Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 152
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Proc Natl Acad Sci U S A ; 120(29): e2218973120, 2023 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-37428928

RESUMO

Antibiotics are among the most used weapons in fighting microbial infections and have greatly improved the quality of human life. However, bacteria can eventually evolve to exhibit antibiotic resistance to almost all prescribed antibiotic drugs. Photodynamic therapy (PDT) develops little antibiotic resistance and has become a promising strategy in fighting bacterial infection. To augment the killing effect of PDT, the conventional strategy is introducing excess ROS in various ways, such as applying high light doses, high photosensitizer concentrations, and exogenous oxygen. In this study, we report a metallacage-based PDT strategy that minimizes the use of ROS by jointly using gallium-metal organic framework rods to inhibit the production of bacterial endogenous NO, amplify ROS stress, and enhance the killing effect. The augmented bactericidal effect was demonstrated both in vitro and in vivo. This proposed enhanced PDT strategy will provide a new option for bacterial ablation.


Assuntos
Fotoquimioterapia , Humanos , Espécies Reativas de Oxigênio/farmacologia , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bactérias
2.
Hepatology ; 76(1): 155-171, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-34717002

RESUMO

BACKGROUND AND AIMS: NAFLD is a key component of metabolic syndrome, ranging from nonalcoholic fatty liver to NASH, and is now becoming the leading cause of cirrhosis and HCC worldwide. However, due to the complex and unclear pathophysiological mechanism, there are no specific approved agents for treating NASH. Breviscapine, a natural flavonoid prescription drug isolated from the traditional Chinese herb Erigeron breviscapus, exhibits a wide range of pharmacological properties, including effects on metabolism. However, the anti-NASH efficacy and mechanisms of breviscapine have not yet been characterized. APPROACH AND RESULTS: We evaluated the effects of breviscapine on the development of hepatic steatosis, inflammation, and fibrosis in vivo and in vitro under metabolic stress. Breviscapine treatment significantly reduced lipid accumulation, inflammatory cell infiltration, liver injury, and fibrosis in mice fed a high-fat diet, a high-fat/high-cholesterol diet, or a methionine- and choline-deficient diet. In addition, breviscapine attenuated lipid accumulation, inflammation, and lipotoxicity in hepatocytes undergoing metabolic stress. RNA-sequencing and multiomics analyses further indicated that the key mechanism linking the anti-NASH effects of breviscapine was inhibition of TGF-ß-activated kinase 1 (TAK1) phosphorylation and the subsequent mitogen-activated protein kinase signaling cascade. Treatment with the TAK1 inhibitor 5Z-7-oxozeaenol abrogated breviscapine-mediated hepatoprotection under metabolic stress. Molecular docking illustrated that breviscapine directly bound to TAK1. CONCLUSION: Breviscapine prevents metabolic stress-induced NASH progression through direct inhibition of TAK1 signaling. Breviscapine might be a therapeutic candidate for the treatment of NASH.


Assuntos
Flavonoides , MAP Quinase Quinase Quinases , Hepatopatia Gordurosa não Alcoólica , Animais , Dieta Hiperlipídica/efeitos adversos , Flavonoides/farmacologia , Inflamação/metabolismo , Metabolismo dos Lipídeos , Fígado/patologia , Cirrose Hepática/complicações , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/prevenção & controle , MAP Quinase Quinase Quinases/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Simulação de Acoplamento Molecular , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/patologia
3.
J Nanobiotechnology ; 21(1): 57, 2023 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-36803772

RESUMO

BACKGROUND: Globally, millions of patients suffer from regenerative deficiencies, such as refractory wound healing, which is characterized by excessive inflammation and abnormal angiogenesis. Growth factors and stem cells are currently employed to accelerate tissue repair and regeneration; however, they are complex and costly. Thus, the exploration of new regeneration accelerators is of considerable medical interest. This study developed a plain nanoparticle that accelerates tissue regeneration with the involvement of angiogenesis and inflammatory regulation. METHODS: Grey selenium and sublimed sulphur were thermalized in PEG-200 and isothermally recrystallised to composite nanoparticles (Nano-Se@S). The tissue regeneration accelerating activities of Nano-Se@S were evaluated in mice, zebrafish, chick embryos, and human cells. Transcriptomic analysis was performed to investigate the potential mechanisms involved during tissue regeneration. RESULTS: Through the cooperation of sulphur, which is inert to tissue regeneration, Nano-Se@S demonstrated improved tissue regeneration acceleration activity compared to Nano-Se. Transcriptome analysis revealed that Nano-Se@S improved biosynthesis and ROS scavenging but suppressed inflammation. The ROS scavenging and angiogenesis-promoting activities of Nano-Se@S were further confirmed in transgenic zebrafish and chick embryos. Interestingly, we found that Nano-Se@S recruits leukocytes to the wound surface at the early stage of regeneration, which contributes to sterilization during regeneration. CONCLUSION: Our study highlights Nano-Se@S as a tissue regeneration accelerator, and Nano-Se@S may provide new inspiration for therapeutics for regenerative-deficient diseases.


Assuntos
Nanocompostos , Nanopartículas , Selênio , Embrião de Galinha , Humanos , Camundongos , Animais , Selênio/farmacologia , Selênio/química , Peixe-Zebra/metabolismo , Espécies Reativas de Oxigênio , Cicatrização , Nanopartículas/química , Inflamação , Enxofre
4.
Acta Biochim Biophys Sin (Shanghai) ; 55(10): 1630-1639, 2023 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-37381672

RESUMO

Umbilical cord blood (UCB) is an advantageous source for hematopoietic stem/progenitor cell (HSPC) transplantation, yet the current strategies for large-scale and cost-effective UCB-HSPC preparation are still unavailable. To overcome these obstacles, we systematically evaluate the feasibility of our newly identified CH02 peptide for ex vivo expansion of CD34 + UCB-HSPCs. We herein report that the CH02 peptide is specifically enriched in HSPC proliferation via activating the FLT3 signaling. Notably, the CH02-based cocktails are adequate for boosting 12-fold ex vivo expansion of UCB-HSPCs. Meanwhile, CH02-preconditioned UCB-HSPCs manifest preferable efficacy upon wound healing in diabetic mice via bidirectional orchestration of proinflammatory and anti-inflammatory factors. Together, our data indicate the advantages of the CH02-based strategy for ex vivo expansion of CD34 + UCB-HSPCs, which will provide new strategies for further development of large-scale HSPC preparation for clinical purposes.


Assuntos
Diabetes Mellitus Experimental , Transplante de Células-Tronco Hematopoéticas , Animais , Camundongos , Sangue Fetal , Células-Tronco Hematopoéticas , Antígenos CD34 , Moléculas de Adesão Celular , Peptídeos/farmacologia , Células Cultivadas
5.
Anal Bioanal Chem ; 413(6): 1533-1540, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33462658

RESUMO

A facile and economic colorimetric strategy was designed for ATP detection by rationally using urease, a pH-responsive molecule, and a metal-mediated switchable DNA probe. By utilizing metal ions as a modulator of urease activity, the concentration of ATP is translated into pH change, which can be readily visualized by naked eye. An unmodified single-stranded DNA probe was designed, which consists of a target binding sequence and two flanked cytosine (C)-rich sequences. This C-rich single-stranded DNA can form a hairpin structure triggered by Ag+ ions via C-Ag+-C base mismatch. Upon introduction of ATP, Ag+-coordinated hairpin DNA structure will be broken and release the included Ag+, thus inhibiting the activity of urease. Conversely, urease can hydrolyze urea and raise pH value of the solution, resulting in the color change of the sensing solution. The proposed assay allows determination of ATP as low as 1.6 nM and shows a satisfactory result in human serum. Because of simple operation and low cost of this method, we believe it has a potential in point-of-care (POC) testing in resource-limited areas. Schematic illustration of pH-responsive colorimetric sensor for ATP detection based on switchable DNA aptamer and metal ion-urease interactions.


Assuntos
Trifosfato de Adenosina/análise , Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais , Colorimetria/métodos , Íons/química , Metais/química , Bioensaio , DNA de Cadeia Simples/química , Humanos , Concentração de Íons de Hidrogênio , Hidrólise , Testes Imediatos , Ligação Proteica , Soro/efeitos dos fármacos , Prata/química , Espectrofotometria Ultravioleta , Urease/química
6.
Int J Cancer ; 147(11): 3007-3018, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-32427348

RESUMO

tRNA-derived fragments, a class of small noncoding RNAs (sncRNAs), have been identified in numerous studies in recent years. tRNA-derived fragments are classified into two main groups, including tRNA halves (tiRNAs) and tRNA-derived small RNA fragments (tRFs), according to different cleavage positions of the precursor or mature tRNAs. Instead of random tRNA degradation debris, a growing body of evidence has shown that tRNA-derived fragments are precise products of specific tRNA modifications and play important roles in biological activities, such as regulating protein translation, affecting gene expression, and altering immune signaling. Recently, the relations between tRNA-derived fragments and the occurrence of human diseases, especially cancers, have generated wide interest. It has been demonstrated that tRNA-derived fragments are involved in cancer cell proliferation, metastasis, progression and survival. In this review, we will describe the biogenesis of tRNA-derived fragments, the distinct expression and function of tRNA-derived fragments in the development of cancers, and their emerging roles as diagnostic and prognostic biomarkers and precise targets of future treatments.


Assuntos
Neoplasias/genética , Pequeno RNA não Traduzido/genética , RNA de Transferência/química , Biomarcadores Tumorais/genética , Proliferação de Células , Sobrevivência Celular , Regulação Neoplásica da Expressão Gênica , Humanos , Prognóstico , Biossíntese de Proteínas , Estabilidade de RNA
7.
Biochem Biophys Res Commun ; 526(4): 1077-1084, 2020 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-32312522

RESUMO

Bilobalide, one of the key bioactive components of Ginkgo biloba leaves, exerts prominent neuroprotective properties in central nervous system (CNS) disease. However, the effect of bilobalide on blood-brain barrier (BBB) permeability remains unknown. In this study, we investigated the effect of bilobalide on BBB permeability and its potential mechanism involved. Both the in vitro and in vivo results showed that significant enhancement of BBB permeability was found following bilobalide treatment, evidenced by the reduced transendothelial electrical resistance (TEER), the increased fluorescein sodium (Na-F) penetration rate in vitro and the leakage of FITC-dextran in vivo. Transmission electron microscope (TEM) images demonstrated that bilobalide modulated BBB permeability by changing the ultrastructure of tight junctions (TJs). In addition, actin-binding proteins ezrin, radixin and moesin (ERM) and Myosin light chain (MLC) phosphorylation was observed following bilobalide treatment. Moreover, the effect of bilobalide on TEER reduction and ERM/MLC phosphorylation was counteracted by adenosine A1 receptor (A1R) siRNA. The current findings suggested that bilobalide might reversibly modulate BBB permeability by the alteration of TJs ultrastructure through A1R-mediated phosphorylation of actin-binding proteins.


Assuntos
Bilobalídeos/farmacologia , Barreira Hematoencefálica/metabolismo , Proteínas dos Microfilamentos/metabolismo , Receptor A1 de Adenosina/metabolismo , Animais , Barreira Hematoencefálica/efeitos dos fármacos , Dextranos/metabolismo , Fluoresceína-5-Isotiocianato/análogos & derivados , Fluoresceína-5-Isotiocianato/metabolismo , Humanos , Masculino , Camundongos , Peso Molecular , Permeabilidade/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Proteínas de Junções Íntimas/metabolismo
8.
Pharmacol Res ; 148: 104417, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31473343

RESUMO

Intact epithelial barrier and mucosal immune system are crucial for maintaining intestinal homeostasis. Previous study indicated that Dendrobium officinale polysaccharides (DOPS) can regulate immune responses and inflammation to alleviate experimental colitis. However, it remains largely unknown whether DOPS can suppress AOM/DSS-induced colorectal cancer (CRC) model through its direct impact on intestinal barrier function and intestinal mucosal immunity. Here, we demonstrated the therapeutic action of DOPS for CRC model and further illustrated its underlying mechanisms. Treatment with 5-aminosalicylic acid (5-ASA) and DOPS significantly improved the clinical signs and symptoms of chronic colitis, relieve colon damage, suppress the formation and growth of colon tumor in CRC mice. Moreover, administration of DOPS effectively preserved the intestinal barrier function via reducing the loss of zonula occludens-1 (ZO-1) and occludin in adjacent tissues and carcinomatous tissues. Further studies demonstrated that DOPS improved the metabolic ability of tumor infiltrated CD8+ cytotoxic T lymphocytes (CTLs) and reduced the expression of PD-1 on CTLs to enhance the anti-tumor immune response in the tumor microenvironments (TME). Together, the conclusions indicated that DOPS restore intestinal barrier function and enhance intestinal anti-tumor immune response to suppress CRC, which may be a novel strategy for the prevention and treatment of CRC.


