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1.
Chem Commun (Camb) ; 2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-31478551

RESUMO

In this work, our theoretical results first demonstrate that varying the metal valence in MOFs plays a significant role in tuning their stable intrinsic electronic structure. Different valence Fe(ii) and Fe(iii) based pristine MOF-74 nanoarrays on nickel foam are further synthesized as electrodes for highly efficient electrocatalytic water oxidation.

2.
Microbiome ; 7(1): 126, 2019 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-31472697

RESUMO

BACKGROUND: The microbiome has been implicated in the initiation and persistence of inflammatory bowel disease. Despite the fact that diet is one of the most potent modulators of microbiome composition and function and that dietary intervention is the first-line therapy for treating pediatric Crohn's disease, the relationships between diet-induced remission, enteropathy, and microbiome are poorly understood. Here, we leverage a naturally-occurring canine model of chronic inflammatory enteropathy that exhibits robust remission following nutritional therapy, to perform a longitudinal study that integrates clinical monitoring, 16S rRNA gene amplicon sequencing, metagenomic sequencing, metabolomic profiling, and whole genome sequencing to investigate the relationship between therapeutic diet, microbiome, and disease. RESULTS: We show that remission induced by a hydrolyzed protein diet is accompanied by alterations in microbial community structure marked by decreased abundance of pathobionts (e.g., Escherichia coli and Clostridium perfringens), reduced severity of dysbiosis, and increased levels of the secondary bile acids, lithocholic and deoxycholic acid. Physiologic levels of these bile acids inhibited the growth of E. coli and C. perfringens isolates, in vitro. Metagenomic analysis and whole genome sequencing identified the bile acid producer Clostridium hiranonis as elevated after dietary therapy and a likely source of secondary bile acids during remission. When C. hiranonis was administered to mice, levels of deoxycholic acid were preserved and pathology associated with DSS colitis was ameliorated. Finally, a closely related bile acid producer, Clostridium scindens, was associated with diet-induced remission in human pediatric Crohn's disease. CONCLUSIONS: These data highlight that remission induced by a hydrolyzed protein diet is associated with improved microbiota structure, an expansion of bile acid-producing clostridia, and increased levels of secondary bile acids. Our observations from clinical studies of exclusive enteral nutrition in human Crohn's disease, along with our in vitro inhibition assays and in vivo studies in mice, suggest that this may be a conserved response to diet therapy with the potential to ameliorate disease. These findings provide insight into diet-induced remission of gastrointestinal disease and could help guide the rational design of more effective therapeutic diets.

3.
Sci Total Environ ; 697: 134103, 2019 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-31476500

RESUMO

The thinking of landscape sustainability discussed the win-win goal of landscape management for both ecological conservation and social development. The China-proposed Belt and Road Initiative has a pathway of green development towards sustainability, which could be benefited from a corporation on transnational landscape management. Although previous remote sensing observations showed that the ecosystem improvement and social development can coexist in most of the Belt and Road region, whether the change tendencies can be sustained have been neglected. Based on the continuous vegetation index, nighttime light and landcover datasets between 1980s-2010s, a detailed observation of the landscape evolution was obtained in this study. Depending on the identifications of temporal breakpoints, the time series was separated to identify the former and latter tendencies, and the evolution score were evaluated. The results showed that the vegetation greening trend weakened in nearly half of the region, and the arid region mostly experienced vegetation browning lately. The evolution patterns of ecological landscape and social landscape were coincided distributed in China and India, and in Southeast Asia was not scored high for both ecological conservation and social development. Consequently, we should not be overly optimistic about the synergy between ecosystem improvement and social development.

4.
Artigo em Inglês | MEDLINE | ID: mdl-31490057

RESUMO

Combination of chemotherapeutics and immunomodulators can generate synergistic anticancer efficacy, exerting efficient chemo-immunotherapy for cancer treatment. Nanoparticulate delivery system holds great promise to promote synergistic anticancer efficacy for the co-delivery of drugs. However, it remains challenges to precisely co-encapsulate and deliver combinational drugs at designed ratio due to the difference of compatibility between drugs and nanocarriers. In this study, co-assembled nanoparticles of lipophilic prodrugs (LPs) were designed to co-deliver chemotherapeutics and immunomodulators for cancer treatment. Such nano-assemblies (NAs) could act as a platform to ratiometrically co-encapsulate chemotherapeutics and immunomodulators. Based on this method, NAs formed by the self-assembly of iRGD peptide derivatives, paclitaxel (PTX) LPs and imiquimod (R837) LPs were demonstrated to target tumor at unified pharmacokinetics, further inducing the effective tumor inhibition and tumor recurrence prevention. This work provided an alternative to prepare chemo-immunotherapeutic NAs with advantages of ratiometric drug co-encapsulation and unified pharmacokinetics, which may advance the future cancer chemo-immunotherapy.

5.
J Psychiatry Neurosci ; 44(5): 1-8, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31368294

RESUMO

Background: White matter network alterations have increasingly been implicated in major depressive disorder, bipolar disorder and schizophrenia. The aim of this study was to identify shared and distinct white matter network alterations among the 3 disorders. Methods: We used analysis of covariance, with age and gender as covariates, to investigate white matter network alterations in 123 patients with schizophrenia, 123 with bipolar disorder, 124 with major depressive disorder and 209 healthy controls. Results: We found significant group differences in global network efficiency (F = 3.386, p = 0.018), nodal efficiency (F = 8.015, p < 0.001 corrected for false discovery rate [FDR]) and nodal degree (F = 5.971, pFDR < 0.001) in the left middle occipital gyrus, as well as nodal efficiency (F = 6.930, pFDR < 0.001) and nodal degree (F = 5.884, pFDR < 0.001) in the left postcentral gyrus. We found no significant alterations in patients with major depressive disorder. Post hoc analyses revealed that compared with healthy controls, patients in the schizophrenia and bipolar disorder groups showed decreased global network efficiency, nodal efficiency and nodal degree in the left middle occipital gyrus. Furthermore, patients in the schizophrenia group showed decreased nodal efficiency and nodal degree in the left postcentral gyrus compared with healthy controls. Limitations: Our findings could have been confounded in part by treatment differences. Conclusion: Our findings implicate graded white matter network alterations across the 3 disorders, enhancing our understanding of shared and distinct pathophysiological mechanisms across diagnoses and providing vital insights into neuroimaging-based methods for diagnosis and research.

6.
Cell Res ; 2019 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-31444468

RESUMO

The transient elevation of cytoplasmic calcium is essential for pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI). However, the calcium channels responsible for this process have remained unknown. Here, we show that rice CDS1 (CELL DEATH and SUSCEPTIBLE to BLAST 1) encoding OsCNGC9, a cyclic nucleotide-gated channel protein, positively regulates the resistance to rice blast disease. We show that OsCNGC9 mediates PAMP-induced Ca2+ influx and that this event is critical for PAMPs-triggered ROS burst and induction of PTI-related defense gene expression. We further show that a PTI-related receptor-like cytoplasmic kinase OsRLCK185 physically interacts with and phosphorylates OsCNGC9 to activate its channel activity. Our results suggest a signaling cascade linking pattern recognition to calcium channel activation, which is required for initiation of PTI and disease resistance in rice.

7.
Biomed Res Int ; 2019: 2931831, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31392210

RESUMO

Background: The apolipoprotein E knockout (ApoE -/-) mouse model is well established for the study of terpenoids in the prevention of atherosclerosis. Studies investigating the clinical benefit of terpenoids in humans are scarce. This systematic review and meta-analysis evaluated the effects of terpenoid administration on atherosclerotic lesion area in ApoE -/- mice. Methods: A comprehensive literature search using PubMed, Embase, and the Cochrane Library databases was performed to identify studies that assessed the effects of terpenoids on atherosclerosis in ApoE -/- mice. The primary outcome was atherosclerotic lesion area, and study quality was estimated using SYRCLE's risk of bias tool. Results: The meta-analysis included 25 studies. Overall, terpenoids significantly reduced atherosclerotic lesion area when compared to vehicle control (P<0.00001; SMD: -0.55; 95% CI: -0.72, -0.39). In terpenoid type and dose subgroup analyses, sesquiterpenoid (P=0.002; SMD -0.93; 95% CI: -1.52, -0.34), diterpenoid (P=0.01; SMD: -0.30; 95% CI: -0.54, -0.06), triterpenoid (P<0.00001; SMD: -0.66; 95% CI: -0.94, -0.39), tetraterpenoid (P<0.0001; SMD: -1.81; 95% CI: -2.70, -0.91), low dose (P=0.0001; SMD: -0.51; 95% CI: -0.76, -0.25), medium dose (P<0.0001; SMD: -0.48; 95% CI: -0.72, -0.24), and high dose (P=0.002; SMD: -1.07; 95% CI: -1.74, -0.40) significantly decreased atherosclerotic lesion area when compared to vehicle control. PROSPERO register number is CRD42019121176. Conclusion: Sesquiterpenoid, diterpenoid, triterpenoid, and tetraterpenoid have potential as antiatherosclerotic agents with a wide range of doses. This systematic review provides a reference for research programs aimed at the development of terpenoid-based clinical drugs.

8.
J Chromatogr A ; : 460369, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31402105

RESUMO

Magnetic carbonized polyaniline nanotube composite (Fe3O4@c-PANI) was synthesized via a self-assemble approach for the extraction and determination of three xanthene colorants including erythrosine B (EB), phloxine B (PB) and rhodamine B (RB). The scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectrometry, X-ray photoelectron spectroscopy and X-ray diffraction were adopted to confirm the successful synthesis of Fe3O4@c-PANI. When Fe3O4@c-PANI was applied for extracting three xanthene colorants, satisfactory extraction recoveries ranging from 89.48% to 94.15% were obtained with the relative standard deviation value of 1.09%-4.01%. Compared with Fe3O4, c-PANI and commercial adsorbents, Fe3O4@c-PANI achieved better retraction recovery for three colorants. Furthermore, adsorption kinetics and isotherms studies were analyzed to prove the adsorption mechanism of anionic and cationic colorants on Fe3O4@c-PANI. The graphite layers and pyrrole groups of the as-prepared composite can provide hydrophobic, π-π and hydrogen bonding interaction with xanthene colorants. Fe3O4 nanoparticles played dual-functional roles contributing to the separation and adsorption. Coupled with high performance liquid chromatography, the established magnetic solid phase extraction method was used for the analysis of beverage and fish samples.

9.
Biol Trace Elem Res ; 2019 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-31407216

RESUMO

The aim of this study was to investigate the long-term effects of low-dose lead exposure on bone microstructure in mice. Ten SPF 12-week-old male C57BL/6J mice were randomly divided into two groups: control (deionized water) and lead exposure (150 ppm of lead acetate in drinking water). After 24 weeks treatment, mice were weighed and the left femurs were collected and stored at - 80 °C. The right femurs of the mice were scanned by Micro-CT for three-dimensional reconstruction, and bone mineral density, bone volume fraction, trabeculae thickness, trabeculae number, and trabeculae separation were measured. The right tibia was collected to investigate histopathological changes in H&E-stained sections. The gene expression of osteoprotegerin (OPG), RANKL, and runt-related transcription factor 2 (Runx2) was determined using real-time PCR. The bone density of femoral cancellous bone and the number of cancellous bone trabeculae in the lead exposure group were both significantly decreased compared with the control group. Bone marrow stromal cell numbers were decreased following lead administration, and lipid droplet vacuoles were observed in the lead group. Levels of OPG were significantly decreased in the lead group, and lead also inhibited the expression of Runx2 compared with the control group. Long-term exposure to low doses of lead can cause bone damage without inducing other obvious symptoms through decreasing bone density and the number of cancellous bone trabeculae, further suppressing bone formation. It suggests that lead may exacerbate bone loss and osteoporosis, especially in the elderly.

10.
Artigo em Inglês | MEDLINE | ID: mdl-31387342

RESUMO

The rising cases of multidrug-resistant Acinetobacter baumannii (Ab) and the lack of effective drugs call for quick attention. Here, based on Tn7 transposon and Xer/dif system, we constructed a stable, selectable marker-free autoluminescent Ab capable of producing visible light without extra substrates. Utilization of this autoluminescent reporter strain has the potential to reduce the time, effort and costs required for the evaluation of activities of anti-Ab drug candidates in vitro.

11.
Theranostics ; 9(18): 5122-5133, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31410205

RESUMO

Controlling bilirubin to a low level is necessary in physiology because of its severe neurotoxicity. Therefore, it is of great interest to understand the regulatory mechanisms for bilirubin homeostasis. In this study, we uncover a critical role for circadian clock in regulation of bilirubin detoxification and homeostasis. Methods: The mRNA and protein levels of Bmal1 (a core clock gene), metabolic enzymes and transporters were measured by qPCR and Western blotting, respectively. Luciferase reporter, mobility shift and chromatin immunoprecipitation were used to investigate transcriptional gene regulation. Experimental hyperbilirubinemia was induced by injection of bilirubin or phenylhydrazine. Unconjugated bilirubin (UCB) and conjugated bilirubin were assessed by ELISA. Results: We first demonstrated diurnal variations in plasma UCB levels and in main bilirubin-detoxifying genes Ugt1a1 and Mrp2. Of note, the circadian UCB levels were antiphase to the circadian expressions of Ugt1a1 and Mrp2. Bmal1 ablation abrogated the circadian rhythms of UCB and bilirubin-induced hepatotoxicity in mice. Bmal1 ablation also decreased mRNA and protein expressions of both Ugt1a1 and Mrp2 in mouse livers, and blunted their circadian rhythms. A combination of luciferase reporter, mobility shift, and chromatin immunoprecipitation assays revealed that Bmal1 trans-activated Ugt1a1 and Mrp2 through specific binding to the E-boxes in the promoter region. Further, Bmal1 ablation caused a loss of circadian time-dependency in bilirubin clearance and sensitized mice to chemical induced-hyperbilirubinemia. Moreover, bilirubin stimulated Bmal1 expression through antagonism of Rev-erbα, constituting a feedback mechanism in bilirubin detoxification. Conclusion: These data supported a dual role for circadian clock in regulation of bilirubin detoxification, generating circadian variations in bilirubin level via direct transactivation of detoxifying genes Ugt1a1 and Mrp2, and defending the body against hyperbilirubinemia via Rev-erbα antagonism. Thereby, our study provided a potential mechanism for management of bilirubin related diseases.

12.
Ying Yong Sheng Tai Xue Bao ; 30(8): 2583-2590, 2019 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-31418181

RESUMO

We explored the effects of microtopography changes from artificial intervention of soil and water conservation (contour reverse-slope terrace, CRT) on tree growth in a degraded woodland on hillslope in water resource area of Songhua dam in Kunming City. The differences of the diameter at breast height (DBH), tree height, new branch increment, and leaf area index (LAI) of dominant tree species in different plots were compared through dynamic monitoring. Then, the causes of differences were analyzed by combining the soil water availability. The results showed that the maximum and mean values of DBH and height of Pinus yunnanensis (dominant species) in contour reverse-slope terrace plot were larger than those in control plot (CK), and the proportion of small-sized and low-dwarf trees in degraded forest community was higher, which indicated that the growth potential of new and seriously degraded forest was stimulated. The annual variation rate of the ave-rage new branch length and diameter of P. yunnanensis in different plots reached 72.4% and 39.1%, respectively. The changes of new branch growth of P. yunnanensis, LAI of plots, and the new branch growth rate were greater in CRT than those in CK. Soil water content was significantly correlated with both the new branch growth and LAI. The ratio of available water in plot (64.2%) was higher than that in CK (54.7%). During the rainy season (from May to September), the available water in CRT existed longer, which was conducive to tree growth and the improvement of plant community structure in degraded woodland.

13.
J Environ Manage ; 249: 109315, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31442906

RESUMO

The perspective of ecosystem services bundle is virtually a spatial clustering on landscape to mapping the relationship between ecosystem services and support the spatial strategy of landscape management. However, the efficiency of various clustering algorithms for geographically different regions are still in obscurity. In this study, we provided landscape functional zoning as a planning tool based on the ecosystem services bundles formed by carbon sequestration, soil retention and water yield. Then we used four landscape pattern indices to evaluate the performance of six clustering algorithms on landscape functional zoning. The case counties include Lankao, Jinggangshan and Luquan in China. The results showed the Natural Breaks (Jenks) scheme should be the most reasonable zone because of its high aggregated distribution and low diversity. This scheme was adjusted using some other schemes and has been employed as the final 7 kinds of zoning types. There were 5 types appeared in Lankao and Jinggangshan, and 6 types appeared in Luquan. We discussed that landscape functional zone can be a nexus connecting landscape planning and social policy. Rural reconstructing process on landscape was depicted, and landscape functional zone was proposed a practical planning tool bridged human wellbeing. The task of landscape functional zoning with the management indications may provide interdisciplinary support to decision-makers and natural resource users on landscape management.

