAM-QTP(01) functional significantly improves the accuracy of the vertical excitation energies especially for the Rydberg states in the test set. It also reproduces many other properties such as geometries, reaction barrier heights, and atomization energies.

19.
J Chem Phys ; 145(2): 024312, 2016 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-27421410

RESUMO

The accurate determination of the preferred Si12C12 isomer is important to guide experimental efforts directed towards synthesizing SiC nano-wires and related polymer structures which are anticipated to be highly efficient exciton materials for the opto-electronic devices. In order to definitively identify preferred isomeric structures for silicon carbon nano-clusters, highly accurate geometries, energies, and harmonic zero point energies have been computed using coupled-cluster theory with systematic extrapolation to the complete basis limit for set of silicon carbon clusters ranging in size from SiC3 to Si12C12. It is found that post-MBPT(2) correlation energy plays a significant role in obtaining converged relative isomer energies, suggesting that predictions using low rung density functional methods will not have adequate accuracy. Utilizing the best composite coupled-cluster energy that is still computationally feasible, entailing a 3-4 SCF and coupled-cluster theory with singles and doubles extrapolation with triple-ζ (T) correlation, the closo Si12C12 isomer is identified to be the preferred isomer in the support of previous calculations [X. F. Duan and L. W. Burggraf, J. Chem. Phys. 142, 034303 (2015)]. Additionally we have investigated more pragmatic approaches to obtaining accurate silicon carbide isomer energies, including the use of frozen natural orbital coupled-cluster theory and several rungs of standard and double-hybrid density functional theory. Frozen natural orbitals as a way to compute post-MBPT(2) correlation energy are found to be an excellent balance between efficiency and accuracy.

20.
Int J Mol Sci ; 16(9): 21070-86, 2015 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-26404255

RESUMO

Titanium (Ti) has been widely used in clinical applications for its excellent biocompatibility and mechanical properties. However, the bioinertness of the surface of Ti has motivated researchers to improve the physicochemical and biological properties of the implants through various surface modifications, such as coatings. For this purpose, we prepared a novel bioactive material, a lanthanum-incorporated hydroxyapatite (La-HA) coating, using a dip-coating technique with a La-HA sol along with post-heat treatment. The XRD, FTIR and EDX results presented in this paper confirmed that lanthanum was successfully incorporated into the structure of HA. The La-HA coating was composed of rod-like particles which densely compacted together without microcracks. The results of the interfacial shear strength test indicated that the incorporation of lanthanum increased the bonding strength of the HA coating. The mass loss ratios under acidic conditions (pH=5.5) suggested that the La-HA coatings have better acid resistance. The cytocompatibility of the La-HA coating was also revealed by the relative activity of alkaline phosphatase, cellular morphology and cell proliferation assay in vitro. The present study suggested that La-HA coated on Ti has promising potential for applications in the development of a new type of bioactive coating for metal implants.


Assuntos
Materiais Revestidos Biocompatíveis/farmacologia , Durapatita/química , Lantânio/química , Titânio/química , Fosfatase Alcalina/metabolismo , Animais , Proliferação de Células/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Materiais Revestidos Biocompatíveis/química , Durapatita/farmacologia , Concentração de Íons de Hidrogênio , Lantânio/farmacologia , Teste de Materiais , Camundongos , Células NIH 3T3 , Resistência ao Cisalhamento , Propriedades de Superfície
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