Assuntos
Antineoplásicos/farmacologia , Carcinogênese/efeitos dos fármacos , Colo/efeitos dos fármacos , Neoplasias Colorretais/tratamento farmacológico , Dendrobium/química , Mucosa Intestinal/efeitos dos fármacos , Polissacarídeos/farmacologia , Animais , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/metabolismo , Colite/tratamento farmacológico , Colite/metabolismo , Colo/metabolismo , Neoplasias Colorretais/metabolismo , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Mucosa Intestinal/metabolismo , Masculino , Mesalamina/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Ocludina/metabolismo , Transdução de Sinais/efeitos dos fármacos , Microambiente Tumoral/efeitos dos fármacos , Proteína da Zônula de Oclusão-1/metabolismo
9.
J Environ Manage ; 239: 271-278, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30903839

RESUMO

This research uses soybean oil/water dual-phase solvents system (SWDS) to achieve high dye fixation as well as minimal discharge of waste effluents. Reactive dyeings are one of the most serious pollution sources and few dyeing technologies developed could successfully reduce the generation of toxic substances without decreasing dyeing qualities. Through a remarkable increase in chemical potential of dyes in dyeing medium, SWDS remarkably increased the dye concentration in the internal solvent phase. As a result, % exhaustion of dye was 100%, and % fixation of dye was up to 92% in SWDS. Final discharges of dyes and salts from SWDS were decreased by 85% and 100%, respectively, compared to that from the conventional aqueous system. More than 99.5% of initially added biodegradable soybean oil could be recycled for reactive dyeing without treatments. Furthermore, SWDS could be readily applied in jet-dyeing machines on a pilot scale. Via the reuse of soybean oil, SWDS could save up to $0.26 per kg of fabric compared to aqueous dyeings in terms of materials cost.


Assuntos
Corantes/química , Fibra de Algodão , Têxteis
10.
Prep Biochem Biotechnol ; 49(3): 215-221, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30794044

RESUMO

Lysozyme, an important antibacterial protein, is an enzyme that cleaves the glycosidic bond between N-acetylmuramic acid and N-acetylglucosamine of peptidoglycan in cell walls. The novel lysozyme was purified and characterized from Chinese Lueyang black-bone silky fowl (CBSF) egg white, and its N-terminal amino acid sequence, enzymatic properties, and antibacterial activity were investigated. The CBSF lysozyme was purified using adsorption chromatography, ammonium sulfate precipitation, ion exchange chromatography, and size-exclusion chromatography. The purification fold and yield were 3.28 and 14.69%, respectively. The purified lysozyme was revealed as a single protein band with SDS-PAGE and had a MALDI-TOF/TOF molecular weight of 14305.57 Da and a final specific activity of 3.49 × 105 U/mg protein using Micrococcus lysodeikticus as a substrate. The optimum temperature and pH of the lysozyme were 50 °C and 6.0, respectively. The 20 N-terminal amino acid residues of the purified lysozyme were determined to be KVFGRCELAAAMKRHGLDNY, showing some homology to the N-terminus of the odontophoridae egg white lysozyme. The purified lysozyme exerted a potent antimicrobial activity toward indicator microorganisms, including Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 25923, and Escherichia coli ATCC 25922. However, its inhibition of gram-negative activity was weaker than that of the Gram-positive bacteria.


Assuntos
Antibacterianos/química , Antibacterianos/isolamento & purificação , Muramidase/química , Muramidase/isolamento & purificação , Sequência de Aminoácidos , Animais , Antibacterianos/farmacologia , Bacillus subtilis/efeitos dos fármacos , Galinhas , Escherichia coli/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Micrococcus/efeitos dos fármacos , Peso Molecular , Muramidase/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Temperatura
11.
J Environ Manage ; 188: 26-31, 2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-27918924

RESUMO

Fully biodegradable textile sizes with satisfactory performance properties were developed from soy protein with controlled hydrolysis and dis-entanglement to tackle the intractable environmental issues associated with the non-biodegradable polyvinyl alcohol (PVA) in textile effluents. PVA derived from petroleum is the primary sizing agent due to its excellent sizing performance on polyester-containing yarns, especially in increasingly prevailing high-speed weaving. However, due to the poor biodegradability, PVA causes serious environmental pollution, and thus, should be substituted with more environmentally friendly polymers. Soy protein treated with high amount of triethanolamine was found with acceptable sizing properties. However, triethanolamine is also non-biodegradable and originated from petroleum, therefore, is not an ideal additive. In this research, soy sizes were developed from soy protein treated with glycerol, the biodegradable triol that could also be obtained from soy. The soy sizes had good film properties, adhesion to polyester and abrasion resistance close to PVA, rendering them qualified for sizing applications. Regarding desizing, consumption of water and energy for removal of soy size could be remarkably decreased, comparing to removal of PVA. Moreover, with satisfactory degradability, the wastewater containing soy sizes was readily dischargeable after treated in activated sludge for two days. In summary, the fully biodegradable soy sizes had potential to substitute PVA for sustainable textile processing.


Assuntos
Proteínas de Soja/química , Indústria Têxtil/métodos , Eliminação de Resíduos Líquidos/métodos , Biodegradação Ambiental , Análise da Demanda Biológica de Oxigênio , Etanolaminas/química , Glicerol/química , Glicerol/metabolismo , Hidrólise , Poliésteres/química , Poliésteres/metabolismo , Álcool de Polivinil/química , Esgotos , Proteínas de Soja/metabolismo , Têxteis , Águas Residuárias/química
12.
J Nucl Cardiol ; 23(3): 414-21, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26002814

RESUMO

BACKGROUND: Cardiac CT is a non-invasive modality with the ability to estimate LVEF. However, given its limited temporal resolution and radiation, there has been initial resistance to use CT to measure LVEF. Developing an accurate, fast, low radiation dose protocol is desirable. OBJECTIVE: The objective of this study is to demonstrate that a 'low radiation dose' 64 slice cardiac computed tomography (CT) protocol is feasible and can accurately measure left ventricular ejection fraction (LVEF) while delivering a radiation dose lower than radionuclide angiography (RNA). METHODS: Patients undergoing RNA were prospectively screened and enrolled to undergo a 'low-dose' 64 slice CT LVEF protocol. LVEF measures, duration of each study and radiation dose between CT and RNA were compared. RESULTS: A total of 77 patients (mean age = 61.8 ± 12.2 years and 58 men) were analyzed. The mean LVEF measured by CT and RNA were 41.9 ± 15.2% and 39.4 ± 13.9%, respectively, (P = 0.154) with a good correlation (r = 0.863). Bland-Altman plot revealed a good agreement between the CT and RNA LVEF (mean difference of -2.4). There was good agreement between CT LVEF and RNA for identifying patients with LVEF ≤30% (kappa = 0.693) and LVEF ≥50% (kappa = 0.749). The mean dose estimated effective dose for CT and RNA were 4.7 ± 1.6 and 9.5 ± 1.0 mSv, respectively. The mean CT LVEF imaging duration (4:32 ± 3:05 minutes) was significantly shorter than the RNA image acquisition time (9:05 ± 2:36 minutes; p < 0.001). CONCLUSION: The results of our study suggest that low-dose CT LVEF protocol is feasible, accurate, and fast while delivering a lower radiation dose than traditional RNA.


Assuntos
Doses de Radiação , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Angiografia Cintilográfica/métodos , Volume Sistólico , Tomografia Computadorizada por Raios X/métodos , Disfunção Ventricular Esquerda/diagnóstico por imagem , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteção Radiológica/métodos , Intensificação de Imagem Radiográfica/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
13.
Biomed Microdevices ; 17(1): 8, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25666984