14.
J Invertebr Pathol ; 166: 107225, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31369733

RESUMO

In this study, we investigated the prevalence of honeybee viruses in Varroa destructor and Varroa underwoodi infesting Apis cerana colonies in China. Deformed wing virus (DWV) was the most prevalent virus in these two mite species, followed by Israeli acute paralysis virus (IAPV), Black queen cell virus (BQCV), Kashmir bee virus (KBV), Chronic bee paralysis virus (CBPV), Apis mellifera filamentous virus (AmFV) and Sacbrood virus (SBV) in V. destructor, while in V. underwoodi, it was followed by CBPV, AmFV, BQCV, IAPV and KBV. In addition, multiple viruses were commonly detectable in both mite species.

15.
Mol Cell ; 75(3): 644-660.e5, 2019 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-31398325

RESUMO

Cell-cell communication via ligand-receptor signaling is a fundamental feature of complex organs. Despite this, the global landscape of intercellular signaling in mammalian liver has not been elucidated. Here we perform single-cell RNA sequencing on non-parenchymal cells isolated from healthy and NASH mouse livers. Secretome gene analysis revealed a highly connected network of intrahepatic signaling and disruption of vascular signaling in NASH. We uncovered the emergence of NASH-associated macrophages (NAMs), which are marked by high expression of triggering receptors expressed on myeloid cells 2 (Trem2), as a feature of mouse and human NASH that is linked to disease severity and highly responsive to pharmacological and dietary interventions. Finally, hepatic stellate cells (HSCs) serve as a hub of intrahepatic signaling via HSC-derived stellakines and their responsiveness to vasoactive hormones. These results provide unprecedented insights into the landscape of intercellular crosstalk and reprogramming of liver cells in health and disease.

16.
ACS Nano ; 13(8): 9473-9481, 2019 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-31373789

RESUMO

Low-dimensional lead halide perovskite materials are an emerging class of solution-processable semiconductors with promising potential applications in optoelectronic devices. Unfortunately, it is impossible to synthesize high-crystalline-quality low-dimensional perovskite single crystals without using chemotoxic solutions such as dimethylformamide/dimethyl sulfoxide or applying heating. Herein we report an economical and universal aqueous method to synthesize 2D layered and 1D chain perovskite single crystals at room temperature. The resultant chiral 2D perovskites can efficiently and selectively emit and detect circularly polarized light at room temperature. The as-synthesized 1D perovskite single crystals exhibit strong quantum confinement and enhanced self-trapped states that give efficient warm circularly polarized white-light emission. This aqueous synthetic method is general for other high-quality low-dimensional lead halide perovskite single crystals, and thus our findings would motivate more fundamental investigations on low-dimensional perovskites for potential optoelectronic applications.

17.
Sci Rep ; 9(1): 9707, 2019 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-31273266

RESUMO

The streamflow of major global rivers changes under the influences of climate change and human activities and varies greatly in different regions. The Yellow River has undergone a dramatic shift during the last six decades. Its streamflow gradually dwindled away and even dried-up severely in the late 20th century, but in recent years it has recovered and remains stable. Comprehensive understanding of the river streamflow change and its driving forces promotes effective water resource management within this complex human-natural system. Here, we develop a runoff identity attribution approach to analyze 61 years of streamflow observations from the Yellow River. We find that between the 1950s and the 1980s, human water consumption contributed more than 90% to streamflow reduction, but from the 1970s onwards, land cover change became the major factor to decrease streamflow. Since 2000, government management schemes have prevented streamflow from declining further and guarantee its stability. Based on the analysis framework we propose, persistent droughts, which are related to abrupt streamflow abatement, may be the most uncontrollable factor in the future. A more resilient management system should be therefore built to grapple with the expected increased frequency of such extreme climate events in the future.

18.
J Cell Biochem ; 2019 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-31297892

RESUMO

Retinoblastoma (RB) is the most common intraocular malignancy in infants and children. S-phase kinase-associated protein 2 (SKP2) has been unmasked as an oncogene in a great many of carcinomas. The biologic function and the detailed molecular mechanism of SKP2 in RB need to be better understood. In this study, real-time quantitative polymerase chain reaction and Western blot showed the ectopic expression of SKP2 in RB tissues and cell lines. Loss of function assays showed the attenuated cell proliferation in RB as a result of SKP2 knockdown. In addition, bioinformatics analysis predicted the interaction between SKP2 and miR-422a. Luciferase reporter assay and Pearson's correlation analysis validated the negative correlation between miR-422a and SKP2. MiR-422a overexpression led to a decline of SKP2 expression and cell growth in RB. The binding capacity between miR-422a and circ_ODC1 was also predicted by bioinformatics analysis. Pearson's correlation analysis and luciferase reporter assay confirmed that circ_ODC1 is negatively correlated with miR-422a. Silencing circ_ODC1 resulted in a rise in miR-422a expression and RB cell growth. Moreover, reduced cell growth was restored by SKP2 overexpression. In a word, SKP2, induced by circ_ODC1 and miR-422a, promotes RB proliferation. Our new findings in this research might expedite the discovery of novel prognostic markers and therapeutic targets of RB.

19.
Biol Pharm Bull ; 42(7): 1112-1119, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31257287

RESUMO

Agarwood is used to treat gastrointestinal diseases. Although our previous studies demonstrated that agarwood ethanol extract produced by the whole-tree agarwood-inducing technique (WTAAE) improves intestinal peristalsis, the intestinal protective effect of WTAAE remains unclear. This study aimed to evaluate the protective effect of WTAAE on the intestinal injury induced by fluorouracil (5-FU) and explore its potential mechanism. Institute of Cancer Research (ICR) mice were given agarwood ethanol extracts (AAEs) (details in materials part), including WTAAE (0.71, 1.42 and 2.84 g/kg), wild agarwood ethanol extract (WAAE) and burning-chisel-drilling agarwood ethanol extract (FBAAE) (2.84 g/kg). A colon injury model was induced by 5-FU. After 14 d of treatment, the histopathology and biochemical and molecular parameters were measured. Our results indicated that WTAAE enhanced the intestinal advancing rate and alleviated the severity of colon injury similar the WAAE and better than FBAAE. Simultaneously, WTAAE reduced the nitric oxide (NO) concentration and increased the glutathione (GSH) and superoxide dismutase (SOD) levels. WTAAE also reduced the levels of interleukin-17 (IL-17) and IL-33 and elevated the level of IL-10. Furthermore, WTAAE upregulated the mRNA expression of the nuclear factor-E2-related factor 2-antioxidant response element (Nrf2-ARE) pathway and downregulated the mRNA levels of the nuclear factor-kappaB (NF-κB) pathway. WTAAE had a mitigating effect on intestinal damage, suggesting that it could be used as an intestinal protective and adjuvant therapy drug for intestinal injury induced by chemical drugs.

20.
Macromol Rapid Commun ; : e1900263, 2019 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-31353755

RESUMO

Photothermal conversion agents (PTCAs) based on π-conjugated polymers are promising for cancer therapy, but the alteration of bandgap energies toward boosted photothermal properties remains challenging. Herein, polymer PTCAs with heterojunctions of a binary optical component are developed by interface hybridization on porous particles. Specifically, polypyrrole (PPy) nanodomains are successfully hosted on the wet-adhesive surface of mesoporous polydopamine nanoparticles through the loading and polymerization of pyrrole in the confined pore space (≈5.0 nm). The near-infrared absorbing polymers in the heterojunctions possess similar five-membered heterocyclic rings and can interact mutually to generate photoinduced electron transfer (PET). Such a large-area optoelectronic interaction progressively reduces the bandgap energy (down to 0.56 eV) by increasing the doped amount of PPy, which consequently enhances the extinction coefficient and photothermal conversion efficiency by 4.6- and 2.2-fold, respectively. Notably, the hybrid PTCA exhibits good biocompatibility, photocytotoxicity, and great potential for cancer therapy.

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