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1.
Macromol Rapid Commun ; 45(3): e2300488, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37793367

RESUMO

Low critical solution temperature (LCST) of commonly used thermoresponsive polymers in water is basically dominated by hydrophobic interactions. Herein, a novel thermoresponsive system based on electrostatic interactions is reported. By simply loading aluminum chloride (AlCl3 ) into non-responsive poly(2-hydroxyethyl acrylate) (PHEA) hydrogels, PHEA-Al gels turn to have reversible thermoresponsive behavior between transparent and opaque without any volume change. Further investigations by changing metal ion-polymer compositions unravel the necessity of specific electrostatic interactions, namely, cation-dipole bonding interactions between hydroxy groups and trivalent metal ions. The thermoresponsive hydrogel demonstrates high transparency (≈95%), excellent luminous modulation capability (>98%), and cyclic reliability, suggesting great potential as an energy-saving material. Although LCST control by salt addition is widely known, salt-induced expression of thermoresponsiveness has barely been discussed before. This design provides a new approach of easy fabrication, low cost, and scalability to develop stimuli-responsive materials.


Assuntos
Hidrogéis , Poli-Hidroxietil Metacrilato/análogos & derivados , Polímeros , Hidrogéis/química , Temperatura , Eletricidade Estática , Reprodutibilidade dos Testes , Polímeros/química
2.
Part Fibre Toxicol ; 21(1): 21, 2024 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-38658944

RESUMO

BACKGROUND: Increasing attention is being paid to the environmental and health impacts of nanoplastics (NPs) pollution. Exposure to nanoplastics (NPs) with different charges and functional groups may have different adverse effects after ingestion by organisms, yet the potential ramifications on mammalian blood glucose levels, and the risk of diabetes remain unexplored. RESULTS: Mice were exposed to PS-NPs/COOH/NH2 at a dose of 5 mg/kg/day for nine weeks, either alone or in a T2DM model. The findings demonstrated that exposure to PS-NPs modified by different functional groups caused a notable rise in fasting blood glucose (FBG) levels, glucose intolerance, and insulin resistance in a mouse model of T2DM. Exposure to PS-NPs-NH2 alone can also lead the above effects to a certain degree. PS-NPs exposure could induce glycogen accumulation and hepatocellular edema, as well as injury to the pancreas. Comparing the effect of different functional groups or charges on T2DM, the PS-NPs-NH2 group exhibited the most significant FBG elevation, glycogen accumulation, and insulin resistance. The phosphorylation of AKT and FoxO1 was found to be inhibited by PS-NPs exposure. Treatment with SC79, the selective AKT activator was shown to effectively rescue this process and attenuate T2DM like lesions. CONCLUSIONS: Exposure to PS-NPs with different functional groups (charges) induced T2DM-like lesions. Amino-modified PS-NPs cause more serious T2DM-like lesions than pristine PS-NPs or carboxyl functionalized PS-NPs. The underlying mechanisms involved the inhibition of P-AKT/P-FoxO1. This study highlights the potential risk of NPs pollution on T2DM, and provides a new perspective for evaluating the impact of plastics aging.


Assuntos
Glicemia , Diabetes Mellitus Tipo 2 , Resistência à Insulina , Nanopartículas , Poliestirenos , Proteínas Proto-Oncogênicas c-akt , Animais , Diabetes Mellitus Tipo 2/induzido quimicamente , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Masculino , Poliestirenos/toxicidade , Poliestirenos/química , Nanopartículas/toxicidade , Proteínas Proto-Oncogênicas c-akt/metabolismo , Diabetes Mellitus Experimental/induzido quimicamente , Camundongos , Proteína Forkhead Box O1/metabolismo , Microplásticos/toxicidade , Fosforilação , Camundongos Endogâmicos C57BL , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia
3.
Macromol Rapid Commun ; 43(22): e2200199, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35380177

RESUMO

Although optical engineering strategy has been utilized to optimize average visible transmittance (AVT) of semi-transparent organic solar cells (ST-OSCs), judicious selection of active layer materials should be more direct and basic. Herein, an efficient ternary active layer is constructed with a wide bandgap (3.0 eV) fluorescent polymer FC-S1 as host donor, a middle bandgap polymer PM6 as guest donor, and a narrow bandgap non-fullerene Y6-BO as acceptor. Using FC-S1 as the host donor can allow more visible photons to penetrate the device. In the absence of optical engineering, the ternary ST-OSC with FC-S1:PM6:Y6-BO = 1:0.3:1.5 active layer of 30 nm thickness displays a much higher AVT of 49.28% than that of 32.34% for a PM6:Y6-BO = 1.3:1.5 based binary ST-OSC. The ternary ST-OSC provides a good power conversion efficiency of 6.01%, only slightly lower than 7.15% for the binary ST-OSC. The ternary ST-OSC also demonstrates a color rendering index (CRI) of 87 and a correlated color temperature (CCT) of 6916 K, all better than CRI of 80 and CCT of 9022 K for the binary ST-OSC. Moreover, the backbone of FC-S1 is mainly composed by fluorene and carbazole, two easily-accessible aromatic rings, which would meet low-cost concern of ST-OSCs.


Assuntos
Corantes , Polímeros , Temperatura , Engenharia
4.
Biomacromolecules ; 22(10): 4228-4236, 2021 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-34499468

RESUMO

Fabricating advanced polymer composites with remarkable mechanical and thermal conductivity performances is desirable for developing advanced devices and equipment. In this study, a novel strategy to prepare anisotropic wood-based scaffolds with a naturally aligned microchannel structure from balsa wood is demonstrated. The wood microchannels were coated with polydopamine-surface-modified small graphene oxide (PGO) nanosheets via assembly. The highly aligned porous microstructures, with thin wood cell walls and large voids along the cellulose microchannels, allow polymers to enter, resulting in the fabrication of the wood-polymer nanocomposite. The tensile stiffness and strength of the resulting nanocomposite reach 8.10 GPa and 90.3 MPa with a toughness of 5.0 MJ m-3. The thermal conductivity of the nanocomposite is improved significantly by coating a PGO layer onto the wood scaffolds. The nanocomposite exhibits not only ultrahigh thermal conductivity (in-plane about 5.5 W m-1 K-1 and through-plane about 2.1 W m-1 K-1) but also satisfactory electrical insulation (volume resistivity of about 1015 Ω·cm). Therefore, the results provide a strategy to fabricate thermal management materials with excellent mechanical properties.


Assuntos
Nanocompostos , Madeira , Celulose , Condutividade Térmica
5.
Ecotoxicol Environ Saf ; 190: 110133, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31896473

RESUMO

Microplastics (MP) are receiving increased attention as a harmful environmental pollutant, however information on the reproduction toxicity of MP in terrestrial animals, especially mammals, is limited. In this experiment, we investigated the impact of polystyrene microplastics (micro-PS) on the reproductive system of male mice. Healthy Balb/c mice were exposed to saline or to different doses of micro-PS for 6 weeks. The results showed that micro-PS exposure resulted in a significant decrease in the number and motility of sperm, and a significant increase in sperm deformity rate. We also detected a decrease in the activity of the sperm metabolism-related enzymes, succinate dehydrogenase (SDH) and lactate dehydrogenase (LDH), and a decrease in the serum testosterone content in the micro-PS exposure group. We found that micro-PS exposure caused oxidative stress and activated JNK and p38 MAPK. In addition, we found that when N-acetylcysteine (NAC) scavenges ROS, and when the p38 MAPK-specific inhibitor SB203580 inhibits p38MAPK, the micro-PS-induced sperm damage is alleviated and testosterone secretion improves. In conclusion, our findings suggest that micro-PS induces reproductive toxicity in mice through oxidative stress and activation of the p38 MAPK signaling pathways.


Assuntos
Microplásticos/toxicidade , Estresse Oxidativo/fisiologia , Poliestirenos/toxicidade , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Acetilcisteína/farmacologia , Animais , Sistema de Sinalização das MAP Quinases/fisiologia , Masculino , Camundongos , Plásticos , Reprodução/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Espermatozoides/metabolismo
6.
Biomacromolecules ; 17(11): 3782-3789, 2016 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-27750002

RESUMO

Melanin, a kind of well-known multifunctional biomacromolecules that are widely distributed in natural sources. In this work, polyurethane (PU)/melanin nanocomposites with enhanced tensile strength and toughness were successfully fabricated via in situ polymerization. It was found that the tensile strength (σ), elongation-at-break (εmax), and toughness (W) were improved from 5.6 MPa, 770%, and 33 MJ/m3 for PU to 51.5 MPa, 1880%, and 413 MJ/m3 for PU/melanin (2 wt %) nanocomposite, respectively. Micromorphology indicated that individualized melanin nanoparticles were specifically linked to the hard domains of PU chains and fine dispersed in matrix. FTIR, DSC, and AFM results suggested melanin induced an improvement in degree of phase separation, which resulted in remarkable enhancements in mechanical properties of PU. However, with further increasing content of melanin, a relatively large-scale phase separation was formed and led to a decrease in mechanical properties of PU. In addition, interactions between melanin and hard segments of PU were increased, leading to a higher TgHS. Moreover, the dynamic mechanical properties and rheological behavior of PU/melanin nanocomposites were further investigated.


Assuntos
Melaninas/química , Nanocompostos/química , Nanopartículas/química , Poliuretanos/química , Melaninas/síntese química , Microscopia Eletrônica de Varredura , Nanocompostos/ultraestrutura , Nanopartículas/ultraestrutura , Poliuretanos/síntese química , Resistência à Tração
7.
Biomacromolecules ; 16(11): 3723-9, 2015 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-26444105

RESUMO

In this work we report the in situ preparation of fully biobased stereocomplex poly(lactide) (SC-PLA) nanocomposites grafted onto nanocrystalline cellulose (NCC). The stereocomplexation rate by compounding high-molar-mass poly(D-lactide) (PDLA) with comb-like NCC grafted poly(L-lactide) is rather high in comparison with mixtures of PDLA and PLLA. The rapid stereocomplexation was evidenced by a high stereocomplexation temperature (Tc-sc = 145 °C) and a high SC crystallinity (Xc-sc = 38%) upon fast cooling (50 °C/min) from the melt (250 °C for 2 min), which are higher than currently reported values. Moreover, the half-life crystallization time (175-190 °C) of the SC-PLA was shortened by 84-92% in comparison with the PDLA/PLLA blends. The high(er) stereocomplexation rate and the melt stability of the SC in the nanocomposites were ascribed to the nucleation effect of the chemically bonded NCC and the "memory effect" of molecular pairs in the stereocomplex melt because of the confined freedom of the grafted PLLA chains.


Assuntos
Celulose/química , Poliésteres/química , Materiais Biocompatíveis/química , Varredura Diferencial de Calorimetria , Cristalização , Meia-Vida , Microscopia de Força Atômica , Peso Molecular , Nanoestruturas/química , Espectroscopia de Infravermelho com Transformada de Fourier , Estereoisomerismo , Difração de Raios X
8.
Int J Biol Macromol ; 261(Pt 2): 129755, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38278385

RESUMO

Utilizing antibacterial packaging material is an effective approach to delay fruit rotting and spoilage thereby minimizing financial losses and reducing health harm. However, the barrier and mechanical properties of biodegradable antibacterial packaging materials are barely compatible with transparency. Herein, antimicrobial nanoparticles encapsulating citral (ANPs) were first prepared by emulsification under the stabilization of oxidized dextran (ODE) and ethylene diamine. Then, composite films with high transparency, good water vapor barrier, and mechanical and antibacterial properties for fruits packaging were prepared from chitosan (CS), carboxymethyl-glucan (CMG), poly(vinyl alcohol) (PVA), and ANPs by solvent casting strategy. The synergistic effects of electrostatic interaction and hydrogen bonding could regulate crystalline architecture, generating high transparency of the composite films (90 %). The mechanical properties of the composite film are improved with elongation at break up to 167 % and stress up to 32 MPa. The water vapor barrier property of the film is appropriate to the packed fruit for less weight loss and firmness remaining. Simultaneously, the addition of ANPs endowed the film with excellent antimicrobial and UV-barrier capabilities to reduce fruit mildew, thereby extending the shelf life of fruits. More importantly, the composite polymer solution could be sprayed or dipped directly on fruits as a coating for food storage to improve food shelf life, substantially expanding its ease of use and scope of use.


Assuntos
Monoterpenos Acíclicos , Anti-Infecciosos , Quitosana , Nanopartículas , Glucanos/farmacologia , Álcool de Polivinil/química , Quitosana/química , Frutas , Vapor , Embalagem de Alimentos , Antibacterianos/farmacologia , Antibacterianos/química , Anti-Infecciosos/farmacologia , Etanol/farmacologia
9.
Sci Total Environ ; 922: 171299, 2024 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-38423318

RESUMO

After aging in the environment, some nanoplastics will carry different charges and functional groups, thereby altering their toxicological effects. To evaluate the potential impact of aging of nanoplastics on the mammalian reproductive system, we exposed C57BL/6 male mice to a dose of 5 mg/kg/d polystyrene nanoparticles (PS-NPs) with different functional groups (unmodified, carboxyl functionalized and amino functionalized) for 45 days for this study. The results suggest that PS-NPs with different functional groups triggered oxidative stress, a decreased in the testis index, disruption of the outer wall of the seminiferous tubules, reduction in the number of spermatogonia cells and sperm counts, and an increased in sperm malformations. We performed GO and KEGG enrichment analysis on the differentially expressed proteins, and found they were mainly enriched in protein transport, RNA splicing and mTOR signaling. We confirmed that the PI3K-AKT-mTOR pathway is over activated, which may lead to reduction of spermatogonia stem cells by over differentiation. Strikingly, PS-NPs with functional group modifications are more toxic than those of unmodified polystyrene, and that PS-NPs with positively charged amino modifications are the most toxic. This study provides a new understanding for correctly evaluating the toxicological effects of plastic aging, and of the mechanism responsible for the reproductive toxicity caused by nanoplastics.


Assuntos
Nanopartículas , Poluentes Químicos da Água , Animais , Camundongos , Masculino , Poliestirenos/toxicidade , Poliestirenos/metabolismo , Microplásticos , Camundongos Endogâmicos C57BL , Fosfatidilinositol 3-Quinases , Poluentes Químicos da Água/toxicidade , Sêmen , Nanopartículas/toxicidade , Nanopartículas/metabolismo , Genitália Masculina/metabolismo , Serina-Treonina Quinases TOR , Mamíferos/metabolismo
10.
Sci Total Environ ; 946: 174482, 2024 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-38969129

RESUMO

Polystyrene microplastics (PS-MP) and dibutyl phthalate (DBP) are plastic pollution derivatives (PPDs) commonly found in the natural environment. To investigate the effects of PPD exposure on the risk of allergic asthma, we established a PPD exposure group in a mouse model. The dose administered for PS-MP was 0.1 mg/d and for DBP was 30 mg/kg/d, with a 5-week oral administration period. The pathological changes of airway tissue and the increase of oxidative stress and inflammatory response confirmed that PPD aggravated eosinophilic allergic asthma in mice. The mitochondrial morphological changes and metabolomics of mice confirmed that ferrotosis and oxidative stress played key roles in this process. Treatment with 100 mg/Kg deferoxamine (DFO) provided significant relief, and metabolomic analysis of lung tissue supported the molecular toxicological. Our findings suggest that the increased levels of reactive oxygen species (ROS) in the lungs lead to Th2-mediated eosinophilic inflammation, characterized by elevated IL-4, IL-5, and eosinophils, and reduced INF-γ levels. This inflammatory response is mediated by the NFκB pathway and exacerbates type I hypersensitivity through increased IL-4 production. In this study, the molecular mechanism by which PPD aggravates asthma in mice was elucidated, which helps to improve the understanding of the health effects of PPD and lays a theoretical foundation for addressing the health risks posed by PPD.


Assuntos
Asma , Ferroptose , Pulmão , Metabolômica , Animais , Asma/induzido quimicamente , Camundongos , Pulmão/efeitos dos fármacos , Pulmão/patologia , Ferroptose/efeitos dos fármacos , Dibutilftalato/toxicidade , Células Th2/imunologia , Estresse Oxidativo , Poluentes Ambientais/toxicidade , Microplásticos/toxicidade , Eosinófilos/efeitos dos fármacos , Plásticos/toxicidade
11.
Int J Mol Sci ; 14(10): 20189-203, 2013 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-24152436

RESUMO

Biodegradable poly(lactide)/poly(butylene adipate-co-terephthalate) (PLA/PBAT) blends were prepared by reactive blending in the presence of chain-extenders. Two chain-extenders with multi-epoxy groups were studied. The effect of chain-extenders on the morphology, mechanical properties, thermal behavior, and hydrolytic degradation of the blends was investigated. The compatibility between the PLA and PBAT was significantly improved by in situ formation of PLA-co-PBAT copolymers in the presence of the chain-extenders, results in an enhanced ductility of the blends, e.g., the elongation at break was increased to 500% without any decrease in the tensile strength. The differential scanning calorimeter (DSC) results reveal that cold crystallization of PLA was enhanced due to heterogeneous nucleation effect of the in situ compatibilized PBAT domains. As known before, PLA is sensitive to hydrolysis and in the presence of PBAT and the chain-extenders, the hydrolytic degradation of the blend was evident. A three-stage hydrolysis mechanism for the system is proposed based on a study of weight loss and molecular weight reduction of the samples and the pH variation of the degradation medium.


Assuntos
Poliésteres/química , Polímeros/química , Concentração de Íons de Hidrogênio , Hidrólise , Peso Molecular
12.
Int J Mol Sci ; 14(11): 22380-94, 2013 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-24232456

RESUMO

A facile method is developed to fabricate nanocomposite double-network (DN) gels with excellent mechanical properties, which do not fracture upon loading up to 78 MPa and a strain above 0.98, by compositing of carbon nanotubes (CNTs) without organic modification. Investigations of swelling behaviors, and compressive and tensile properties indicate that equilibrium swelling ratio, compressive modulus and stress, fracture stress, Young's modulus, and yield stress are significantly improved in the presence of CNTs. Scanning electron microscopy (SEM) reveals that the pore size of nanocomposite DN gels is decreased and some embedded micro-network structures are observed on the fracture surface in comparison to DN gels without CNTs, which leads to the enhancement of mechanical properties. The compressive loading-unloading behaviors show that the area of hysteresis loop, dissipated energy, for the first compressive cycle, increases with addition of CNTs, which is much higher than that for the successive cycles. Furthermore, the energy dissipation mechanism, similar to the Mullins effect observed in filled rubbers, is demonstrated for better understanding the nanocomposite DN polymer gels with CNTs.


Assuntos
Hidrogéis/química , Nanotubos de Carbono/química , Estresse Mecânico , Microscopia Eletrônica de Varredura , Nanocompostos/química , Nanocompostos/ultraestrutura , Nanotubos de Carbono/ultraestrutura , Polímeros/química
13.
Toxicol Lett ; 384: 73-85, 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37500026

RESUMO

Increasing attention has been paid to the potential impact of microplastics (MPs) pollution on human health. MPs and phthalates coexist in the environment, however, the effects of exposure to MPs alone or to a combination of di-(2-ethylhexyl) phthalate (DEHP) and MPs on allergic asthma are unclear. This study investigates the effects of exposure to polystyrene microplastics (PS-MPs) or co-exposure with DEHP, on allergic asthma, and the underlying molecular mechanisms. We established an allergic asthma model using ovalbumin, and mice were exposed to PS-MPs (5 mg/kg bw/day) alone, or combined with DEHP (0.5, 5 mg/kg bw/day), for 28 days. The results showed that in the presence of ovalbumin (OVA) sensitization, exposure to PS-MPs alone slightly affected airway inflammation, and airway hyperresponsiveness, while co-exposure to PS-MPs and DEHP caused more significant damage. Co-exposure also induced more oxidative stress and Th2 immune responses, and activation of the TRPA1 and p38 MAPK pathways. The aggravation of asthmatic symptoms induced by co-exposure to PS-MPs and DEHP were inhibited by blocking TRPA1 ion channel or p38 MAPK pathway. The results demonstrated that co-exposure to PS-MPs and DEHP exacerbates allergic asthma, by exacerbating oxidative stress and inflammatory responses, and activating the TRPA1-p38 MAPK pathway.


Assuntos
Asma , Dietilexilftalato , Animais , Camundongos , Dietilexilftalato/toxicidade , Microplásticos/toxicidade , Ovalbumina/imunologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Plásticos/toxicidade , Plásticos/metabolismo , Poliestirenos/toxicidade , Canal de Cátion TRPA1
14.
Food Chem Toxicol ; 173: 113642, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36736609

RESUMO

Nanoplastics have become ubiquitous in the global environment and have attracted increasing attention. However, whether there is an influence between exposure to nanoplastics and diabetes is unclear. To determine the effects of exposure to Polystyrene nanoplastics (PS-NPs) and evaluate the underlying mechanisms, mice were orally exposed to PS-NPs at dosages of 1, 10, 30 mg/kg/day for 8 weeks, alone or combined with a high fat diet and streptozocin (STZ) injection. Our data showed that exposure to 30 mg/kg/day PS-NPs alone induced a significant increase in blood glucose, glucose intolerance and insulin resistance. Combined with a high fat diet and STZ injection, PS-NPs exposure markedly aggravated oxidative stress, glucose intolerance, insulin tolerance and insulin resistance, and induced lesions in the liver and pancreas. PS-NPs exposure could decrease the phosphorylation of AKT and GSK3ß, and treatment with SC79, a selective AKT activator, could increase the level of AKT and GSK3ß phosphorylation, effectively alleviating the increase in ROS levels in the liver or pancreas, and slightly attenuating the increase in fasting blood glucose levels and insulin resistance induced by PS-NPs exposure. This showed that exposure to PS-NPs aggravated type 2 diabetes and the underlying mechanism partly involved in the inhibition of AKT/GSK3ß phosphorylation.


Assuntos
Diabetes Mellitus Tipo 2 , Intolerância à Glucose , Resistência à Insulina , Nanopartículas , Poluentes Químicos da Água , Camundongos , Animais , Poliestirenos/toxicidade , Diabetes Mellitus Tipo 2/induzido quimicamente , Microplásticos , Glicogênio Sintase Quinase 3 beta , Proteínas Proto-Oncogênicas c-akt , Glicemia , Modelos Animais de Doenças , Nanopartículas/toxicidade , Plásticos
15.
Toxicology ; 465: 153059, 2022 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-34864092

RESUMO

Microplastics (MPs) may have an impact on the reproductive development of humans and mammals. However, any effects of MPs exposure on male and female reproductive systems and fertility are still ambiguous. In this study, male and female C57BL/6 mice were exposed to saline or 0.1 mg/d polystyrene microplastics (PS-MPs) for 30 days or 44 days to determine the effects of MPs on reproductive systems, following which some of the mice were caged for 10 days to mate to test fertility. Another group of mice were given fluorescent PS-MPs to determine the accumulation of MPs. The results show that PS-MPs exposure resulted in more significant accumulation and oxidative stress in the ovary than in the testis. In male mice, the number of viable epididymis sperm and spermatogenic cells in the testes after PS-MPs exposure was significantly reduced, and the rate of sperm deformity increased. In female mice, PS-MPs exposure induced a decrease in ovary size and number of follicles. After exposure to PS-MPs, the levels of Follicle stimulating hormone, Luteinizing hormone and testosterone were reduced, and the estradiol levels increased in the serum of male mice, while the changes in these hormone levels of female mice was the opposite. The mice exposed to PS-MPs had a reduced pregnancy rate and produced fewer embryos. These findings suggest that exposure to PS-MPs damaged the testes and ovaries, induced oxidative stress, altered the serum hormone levels, and induced changes in reproduction and fertility. Female mice appear to be more susceptible to MPs in reproduction and fertility than male mice.


Assuntos
Fertilidade/efeitos dos fármacos , Microplásticos/toxicidade , Ovário/efeitos dos fármacos , Poliestirenos/toxicidade , Reprodução/efeitos dos fármacos , Testículo/efeitos dos fármacos , Animais , Estradiol/sangue , Feminino , Hormônio Foliculoestimulante/sangue , Hormônio Luteinizante/sangue , Masculino , Camundongos Endogâmicos C57BL , Folículo Ovariano/efeitos dos fármacos , Folículo Ovariano/metabolismo , Folículo Ovariano/patologia , Ovário/metabolismo , Ovário/patologia , Estresse Oxidativo/efeitos dos fármacos , Gravidez , Taxa de Gravidez , Fatores Sexuais , Contagem de Espermatozoides , Espermatozoides/efeitos dos fármacos , Espermatozoides/metabolismo , Espermatozoides/patologia , Testículo/metabolismo , Testículo/patologia , Testosterona/sangue
16.
ACS Appl Mater Interfaces ; 14(41): 47148-47156, 2022 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-36205693

RESUMO

Recently, flexible wearable and implantable electronic devices have attracted enormous interest in biomedical applications. However, current bioelectronic systems have not solved the problem of mechanical mismatch of tissue-electrode interfaces. Therefore, the biomimetic hydrogel with tissue-like mechanical properties is highly desirable for flexible electronic devices. Herein, we propose a strategy to fabricate a biomimetic hydrogel with strain-stiffening property via regional chain entanglements. The strain-stiffening property of the biomimetic hydrogel is realized by embedding highly swollen poly(acrylate sodium) microgels to act as the microregions of dense entanglement in the soft polyacrylamide matrix. In addition, poly(acrylate sodium) microgels can release Na+ ions, endowing hydrogel with electrical signals to serve as strain sensors for detecting different human movements. The resultant sensors own a low Young's modulus (22.61-112.45 kPa), high nominal tensile strength (0.99 MPa), and high sensitivity with a gauge factor up to 6.77 at strain of 300%. Based on its simple manufacture process, well mechanical matching suitability, and high sensitivity, the as-prepared sensor might have great potential for a wide range of large-scale applications such as wearable and implantable electronic devices.


Assuntos
Microgéis , Dispositivos Eletrônicos Vestíveis , Humanos , Hidrogéis , Biomimética , Íons , Acrilatos , Sódio , Condutividade Elétrica
17.
Int J Biol Macromol ; 184: 797-803, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34166698

RESUMO

The poor mechanical properties induced by unsatisfactory crystallization ability limit the widespread use of biosynthesized poly (3-hydroxybutyrate-co-3-hydroxyhexanate) (PHBH). In this work, poly (3-hydroxybutyrate) (PHB) with a high melting point was first used as a homogeneous nucleating agent to increase the crystallization rate of PHBH by a self-nucleation method with a wider processing temperature window and crystallization kinetics and storage stability of mechanical properties of the PHBH/PHB mixtures were systematically investigated. By controlling the processing temperature and PHB content, the crystal nucleus density and crystallization rate of PHBH could be greatly increased while secondary crystallization was inhibited. When the processing temperature is 185 °C and PHB content is 20 wt%, the half crystallization time is shortened by 96% and the crystallinity was increased to 37.2%. Meanwhile, the mechanical performance of PHBH and its storage stability are greatly improved. Therefore, this work provides a simple and efficient way to improve the crystallization and mechanical performance of PHBH, which is expected to be applied to industrial production on a large scale.


Assuntos
Ácido 3-Hidroxibutírico/química , Hidroxibutiratos/química , Poliésteres/química , Cristalização , Estabilidade de Medicamentos , Fenômenos Mecânicos
18.
ACS Macro Lett ; 10(2): 215-222, 2021 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-35570790

RESUMO

Hepatic ischemia-reperfusion injury (IRI) is a pathophysiological and huge challenge during liver surgical procedures. Herein, virus-mimicking liposomal system based on dendritic lipopeptides for efficient prevention of IRI is reported. These virus-mimicking liposomes not only have virus-like nanostructures and components, but also possess virus-like infections to liver tissue, liver cells, and organelles. The distinguished features for prevention of IRI of viral mimics are as follows: (i) viral envelope-like structure to help avoid the host immune system; (ii) well-defined nanostructure and surface to improve the accumulated efficiency in liver tissue; (iii) viral capsids mimic to enhance liver cell uptake and achieve mitochondrial targeting. This type of virus-mimicking design makes prevention of IRI by drug-loading greatly exceed the control groups with high biocompatibility and facile manufacturing.


Assuntos
Lipossomos , Traumatismo por Reperfusão , Animais , Isquemia/metabolismo , Lipopeptídeos/farmacologia , Lipossomos/metabolismo , Fígado , Camundongos , Traumatismo por Reperfusão/prevenção & controle
19.
Langmuir ; 26(17): 14247-54, 2010 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-20704343

RESUMO

A novel photosensitive C-PNIPAAm comprising hydrophilic PNIPAAm conjugated with a relatively short but very hydrophobic coumarin part was designed and prepared using a coumarin-containing disulfide derivative (C-S-S-C) as transfer agent in the presence of Bu(3)P and water. It was found that C-PNIPAAm can form polymer micelles in aqueous solution. And the micellar morphology in aqueous solution can be photoswitched into hollow spheres according to the photodimerization of coumarin end groups upon 365 nm irradiation and reform the micellar morphology after the subsequent photoscission of dimers upon 254 nm. This instant morphology changing phenomenon was successfully monitored by dynamic light scattering (DLS) and transmission electron microscopy (TEM) measurements. TEM observations showed the small spherical shape of micelles with diameter at 30-50 nm before photo-cross-linking, the big vesicles with diameter at 200-350 nm after photo-cross-linking, and the small micelles with diameter at 30-50 nm after the subsequent photo-de-cross-linking in the first irradiation cycle. The reason for this significant morphology switching can be attributed to the reversible photoinduced amphiphilic structure transformation between the telechelic "hydrophobic end-hydrophilic chain" structure and the ABA type of "hydrophilic chain-hydrophobic center-hydrophilic chain" one upon alternating irradiation.


Assuntos
Acrilamidas/síntese química , Nanoestruturas/química , Polímeros/síntese química , Acrilamidas/química , Resinas Acrílicas , Dissulfetos/síntese química , Dissulfetos/química , Estrutura Molecular , Fotoquímica , Polímeros/química , Soluções , Água/química
20.
Guang Pu Xue Yu Guang Pu Fen Xi ; 29(1): 172-5, 2009 Jan.
Artigo em Zh | MEDLINE | ID: mdl-19385232

RESUMO

In the present paper, the preparation and properties of Eu(III) on poly(N-isopropylacrylamide-co-acrylic acid) (P(NIPAM-co-AAc)) were described. At first, P(NIPAM-co-AAc) microgel nanoparticles were prepared by the precipitation copolymerization of N-isopropylacrylamide with acrylic acid in the presence of N, N-methylenebisacrylamide in water. The morphology and size of the P(NIPAM-co-AAc) nanoparticles were characterized by the scanning electron microscope (SEM) method. The result of SEM shows that the sample is uniformly sized spherical particle and the average particle size of the P(NIPAM-co-AAc) is about 365 nm. Then, EuCl3 was chosen to interact with P(NIPAM-co-AAc) nanoparticles and formed the complex of P(NIPAM-co-AAc)-Eu(III). The complex was characterized by Fourier transform infrared spectroscopy, ultraviolet-visible and fluorescence spectroscopy. It was found that the complex shows thermo-responsive fluorescence from the experimental results. There exists a energy transfer between the polymer ligand and the Eu(III), which can enhance fluorescence emission of the polymer ligand and Eu(III) at the same time. The LCST of P(NIPAM-co-AAc) containing Eu(III) has changed little after the formation of the complex of P(NIPAM-co-AAc)-Eu(III). Therefore, the complex can be used for developing the new applications in biomedical and fluorescence field.


Assuntos
Acrilamidas/química , Acrilatos/química , Európio/química , Portadores de Fármacos/farmacocinética , Fluorescência , Géis , Nanopartículas , Nanotecnologia/métodos , Tamanho da Partícula , Polímeros
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