Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Anim Nutr ; 17: 36-48, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38464951

RESUMO

Previous studies have shown that maternal resveratrol improved growth performance and altered the microbial composition of suckling piglets under hot summer conditions. However, it remains unclear how maternal resveratrol improves growth performance of suckling piglets during high summer temperatures. A total of 20 sows (Landrace × Large White; three parity) were randomly assigned to 2 groups (with or without 300 mg/kg resveratrol) from d 75 of gestation to d 21 of lactation during high ambient temperatures (from 27 to 30 °C). The results showed that maternal resveratrol supplementation increased total daily weight gain of piglets under hot summer conditions, which is consistent with previous studies. Furthermore, we found that maternal resveratrol improved the intestinal morphology and intestinal epithelial proliferation in suckling piglets. Dietary resveratrol supplementation affected the characteristics of exosome-derived microRNAs (miRNAs) in sow colostrum, as well as the genes targeted by differentially produced miRNAs. MiRNAs are concentrated in the tight junction pathway. As a result, the expression of intestinal tight junction proteins was increased in suckling piglets (P < 0.05). Notably, maternal resveratrol increased the intestinal secretory immunoglobulin A (sIgA) levels of suckling piglets via colostrum immunoglobin (P < 0.05), which could increase the abundance of beneficial microbiota to further increase the concentration of short chain fatty acids (SCFA) in suckling piglets' intestine (P < 0.05). Finally, our correlation analysis further demonstrated the positive associations between significantly differential intestinal microbiota, intestinal sIgA production and SCFA concentrations, as well as the positive relation between total daily weight gain and intestinal health of suckling piglets. Taken together, our findings suggested that maternal resveratrol could promote intestinal health to improve piglet growth during high summer temperatures, which might be associated with the immunoglobin and exosome-derived miRNAs in sows' colostrum.

2.
J Anim Sci Biotechnol ; 15(1): 11, 2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-38273345

RESUMO

Oxidative stress has been associated with a number of physiological problems in swine, including reduced production efficiency. Recently, although there has been increased research into regulatory mechanisms and antioxidant strategies in relation to oxidative stress-induced pig production, it remains so far largely unsuccessful to develop accurate models and nutritional strategies for specific oxidative stress factors. Here, we discuss the dose and dose intensity of the causes of oxidative stress involving physiological, environmental and dietary factors, recent research models and the antioxidant strategies to provide theoretical guidance for future oxidative stress research in swine.

3.
Nat Commun ; 14(1): 6824, 2023 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-37884495

RESUMO

RNA-binding proteins play crucial roles in the regulation of gene expression, and understanding the interactions between RNAs and RBPs in distinct cellular conditions forms the basis for comprehending the underlying RNA function. However, current computational methods pose challenges to the cross-prediction of RNA-protein binding events across diverse cell lines and tissue contexts. Here, we develop HDRNet, an end-to-end deep learning-based framework to precisely predict dynamic RBP binding events under diverse cellular conditions. Our results demonstrate that HDRNet can accurately and efficiently identify binding sites, particularly for dynamic prediction, outperforming other state-of-the-art models on 261 linear RNA datasets from both eCLIP and CLIP-seq, supplemented with additional tissue data. Moreover, we conduct motif and interpretation analyses to provide fresh insights into the pathological mechanisms underlying RNA-RBP interactions from various perspectives. Our functional genomic analysis further explores the gene-human disease associations, uncovering previously uncharacterized observations for a broad range of genetic disorders.


Assuntos
Proteínas de Ligação a RNA , RNA , Humanos , RNA/genética , RNA/metabolismo , Proteínas de Ligação a RNA/metabolismo , Sítios de Ligação/genética , Ligação Proteica , Sequenciamento de Cromatina por Imunoprecipitação
4.
Front Nutr ; 9: 971496, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36159472

RESUMO

Background: Resveratrol has numerous beneficial properties, including antioxidant, anti-inflammatory, and immunomodulatory properties. High summer temperatures in Southern China affect the reproductive performance of sows. The present study aimed to investigate the effects of dietary resveratrol supplementation in different thermal environments on the reproductive performance, antioxidant capacity, immune function, and intestinal microbes of sows and piglets during late gestation and lactation, as well as their relationship with colostrum immunoglobulin. Methods: A two-phase experiment was conducted with 40 healthy multiparous sows. In the first phase of the experiment, 20 sows were used in a moderate temperature environment, and in the second phase of the experiment, the remaining 20 sows were used in a high-temperature environment. In both phases, sows were fed either a control diet or a diet consists of control diet and 300 mg/kg resveratrol starting on day 75 of gestation. Plasma, milk, and fecal samples were collected to obtain the indices of antioxidant capacity, immune function, and intestinal microbes. Results: The results showed that resveratrol supplementation increased the number of live births by 13.24 and 26.79% in the first and second phases, respectively, compared with the control group. In the second phase, resveratrol supplementation increased litter weight at weaning and in the concentrations of growth hormone (GH), insulin (INS), progesterone (PROG), triglycerides, and uric acid (UA). The plasma superoxide dismutase (SOD) level on day 110 of gestation and day 14 of lactation, as well as glutathione peroxidase (GSH-Px) on day 14 of lactation in the first phase, showed an increasing trend (p = 0.0728, p = 0.0932, and p = 0.067, respectively) in the resveratrol group, compared with the control group. On day 14 of lactation, the plasma total antioxidant capability (T-AOC) level was higher in the second phase, while the plasma malondialdehyde (MDA) level was lower in both phases in the resveratrol group. Resveratrol supplementation increased the abundance of immunoglobulin A (IgA), immunoglobulin G (IgG), and immunoglobulin M (IgM) in colostrum and the relative abundance of Lactobacillus and Alloprevotella but decreased the relative abundance of Escherichia-shigella in piglet feces in the second phase. In addition, Spearman's correlation analysis indicated that the weight gain of weaned piglets was positively (p < 0.05) associated with IgM content in colostrum and the abundance of Lactobacillus in the fecal microbiota of piglets in the second phase. Moreover, the abundance of Alloprevotella was positively correlated with the contents of IgA and IgG in colostrum, while the abundance of Lactobacillus was positively correlated with IgM content. Conclusion: These findings indicated that maternal resveratrol supplementation could enhance the growth performance, antioxidant capacity, and intestinal health of piglets in a high temperature environment, which might be associated with increased immunoglobin secretion from colostrum.

5.
J Sci Food Agric ; 102(3): 940-948, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34265089

RESUMO

BACKGROUND: The beneficial function of phytase and 25-hydroxyvitamin D3 (HyD) on the feed utilization rate has been widely investigated. However, studies concerning its influence on weaned piglets largely lag behind. The aim of this study was to investigate the effects of phytase and HyD supplementation on the growth performance and bone development in weaned piglets under dietary Ca and P deficiency. RESULTS: The results showed that dietary Ca and P deficiency decreased (P < 0.05) the content of serum P in 6-10 kg piglets, as well as reducing (P < 0.05) the contents of serum Ca and P, average daily gain (ADG), bone mineral density (BMD), breaking force (BF), bone ash and femur Ca in 10-20 kg piglets. Compared with the control group, the feed-to-gain ratio (F/G) of 6-10 kg piglets in the Phy group was decreased (P < 0.05), whereas the ADG, blood Ca and P, BMD, BF, bone ash, P apparent digestibility, Ca and P retention rate of 10-20 kg piglets were increased (P < 0.05). The contents of serum osteocalcin and HyD in 6-10 kg piglets and ADG were higher than in the control group (P < 0.05), as well as the contents of serum Ca and HyD in 10-20 kg piglets in the HyD treatment group. Supplementation with both Phy and HyD decreased the F/D (P < 0.05) and increased the contents of serum Ca, P and HyD in 6-10 kg piglets as well as enhancing the ADG, BMD, BF, bone ash, femur Ca and P, serum Ca and P, HyD, and the apparent digestibility and retention of Ca and P (P < 0.05) in 10-20 kg piglets. Supplementation with Phy and HyD in Ca- and P-deficient dietary decreased bone resorption, and improved tight arrangement of collagen fibers and oblique fibers in weaned piglets. CONCLUSION: These data indicated that supplementation with both 1500 U kg-1 Phy and 50 µg kg-1 HyD could enhance dietary Ca and P utilization and promote bone development in low Ca and P dietary, and supplementation with both Phy and HyD had a significant synergy effect compared to single supplement. © 2021 Society of Chemical Industry.


Assuntos
6-Fitase/metabolismo , Desenvolvimento Ósseo , Calcifediol/metabolismo , Cálcio/deficiência , Fósforo/deficiência , Suínos/crescimento & desenvolvimento , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Densidade Óssea , Osso e Ossos/metabolismo , Dieta/veterinária , Suplementos Nutricionais/análise , Feminino , Masculino , Suínos/metabolismo
6.
Front Vet Sci ; 8: 807301, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35097052

RESUMO

Deoxynivalenol (DON) reduces growth performance and damage intestinal function, and resveratrol (RES) has positive effects on growth performance and intestinal function. The purpose of this study was to investigate the protective mechanism of RES in vitro and vivo challenged with DON. The results showed that dietary supplementation with DON significantly increase the mRNA expression levels of mitophagy- related genes, and protein level for PINK1, Parkin, Beclin-1, Lamp, Atg5, Map1lc, Bnip3, Fundc1, Bcl2l1 and SQSTMS1 (P < 0.05), while supplementation with both RES and DON decreased those indexes in the ileum. Besides DON significantly decreased protein level for Pyruvate Dehydrogenase, Cytochrome c, MFN1, OPA1, and PHB1 (P < 0.05), while supplementation with both RES and DON increased protein level for PHB1, SDHA, and VDAC in the ileum. Moreover, in vitro, we found that DON significantly decreased mitochondrial respiration (P < 0.05), while RES + DON increased the rate of spare respiratory capacity. Also, DON significantly decreased total NAD and ATP (P < 0.05), while RES + DON increased the total NAD and ATP. These results indicate that RES may ameliorates the intestinal damage challenged with deoxynivalenol through mitophagy in weaning piglets.

7.
Materials (Basel) ; 13(17)2020 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-32846913

RESUMO

The microstructures, mechanical properties, and thermal conductivity (TC) of Al-2Fe-xCo (x = 0~0.8) alloys in as-cast, homogeneous annealed, and cool rolled states are systematically studied. Results indicate that appropriate Co modification (x ≤ 0.5) simultaneously improves the thermal and mechanical properties of as-cast Al-2Fe alloys. The improvement of TC is attributed to ameliorating the morphology of primary Al3Fe phases from needles to short rods and fine particles, which decreases the scattering probability of free electrons during the electronic transmission. However, further increasing the Co content (x = 0.8) decreases the TC due to the formation of a coarse plate-like Al2FeCo phase. Besides, the thermal conductivity of annealed Al-2Fe-xCo alloys is higher than that of as-cast alloys because of the elimination of lattice defects and spheroidization of Al3Fe phases. After cool rolling with 80 % deformation, thermal conductivity of alloys slightly increases due to the breaking down of Al2FeCo phases. The rolled Al-2Fe-0.3Co alloy exhibits the highest thermal conductivity, which is about 225 W/(m·K), approximately 11 % higher than the as-cast Al-2Fe sample. The ultimate tensile strength (UTS) and elongation (EL) of as-cast Al-2Fe-0.5Co (UTS: 138 MPa; EL: 22.0 %) are increased by 35 % and 69 %, respectively, compared with those of unmodified alloy (UTS: 102 MPa; EL: 13.0 %).

8.
Proc Natl Acad Sci U S A ; 113(23): E3193-202, 2016 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-27217558

RESUMO

Over 130 y have passed since Charles Darwin first discovered that the adventitious roots of English ivy (Hedera helix) exude a yellowish mucilage that promotes the capacity of this plant to climb vertical surfaces. Unfortunately, little progress has been made in elucidating the adhesion mechanisms underlying this high-strength adhesive. In the previous studies, spherical nanoparticles were observed in the viscous exudate. Here we show that these nanoparticles are predominantly composed of arabinogalactan proteins (AGPs), a superfamily of hydroxyproline-rich glycoproteins present in the extracellular spaces of plant cells. The spheroidal shape of the AGP-rich ivy nanoparticles results in a low viscosity of the ivy adhesive, and thus a favorable wetting behavior on the surface of substrates. Meanwhile, calcium-driven electrostatic interactions among carboxyl groups of the AGPs and the pectic acids give rise to the cross-linking of the exuded adhesive substances, favor subsequent curing (hardening) via formation of an adhesive film, and eventually promote the generation of mechanical interlocking between the adventitious roots of English ivy and the surface of substrates. Inspired by these molecular events, a reconstructed ivy-mimetic adhesive composite was developed by integrating purified AGP-rich ivy nanoparticles with pectic polysaccharides and calcium ions. Information gained from the subsequent tensile tests, in turn, substantiated the proposed adhesion mechanisms underlying the ivy-derived adhesive. Given that AGPs and pectic polysaccharides are also observed in bioadhesives exuded by other climbing plants, the adhesion mechanisms revealed by English ivy may forward the progress toward understanding the general principles underlying diverse botanic adhesives.


Assuntos
Adesivos/química , Hedera/química , Mucoproteínas/química , Sequência de Aminoácidos , Sequência de Bases , Cálcio/química , Reagentes de Ligações Cruzadas , DNA de Plantas/genética , Hedera/genética , Microscopia de Força Atômica , Modelos Moleculares , Estrutura Molecular , Mucoproteínas/genética , Mucoproteínas/ultraestrutura , Nanosferas/química , Nanosferas/ultraestrutura , Pectinas/química , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/ultraestrutura , Molhabilidade
9.
Nat Nanotechnol ; 11(4): 388-94, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26751169

RESUMO

Peptide nanostructures are biodegradable and are suitable for many biomedical applications. However, to be useful imaging probes, the limited intrinsic optical properties of peptides must be overcome. Here we show the formation of tryptophan-phenylalanine dipeptide nanoparticles (DNPs) that can shift the peptide's intrinsic fluorescent signal from the ultraviolet to the visible range. The visible emission signal allows the DNPs to act as imaging and sensing probes. The peptide design is inspired by the red shift seen in the yellow fluorescent protein that results from π-π stacking and by the enhanced fluorescence intensity seen in the green fluorescent protein mutant, BFPms1, which results from the structure rigidification by Zn(II). We show that DNPs are photostable, biocompatible and have a narrow emission bandwidth and visible fluorescence properties. DNPs functionalized with the MUC1 aptamer and doxorubicin can target cancer cells and can be used to image and monitor drug release in real time.


Assuntos
Dipeptídeos/farmacocinética , Corantes Fluorescentes/farmacocinética , Nanopartículas/química , Neoplasias/patologia , Imagem Óptica/métodos , Animais , Antineoplásicos/química , Antineoplásicos/farmacocinética , Linhagem Celular Tumoral , Dipeptídeos/química , Doxorrubicina/química , Doxorrubicina/farmacocinética , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Liberação Controlada de Fármacos , Corantes Fluorescentes/química , Humanos , Camundongos , Neoplasias/metabolismo
10.
ACS Appl Mater Interfaces ; 8(3): 2423-34, 2016 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-26731614

RESUMO

The potential to harness the unique physical, chemical, and biological properties of the sundew (Drosera) plant's adhesive hydrogels has long intrigued researchers searching for novel wound-healing applications. However, the ability to collect sufficient quantities of the sundew plant's adhesive hydrogels is problematic and has eclipsed their therapeutic promise. Inspired by these natural hydrogels, we asked if sundew-inspired adhesive hydrogels could overcome the drawbacks associated with natural sundew hydrogels and be used in combination with stem-cell-based therapy to enhance wound-healing therapeutics. Using a bioinspired approach, we synthesized adhesive hydrogels comprised of sodium alginate, gum arabic, and calcium ions to mimic the properties of the natural sundew-derived adhesive hydrogels. We then characterized and showed that these sundew-inspired hydrogels promote wound healing through their superior adhesive strength, nanostructure, and resistance to shearing when compared to other hydrogels in vitro. In vivo, sundew-inspired hydrogels promoted a "suturing" effect to wound sites, which was demonstrated by enhanced wound closure following topical application of the hydrogels. In combination with mouse adipose-derived stem cells (ADSCs) and compared to other therapeutic biomaterials, the sundew-inspired hydrogels demonstrated superior wound-healing capabilities. Collectively, our studies show that sundew-inspired hydrogels contain ideal properties that promote wound healing and suggest that sundew-inspired-ADSCs combination therapy is an efficacious approach for treating wounds without eliciting noticeable toxicity or inflammation.


Assuntos
Adesivos/farmacologia , Tecido Adiposo/citologia , Drosera/química , Hidrogéis/farmacologia , Transplante de Células-Tronco , Células-Tronco/citologia , Cicatrização/efeitos dos fármacos , Animais , Linhagem Celular , Separação Celular , Sobrevivência Celular/efeitos dos fármacos , Feminino , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Humanos , Camundongos Endogâmicos C57BL , Células-Tronco/efeitos dos fármacos
11.
Oncotarget ; 7(5): 5877-91, 2016 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-26716507

RESUMO

An infusion-dialysis based procedure has been developed as an approach to isolate organic nanoparticles from green tea. Tea nanoparticle (TNP) can effectively load doxorubicin (DOX) via electrostatic and hydrophobic interactions. We established an ABCB1 overexpressing tumor xenograft mouse model to investigate whether TNP can effectively deliver DOX into tumors and bypass the efflux function of the ABCB1 transporter, thereby increasing the intratumoral accumulation of DOX and potentiating the anticancer activity of DOX. MTT assays suggested that DOX-TNP showed higher cytotoxicity toward CCD-18Co, SW620 and SW620/Ad300 cells than DOX. Animal study revealed that DOX-TNP resulted in greater inhibitory effects on the growth of SW620 and SW620/Ad300 tumors than DOX. In pharmacokinetics study, DOX-TNP greatly increased the SW620 and SW620/Ad300 intratumoral concentrations of DOX. But DOX-TNP had no effect on the plasma concentrations of DOX. Furthermore, TNP is a safe nanocarrier with excellent biocompatibility and minimal toxicity. Ex vivo IHC analysis of SW620 and SW620/Ad300 tumor sections revealed evidence of prominent antitumor activity of DOX-TNP. In conclusion, our findings suggested that natural nanomaterials could be useful in combating multidrug resistance (MDR) in cancer cells and potentiating the anticancer activity of chemotherapeutic agents in cancer treatment.


Assuntos
Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/patologia , Doxorrubicina/farmacologia , Portadores de Fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Nanopartículas/química , Chá/química , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Animais , Antibióticos Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Western Blotting , Proliferação de Células/efeitos dos fármacos , Neoplasias do Colo/metabolismo , Sistemas de Liberação de Medicamentos , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Imunofluorescência , Humanos , Técnicas Imunoenzimáticas , Masculino , Camundongos , Camundongos Nus , Nanopartículas/administração & dosagem , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
12.
Acta Biomater ; 25: 268-83, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26219859

RESUMO

Arabinoglactan protein (AGP)-rich nanoparticles obtained from the sticky exudates of Hedera helix (English ivy), have shown promising potential to be used in nanomedicine owing to their excellent aqueous solubility, low intrinsic viscosity, biocompatibility, and biodegradability. In this study, the feasibilities of utilizing ivy nanoparticles (INPs) as nano-carriers for delivering chemotherapeutic drugs in cancer therapy and as nano-fillers to develop novel scaffolds for tissue engineering in regenerative medicine are evaluated. Via electrostatic and hydrophobic interactions, pH-responsive nanoconjugates are formed between the INPs and the doxorubicin (DOX) with an entrapment ratio of 77.9±3.9%. While the INPs show minimal cytotoxicity, the formed INP-DOX conjugates exhibit substantially stronger cytotoxic activity than free DOX against multiple cancer cell lines, suggesting a synergistic effect is established upon conjugation. The anti-cancer effects of the INP-DOX conjugates are further evaluated via in vivo xenograft assays by subcutaneously implanting DOX resistant cell line, SW620/Ad-300, into nude mice. The tumor volumes in mice treated with the INP-DOX conjugates are significantly less than those of the mice treated with free DOX. In addition, the INPs are further exploited as nano-fillers to develop fibrous scaffolds with collagen, via mimicking the porous matrix where the INPs are embedded under natural condition. Enhanced adhesion of smooth muscle cells (SMCs) and accelerated proliferation of mouse aortic SMCs are observed in this newly constructed scaffold. Overall, the results obtained from the present study suggest great potential of the INPs to be used as biocompatible nanomaterials in nanomedicine. The AGP-rich INP renders a glycoprotein architecture that is amenable for modification according to the functional designs, capable of being developed as versatile nanomaterials for extensive biomedical applications. STATEMENT OF SIGNIFICANCE: Naturally occurring organic nanomaterials have drawn increasing interest for their potential biomedical applications in recent years. In this study, a new type of naturally occurring nanoparticles obtained from the sticky exudates on the adventitious roots of English ivy (H. helix), was explored for its potential biomedical application. In particular, the feasibilities of utilizing ivy nanoparticles (INPs) as nano-carriers for delivering chemotherapeutic drugs in cancer therapy and as nano-fillers to develop novel scaffolds for tissue engineering in regenerative medicine were evaluated both in vitro and in vivo. Overall, the results obtained from the present study suggest the great potential of the INPs to be used as biocompatible nanomaterials in nanomedicine. This study may open a totally new frontier for exploring the biomedical application of naturally occurring nanomaterials.


Assuntos
Materiais Biocompatíveis/farmacologia , Hedera/química , Nanopartículas/química , Animais , Antineoplásicos/farmacologia , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cromatografia em Gel , Cromatografia Líquida de Alta Pressão , Doxorrubicina/farmacologia , Endocitose/efeitos dos fármacos , Fluoresceína-5-Isotiocianato/química , Humanos , Concentração de Íons de Hidrogênio , Espaço Intracelular/química , Masculino , Camundongos , Camundongos Nus , Nanopartículas/ultraestrutura , Concentração Osmolar , Raízes de Plantas/química , Eletricidade Estática
13.
J R Soc Interface ; 12(107)2015 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-25948615

RESUMO

Bioadhesives have drawn increasing interest in recent years, owing to their eco-friendly, biocompatible and biodegradable nature. As a typical bioadhesive, sticky exudate observed on the stalked glands of sundew plants aids in the capture of insects and this viscoelastic adhesive has triggered extensive interests in revealing the implied adhesion mechanisms. Despite the significant progress that has been made, the structural traits of the sundew adhesive, especially the morphological characteristics in nanoscale, which may give rise to the viscous and elastic properties of this mucilage, remain unclear. Here, we show that the sundew adhesive is a naturally occurring hydrogel, consisting of nano-network architectures assembled with polysaccharides. The assembly process of the polysaccharides in this hydrogel is proposed to be driven by electrostatic interactions mediated with divalent cations. Negatively charged nanoparticles, with an average diameter of 231.9 ± 14.8 nm, are also obtained from this hydrogel and these nanoparticles are presumed to exert vital roles in the assembly of the nano-networks. Further characterization via atomic force microscopy indicates that the stretching deformation of the sundew adhesive is associated with the flexibility of its fibrous architectures. It is also observed that the adhesion strength of the sundew adhesive is susceptible to low temperatures. Both elasticity and adhesion strength of the sundew adhesive reduce in response to lowering the ambient temperature. The feasibility of applying sundew adhesive for tissue engineering is subsequently explored in this study. Results show that the fibrous scaffolds obtained from sundew adhesive are capable of increasing the adhesion of multiple types of cells, including fibroblast cells and smooth muscle cells, a property that results from the enhanced adsorption of serum proteins. In addition, in light of the weak cytotoxic activity exhibited by these scaffolds towards a variety of mammal cells, evidence is sufficient to propose that sundew adhesive is a promising nanomaterial worth further exploitation in the field of tissue engineering.


Assuntos
Adesivos/química , Drosera/química , Hidrogéis/química , Teste de Materiais , Polissacarídeos/química , Animais , Adesão Celular , Drosera/metabolismo , Humanos , Camundongos , Células NIH 3T3
14.
Soft Matter ; 11(19): 3822-32, 2015 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-25858105

RESUMO

While tremendous efforts have been made in investigating scalable approaches for fabricating nanoparticles, less progress has been made in scalable synthesis of cyclic peptide nanoparticles and nanotubes, despite their great potential for broader biomedical applications. In this paper, tunable synthesis of self-assembled cyclic peptide nanotubes and nanoparticles using three different methods, phase equilibrium, pH-driven, and pH-sensitive methods, were proposed and investigated. The goal is scalable nanomanufacturing of cyclic peptide nanoparticles and nanotubes with different sizes in large quality by controlling multiple process parameters. Cyclo-(L-Gln-D-Ala-L-Glu-D-Ala-)2 was applied to illustrate the proposed ideas. In the study, mass spectrometry and high performance liquid chromatography were employed to verify the chemical structures and purity of the cyclic peptides. Morphology and size of the synthesized nanomaterials were characterized using atomic force microscopy and dynamic light scattering. The dimensions of the self-assembled nanostructures were found to be strongly influenced by the cyclic peptide concentration, side chain modification, pH values, reaction time, stirring intensity, and sonication time. This paper proposed an overall strategy to integrate all the parameters to achieve optimal synthesis outputs. Mechanisms of the self-assembly of the cyclic peptide nanotubes and nanoparticles under variable conditions and tunable parameters were discussed. This study contributes to scalable nanomanufacturing of cyclic peptide based self-assembled nanoparticles and nanotubes for broader biomedical applications.


Assuntos
Nanopartículas/química , Nanotecnologia/métodos , Nanotubos de Peptídeos/química , Sequência de Aminoácidos , Técnicas de Química Sintética , Concentração de Íons de Hidrogênio , Cinética , Sonicação
15.
Acta Biomater ; 10(10): 4269-84, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24952072

RESUMO

A carnivorous fungus, Arthrobotrys oligospora, has been shown to secrete nanoparticles. In the present work, the potential of two charge-selective fractions of fungal nanoparticles (FNPs) as bioactive nanocarriers in cancer therapy is explored by investigating their immunostimulatory activities, cytotoxic mechanisms and in vitro immunochemotherapeutic effects. A surface charge-selective fractionation procedure to purify crude FNPs has been established, and two FNP fractions (i.e. FNP1 and FNP2), with different surface charges and similarly reduced diameters of 100-200nm, are obtained. Both FNP fractions enhance the secretion of multiple proinflammatory cytokines and chemokines from macrophages and splenocytes. However, FNP2 has stronger cytotoxicity than FNP1. It is FNP2 not FNP1 that could clearly inhibit cell proliferation by inducing apoptosis and arresting cells at the sub G0/G1 phase. Both the FNP fractions can form pH-responsive nanocomplexes with doxorubicin (DOX) via electrostatic interactions. For direct cytotoxicity, DOX-FNP2 complexes demonstrate higher activity than DOX against multiple tumor cells, while DOX-FNP1 complexes show weaker activity than DOX. Interestingly, in a co-culture experiment where splenocytes are co-cultured with tumor cells, both DOX-FNP complexes demonstrate higher cytotoxicity than DOX. In conclusion, this work proposes a combined therapeutics for cancer treatment using charge-selective fractions of FNPs as bioactive nanocarriers.


Assuntos
Antibióticos Antineoplásicos , Ascomicetos/química , Doxorrubicina , Sistemas de Liberação de Medicamentos , Nanopartículas/química , Neoplasias/tratamento farmacológico , Animais , Antibióticos Antineoplásicos/química , Antibióticos Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Quimiocinas/metabolismo , Doxorrubicina/química , Doxorrubicina/farmacologia , Humanos , Macrófagos/metabolismo , Macrófagos/patologia , Camundongos , Neoplasias/metabolismo , Neoplasias/patologia , Baço/metabolismo , Baço/patologia
16.
J Biomed Nanotechnol ; 10(6): 1016-29, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24749396

RESUMO

Many health benefits have been associated with tea consumption. In an effort to elucidate the source of these health benefits, numerous phytochemicals have been extracted from tea infusions, some of which have demonstrated promise as clinical therapeutics for cancer therapy. Considering the advantageous properties of organic nanoparticles, the purpose of this study is to develop a method for isolating nanoparticles from tea leaves, and explore potential biomedical applications for these nanoparticles. First, an infusion-dialysis procedure for isolating tea nanoparticles (TNPs) from green tea infusions is developed. Second, atomic force microscopy and scanning electron microscopy reveal that the TNPs are spherical with diameters of 100-300 nm. Third, electrophoretic light scattering is used to determine that the TNPs have a zeta potential of -26.52 mV at pH 7.0. Finally, chemical analysis demonstrates that (-) Epigallocatechin gallate, caffeine, and theobromine are not found in the TNPs. Interestingly, the TNPs do enhance the in vitro secretion of cytokines IL-6, TNF-alpha, and G-CSF, as well as the chemokines RANTES, IP-10, MDC from mouse macrophages RAW264.7, indicating an immunostimulatory effect. As a nanocarrier, the TNPs are able to form complexes with doxorubicin (DOX) and have the potential for applications in drug delivery. Further the DOX-loaded TNPs increase the cellular DOX uptake, compared to free DOX, leading to higher cytotoxicity in the A549 human lung cancer and MCF-7 breast cancer cells. More importantly, the DOX-loaded TNPs significantly increase the DOX uptake and cytotoxicity in MCF-7/ADR multidrug resistant breast cancer cells. In this work, an infusion-dialysis procedure is developed for isolation of the TNPs from green tea, and the potential of these nanoparticles as a multifunctional nanocarrier for cancer therapy in vitro is explored.


Assuntos
Adjuvantes Imunológicos/administração & dosagem , Camellia sinensis/química , Doxorrubicina/administração & dosagem , Doxorrubicina/química , Nanocápsulas/administração & dosagem , Neoplasias Experimentais/tratamento farmacológico , Extratos Vegetais/administração & dosagem , Adjuvantes Imunológicos/química , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Linhagem Celular Tumoral , Difusão , Humanos , Imunização/métodos , Nanocápsulas/química , Nanocápsulas/ultraestrutura , Neoplasias Experimentais/patologia , Extratos Vegetais/química , Resultado do Tratamento
17.
J Biomed Nanotechnol ; 10(3): 445-54, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24730240

RESUMO

The purpose of this study was to design and fabricate a new cyclic peptide-based nanotube (CPNT) and to explore its potential application in cancer therapy. For such a purpose, the CPNT bundles with a diameter of -10 nm and a length of -50-80 nm, self-assembled in a micro-scaled aggregate, were first prepared using a glutamic acid and a cysteine residue-containing cyclic octapeptide. In order to explore the potential application of these supramolecular structures, the CPNTs were loaded with doxorubicin (DOX), and further modified using polyethylene glycol (PEG). The PEG-modified DOX-loaded CPNTs, showing high drug encapsulation ratio, were nano-scaled dispersions with a diameter of -50 nm and a length of -200-300 nm. More importantly, compared to free DOX, the PEG-modified DOX-loaded CPNT bundles demonstrated higher cytotoxicity, increased DOX uptake and altered intracellular distribution of DOX in human breast cancer MCF-7/ADR cells in vitro. In addition, an enhanced inhibition of P-gp activity was observed in MCF-7/ADR cells by the PEG-modified DOX-loaded CPNT bundles, which shows their potential to overcome the multidrug resistance in tumor therapy. These findings indicate that using cyclic peptide-based supramolecular structures as nanocarriers is a feasible and a potential solution for drug delivery to resistant tumor cells.


Assuntos
Antibióticos Antineoplásicos/administração & dosagem , Neoplasias da Mama/tratamento farmacológico , Doxorrubicina/administração & dosagem , Portadores de Fármacos/química , Resistencia a Medicamentos Antineoplásicos , Nanotubos de Peptídeos/química , Antibióticos Antineoplásicos/farmacocinética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Doxorrubicina/farmacocinética , Portadores de Fármacos/farmacocinética , Avaliação Pré-Clínica de Medicamentos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Feminino , Humanos , Concentração de Íons de Hidrogênio , Células MCF-7 , Nanoconjugados/administração & dosagem , Nanoconjugados/química , Polietilenoglicóis/química , Polietilenoglicóis/farmacocinética , Polimerização , Distribuição Tecidual
18.
J R Soc Interface ; 10(87): 20130392, 2013 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-23883948

RESUMO

Bio-inspiration for novel adhesive development has drawn increasing interest in recent years with the discovery of the nanoscale morphology of the gecko footpad and mussel adhesive proteins. Similar to these animal systems, it was discovered that English ivy (Hedera helix L.) secretes a high strength adhesive containing uniform nanoparticles. Recent studies have demonstrated that the ivy nanoparticles not only contribute to the high strength of this adhesive, but also have ultraviolet (UV) protective abilities, making them ideal for sunscreen and cosmetic fillers, and may be used as nanocarriers for drug delivery. To make these applications a reality, the chemical nature of the ivy nanoparticles must be elucidated. In the current work, a method was developed to harvest bulk ivy nanoparticles from an adventitious root culture system, and the chemical composition of the nanoparticles was analysed. UV/visible spectroscopy, inductively coupled plasma mass spectrometry, Fourier transform infrared spectroscopy and electrophoresis were used in this study to identify the chemical nature of the ivy nanoparticles. Based on this analysis, we conclude that the ivy nanoparticles are proteinaceous.


Assuntos
Adesivos/química , Hedera/química , Nanopartículas/química , Eletroforese , Glicoproteínas/química , Glicoproteínas/isolamento & purificação , Espectrometria de Massas , Nanopartículas/análise , Nanopartículas/ultraestrutura , Proteínas de Plantas/química , Proteínas de Plantas/isolamento & purificação , Espectroscopia de Infravermelho com Transformada de Fourier
19.
J Nanosci Nanotechnol ; 13(3): 1649-59, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23755570

RESUMO

Gold nanoparticles (AuNPs) have drawn significant interest in recent years due to unique properties that make them advantageous in biomedical applications, including drug delivery and tissue engineering. In this paper, we have developed multiple methods for the synthesis of AuNPs using English ivy as the substrate. In the first method, we have used actively growing English ivy shoots to develop a sustainable system for the production of ivy nanoparticles. The second method was developed using the extract from the adventitious roots of English ivy. The nanoparticles formed using both methods were compared to determine the size distribution, morphology, and chemical structure of the nanoparticles. Characterization of the AuNPs was conducted using ultraviolet-visible (UV-Vis) spectroscopy, dynamic light scattering (DLS), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). In addition to the structural differences between the AuNPs formed from the different methods, details of the methods in terms of yield, duration, and speed of AuNP formation are also discussed. Further, this paper will show that AuNPs formed using both methods demonstrated efficient uptake in mammalian cells, which provides the potential for biomedical applications. The two methods developed through this research for eco-friendly synthesis of AuNPs present an alternative to traditional chemical synthesis methods.


Assuntos
Ouro/química , Hedera/metabolismo , Nanopartículas Metálicas , Microscopia Eletrônica de Varredura , Espectrometria por Raios X , Espectrofotometria Ultravioleta
20.
J Nanobiotechnology ; 11: 3, 2013 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-23375001

RESUMO

BACKGROUND: Naturally occurring nanoparticles isolated from English ivy (Hedera helix) have previously been proposed as an alternative to metallic nanoparticles as sunscreen fillers due to their effective UV extinction property, low toxicity and potential biodegradability. METHODS: This study focused on analyzing the physicochemical properties of the ivy nanoparticles, specifically, those parameters which are crucial for use as sunscreen fillers, such as pH, temperature, and UV irradiation. The visual transparency and cytotoxicity of ivy nanoparticles were also investigated comparing them with other metal oxide nanoparticles. RESULTS: Results from this study demonstrated that, after treatment at 100°C, there was a clear increase in the UV extinction spectra of the ivy nanoparticles caused by the partial decomposition. In addition, the UVA extinction spectra of the ivy nanoparticles gradually reduced slightly with the decrease of pH values in solvents. Prolonged UV irradiation indicated that the influence of UV light on the stability of the ivy nanoparticle was limited and time-independent. Compared to TiO2 and ZnO nanoparticles, ivy nanoparticles showed better visual transparency. Methylthiazol tetrazolium assay demonstrated that ivy nanoparticles exhibited lower cytotoxicity than the other two types of nanoparticles. Results also suggested that protein played an important role in modulating the three-dimensional structure of the ivy nanoparticles. CONCLUSIONS: Based on the results from this study it can be concluded that the ivy nanoparticles are able to maintain their UV protective capability at wide range of temperature and pH values, further demonstrating their potential as an alternative to replace currently available metal oxide nanoparticles in sunscreen applications.


Assuntos
Cosméticos/química , Hedera/química , Nanopartículas de Magnetita/química , Protetores Solares/química , Fenômenos Químicos , Cosméticos/análise , Temperatura Alta , Concentração de Íons de Hidrogênio , Raízes de Plantas/química , Protetores Solares/análise , Raios Ultravioleta , Óxido de Zinco/análise , Óxido de Zinco/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA