Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Environ Manage ; 347: 119204, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37804634

RESUMO

This paper is likely the first attempt to empirically investigate the direct effect of geopolitical risk on sustainable development goals (SDGs). We employ a newly developed SDG index along with its 17 sub-indices from the United Nations to capture various aspects of sustainable development. On a panel sample covering 41 countries from 2015 to 2021, we find that elevated geopolitical tensions can hinder the progress towards achieving sustainable development goals. This result is robust to various model specifications and estimation approaches. Further analyses show that the two dimensions affected are Decent Work and Economic Growth (SDG8) and Climate Action (SDG13). Heterogeneity test finds that the negative effect of geopolitical risks is only present in countries highly dependent on natural resources. More importantly, improvements in institutional quality could partially offset the detrimental effect of geopolitical risks on sustainable development goals. Therefore, this study provides important implications for policymakers in devising measures to maintain the progress to achieve SDGs in the era of rising global uncertainties.


Assuntos
Saúde Global , Desenvolvimento Sustentável , Recursos Naturais , Desenvolvimento Econômico , Clima , Objetivos
2.
Int J Biol Macromol ; 243: 125248, 2023 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-37307971

RESUMO

Dual-drug delivery systems for anticancer therapy have recently attracted substantial attention due to their potency to overcome limitations of conventional anti-cancer drugs, tackle drug resistance problems, as well as improve the therapeutic efficacy. In this study, we introduced a novel nanogel based on folic acid-gelatin-pluronic P123 (FA-GP-P123) conjugate to simultaneously deliver quercetin (QU) and paclitaxel (PTX) to the targeted tumor. The results indicated that the drug loading capacity of FA-GP-P123 nanogels was significantly higher than that of P123 micelles. The kinetic release profiles of QU and PTX from the nanocarriers were governed by Fickian diffusion and swelling behavior, respectively. Notably, FA-GP-P123/QU/PTX dual-drug delivery system induced higher toxicity to MCF-7 and Hela cancer cells than either QU or PTX individual delivery system, and the non-targeted dug delivery system (GP-P123/QU/PTX), indicating the synergistic combination of dual drugs and FA positive targeting effect. Furthermore, FA-GP-P123 could effectively deliver QU and PTX to tumors in vivo after administration into MCF-7 tumor-bearing mice, which resulted in 94.20 ± 5.90 % of tumor volume reduced at day 14. Moreover, the side effects of the dual-drug delivery system were significantly reduced. Overall, we suggest FA-GP-P123 as potential nanocarrier for dual-drug delivery for targeted chemotherapy.


Assuntos
Gelatina , Paclitaxel , Camundongos , Animais , Paclitaxel/farmacologia , Paclitaxel/uso terapêutico , Gelatina/farmacologia , Quercetina/farmacologia , Nanogéis , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Sistemas de Liberação de Medicamentos/métodos , Micelas , Ácido Fólico/farmacologia , Portadores de Fármacos/farmacologia
3.
Curr Drug Deliv ; 19(9): 966-979, 2022 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-35366771

RESUMO

INTRODUCTION: Multi-drug nanosystem has been employed in several therapeutic models due to the synergistic effect of the drugs and/or bioactive compounds, which help in tumor targeting and limit the usual side effects of chemotherapy. METHODS: In this research, we developed the amphiphilic Heparin-poloxamer P403 (HSP) nanogel that could load curcumin (CUR) and Paclitaxel (PTX) through the hydrophobic core of Poloxamer P403. The features of HSP nanogel were assessed through Fourier-transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), differential light scattering (DLS), and critical micelle concentration (CMC). Nanogel and its dual drug-loaded platform showed high stability and spherical morphology. RESULTS: The drug release profile indicated fast release at pH 5.5, suggesting effective drug distribution at the tumor site. In vitro research confirms lower cytotoxicity of HSP@CUR@PTX compared to free PTX and higher inhibition effect with MCF-7 than HSP@PTX. These results support the synergism between PTX and CUR. CONCLUSION: HSP@CUR@PTX suggests a prominent strategy for achieving the synergistic effect of PTX and CUR to circumvent undesirable effects in breast cancer treatment.


Assuntos
Antineoplásicos , Neoplasias da Mama , Curcumina , Nanopartículas , Antineoplásicos/química , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Curcumina/química , Portadores de Fármacos/química , Feminino , Heparina/uso terapêutico , Humanos , Nanogéis , Nanopartículas/química , Paclitaxel/química , Paclitaxel/farmacologia , Poloxâmero/uso terapêutico , Espectroscopia de Infravermelho com Transformada de Fourier
4.
Gels ; 8(1)2022 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-35049594

RESUMO

Nanosized multi-drug delivery systems provide synergistic effects between drugs and bioactive compounds, resulting in increased overall efficiency and restricted side effects compared to conventional single-drug chemotherapy. In this study, we develop an amphiphilic heparin-poloxamer P403 (HP403) nanogel that could effectively co-load curcuminoid (Cur) and cisplatin hydrate (CisOH) (HP403@CisOH@Cur) via two loading mechanisms. The HP403 nanogels and HP403@CisOH@Cur nanogels were closely analyzed with 1H-NMR spectroscopy, FT-IR spectroscopy, TEM, and DLS, exhibiting high stability in spherical forms. In drug release profiles, accelerated behavior of Cur and CisOH at pH 5.5 compared with neutral pH was observed, suggesting effective delivery of the compounds in tumor sites. In vitro studies showed high antitumor activity of HP403@CisOH@Cur nanogels, while in vivo assays showed that the dual-drug platform prolonged the survival time of mice and prevented tail necrosis. In summary, HP403@CisOH@Cur offers an intriguing strategy to achieve the cisplatin and curcumin synergistic effect in a well-designed delivery platform that increases antitumor effectiveness and overcomes undesired consequences caused by cisplatin in breast cancer treatment.

5.
J Biomater Sci Polym Ed ; 33(4): 426-442, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34641768

RESUMO

In this study, we investigated two formulations of chitosan-Pluronic P123 with different folate ligand designation for targeted delivery of Paclitaxel (PTX), in which folic acid (FA) was directly conjugated to chitosan (FA-Cs-P123) or substituted onto P123 (Cs-P123-FA). The results showed that the FA content of Cs-P123-FA was determined at 0.71 wt/wt% which was significantly higher than that of FA-Cs-P123 (0.31 wt/wt%). Two copolymers were low critical gel concentrations (CGC). FA-Cs-P123 and Cs-P123-FA nanogels performed high PTX encapsulation efficiency reaching 95.57 ± 5.51 and 92.51 ± 6.68 wt/wt%, respectively. Transmission electron microscopy (TEM) and zeta potential analysis indicated that the PTX-loaded nanogels were spherically formed around 60 nm in diameter along with positive charge. Furthermore, the PTX release profile was slow and it was controlled by the pH of the medium. In particular, in vitro biocompatibility assays indicated that both FA-Cs-P123 and Cs-P123-FA exhibited good biological compatibility with a human foreskin fibroblast cell line and well uptake efficiency into MCF-7 cancer cells. Cs-P123-FA nanogel significantly enhanced the cytotoxicity of PTX in comparison with FA-Cs-P123. The result indicates that Cs-P123-FA nanogels with a higher decorated FA content perform a better targeting efficiency; therefore, they could have great potential application towards breast cancer treatment.


Assuntos
Quitosana , Nanopartículas , Neoplasias , Linhagem Celular Tumoral , Quitosana/química , Portadores de Fármacos/química , Ácido Fólico/química , Humanos , Ligantes , Células MCF-7 , Nanogéis , Nanopartículas/química , Paclitaxel/química , Paclitaxel/farmacologia , Poloxâmero
6.
Int J Biol Macromol ; 185: 592-603, 2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34216661

RESUMO

This paper presents a new thermal sensitive hydrogel system based on cystamine-functionalised sodium alginate-g-pluronic F127 (ACP). The introduction of cystamine to the alginate backbone not only creates a covalent bond with pluronic F127 but also provides intrinsic anti-bacterial activity for the resultant hydrogel. The amount of water uptake inside the hydrogel remained ~200% for 6 days and the degradation was completed in 12 days in physiological media. The ACP copolymer solution could form a hydrogel at body temperature (~37 °C) and could return to the solution phase if the temperature decreased below 25o °C. Fibroblast encapsulated in situ in the ACP hydrogel maintained their viability (≥90% based on the live/dead assay) for 7 days, demonstrating the good biocompatibility of the ACP hydrogel for long-term cell cultivation. In addition, three-dimensional (3D) culture showed that fibroblast attached to the hydrogels and successfully mimicked the porous structure of the ACP hydrogel after 5 days of culture. Fibroblast cells could migrate from the cell-ACP clusters and form a confluent cell layer on the surface of the culture dish. Altogether, the obtained results indicate that the thermal-responsive ACP hydrogel synthesised in this study may serve as a cellular delivery platform for diverse tissue engineering applications.


Assuntos
Alginatos/farmacologia , Antibacterianos/farmacologia , Cistamina/química , Poloxâmero/química , Alginatos/química , Antibacterianos/química , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Humanos , Hidrogéis/química , Injeções , Termodinâmica , Engenharia Tecidual
7.
Int J Biol Macromol ; 177: 360-369, 2021 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-33631259

RESUMO

Hematin has been used as an alternative enzyme catalyst to horseradish peroxidase (HRP) due to its iron-containing activity center. Although hematin and it derivatives have been widely used for polymerization of phenol/analine compounds, it has some drawbacks such as the limited solubility and reaction only at high pH condition. Herein, we report a nanosized biomimetic catalyst, hematin-decorated polyamidoamine dendrimer (G3.0-He) that can effectively catalyze the in situ hydrogelation of phenol-conjugated polymers under neutral pH condition. We demonstrate that G3.0-He particles are smaller than 100 nm and have excellent enzyme-mimetic functions. Interestingly, the nanosized catalyst is not inactivated at high H2O2 concentration. Compared to pure hematin, G3.0-He has significantly higher dispersion in acidic and neutral media, and preserves the percentage of survival of fibroblasts over 90%. Notably, G3.0-He possesses an exquisite HRP-mimicking activity in gelation of gelatin derivative with phenolic hydroxyl (tyamine) moieties under mild physiological conditions. The in vitro study demonstrated that Gel-Tyr hydrogel by G3.0-He catalyzed reaction had excellent cytocompatibility and an excellent scaffold for adhesion to fibroblast cells. Therefore, the designed minimalistic G3.0-He catalyst could serve as an effective catalytic alternative for HRP enzyme in the preparation of biomedical hydrogels.


Assuntos
Materiais Biomiméticos , Dendrímeros , Fibroblastos/metabolismo , Hemina , Teste de Materiais , Nanopartículas/química , Materiais Biomiméticos/química , Materiais Biomiméticos/farmacologia , Linhagem Celular , Dendrímeros/química , Dendrímeros/farmacologia , Hemina/química , Hemina/farmacologia , Peroxidase do Rábano Silvestre/química , Peroxidase do Rábano Silvestre/farmacologia , Humanos
8.
Polymers (Basel) ; 11(5)2019 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-31067644

RESUMO

Herein, a new process to manufacture multicore micelles nanoparticles reinforced with co-assembly via hydrophobic interaction and electrostatic interaction under the help of ultrasonication was developed. The precise co-assembly between negative/hydrophobic drug and positive charged amphiphilic copolymer based pluronic platform allows the formation of complex micelles structures as the multicore motif with predefined functions. In this study, curcumin was selected as a drug model while positively charged copolymer was based on a pluronic-conjugated gelatin with different hydrophobicity length of Pluronic F87 and Pluronic F127. Under impact of dual hydrophobic and electrostatic interactions, the nCur-encapsulated core-shell micelles formed ranging from 40 nm to 70 nm and 40-100 nm by transmission electron microscopy (TEM) and Dynamic Light Scattering (DLS), respectively. It is found that the structures emerged depended on the relative lengths of the hydrophobic blocks in pluronic. Regarding g2(τ) behavior from DLS measurement, the nanogels showed a high stability in spherical form. Surprisingly, the release profiles showed a sustainable behavior of Cur from this system for drug delivery approaches. In vitro study exhibited that nCur-encapsulated complex micelles increased inhibitory activity against cancer cells growth with IC50 is 4.02 ± 0.11 mg/L (10.92 ± 0.3 µM) which is higher than of free curcumin at 9.40 ± 0.17 mg/L (25.54 ± 0.18 µM). The results obtained can provide the new method to generate the hierarchical assembly of copolymers with incorporated loading with the same property.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...