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1.
Biomacromolecules ; 24(2): 841-848, 2023 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-36608216

RESUMO

With the rapid increase of diabetes cases in the world, there is an increasing demand for slowing down and managing diabetes and its effects. It is considered that a viable prophylactic treatment for type 2 diabetes mellitus (T2DM) is to reduce carbohydrate digestibility by controlling the activities of α-amylase and α-glucosidase to control postprandial hyperglycemia and promote the growth of intestinal beneficial bacteria. In this work, the effects of sulfonated lignin with different sulfonation degrees (0.8 mmol/g, SL1; 2.9 mmol/g, SL2) on the inhibition of α-amylase and α-glucosidase and the proliferation of intestinal beneficial bacteria in vitro were investigated. The results showed that both SL1 and SL2 can inhibit the activity of α-amylase and α-glucosidase. The inhibition capacity (IC50, 32.35 µg/mL) of SL2 with a low concentration (0-0.5 mg/mL) to α-amylase was close to that of acarbose to α-amylase (IC50, 27.33 µg/mL). Compared with the control groups, the bacterial cell concentrations of Bifidobacteria adolescentis and Lactobacillus acidophilus cultured with SL1 and SL2 increased in varying degrees (8-36%), and the produced short-chain fatty acids were about 1.2 times higher. This work demonstrates the prospect of sulfonated lignin as a prebiotic for the prevention and treatment of T2DM, which provides new insights for opening up a brand new field of lignin.


Assuntos
Diabetes Mellitus Tipo 2 , Humanos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/prevenção & controle , Lignina , Inibidores de Glicosídeo Hidrolases/farmacologia , Glicemia , alfa-Glucosidases , alfa-Amilases , Extratos Vegetais/farmacologia
2.
Biomacromolecules ; 24(3): 1377-1387, 2023 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-36799412

RESUMO

The abundant and low-cost features of lignin in combination with its natural activities make it a fascinating biopolymer for valorization, especially, in agriculture as an active plant growth regulator. However, the structure-activity relationship of lignin in regulating plant growth and metabolism remains unclear. In this work, rice-straw-based low-molecular-weight (LWM, 1860 Da) and high-molecular-weight (HMW, 6840 Da) alkali-oxygen lignins are structurally and comparatively investigated to understand their effects on the growth and metabolism of maize seedlings. The results indicate that LMW lignin at 150 mg·L-1 displays early growth stimulation in maize. Under the optimal concentration of LMW lignin (25 mg·L-1), the growth of maize shoot is ∼83% higher than that of the control one. Furthermore, LMW lignin also has a positive effect on the upregulation of photosynthetic pigment, carbohydrate, and protein synthesis. In contrast, HMW lignin shows an overall inhibitory effect on the above-mentioned biochemical parameters. Based on the structural characterization, LMW lignin contains a higher syringyl/guaiacyl ratio (0.78) and carboxyl content (1.64 mmol·g-1) than HMW lignin (0.43 and 1.27 mmol·g-1, respectively), which demonstrates that methoxyl and carboxyl content of lignin may play a decisive role in seedling growth.


Assuntos
Lignina , Oryza , Lignina/química , Zea mays , Oryza/química , Plântula , Peso Molecular , Álcalis/química , Oxigênio
3.
Int J Mol Sci ; 24(10)2023 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-37240006

RESUMO

As a natural polymer, lignin is only less abundant in nature than cellulose. It has the form of an aromatic macromolecule, with benzene propane monomers connected by molecular bonds such as C-C and C-O-C. One method to accomplish high-value lignin conversion is degradation. The use of deep eutectic solvents (DESs) to degrade lignin is a simple, efficient and environmentally friendly degradation method. After degradation, the lignin is broken due to ß-O-4 to produce phenolic aromatic monomers. In this work, lignin degradation products were evaluated as additives for the preparation of polyaniline conductive polymers, which not only avoids solvent waste but also achieves a high-value use of lignin. The morphological and structural characteristics of the LDP/PANI composites were investigated using 1H NMR, Fourier-transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis and elemental analysis. The LDP/PANI nanocomposite provides a specific capacitance of 416.6 F/g at 1 A/g and can be used as a lignin-based supercapacitor with good conductivity. Assembled as a symmetrical supercapacitor device, it provides an energy density of 57.86 Wh/kg, an excellent power density of 952.43 W/kg and, better still, a sustained cycling stability. Thus, the combination of polyaniline and lignin degradate, which is environmentally friendly, amplifies the capacitive function on the basis of polyaniline.


Assuntos
Lignina , Fenol , Fenóis , Condutividade Elétrica , Polímeros
4.
Molecules ; 27(13)2022 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-35807313

RESUMO

The most versatile furanic building block for chemical and polymer applications is 2,5-furandicarboxylic acid. However, the classical 2,5-furandicarboxylic acid production methodology has been found to have significant drawbacks that hinder industrial-scale production. This review highlights new alternative methods to synthesize 2,5-furandicarboxylic acid that are both more advantageous and attractive than conventional oxidation of 5-hydroxymethylfurfural. This review also focuses on the use of 2,5-furandicarboxylic acid as a polymer precursor and the various potential applications that arise from these furan-based materials.


Assuntos
Ácidos Dicarboxílicos , Polímeros , Furanos , Oxirredução
5.
Cancer ; 127(12): 2099-2110, 2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-33620741

RESUMO

BACKGROUND: Sexual behavior is associated with human papillomavirus (HPV)-positive head and neck cancer, whereas tobacco and alcohol use are associated with HPV-negative cancer. A case-control study was designed to investigate additional demographic and behavioral factors independently associated with these distinct oral cancers. METHODS: From 2011 to 2014, 249 newly diagnosed oral cavity and oropharyngeal squamous cell carcinoma (OSCC) cases were matched (1:2) on age, gender, and self-identified race to 498 controls without a cancer history attending the outpatient otolaryngology clinic at The Ohio State University in Columbus. Cases were stratified by detection of high-risk HPV DNA and RNA in tumors. Demographic and behavioral data were collected using an audio computer-assisted self-interview, and associations with HPV-positive versus HPV-negative OSCCs were investigated by use of univariable and multivariable conditional logistic regression models. RESULTS: After adjustment for oral sexual behavior, the odds of HPV-positive cancer decreased with the patient's years of education. Annual income, tobacco smoking, alcohol drinking, marijuana smoking, and poor oral hygiene were not associated with HPV-positive OSCC. In contrast, the odds of HPV-negative OSCC increased independently with decreased annual income, decreased with a high number of marijuana hit-years, and increased with fewer than annual dental visits after adjustment for lifetime tobacco and alcohol use. Sexual behavior and education were not associated with HPV-negative OSCC. CONCLUSIONS: The distinct risk-factor profiles for HPV-positive and HPV-negative OSCC are confirmed and extended in this case-control study, thus supporting 2 principal etiological pathways for OSCC development. LAY SUMMARY: Sexually acquired human papillomavirus (HPV) infection is an established cause of tonsil and base of tongue cancers. This study compared and contrasted risk factors for HPV-positive and HPV-negative oral cancers. Low number of years of education and sexual behavior are associated with HPV-positive cancer. In contrast, low annual income, infrequent dental visits, and tobacco and alcohol use are associated with HPV-negative cancers. Long-term marijuana use appears protective for HPV-negative cancer. Public health efforts to address these modifiable risk factors may prevent oral cancer.


Assuntos
Neoplasias de Cabeça e Pescoço , Fumar Maconha , Uso da Maconha , Neoplasias Orofaríngeas , Infecções por Papillomavirus , Estudos de Casos e Controles , Neoplasias de Cabeça e Pescoço/complicações , Humanos , Fumar Maconha/efeitos adversos , Fumar Maconha/epidemiologia , Higiene Bucal , Neoplasias Orofaríngeas/complicações , Neoplasias Orofaríngeas/etiologia , Papillomaviridae , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/epidemiologia , Infecções por Papillomavirus/patologia , Fatores de Risco , Carcinoma de Células Escamosas de Cabeça e Pescoço/complicações , Carcinoma de Células Escamosas de Cabeça e Pescoço/epidemiologia
6.
Small ; 17(18): e2008011, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33759326

RESUMO

The huge consumption of single-use plastic straws has brought a long-lasting environmental problem. Paper straws, the current replacement for plastic straws, suffer from drawbacks, such as a high cost of the water-proof wax layer and poor water stability due to the easy delamination of the wax layer. It is therefore crucial to find a high-performing alternative to mitigate the environmental problems brought by plastic straws. In this paper, all natural, degradable, cellulose-lignin reinforced composite straws, inspired by the reinforcement principle of cellulose and lignin in natural wood are developed. The cellulose-lignin reinforced composite straw is fabricated by rolling up a wet film made of homogeneously mixed cellulose microfibers, cellulose nanofibers, and lignin powders, which is then baked in oven at 150 °C. When baked, lignin melts and infiltrates the micro-nanocellulose network, acting as a polyphenolic binder to improve the mechanical strength and hydrophobicity performance of the resulting straw. The obtained straws demonstrate several advantageous properties over paper straws, including 1) excellent mechanical performance, 2) high hydrostability, and 3) low cost. Moreover, the natural degradability of the cellulose-lignin reinforced composite straws makes them promising candidates to replace plastic straws and suggests possible substitutes for other petroleum-based plastics.


Assuntos
Lignina , Nanofibras , Celulose , Interações Hidrofóbicas e Hidrofílicas , Madeira
7.
Biomacromolecules ; 22(12): 4905-4918, 2021 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-34806363

RESUMO

Bioactive substances, displaying excellent biocompatibility, chemical stability, and processability, could be extensively applied in biomedicine and tissue engineering. In recent years, plant-based bioactive substances such as flavonoids, vitamins, terpenes, and lignin have received considerable attention due to their human health benefits and pharmaceutical/medical applications. Among them is lignin, an amorphous biomacromolecule mainly derived from the combinatorial radical coupling of three phenylpropane units (p-hydroxypenyl, guaiacyl, and syringyl) during lignification. Lignin possesses intrinsic bioactivities (antioxidative, antibacterial, anti-UV activities, etc.) against phytopathogens. Lignin also enhances the plant resistance (adaptability) against environmental stresses. The abundant structural features of lignin offer other significant bioactivities including antitumor and antivirus bioactivities, regulation of plant growth, and enzymatic hydrolysis of cellulose. This Review reports the latest research results on the bioactive potential of lignin and lignin-based substances in biomedicine, agriculture, and biomass conversion. Moreover, the interfacial reactions and bonding mechanisms of lignin with biotissue/cells and other constituents were also discussed, aiming at promoting the conversion or evolution of lignin from industrial wastes to value-added bioactive materials.


Assuntos
Celulose , Lignina , Biomassa , Humanos , Hidrólise , Lignina/química , Plantas/química
8.
Macromol Rapid Commun ; 42(12): e2100116, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33938056

RESUMO

Polymer-based film capacitors with high breakdown strength and excellent flexibility are crucial in the field of advanced electronic devices and electric power systems. Although massive works are carried to enhance the energy storage performances, it is still a great challenge to improve the energy density of polymer composites under the premise of large-scale industrial production. Herein, a general strategy is proposed to improve the intrinsic breakdown strength and energy storage performances by blending core-shell structured methyl methacrylate-butadiene-styrene (MBS) rubber particles into a polymer matrix. Good compatibility and uniform dispersion state of MBS particles are observed in the matrix. Polarizing microscopy images show that blended films exhibit clear reduction of crystalline grains with the addition of MBS particles. Accordingly, an increased breakdown strength of 515 MV m-1 and discharged energy density of 12.33 J cm-3 are observed in poly(vinylidene fluoride-co-hexafluoropropylene)-based composite films. Through comprehensive characterizations, it is believed that the superior energy storage performance of composite films is attributed to decreased crystalline grains, improved mechanical properties, and restriction on carrier motion. These results provide a novel design of dielectric polymers for high breakdown strength and discharged energy density applications.


Assuntos
Eletricidade , Polímeros
9.
J Nanobiotechnology ; 19(1): 337, 2021 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-34689758

RESUMO

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a devastatingly malignant tumor with a high mortality. However, current strategies to treat PDAC generally have low efficacy and high side-effects, therefore, effective treatment against PDAC remains an urgent need. RESULTS: We report a semiconducting polymer nano-radiopharmaceutical with intrinsic photothermal capability and labeling with therapeutic radioisotope 177Lu (177Lu-SPN-GIP) for combined radio- and photothermal therapy of pancreatic tumor. 177Lu-SPN-GIP endowed good stability at physiological conditions, high cell uptake, and long retention time in tumor site. By virtue of combined radiotherapy (RT) and photothermal therapy (PTT), 177Lu-SPN-GIP exhibited enhanced therapeutic capability to kill cancer cells and xenograft tumor in living mice compared with RT or PTT alone. More importantly, 177Lu-SPN-GIP could suppress the growth of the tumor stem cells and reverse epithelial mesenchymal transition (EMT), which may greatly reduce the occurrence of metastasis. CONCLUSION: Such strategy we developed could improve therapeutic outcomes over traditional RT as it is able to ablate tumor with relatively lower doses of radiopharmaceuticals to reduce its side effects.


Assuntos
Neoplasias Pancreáticas/metabolismo , Fototerapia/métodos , Pontos Quânticos , Compostos Radiofarmacêuticos , Animais , Linhagem Celular Tumoral , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Polímeros/química , Polímeros/farmacologia , Compostos Radiofarmacêuticos/química , Compostos Radiofarmacêuticos/farmacologia , Nanomedicina Teranóstica , Ensaios Antitumorais Modelo de Xenoenxerto
10.
Small ; 16(31): e1907212, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32597027

RESUMO

3D printing of lignocellulosic biomass (cellulose, hemicellulose, and lignin) has attracted increasing attention by using this abundant, sustainable, and ecofriendly material. While cellulose can be easily tailored into a highly viscous ink for 3D printing, after solvent evaporation, the final printed structures become highly porous, fragile, and easily fall apart in water due to its hydrophilic nature. Lignin, another crucial component of natural lignocellulose, has not yet been reported for ink printing due to its unfavorable rheological behavior. Herein, a low-cost direct ink printing strategy is developed to fabricate lignin-based 3D structures with lignin no further refined and a more compact microstructure as well as different functionalities compared with printed cellulose. By using a soft triblock copolymer as the crosslinking agent, the rheology of lignin-based inks can be adjusted from soft to rigid, and even enables vertical printing which requires stiff and self-supporting features. The lignin-based inks contain less water (≈40 wt%) and exhibit a much denser, stiffer structure, resulting in a wet tensile strength of ≈30 MPa, compared to only ≈0.6 MPa for printed cellulose. In addition, the unique macromolecular structure of lignin also demonstrates significantly improved stability in water and under heat, as well as UV-blocking performance.


Assuntos
Tinta , Lignina , Celulose , Hidrogéis , Impressão Tridimensional
11.
J Am Chem Soc ; 141(39): 15605-15610, 2019 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-31536338

RESUMO

The formation of oligomeric soluble aggregates is related to the toxicity of amyloid peptides and proteins. In this manuscript, we report the use of a ruthenium polypyridyl complex ([Ru(bpy)2(dpqp)]2+) to track the formation of amyloid oligomers at different times using photoluminescence anisotropy. This technique is sensitive to the rotational correlation time of the molecule under study, which is consequently related to the size of the molecule. [Ru(bpy)2(dpqp)]2+ presents anisotropy values of zero when free in solution (due to its rapid rotation and long lifetime) but larger values as the size and concentration of amyloid-ß (Aß) oligomers increase. Our assays show that Aß forms oligomers immediately after the assay is started, reaching a steady state at ∼48 h. SDS-PAGE, DLS, and TEM were used to confirm and characterize the formation of oligomers. Our experiments show that the rate of formation for Aß oligomers is temperature dependent, with faster rates as the temperature of the assay is increased. The probe was also effective in monitoring the formation of α-synuclein oligomers at different times.


Assuntos
Amiloide/química , Medições Luminescentes/métodos , Polímeros/química , Anisotropia , Processos Fotoquímicos , Compostos de Rutênio/química
12.
Macromol Rapid Commun ; 40(20): e1900293, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31454131

RESUMO

In this report, highly active metallocene initiators are used for the polymerization of a ketene monomer, dimethylketene, which typically contains two adjacent double bonds (R2 CCO). By using the methylzirconocene methyltriarylborate complex (Cp2 ZrMe+ MeB(C6 F5 )3 - ) as the activation system, associated with the possible cleavage of CC and CO bonds in ketene monomers, a structure-specific and high-molecular-weight polyester ( M n ¯ > 300 000 g mol-1 ) can be afforded. The resulting polyester structure, comprehensively characterized by NMR, indicates a significant reactive selectivity of the "bent-sandwich" cationic site Cp2 ZrMe+ . It reveals that the positively charged zirconium (Zr+ ) prefers to coordinate with a negatively charged oxygen (O- ) when it is already bonded to the carbon, while a negatively charged carbon (C- ) will be assigned in priority if the oxygen-zirconium bond exists. This report allows for broadening the application field of metallocene initiators in non-olefin reactions and deepening our insight into the mechanism of the living insertion/Ziegler-Natta polymerization.


Assuntos
Alcenos/química , Metalocenos/química , Poliésteres/química , Polimerização , Varredura Diferencial de Calorimetria , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Eletricidade , Etilenos/química , Peso Molecular , Espectroscopia de Prótons por Ressonância Magnética , Espectroscopia de Infravermelho com Transformada de Fourier
13.
Anal Chem ; 90(4): 2671-2677, 2018 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-29381334

RESUMO

Boronate affinity materials have been successfully used for the selective recognition of glycoproteins. However, by such materials, the large-scale glycoproteins enrichment from human plasma under physiological conditions is rarely reported. In this work, 3-carboxybenzoboroxole (CBX) functionalized polyethylenimine (PEI) modified magnetic graphene oxide nanocomposites were synthesized. Benefitting from the low pKa value of CBX (∼6.9) and PEI dendrimer-assisted multivalent binding, the Freundlich constant (KF) for the adsorption of horseradish peroxidase (HRP) was 3.0-7.3 times higher than that obtained by previous work, displaying the high enrichment capacity. Moreover, PEI could improve the hydrophilicity of nanocomposites and reduce nonglycoprotein adsorption. Therefore, such nanocomposites were successfully applied to the analysis of human plasma glycoproteome under physiological conditions, and the identified glycoproteins number and recognition selectivity was increased when compared to the results obtained by previous boronic acid-functionalized particles (Sil@Poly(APBA-co-MBAAm)) under common alkaline condition (137 vs 78 and 67.8% vs 57.8%, respectively). In addition, thrombin (F2), an important plasma glycoprotein, labile under alkaline conditions, was specifically identified by our method, demonstrating the great promise of such nanocomposites in the deep-coverage glycoproteome analysis.


Assuntos
Compostos de Boro/química , Glicoproteínas/química , Grafite/química , Compostos Heterocíclicos com 2 Anéis/química , Nanocompostos/química , Polietilenoimina/química , Adsorção , Glicoproteínas/sangue , Peroxidase do Rábano Silvestre/química , Peroxidase do Rábano Silvestre/metabolismo , Humanos , Fenômenos Magnéticos , Modelos Moleculares , Estrutura Molecular
14.
Chemistry ; 22(21): 7174-8, 2016 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-27072776

RESUMO

Mesoporous Trimetallic PtPdRu Spheres with well-defined spherical morphology and uniformly sized pores were synthesized in an aqueous solution using ascorbic acid as the reducing agent and triblock copolymer F127 as the pore directing agent. These mesoporous PtPdRu spheres exhibited enhanced electrocatalytic activity compared to commercial Pt black, resulting in a ∼4.9 times improvement in mass activity for the methanol oxidation reaction. The excellent electrocatalytic activity and stability are due to the unique mesoporous architecture and electronic landscape between different elements.


Assuntos
Paládio/química , Platina/química , Rutênio/química , Ácido Ascórbico/química , Catálise , Técnicas Eletroquímicas , Metanol/química , Oxirredução , Tamanho da Partícula , Polietilenos/química , Polipropilenos/química , Porosidade
15.
Mol Pharm ; 13(5): 1711-22, 2016 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-26998644

RESUMO

PLGA nanoparticles are widely used in tumor targeting drug delivery systems. However, the naked PLGA nanoparticles (NNPs) not only have low drug loading but also can be rapidly removed from blood circulation by the immune system. The aim of this study was to prepare pH-triggered surface charge reversed lipid hybrid PLGA nanoparticles (LNPs) to enhance drug loading and drug delivery efficiency. CHO-Arg-His-OMe and FA-PEG-DSPE were synthesized to modify PLGA nanoparticles to prepare LNPs. The drug loading and encapsulation rate of LNPs were greatly improved as compared with NNPs. In pH 7.4 medium, doxorubicin (DOX)-loaded LNPs showed negative charge and released DOX slowly. In pH 5.0 medium, DOX-loaded LNPs exhibited positive charge and released DOX quickly. DOX-loaded LNPs delivered more DOX to the nucleus of KB cells and MBA-MD-231/ADR cells than did free DOX. In addition, DOX-loaded LNPs significantly inhibited the proliferation of KB cells and MBA-MD-231/ADR cells. Compared with free DOX, the same dose of the DOX-loaded LNPs delivered more DOX to tumor tissue. Thus, DOX-loaded LNPs significantly inhibited the growth of tumor in tumor-bearing nude mice and obviously reduced the systemic toxicity of DOX. In conclusion, pH-triggered surface charge reversed DOX-loaded LNPs significantly enhanced the antitumor activity of DOX in vitro and in vivo. DOX-loaded LNPs had great potential in tumor targeted chemotherapy.


Assuntos
Antineoplásicos/química , Doxorrubicina/química , Nanopartículas/química , Células A549 , Animais , Antineoplásicos/farmacologia , Doxorrubicina/farmacologia , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Ácido Fólico/análogos & derivados , Ácido Fólico/química , Humanos , Concentração de Íons de Hidrogênio , Células KB , Ácido Láctico/química , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Fosfatidilcolinas/química , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Ratos , Ratos Sprague-Dawley
16.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(12): 3454-8, 2015 Dec.
Artigo em Zh | MEDLINE | ID: mdl-26964229

RESUMO

Vapours of organic matters were determined qualitatively employed with ultraviolet-visible absorption spectroscopy. Vapours of organic matters were detected using ultraviolet-visible spectrophotometer employing polyethylene film as medium, the ultraviolet and visible absorption spectra of vegetable oil vapours of soybean oil, sunflower seed oil, peanut oil, rapeseed oil, sesame oil, cotton seed oil, tung tree seed oil, and organic compound vapours of acetone, ethyl acetate, 95% ethanol, glacial acetic acid were obtained. Experimental results showed that spectra of the vegetable oil vapour and the organic compound vapour could be obtained commendably, since ultra violet and visible spectrum of polyethylene film could be deducted by spectrograph zero setting. Different kinds of vegetable oils could been distinguished commendably in the spectra since the λ(max), λ(min), number of absorption peak, position, inflection point in the ultra violet and visible spectra obtained from the vapours of the vegetable oils were all inconsistent, and the vapours of organic compounds were also determined perfectly. The method had a good reproducibility, the ultraviolet and visible absorption spectra of the vapours of sunflower seed oil in 10 times determination were absolutely the same. The experimental result indicated that polyethylene film as a kind of medium could be used for qualitative analysis of ultraviolet and visible absorption spectroscopy. The method for determination of the vapours of the vegetable oils and organic compounds had the peculiarities of fast speed analysis, well reproducibility, accuracy and reliability and low cost, and so on. Ultraviolet and visible absorption spectrum of organic vapour could provide feature information of material vapour and structural information of organic compound, and provide a novel test method for identifying vapour of compound and organic matter.


Assuntos
Gases/análise , Óleos de Plantas/química , Espectrofotometria Ultravioleta , Óleo de Sementes de Algodão , Ácidos Graxos Monoinsaturados , Óleo de Amendoim , Polietilenos , Óleo de Brassica napus , Reprodutibilidade dos Testes , Sementes , Óleo de Gergelim , Óleo de Soja , Óleo de Girassol
17.
Anticancer Drugs ; 25(7): 751-66, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24590167

RESUMO

The experiment aimed to increase the drug-delivery efficiency of poly-lactic-co-glycolic acid (PLGA) nanoparticles. Lipid-polymer hybrid nanoparticles (LPNs-1) were prepared using PLGA as a hydrophobic core and FA-PEG-hyd-DSPE as an amphiphilic shell. Uniform and spherical nanoparticles with an average size of 185 nm were obtained using the emulsification solvent evaporation method. The results indicated that LPNs-1 showed higher drug loading compared with naked PLGA nanoparticles (NNPs). Drug release from LPNs-1 was faster in an acidic environment than in a neutral environment. LPNs-1 showed higher cytotoxicity on KB cells, A549 cells, MDA-MB-231 cells, and MDA-MB-231/ADR cells compared with free doxorubicin (DOX) and NNPs. The results also showed that, compared with free DOX and NNPs, LPNs-1 delivered more DOX to the nuclear of KB cells and MDA-MB-231/ADR cells. LPNs-1 induced apoptosis in KB cells and MDA-MB-231/ADR cells in a dose-dependent manner. The above data indicated that DOX-loaded LPNs-1 could kill not only normal tumor cells but also drug-resistant tumor cells. These results indicated that modification of PLGA nanoparticles with FA-PEG-hyd-DSPE could considerably increase the drug-delivery efficiency and LPNs-1 had potential in the delivery of chemotherapeutic agents in the treatment of cancer.


Assuntos
Antineoplásicos/farmacologia , Ácido Fólico/análogos & derivados , Nanopartículas/química , Fosfatidilcolinas/química , Polietilenoglicóis/química , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Doxorrubicina/administração & dosagem , Doxorrubicina/química , Doxorrubicina/farmacologia , Portadores de Fármacos , Ácido Fólico/química , Ácido Fólico/metabolismo , Humanos , Ácido Láctico/química , Ácido Láctico/metabolismo , Nanopartículas/metabolismo , Fosfatidilcolinas/metabolismo , Polietilenoglicóis/metabolismo , Ácido Poliglicólico/química , Ácido Poliglicólico/metabolismo , Copolímero de Ácido Poliláctico e Ácido Poliglicólico
18.
Int J Biol Macromol ; 259(Pt 1): 128942, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38143066

RESUMO

The reserve of lignin in the biological world is the second largest biomass resource after cellulose. Lignin has the characteristics of wide sources, low cost, and rich active components. Due to environmental pollution and energy scarcity, lignin is often used as a substitute good for petrochemical products. Lignin-based functional materials can be prepared by chemical modification or compounding, which are widely used in the fields of energy storage, chemical industry, and medicine. Among them, lignin-based carbon materials have the features of stable chemical properties, large pH application range, ideal electrical conductivity, developed pore size, and high specific surface area, which have great application prospects as supercapacitor materials. This paper mainly introduces the structural properties of lignin, the methods, and mechanisms of carbonization, pore-making, and pore-expansion, as well as the research progress of lignin-based carbon materials for supercapacitors, while looking forward to the future research direction of lignin carbon materials.


Assuntos
Celulose , Lignina , Biomassa , Carbono , Eletrodos
19.
Int J Biol Macromol ; 258(Pt 1): 128721, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38101687

RESUMO

Phenylboronic acid (PBA) groups are effective in building glucose-responsive drug delivery systems. Chitosan (CS) offers distinct advantages in the construction of PBA-based biomaterials, such as biodegradability and biocompatibility. However, challenges still persist due to the limited solubility of CS. This study proposes an efficient approach to introduce PBA groups into CS chains within 1 h via the O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HATU)-mediated amidation between 3-carboxyphenylboronic acid (CPBA) and O-hydroxypropyl chitosan (HPCS). The results showed that a wide range of substitution degrees, from 0.15 to 0.78, could be finely controlled by the amount of CPBA added. Furthermore, the obtained novel carboxyphenylboronic acid-grafted hydroxypropyl chitosan (PBA-HPCS) derivative showed enhanced crystallinity and thermostability compared to HPCS, and it demonstrated solubility in an alkaline solution. Based on the reversible bonding between the boronic acid group and cis-1,2/1,3-diols, PBA-HPCS was successfully used as an efficient crosslinker for the preparation of hydrogels incorporating sorbitol and polyhydroxy polymers, such as guar gum and polyvinyl alcohol. These hydrogels exhibited rapid gelation, rapid self-healing, injectability, and responsiveness to glucose and pH. These findings suggest that PBA-HPCS holds promise for advancing the development of PBA-based biomaterials.


Assuntos
Quitosana , Quitosana/química , Concentração de Íons de Hidrogênio , Hidrogéis/química , Ácidos Borônicos/química , Glucose/química , Materiais Biocompatíveis , Derivados da Hipromelose
20.
ACS Nano ; 18(5): 4329-4342, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38261787

RESUMO

Lignin, as an abundant aromatic biopolymer in plants, has great potential for medical applications due to its active sites, antioxidant activity, low biotoxicity, and good biocompatibility. In this work, a simple and ecofriendly approach for lignin fractionation and modification was developed to improve the antitumor activity of lignin. The lignin fraction KL-3 obtained by the lignin gradient acid precipitation at pH = 9-13 showed good cytotoxicity. Furthermore, the cell-feeding lignin after additional structural modifications such as demethylation (DKL-3), sulfonation (SL-3), and demethylsulfonation (DSKL-3) could exhibit higher glutathione responsiveness in the tumor microenvironment, resulting in reactive oxygen species accumulation and mitochondrial damage and eventually leading to apoptosis in HepG2 cells with minimal damage to normal cells. The IC50 values for KL-3, SL-3, and DSKL-3 were 0.71, 0.57, and 0.41 mg/mL, respectively, which were superior to those of other biomass extractives or unmodified lignin. Importantly, in vivo experiments conducted in nude mouse models demonstrated good biosafety and effective tumor destruction. This work provides a promising example of constructing carrier-free functionalized lignin antitumor materials with different structures for inhibiting the growth of human hepatocellular carcinoma (HepG2) cells, which is expected to improve cancer therapy outcomes.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Poliuretanos , Animais , Camundongos , Humanos , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/patologia , Células Hep G2 , Lignina/farmacologia , Microambiente Tumoral
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