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1.
Int J Biol Macromol ; 267(Pt 1): 131539, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38608994

RESUMO

Sustainable strategies to improve the water resistance of cellulose paper are actively sought. In this work, polymeric microspheres (PMs), prepared through emulsion polymerization of cellulose nanofibers stabilized rubber seed oil-derived monomer, were investigated as coatings on corrugated medium paper (CMP). After infiltrating porous paper with PMs, the water-resistant corrugated papers (WRCPn) with enhanced mechanical properties were obtained. When 30 wt% PMs were introduced, WRCP30 turned out to be highly compacted with an increased water contact angle of 106.3° and a low water vapor transmission rate of 81 g/(m2 d) at 23 °C. Meanwhile, the tensile strength of WRCP30 increased to 22.2 MPa, a 4-fold increase from CMP. When tested in a well-hydrated state, 71% of its mechanical strength in the dry state was maintained. Even with a low content of 10 wt% PMs, WRCP10 also exhibited stable tensile strength and water wettability during the cyclic soaking-drying process. Thus, the plant oil based sustainable emulsion polymers provide a convenient route for enhancing the overall performance of cellulose paper.


Assuntos
Celulose , Microesferas , Óleos de Plantas , Resistência à Tração , Água , Celulose/química , Água/química , Óleos de Plantas/química , Papel , Molhabilidade , Polímeros/química , Emulsões/química , Porosidade , Nanofibras/química
2.
Int J Biol Macromol ; 260(Pt 1): 129245, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38191109

RESUMO

Aerogels with low thermal conductivity and high adsorption capacity present a promising solution to curb water pollution caused by organic reagents as well as mitigate heat loss. Although aerogels exhibiting good adsorption capacity and thermal insulation have been reported, materials with mechanical integrity, high flexibility and shear resistance still pose a formidable task. Here, we produced bacterial cellulose-based ultralight multifunctional hybrid aerogels by using freeze-drying followed by chemical vapor deposition silylation method. The hybrid aerogels displayed a low density of 10-15 mg/cm3, high porosity exceeding 99.1 %, low thermal conductivity (27.3-29.2 mW/m.K) and superior hydrophobicity (water contact angle>120o). They also exhibited excellent mechanical properties including superelasticity, high flexibility and shear resistance. The hybrid aerogels demonstrated high heat shielding efficiency when used as an insulating material. As a selective oil absorbent, the hybrid aerogels exhibit a maximum adsorption capacity of up to approximately 156 times its own weight and excellent recoverability. Especially, the aerogel's highly accessible porous microstructure results in an impressive flux rate of up to 162 L/h.g when used as a filter in a continuous oil-water separator to isolate n-hexane-water mixtures. This work presents a novel endeavor to create high-performance, sustainable, reusable, and adaptable multifunctional aerogels.


Assuntos
Celulose , Gases , Adsorção , Liofilização , Temperatura Alta
3.
Molecules ; 23(12)2018 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-30487471

RESUMO

Berberine (BBR), a natural isoquinoline alkaloid derived from Chinese herbs, exerts many biological effects, including antiviral, antimicrobial, antidiarrhea, anti-inflammatory, and antitumor effects. In this study, a novel berberine nanoparticle (NP) consisting of heparin (HP) and BBR with or without being shelled with linear polyethyleneimine (LPEI) was developed to enhance its antitumor activity on osteosarcoma U-2 OS cells. With varying ratios of HP to BBR, HP/BBR NPs had a size ranging from 218.4 ± 3.9 to 282.0 ± 5.1 nm and zeta potential from -35.7 ± 0.4 to -51.9 ± 1.8 mV. After shelling with LPEI, the resultant NPs (HP/BBR/LPEI) possessed a size ranging from 226.3 ± 3.0 to 405.7 ± 85.2 nm and zeta potential from -46.5 ± 0.3 to -35.6 ± 0.5 mV; the encapsulation rate of BBR was close to 80%. The release profiles of both NPs were revealed to be slower than that of BBR solution. Results also showed that BBR and its two derived NPs reduced the viability of U-2 OS cells, and BBR NPs increased the cellular uptake of BBR. Cells were arrested at the G1 phase when treated individually with BBR and the two NPs (HP/BBR and HP/BBR/LPEI) and DNA condensation was induced. In addition, BBR and BBR NPs reduced the expression of mouse double minute 2 homolog (MDM2) but increased that of p53, and BBR NPs enhanced apoptotic effects. In short, heparin-based nanoparticles could be potential carriers for osteosarcoma treatment.


Assuntos
Antineoplásicos , Berberina , Neoplasias Ósseas/tratamento farmacológico , Portadores de Fármacos , Heparina , Nanopartículas , Osteossarcoma/tratamento farmacológico , Polietilenoimina , Antineoplásicos/química , Antineoplásicos/farmacologia , Berberina/química , Berberina/farmacologia , Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/patologia , Portadores de Fármacos/química , Portadores de Fármacos/farmacologia , Heparina/química , Heparina/farmacologia , Humanos , Nanopartículas/química , Nanopartículas/uso terapêutico , Osteossarcoma/metabolismo , Osteossarcoma/patologia , Polietilenoimina/química , Polietilenoimina/farmacologia
4.
Molecules ; 22(1)2017 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-28054985

RESUMO

The efficient delivery of sufficient amounts of nucleic acids into target cells is critical for successful gene therapy and gene knockdown. The DNA/siRNA co-delivery system has been considered a promising approach for cancer therapy to simultaneously express and inhibit tumor suppressor genes and overexpressed oncogenes, respectively, triggering synergistic anti-cancer effects. Polyethylenimine (PEI) has been identified as an efficient non-viral vector for transgene expression. In this study, we created a very high efficient DNA/siRNA co-delivery system by incorporating a negatively-charged poly-γ-glutamic acid (γ-PGA) into PEI/nucleic acid complexes. Spherical nanoparticles with about 200 nm diameter were formed by mixing PEI/plasmid DNA/siRNA/γ-PGA (dual delivery nanoparticles; DDNPs) with specific ratio (N/P/C ratio) and the particles present positive surface charge under all manufacturing conditions. The gel retardation assay shows both nucleic acids were effectively condensed by PEI, even at low N/P ratios. The PEI-based DDNPs reveal excellent DNA/siRNA transfection efficiency in the human hepatoma cell line (Hep 3B) by simultaneously providing high transgene expression efficiency and high siRNA silencing effect. The results indicated that DDNP can be an effective tool for gene therapy against hepatoma.


Assuntos
Nanopartículas/química , Plasmídeos/metabolismo , Polietilenoimina/química , Ácido Poliglutâmico/análogos & derivados , RNA Interferente Pequeno/genética , Transfecção/métodos , Transporte Biológico , Linhagem Celular Tumoral , Expressão Gênica , Inativação Gênica , Genes Reporter , Proteínas de Fluorescência Verde/antagonistas & inibidores , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Hepatócitos/citologia , Hepatócitos/metabolismo , Humanos , Proteínas Luminescentes/antagonistas & inibidores , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Nanopartículas/ultraestrutura , Plasmídeos/química , Ácido Poliglutâmico/química , RNA Interferente Pequeno/química , RNA Interferente Pequeno/metabolismo
5.
J Clin Endocrinol Metab ; 90(6): 3715-23, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15769981

RESUMO

Pituitary tumor-transforming gene-1 (PTTG-1) is a novel protooncogene overexpressed in numerous cancer cell lines and cancers. In this study we elucidate the expression of PTTG-1 in uterine leiomyomas and its functional role in the development of this disease. By comparing 23 pairs of leiomyomas and matched pairs of myometria, we found that the expression of PTTG-1 is significantly elevated in leiomyoma. The expression of PTTG-1 is independent of the menstrual cycle and is not affected by ovarian hormones. In contrast, basic fibroblast growth factor (bFGF) time- and dose-dependently stimulates PTTG-1 expression, which results in increasing cell proliferation. Forced expression of PTTG-1 by transient transfection stimulates bFGF and VEGF expression as well as changes the expression pattern of cell cycle proteins. Western blotting analysis demonstrates that the expressions of PTTG-1, bFGF, and the cell proliferation marker, proliferating cell nuclear antigen, are positively correlated with each other, which supports the hypothesis that the positive feedback loop between PTTG-1 and bFGF increases leiomyoma cell proliferation. In summary, we have shown for the first time that PTTG-1 is up-regulated in human uterine leiomyomas and that the positive feedback loop between PTTG-1 and bFGF may be pivotal in the growth of leiomyoma cells.


Assuntos
Regulação Neoplásica da Expressão Gênica , Leiomioma/genética , Proteínas de Neoplasias/genética , Neoplasias Uterinas/genética , Sequência de Bases , Primers do DNA , Retroalimentação , Feminino , Fator 2 de Crescimento de Fibroblastos/genética , Humanos , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Securina , Transcrição Gênica , Células Tumorais Cultivadas
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