RESUMO
As compared with exogenous components, non-starch components (NSCS), such as proteins, lipids, non-starch polysaccharides (NSPs), and polyphenols, inherently present in cereals, are more effective at inhibiting starch digestibility. Existing research has mostly focused on complex systems but overlooked the analysis of the in-situ role of the NSCS. This study reviews the crucial mechanisms by which endogenous NSCS inhibit starch digestion, emphasizing the spatial distribution-function relationship. Starch granules are filled with pores/channels-associated proteins and lipids, embedding in the protein matrix, and maintained by endosperm cell walls. The potential starch digestion inhibition of endogenous NSCS is achieved by altering starch gelatinization, molecular structure, digestive enzyme activity, and accessibility. Starch gelatinization is constrained by endogenous NSCS, particularly cell wall NSPs and matrix proteins. The stability of the starch crystal structure is enhanced by the proteins and lipids distributed in the starch granule pores and channels. Endogenous polyphenols greatly inhibit digestive enzymes and participate in the cross-linking of NSPs in the cell wall space, which together constitute a physical barrier that hinders amylase diffusion. Additionally, the spatial entanglement of NSCS and starch under heat and non-heat processing conditions reduces starch accessibility. This review provides novel evidence for the health benefits of whole cereals.
RESUMO
INTRODUCTION: To explore and evaluate the performance of MRI-based brain tumor super-resolution generative adversarial network (MRBT-SR-GAN) for improving the MRI image resolution in brain tumors. METHODS: A total of 237 patients from December 2018 and April 2020 with T2-fluid attenuated inversion recovery (FLAIR) MR images (one image per patient) were included in the present research to form the super-resolution MR dataset. The MRBT-SR-GAN was modified from the enhanced super-resolution generative adversarial networks (ESRGAN) architecture, which could effectively recover high-resolution MRI images while retaining the quality of the images. The T2-FLAIR images from the brain tumor segmentation (BRATS) dataset were used to evaluate the performance of MRBT-SR-GAN contributed to the BRATS task. RESULTS: The super-resolution T2-FLAIR images yielded a 0.062 dice ratio improvement from 0.724 to 0.786 compared with the original low-resolution T2-FLAIR images, indicating the robustness of MRBT-SR-GAN in providing more substantial supervision for intensity consistency and texture recovery of the MRI images. The MRBT-SR-GAN was also modified and generalized to perform slice interpolation and other tasks. CONCLUSIONS: MRBT-SR-GAN exhibited great potential in the early detection and accurate evaluation of the recurrence and prognosis of brain tumors, which could be employed in brain tumor surgery planning and navigation. In addition, this technique renders precise radiotherapy possible. The design paradigm of the MRBT-SR-GAN neural network may be applied for medical image super-resolution in other diseases with different modalities as well.
Assuntos
Neoplasias Encefálicas , Aprendizado Profundo , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Redes Neurais de Computação , Neoplasias Encefálicas/diagnóstico por imagemRESUMO
BACKGROUND: Malignant glioma is one of the essentially incurable tumors with chemoresistance and tumor recurrence. As a histone methyltransferase, SUV39H2 can trimethylate H3K9. SUV39H2 is highly expressed in many types of human tumors, while the function of SUV39H2 in the development and progression of glioma has never been elucidated. METHODS: RT-qPCR and IHC were used to test SUV39H2 levels in glioma tissues and paired normal tissues. The clinical relevance of SUV39H2 in glioma was analyzed in a public database. Colony formation assays, CCK-8 assays, and flow cytometry were conducted to explore the role of SUV39H2 in the growth of glioma cells in vitro. A cell line-derived xenograft model was applied to explore SUV39H2's role in U251 cell proliferation in vivo. Sphere formation assays, RT-qPCR, flow cytometry, and IF were conducted to illustrate the role of SUV39H2 in the stemness and chemosensitivity of glioma. Luciferase reporter assays and WB were applied to determine the function of SUV39H2 in Hh signaling. RESULTS: SUV39H2 was highly expressed in glioma tissues relative to normal tissues. SUV39H2 knockdown inhibited cell proliferation and stemness and promoted the chemosensitivity of glioma cells in vitro. In addition, SUV39H2 knockdown also significantly inhibited glioma cell growth in vivo. Moreover, we further uncovered that SUV39H2 regulated hedgehog signaling by repressing HHIP expression. CONCLUSIONS: Our findings delineate the role of SUV39H2 in glioma cell growth and chemosensitivity as a pivotal regulator of the hedgehog signaling pathway and may support SUV39H2 as a potential target for diagnosis and therapy in glioma management.
RESUMO
A 52-year-old male who had chronic hypertension for several years presented with abrupt epistaxis. The CT scan revealed a 40âmmâ×â40âmm mass in the nasal cavity intended to the maxillary sinus and the base of skull. Nasal endoscope biopsy and serum/urinary catecholamine detection conformed an ectopic noradrenaline-secreting pheochromocytoma. The present research was to discuss the clinical characteristics of the rare pheochromocytoma and the palliative interventional embolization for it.
Assuntos
Neoplasias das Glândulas Suprarrenais/terapia , Cavidade Nasal/patologia , Feocromocitoma/terapia , Neoplasias das Glândulas Suprarrenais/complicações , Neoplasias das Glândulas Suprarrenais/metabolismo , Embolização Terapêutica , Epistaxe/etiologia , Humanos , Masculino , Seio Maxilar , Pessoa de Meia-Idade , Norepinefrina/metabolismo , Cuidados Paliativos , Feocromocitoma/complicações , Feocromocitoma/metabolismo , Tomografia Computadorizada por Raios XRESUMO
The aim of this study was to investigate the effect of plasma-activated water (PAW) during extrusion on the formation of endogenous starch complexes with wheat starch (WS) as a model material. Using PAW during the extrusion process resulted in an increase in amylose content from 27.87 % to 30.07 %. Results from Fourier transform infrared spectroscopy, X-ray diffraction, and differential scanning calorimetry indicated that the PAW facilitated the formation of endogenous starch-lipid complexes during extrusion. PAW120 (distilled water treated by plasma for 120 s) showed a better promotion effect than PAW60 (distilled water treated by plasma for 60 s). EWS120 (WS extruded using PAW120) exhibited lower peak viscosity and swelling power, but higher solubility, particle size, and resistant starch content compared with EWS0 (WS extruded using distilled water) and EWS60 (WS extruded using PAW60). In a word, the acidic substances in PAW may lead to hydrolysis of starch and generate more amylose, thus improving the amount of endogenous starch-lipid complexes. The present study provides a novel extrusion method to obtain modified starch with higher RS content than common extrusion, which has potential application in the industrial production of functional foods with low glycemic index.
Assuntos
Amilose , Amido , Amido/química , Amilose/química , Triticum/química , Água/química , Difração de Raios X , LipídeosRESUMO
Starch, lipids, and proteins are key macronutrients in starchy foods. Their interactions during processing can form starch-lipid-protein ternary complexes, significantly affecting food quality. Ultrasonic treatment, as a common processing method, is expected to regulate the quality of starchy foods by influencing the formation of ternary complexes. This study aimed to understand the effect of ultrasonic pretreatment on the formation of starch-lipid-protein ternary complexes using various types of starches. Wheat starch (WS), maize starch (MS), and potato starch (PS) were gelatinized and treated with ultrasound at various power densities (0-40 W/L) to form complexes with lauric acid (LA) and ß-lactoglobulin (ßLG), respectively. Ultrasound increased the amylose content of gelatinized WS, MS, and PS and shifted their chain length distribution towards the short chains. Results from Fourier transform infrared spectroscopy, laser confocal micro-Raman, X-ray diffraction, and differential scanning calorimetry showed that the largest amount of WS-LA-ßLG complexes was formed at the ultrasonic power density of 10 W/L, and MS-LA-ßLG and PS-LA-ßLG complexes at 20 W/L. Additionally, ultrasound enhanced the content of resistant starch (RS) in the starch-LA-ßLG complexes. The RS content increased from 14.12 % to 18.31 % for WS-LA-ßLG, and from 19.18 % and 20.69 % to 27.60 % and 28.63 % for MS-LA-ßLG and PS-LA-ßLG complexes, respectively. This study presents an approach for facilitating the formation of ternary complexes, contributing to the development of low-GI functional foods.
Assuntos
Lactoglobulinas , Ácidos Láuricos , Amido , Ácidos Láuricos/química , Amido/química , Lactoglobulinas/química , Ondas Ultrassônicas , DigestãoRESUMO
Location influences the properties of potato starch. Potato starch granules cultivated in highland of China were separated into three fractions according to the sedimentation time: large- (â¼81 µm, large fraction potato starch, LFPS), medium- (â¼28 µm, medium fraction potato starch, MFPS), and small-size (â¼15 µm, small fraction potato starch, SFPS) fractions. SFPS showed a spherical shape, MFPS showed an ellipsoid shape and LFPS showed an elongated shape. The three fractions showed the similar XRD patterns, while the relative crystallinity decreased with the decrease of granule size (LFPS 23.61%, MFPS 20.74% and SFPS 20.48%). The water solubility was positively corelated with the granule size, while the swelling power showed a negative relationship with the granule size. For the rheological properties, all the three fractions showed a shear-shinning behavior; and SFPS had the highest peak temperature. However, the MFPS showed the lowest storage modulus during the temperature sweep. The granule size didn't influence the nutritional properties of potato starch and LFPS had the highest slowly digestible starch (SDS) (83.77%) and resistant starch (RS) (13.66%) contents. Some of the properties are different from the previous studies.
Assuntos
Solanum tuberosum , Solanum tuberosum/química , Amilose/química , Amido/química , Solubilidade , ChinaRESUMO
The digestive properties of oat-based food have garnered considerable interest. This study aimed to explore the internal and external factors contributing to different digestion properties of oat flour under actual processing conditions. Analysis of the ordered structure of oat starch revealed that an increase in gelatinization moisture to 60 % led to a decrease in crystallinity, R1047/1022 value, and helical structures content to 0, 0.48 %, and 1.45 %, respectively. Even when the crystal structure was completely destroyed, the short-range structure retained a certain degree of order. Surface structure observations of starch granules and penetration experiments with amylase-sized polysaccharide fluorescence probes indicated that non-starch components and small pores effectively hindered the diffusion of the probes but low-moisture (20 %) gelatinization substantially damaged this barrier. Furthermore, investigations into starch digestibility and starch molecular structure revealed that the ordered structure remaining inside the starch after high gelatinization delayed the digestion rate (0.028 min-1) and did not increase the content of resistant starch (7.10 %). It was concluded that the surface structure and non-starch components of starch granules limited the extent of starch digestion, whereas the spatial barrier of the residual ordered structure affected the starch digestion rate.
Assuntos
Avena , Amido , Amido/química , Avena/química , Farinha , Digestão , AmilasesRESUMO
Introduction: Glioblastoma multiforme (GBM), the most common primary malignant brain tumor, is notorious for its aggressive growth and dismal prognosis. This study aimed to elucidate the molecular underpinnings of GBM, particularly focusing on the role of AGBL4 and its connection to inflammatory pathways, to discover viable therapeutic targets. Methods: Single-cell sequencing was utilized to examine the expression levels of AGBL4 and functional assays were performed to assess the effects of AGBL4 modulation. Results: Our findings identified the significant upregulation of AGBL4 in GBM, which correlated with adverse clinical outcomes. Functional assays demonstrated that AGBL4 knockdown inhibited GBM cell proliferation, migration, and invasion and influenced inflammatory response pathways, while AGBL4 overexpression promoted these activities. Further investigation revealed that AGBL4 exerted its oncogenic effects through modulation of MMP-1, establishing a novel regulatory axis critical for GBM progression and inflammation. Discussion: Both AGBL4 and MMP-1 may be pivotal molecular targets, offering new avenues for targeted therapy in GBM management.
Assuntos
Neoplasias Encefálicas , Glioblastoma , Metaloproteinase 1 da Matriz , Glioblastoma/patologia , Glioblastoma/metabolismo , Glioblastoma/genética , Humanos , Metaloproteinase 1 da Matriz/metabolismo , Metaloproteinase 1 da Matriz/genética , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/imunologia , Linhagem Celular Tumoral , Proliferação de Células , Movimento Celular/genética , Progressão da Doença , Inflamação/metabolismo , Regulação Neoplásica da Expressão Gênica , Transdução de Sinais , MasculinoRESUMO
BACKGROUND: Circular RNAs are closed endogenous RNAs that are involved in the progression of diverse tumors. Even with the most advanced combined treatments, patients with glioblastoma multiforme have a median survival time of <15 months. This study aimed to investigate the roles of circular PLOD2 (circPLOD2) in glioma tumorigenesis and tumor development and to clarify its tumor-promoting effects by bioinformatics analysis and molecular experiments. METHODS: To determine the characteristics of circPLOD2 expression, quantitative real-time polymerase chain reaction was conducted. Stable knockdown of circPLOD2 was implemented for functional assays. Cell Counting Kit-8 and colony formation assays were used to measure cell proliferation. Transwell assays and tube formation assays were used to evaluate cell invasion and angiogenesis abilities, respectively. An intracranial xenograft model was established to determine the function of circPLOD2 in vivo. Further biochemical and Western blot analyses were conducted to evaluate proteins associated with circPLOD2. RESULTS: circPLOD2 was upregulated in glioma tissues and cells. High expression of circPLOD2 was significantly associated with tumor size, World Health Organization grade, and molecular characteristics of glioma. circPLOD2 deregulation affected glioblastoma multiforme cell proliferation, invasion, and angiogenesis. Knockdown of circPLOD2 inhibited tumorigenesis in vivo. Further biochemical analysis showed that circPLOD2 was involved in oncogenic pathways and correlated with the expression of proteins related to proliferation, invasion, and angiogenesis. CONCLUSIONS: Our data indicate that circPLOD2 promotes glioma tumorigenesis and tumor development in vitro and in vivo and that suppressing circPLOD2 could be a novel therapeutic strategy for glioma.
Assuntos
Neoplasias Encefálicas , Glioblastoma , Glioma , MicroRNAs , Humanos , Glioblastoma/patologia , MicroRNAs/metabolismo , Neoplasias Encefálicas/patologia , Glioma/patologia , Proliferação de Células/genética , Carcinogênese/genética , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica/genética , Movimento Celular/genética , Pró-Colágeno-Lisina 2-Oxoglutarato 5-Dioxigenase/metabolismoRESUMO
In this study, the widely used varieties in China were selected to explore the low starch digestive properties of highland barley from three aspects of composition, starch structural orders, and kernel structure. Two digestive systems were constructed, with highland barley in flour and chyme forms, to investigate the contribution of these inherent properties to starch digestion under different physical forms. Compared with white and black highland barley, blue varieties showed poor chemical composition, lower starch crystallinity, and higher short-range structural order degree, but the starch digestibility as flour was only slightly higher. All varieties of chyme demonstrated lower starch digestibility compared to flour; however, blue highland barley chyme showed much lower starch digestibility than other chyme. Furthermore, kernel structural analysis showed that the blue highland barley kernel structure effectively inhibited digestion. These results indicated that the kernel structure had a critical influence on the starch digestibility of highland barley.
Assuntos
Líquidos Corporais , Hordeum , Amido , Farinha , DigestãoRESUMO
An increased interest has been observed in the application of soybean protein isolate (SPI) into O/W emulsion because of the amphipathic characteristics of SPI. However, at pH around 4.5, SPI was almost lost its hydrophilic characteristic, thus greatly limiting its application in emulsion under an acidic environment. Therefore, this drawback of SPI needs to be urgently solved. This study aims to investigate the effect of γ-polyglutamic acid (γ-PGA) on physicochemical properties of SPI-stabilized O/W emulsion. The results suggested that the interaction between γ-PGA and SPI improved the SPI solubility in solution, and increased emulsifying properties of SPI in the pH range of 4.0-5.0 via electrostatic interaction. Meanwhile, the charge neutralisation between SPI emulsions with γ-PGA was confirmed via ζ-potentiometry. With the presence of γ-PGA in emulsion at pH 4.0 and 5.0, the electrostatic complexation between SPI and anionic γ-PGA exhibited decreased the viscosity of SPI emulsion, which might be related to the phenomenon as indicated by the confocal laser scanning microscope measurements. Therefore, the electrostatic complexation between SPI and γ-PGA suggested that the promising potential of γ-PGA to be used in SPI-stabilized O/W emulsion under an acidic environment.
RESUMO
Ceramic dielectric capacitors have attracted increasing interest due to their wide applications in pulsed power electronic systems. Nevertheless, synchronously achieving the high energy storage density, high energy storage efficiency and good thermal stability in dielectric ceramics is still a great challenge. Herein, lead free Sr3SmNa2Fe0.5Nb9.5O30 (SSNFN) ceramic with tetragonal tungsten bronze structure was synthesized and characterized, high total energy storage density (2.1 J cm-3), recoverable energy storage density (1.7 J cm-3), energy storage efficiency (80%) and good thermal stability are obtained simultaneously in the compound, due to the contribution of high maximum polarization (P max), low remanent polarization (P r) and large breakdown strength (E b). The high P max is related with the intrinsic characteristic of Sr4Na2Nb10O30 (SNN) based system, while the small P r and good thermal stability stem from the significantly enhanced relaxor behavior. In addition, the large E b originates from the improved microstructure with fewer defects and decreased average grain size, and the reduction of electrical heterogeneity compared with SNN. The capacitive performance obtained in this work points out the great potential of tungsten bronze ceramic designed for energy storage applications and pave a feasible way to develop novel lead-free dielectric capacitors.
RESUMO
The composition and structure of starch are important indicators to evaluate the quality of rice, but the effect of protein on structural properties of rice has always been controversial. In the present study, the rheological properties and thermal properties were combined to investigate the effects of protein on mechanical and inner structure changes of rice kernel during cooking. The morphologic changes in overall form and inner structure of the kernel showed the limited and uneven gelatinization of starch, and reflected the good heating stability of protein. The comparison of molecular mobility in H2O/D2O reflected the special gelatinization behavior of starch and the hydrophobicity of protein during cooking. The similar proton distributions between starch, starch-protein mixture and rice flour indicated the weak interactions between starch and protein. The results of Fourier transform infrared spectra, thermogravimetric analysis and transmission electron microscope confirmed the wrapping effect of starch and surface interactions with protein.
Assuntos
Culinária , Oryza/química , Amido/química , Farinha/análise , Gelatina/químicaRESUMO
Pseudogenes, which are long noncoding RNAs that originate from protein-coding genes, have been suggested to play important roles in disease. Although studies have revealed high expression of legumain (LGMN) in many types of tumors, the regulation of LGMN remains largely unknown. Here, we found that a novel LGMN pseudogene (LGMNP1) was upregulated in glioblastoma (GBM) tissues and high LGMNP1 expression in GBM cells enhanced proliferation and invasion. Biochemical analysis showed that cytoplasmic LGMNP1 functionally targeted miR-495-3p in a manner involving an RNA-induced silencing complex. Dual-luciferase reporter assays demonstrated that LGMN was a target of miR-495-3p, and LGMN was upregulated and positively correlated with LGMNP1 in GBM. Moreover, miR-495-3p was downregulated and negatively correlated with LGMNP1 in GBM tissues. Notably, the tumor-promoting effects of LGMNP1 upregulation could be alleviated by miR-495-3p mimics. Furthermore, GBM cells overexpressing LGMNP1 exhibited more aggressive tumor progression and elevated LGMN expression in vivo. Thus, our data illustrate that LGMNP1 exerts its oncogenic activity, at least in part, as a competitive endogenous RNA (ceRNA) that elevates LGMN expression by sponging miR-495-3p. CeRNA-mediated miRNA sequestration might be a novel therapeutic strategy in GBM.
Assuntos
Neoplasias Encefálicas/patologia , Cisteína Endopeptidases/genética , Regulação Neoplásica da Expressão Gênica/genética , Glioblastoma/patologia , MicroRNAs/metabolismo , Animais , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Cisteína Endopeptidases/metabolismo , Progressão da Doença , Glioblastoma/genética , Glioblastoma/metabolismo , Xenoenxertos , Humanos , Camundongos , Camundongos Nus , Pseudogenes/genética , RNA Longo não Codificante/genéticaRESUMO
Owing to its importance in food and pharmaceutical applications, complexation of amylose with amphiphilic molecules has been experimentally and theoretically investigated. Most theoretical studies have involved only a single amphiphilic molecule as the guest. In the present work, Molecular Dynamics (MD) is utilized to study this complexation process when more than one amphiphilic molecule (linoleic acid) is complexing with an amylose fragment. Results showed that the amylose fragment complexed with linoleic acid to form a V-type structure, and more glucose residues participated when the number of linoleic acid molecules increased. Intra-molecular hydrogen bonds are the main interactions that stabilize the formation of the amylose helical structure. The preferred location of the linoleic acids molecules was in the central region of the amylose fragment, which induced a larger fluctuation of the two terminal regions of the complex. Alike when a single linoleic acid molecule is considered, the aliphatic tails of the linoleic acid molecules complexed with the hydrophobic cavity of the amylose fragment and the carboxyl heads were exposed to the polar water molecules.
Assuntos
Amilose/química , Ácido Linoleico/química , Ligação de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Conformação Molecular , Simulação de Dinâmica Molecular , Água/químicaRESUMO
The quality of cooked rice and its influence factors have always been the focus of researches. However, the formative mechanisms of its eating quality and structural changes of rice during cooking have seldom been evaluated. In this study, sectional real-time cooking was performed by differential scanning calorimetry (DSC) and dynamic viscoelasticity analysis to monitor the phase transitions and mechanical changes of kernels, which exhibited different characteristics in different stages. Both glass transition and pasting behavior were captured, and showed more viscoelasticity of cooked rice at higher soaking temperatures. Meanwhile, the enzyme activity of rice during soaking was successfully measured by a rapid viscosity analyzer (RVA). Along with the differences of morphologies and crystalline structure at different soaking conditions, the findings of DSC and rheometer were further verified. This study provides effective methods to evaluate changes in rice during cooking and explains the mechanism of differences formed by the soaking temperature.
Assuntos
Culinária , Oryza/enzimologia , Varredura Diferencial de Calorimetria , Temperatura Alta , Oryza/química , Reologia , Amido , Viscosidade , Água/análiseRESUMO
The effects of different processing methods were investigated, including on the fluidity, solubility, nutrient composition, digestibility, color and aroma constituent of instant brown rice powder. It showed that, except for flavonoids, different processing methods significantly influenced the indexes of the instant brown rice flour (pâ¯<â¯0.05). Germination could deteriorate the fluidity and solubility of brown rice powder and reduce the digestibility of protein, and starch. Exogenous enzyme treatment improved the fluidity and solubility of the brown rice powder as well as the digestion rate of protein and starch. The synergistic treatment of germination and exogenous enzymes significantly increased the digestibility of starch, but it deteriorated the fluidity, the rate of agglomeration and dispersion time. Comparing with DGBRE, DBRE produced a better quality instant brown rice powder.
Assuntos
Culinária/métodos , Valor Nutritivo , Oryza/química , Oryza/metabolismo , Cor , Digestão , Proteínas de Plantas/análise , Pós , Solubilidade , Amido/análiseRESUMO
Amylose is a linear polymer formed by α-1,4 linkages and one of the major components of starch. It is often used to encapsulate hydrophobic molecules of health benefit, such as fatty acids (FA), flavonoids or polyphenols. Amylose and linoleic acid form a complex when the amylose molecule is folded in a V-type conformation. However, it is still not clear how amylose and linoleic acid interact with each other and what is the conformation of the complex adopts under different conditions. Molecular dynamics (MD) simulation is a useful tool used to describe the structure of molecules and complex systems. In this work, MD simulations were used to illustrate conformational changes of the amylose-FA complex and the single amylose molecule, which was used as a reference, in water. During simulations, the conformation of the complex remained stable and the linoleic acid and the amylose molecules formed a helical structure. Furthermore, fatty acid molecules were located in cavity of the amylose helix with the hydrophobic tail inside it. Results also showed that 4C1 was the predominant ring conformation of glucose unit in amylose during interaction with fatty acids. Once the fatty acid was able to form the complex with amylose, the inter turn hydrogen bonds between O6 and neighboring O2/O3 groups were preferentially retained and allowed the complex to keep its helix conformation. Our analysis also shows that the amylose-linoleic acid complex is slightly less stable than the one formed between stearic acid and amylose.
Assuntos
Amilose/química , Ácido Linoleico/química , Simulação de Dinâmica Molecular , Água/química , Configuração de Carboidratos , Estabilidade de Medicamentos , Ligação de HidrogênioRESUMO
We report a study that investigates the biocompatibility of materials that form lyotropic liquid crystals (LCs) with viruses and mammalian cells that support the replication of viruses. This study is focused on aqueous solutions of tetradecyldimethyl-amineoxide (C(14)AO) and decanol (D), or disodium cromoglycate (DSCG; C(23)H(14)O(11)Na(2)), which can form optically birefringent, liquid crystalline phases. The influence of these materials on the ability of vesicular stomatitis virus (VSV) to infect human epitheloid cervical carcinoma (HeLa) cells was examined by two approaches. First, VSV was dispersed in aqueous C(14)AO+ D or DSCG, and then HeLa cells were inoculated by contacting the cells with the aqueous C(14)AO + D or DSCG containing VSV. The infectivity of VSV to the HeLa cells was subsequently determined. Second, VSV was incubated in LC phases of either C(14)AO + D or DSCG for 4 h, and the concentration (titer) of infectious virus in the LC was determined by dilution into cell culture medium and subsequent inoculation of HeLa cells. Using these approaches, we found that the LC containing C(14)AO + D caused inactivation of virus as well as cell death. In contrast, we determined that VSV retained its infectivity in the presence of aqueous DSCG, and that greater than 74-82% of the HeLa cells survived contact with aqueous DSCG (depending on concentration of DSCG). Because VSV maintained its function (and we infer structure) in LCs formed from DSCG, we further explored the influence of the virus on the ordering of the LC. Whereas the LC formed from DSCG was uniformly aligned on surfaces prepared from self-assembled monolayers (SAMs) of HS(CH(2))(11)(OCH(2)CH(2))(4)OH on obliquely deposited films of gold in the absence of VSV, the introduction of 10(7)-10(8) infectious virus particles per milliliter caused the LC to assume a non-uniform orientation and a colorful appearance that was readily distinguished from the uniformly aligned LCs. Control experiments using cell lysates with equivalent protein concentrations but no virus did not perturb the uniform alignment of the LC.