RESUMO

In this research, controlled delivery of hollow nanoparticles from zein, the corn storage protein, to different organs of mice was achieved via crosslinking using citric acid, a non-toxic polycarboxylic acid derived from starch. Besides, crosslinking significantly enhanced water stability of nanoparticles while preserving their drug loading efficiency. Protein nanoparticles have been widely investigated as vehicles for delivery of therapeutics. However, protein nanoparticles were not stable in physiological conditions, easily cleared by mononuclear phagocyte system (MPS), and thus mainly accumulated and degraded in spleen and liver, the major MPS organs. Effective delivery to major non-MPS organs, such as kidney, was usually difficult to achieve, as well as long resident time of nanoparticles. In this research, hollow zein nanoparticles were chemically crosslinked with citric acid. Controlled delivery and prolonged accumulation of the nanoparticles in kidney, one major non-MPS organ, were achieved. The nanoparticles showed improved stability in aqueous environment at pH 7.4 without affecting the adsorption of 5-FU, a common anticancer drug. In summary, citric acid crosslinked hollow zein nanoparticles could be potential vehicles for controllable delivery of anticancer therapeutics.


Assuntos
Antineoplásicos , Ácido Cítrico/química , Reagentes de Ligações Cruzadas/química , Nanopartículas/química , Proteínas de Armazenamento de Sementes/química , Zea mays/química , Animais , Antineoplásicos/química , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacocinética , Preparações de Ação Retardada/farmacologia , Concentração de Íons de Hidrogênio , Camundongos
14.
Environ Sci Technol ; 49(4): 2391-7, 2015 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-25687520

RESUMO

Biodegradable sizing agents from triethanolamine (TEA) modified soy protein could substitute poly(vinyl alcohol)(PVA) sizes for high-speed weaving of polyester and polyester/cotton yarns to substantially decrease environmental pollution and impel sustainability of textile industry. Nonbiodegradable PVA sizes are widely used and mainly contribute to high chemical oxygen demand (COD) in textile effluents. It has not been possible to effectively degrade, reuse or replace PVA sizes so far. Soy protein with good biodegradability showed potential as warp sizes in our previous studies. However, soy protein sizes lacked film flexibility and adhesion for required high-speed weaving. Additives with multiple hydroxyl groups, nonlinear molecule, and electric charge could physically modify secondary structure of soy protein and lead to about 23.6% and 43.3% improvement in size adhesion and ability of hair coverage comparing to unmodified soy protein. Industrial weaving results showed TEA-soy protein had relative weaving efficiency 3% and 10% higher than PVA and chemically modified starch sizes on polyester/cotton fabrics, and had relative weaving efficiency similar to PVA on polyester fabrics, although with 3- 6% lower add-on. In addition, TEA-soy sizes had a BOD5/COD ratio of 0.44, much higher than 0.03 for PVA, indicating that TEA-soy sizes were easily biodegradable in activated sludge.


Assuntos
Teste de Materiais , Proteínas de Soja/química , Indústria Têxtil , Biodegradação Ambiental , Análise da Demanda Biológica de Oxigênio , Etanolaminas/química , Poliésteres/química , Álcool de Polivinil/química , Conformação Proteica , Esgotos , Têxteis
15.
Bioorg Med Chem ; 23(17): 5672-80, 2015 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-26211460

RESUMO

A novel series of naphthalimide-cyclam conjugates were designed and synthesized. Among them, compounds 4c, 4d, 8c and 8d which bearing long lipophilic alkyl chains, displayed comparable or more potent cytotoxic activities against human tumor cell lines than amonafide. Furthermore, the four compounds were proved to possess strong inhibition against both topoisomerase I and II. The representative compound 8c exhibited moderate DNA intercalation activity. Molecular modeling studies identified the possible interaction of compound 8c with the molecular target by forming topoisomerase/DNA/drug ternary complex. Finally, derivatives with long lipophilic alkyl chains could efficiently induce apoptosis.


Assuntos
Compostos Heterocíclicos/metabolismo , Naftalimidas/metabolismo , Inibidores da Topoisomerase II/farmacologia , Apoptose , Humanos , Estrutura Molecular
16.
Langmuir ; 30(28): 8461-70, 2014 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-25010870

RESUMO

Intrinsically water-stable scaffolds composed of ultrafine keratin fibers oriented randomly and evenly in three dimensions were electrospun for cartilage tissue engineering. Keratin has been recognized as a biomaterial that could substantially support the growth and development of multiple cell lines. Besides, three-dimensional (3D) ultrafine fibrous structures were preferred in tissue engineering due to their structural similarity to native extracellular matrices in soft tissues. Recently, we have developed a nontraditional approach to developing 3D fibrous scaffolds from alcohol-soluble corn protein, zein, and verified their structural advantages in tissue engineering. However, keratin with highly cross-linked molecular structures could not be readily dissolved in common solvents for fiber spinning, which required the remarkable drawability of solution. So far, 3D fibrous scaffolds from pure keratin for biomedical applications have not been reported. In this research, the highly cross-linked keratin from chicken feathers was de-cross-linked and disentangled into linear and aligned molecules with preserved molecular weights, forming highly stretchable spinning dope. The solution was readily electrospun into scaffolds with ultrafine keratin fibers oriented randomly in three dimensions. Due to the highly cross-linked molecular structures, keratin scaffolds showed intrinsic water stability. Adipose-derived mesenchymal stem cells could penetrate much deeper, proliferate, and chondrogenically differentiate remarkably better on the 3D keratin scaffolds than on 2D PLA fibrous scaffolds, 3D soy protein fibrous scaffolds, or 3D commercial nonfibrous scaffolds. In summary, the electrospun 3D ultrafine fibrous scaffolds from keratin could be promising candidates for cartilage tissue engineering.


Assuntos
Materiais Biocompatíveis/química , Cartilagem , Queratinas/química , Engenharia Tecidual/métodos , Alicerces Teciduais/química , Água/química , Animais , Materiais Biocompatíveis/efeitos adversos , Humanos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Material Particulado , Silicones , Solubilidade , Alicerces Teciduais/efeitos adversos
17.
J Mater Sci Mater Med ; 25(7): 1789-800, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24728742

RESUMO

In this research, ultrafine fibrous scaffolds with deep cell infiltration and sufficient water stability have been developed from gelatin, aiming to mimic the extracellular matrices (ECMs) as three dimensional (3D) stromas for soft tissue repair. The ultrafine fibrous scaffolds produced from the current technologies of electrospinning and phase separation are either lack of 3D oriented fibrous structure or too compact to be penetrated by cells. Whilst electrospun scaffolds are able to emulate two dimensional (2D) ECMs, they cannot mimic the 3D ECM stroma. In this work, ultralow concentration phase separation (ULCPS) has been developed to fabricate gelatin scaffolds with 3D randomly oriented ultrafine fibers and loose structures. Besides, a non-toxic citric acid crosslinking system has been established for the ULCPS method. This system could endow the scaffolds with sufficient water stability, while maintain the fibrous structures of scaffolds. Comparing with electrospun scaffolds, the ULCPS scaffolds showed improved cytocompatibility and more importantly, cell infiltration. This research has proved the possibility of using gelatin ULCPS scaffolds as the substitutes of 3D ECMs.


Assuntos
Matriz Extracelular/metabolismo , Gelatina/química , Alicerces Teciduais/química , Animais , Materiais Biocompatíveis/química , Diferenciação Celular , Sobrevivência Celular , Reagentes de Ligações Cruzadas/química , Fibroblastos/metabolismo , Teste de Materiais , Camundongos , Células NIH 3T3 , Células-Tronco/citologia , Fatores de Tempo , Engenharia Tecidual/métodos , Água/química
18.
Int J Biol Macromol ; 261(Pt 1): 129628, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38272415

RESUMO

Conventional nondegradable packaging and mulch films, after reaching the end of their use, become a major source of waste and are primarily disposed of in landfills. Accumulation of non-degradable film residues in the soil leads to diminished soil fertility, reduced crop yield, and can potentially affect humans. Application of degradable films is still limited due to the high cost, poor mechanical, and gas barrier properties of current biobased synthetic polymers. In this respect, natural polysaccharides and proteins can offer potential solutions. Having versatile functional groups, three-dimensional network structures, biodegradability, ease of processing, and the potential for surface modifications make polysaccharides and proteins excellent candidates for quality films. Besides, their low-cost availability as industrial waste/byproducts makes them cost-effective alternatives. This review paper covers the performance properties, cost assessment, and in-depth analysis of macromolecular structures of some natural polysaccharides and proteins-based films that have great potential for packaging and mulch applications. Proper dissolution of biopolymers to improve molecular interactions and entanglement, and establishment of crosslinkages to form an ordered and cohesive polymeric structure can help to obtain films with good properties. Simple aqueous-based film formulation techniques and utilization of waste/byproducts can stimulate the adoption of affordable biobased films on a large-scale.


Assuntos
Embalagem de Alimentos , Polímeros , Humanos , Embalagem de Alimentos/métodos , Biopolímeros/química , Polissacarídeos , Solo
19.
Int Immunopharmacol ; 133: 112115, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38652959

RESUMO

BACKGROUND: Human T cells play an important role in immunity against tuberculosis (TB) infection. Activating receptor HLA-DR and inhibitory receptor KLRG1 are critical regulators of T cell function during viral infection and tumorigenesis, but they have been less studied in TB infection. METHODS: In this study, we explored the relationship between CD3+ T cell expression of HLA-DR and KLRG1 receptors and function against TB infection. Flow cytometry was conducted to assess the immunomodulatory effects of HLA-DR and KLRG1 receptors on CD3+ T cells in patients with different TB infection status. RESULTS: We found activating receptors HLA-DR, NKG2C, CD57 and NKP46, and inhibitory receptors KLRG1 and KIR on CD3+ T cells in different TB infection status showed different distribution patterns; the cytotoxic potential and cytokine secretion capacity of CD3+ T cells after Mtb-specific antigen stimulation were significantly enhanced in TB infection groups. Further studies revealed HLA-DR+ T and KLRG1+ T cells expressed higher activating and inhibitory receptors than the negative population. In addition, the expression of cytotoxic potential and cytokine secretion capacity of HLA-DR+ T and KLRG1+ T cells was significantly higher than that of HLA-DR- T and KLRG1- T cells. CONCLUSIONS: Expression of HLA-DR and KLRG1 enhances the cytotoxic potential and cytokine secretion capacity of CD3+ T cells in TB patients, suggesting CD3+ T cells expressing HLA-DR and KLRG1 are important effector cell phenotypes involved in the host anti-TB infection. HLA-DR and KLRG1 expressed by CD3+ T cells may be potential predictive markers of TB disease progression and clinical immune assessment.


Assuntos
Citocinas , Antígenos HLA-DR , Lectinas Tipo C , Receptores Imunológicos , Tuberculose , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Complexo CD3/metabolismo , Complexo CD3/imunologia , Células Cultivadas , Citocinas/metabolismo , Citotoxicidade Imunológica , Antígenos HLA-DR/metabolismo , Antígenos HLA-DR/imunologia , Lectinas Tipo C/metabolismo , Mycobacterium tuberculosis/imunologia , Receptores Imunológicos/metabolismo , Linfócitos T/imunologia , Linfócitos T/metabolismo , Tuberculose/imunologia
20.
Sci Total Environ ; 931: 172752, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38677427

RESUMO

The objective of this work is to develop a closed-loop recycling method specifically tailored for acrylic fibers. Recycling waste acrylic is essential, given the vast volumes of acrylic-containing textiles produced yearly and the strong capability of acrylics to generate toxic microplastics. However, none of the available closed-loop recycling, mechanical recycling, chemical recycling, and direct extrusion technologies work for acrylics. Acrylic fibers are always blended with other textile fibers, making fiber separation via mechanical recycling almost impossible. Polyacrylonitrile, an addition-polymerized thermoplastic material, cannot be depolymerized into its original monomer. Direct extrusion of waste acrylics faces issues of uncontrollable colors on fibers and pollution of spinning lines due to the influence of existing colorants. In our method, acrylic fibers were extracted from waste textiles using a novel approach involving maximized acrylic swelling and dissolution with dimethyl sulfoxide and butanediol. Cationic dyes were effectively removed through cost-effective recycling technology. This work demonstrates that cationic dyes seriously affect the acrylic dissolution, color consistency, and dyeability of regenerated fibers via direct wet extrusion. Such negative impacts of dyes have been eliminated by our cost-effective and closed-loop acrylic recycling technology, which enables the efficient separation of non-acrylic fibers and dyes from acrylic fibers. Our recycling system achieved zero discharges through recycling solvents, dyes, and acrylics. The regenerated acrylic fibers exhibited mechanical properties and dyeability comparable to virgin acrylic fibers. The material and energy costs to produce pure acrylic from waste textiles were only 40 % of those from fossils. This study successfully introduces a closed-loop recycling method for acrylic fibers from waste textiles, addressing key challenges in acrylic fiber recycling. Further research and implementation of this technology are recommended to advance its commercial viability and widespread adoption.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA