Research progress on occupational exposure to carbon nanotubes and carbon nanotubes-induced pulmonary fibrosis / 中国职业医学

Carbon nanotube (CNT), as a new nanomaterial, is widely used in commercial and industrial production. The occupational exposure of workers involved in CNT production and manufacturing is gradually increasing. CNT mainly enters the human body through the respiratory system, and mainly exerts toxic effects on the respiratory system, including decreased lung function, lung inflammation, and pulmonary fibrosis. Pulmonary fibrosis, as one of the important diseases caused by CNT exposure, has attracted attention and been studied. The process of pulmonary fibrosis induced by CNT has four stages: acute pulmonary inflammatory response, structural destruction and parenchymal injury of lung tissue, impaired lung tissue repair and pulmonary fibrosis. The molecular mechanisms of CNT induced pulmonary fibrosis may be related to cell proliferation, epithelial-mesenchymal transition, fibroblast-myofibroblast differentiation, pulmonary inflammation, immune response and oxidative stress. In the future, it is needed to explore the pathogenesis of pulmonary fibrosis caused by CNT through animal experiments, and carry out large sample and multi-center epidemiological studies for verification.

A novel method for detecting circulating tumor cells immunity based on micro-nano technique / 生物工程学报

This study was to develop a new method for detecting circulating tumor cells (CTCs) with high sensitivity and specificity, therefore to detect the colorectal cancer as early as possible for improving the detection rate of the disease. To this end, we prepared some micro-column structure microchips modified with graphite oxide-streptavidin (GO-SA) on the surface of microchips, further coupled with a broad-spectrum primary antibody (antibody1, Ab1), anti-epithelial cell adhesion molecule (anti-EpCAM) monoclonal antibody to capture CTCs. Besides, carboxylated multi-walled carbon nanotubes (MWCNTs-COOH) were coupled with colorectal cancer related antibody as specific antibody 2 (Ab2) to prepare complex. The sandwich structure consisting of Ab1-CTCs-Ab2 was constructed by the microchip for capturing CTCs. And the electrochemical workstation was used to detect and verify its high sensitivity and specificity. Results showed that the combination of immunosensor and micro-nano technology has greatly improved the detection sensitivity and specificity of the immunosensor. And we also verified the feasibility of the immunosensor for clinical blood sample detection, and successfully recognitized detection and quantization of CTCs in peripheral blood of colorectal cancer patients by this immunosensor. In conclusion, the super sandwich immunosensor based on micro-nano technology provides a new way for the detection of CTCs, which has potential application value in clinical diagnosis and real-time monitoring of disease.

Effects of Interaction Between Carbon Nanotubes on Membrane-Wrapped Carbon Nanotubes / 医用生物力学

Objective For the system of two single-walled carbon nanotubes (CNTs) placed in parallel onto a cell membrane, effects of the interaction between carbon nanotubes on wrapping manner of carbon tubes by the membrane were investigated, and the energy-optimized configurations were obtained. Methods A physical model for membrane-wrapped CNTs considering the interaction between two CNTs, and parameters describing the morphology of cell membrane and positions of CNTs were introduced. The Helfrich model based on continuum mechanics was used to calculate the membrane’s bending energy and the Lennard-Jones potential was introduced to describe the interaction between CNTs. Free energy of the system at different distances of NTs was calculated by the look-up table method, and the typical configurations of the membrane-wrapped CNTs was obtained. Results Compared with the case wherein the interaction between CNTs was not considered, the free energy profile of the system significantly changed. Deep well appeared on energy curve, when the distance between CNTs of carbon was 0.3 times of the tube diameter; as the distance between CNTs increased, the energy returned to the case wherein the interaction between CNTs was not considered. Conclusions With introduction of the interaction between CNTs, the wrapping manner of CNTs by the cell membrane changed, and the two CNTs tended to contact during their endocytosis. These results provide theoretical references for understanding and developing novel nanotube-based system for drug delivery.

Ácido L-poliláctico (PLA) y na-notubos de carbono de pared múltiple (NTCPM) con potenciales aplicaciones industriales / L-polylactic acid (PLA) and multi-walled carbon nano-tubes (CNTMW) with potential industrial applications / Ácido L-polilático (PLA) e na-notubos de carbono de paredes múltiplas (NTCPM) com possíveis aplicações industriais

Resumen En términos generales, es bien conocida la cualidad que poseen algunos polímeros de cambiar sus propiedades físicas y químicas finales mediante la adición de nanopartículas a la matriz polimérica para producir un material compuesto (MC). Esta investigación está basada en la obtención de un MC a partir de ácido poliláctico (PLA) y nanotubos de carbono de pared múltiple (NTCPM), muy empleado en la industria del envasado y dispositivos biomédicos, con el fin de ampliar su perfil industrial. Se desarrollaron cuatro mezclas de PLA y NTCPM, y se empleó polietilenglicol (PEG) como plastificante. Se evaluaron sus propiedades morfológicas, térmicas, mecánicas, termo-mecánicas, espectroscópicas, ángulo de contacto y cristalográficas. Se observó que los MCs presentaron degradación térmica a temperaturas inferiores a la matriz sin NTCPM, así como un aumento en el módulo de flexión y tensión en algunas de las muestras. Así mismo, se observó que los NTCPM pueden aumentar la cristalinidad del material y que, en algunos casos, se incrementa su rigidez, actuando como un aditivo útil para aplicaciones de mayor esfuerzo mecánico que la matriz. Del efecto de agregar PEG en los MC, se determinó que los NTCPM no restringen la movilidad de las cadenas poliméricas y se da un efecto plastificante, lo que permite mayor movilidad de la zona amorfa de las cadenas de polímero, como indica la literatura consultada. Finalmente, se concluyó que a mayores contenidos de NTCPM, se generan mejores valores en el módulo de flexión, esfuerzo máximo de flexión, módulo de elongación, esfuerzo de carga máxima y esfuerzo de ruptura, entre otras propiedades evaluadas.

Abstract The quality of some polymers to change their final physical and chemical properties by adding nanoparticles to the polymer matrix to produce a composite material (MC) is well known. This research is based on obtaining a MC from polylactic acid (PLA) and multi-walled carbon nanotubes (CNTMW), widely used in the packaging industry and biomedical devices, in order to expand its industrial profile. Four mixtures of PLA and CNTMW were developed, and polyethylene glycol (PEG) was used as a plasticizer. Their morphological, thermal, mechanical, thermo-mechanical, spectroscopic, contact angle, and crystallographic properties were evaluated. It was observed that the composites showed thermal degradation at temperatures below the matrix without CNTMW, as well as an increase in the modulus of flexion and tension in some of the samples. Likewise, it was observed that the CNTMW can increase the crystallinity of the material and that, in some cases, its rigidity is increased, acting as a useful additive for applications of greater mechanical stress than the matrix. From the effect of adding PEG in the composites, the CNTMW do not restrict the mobility of the polymer chains and a plasticizing effect occurs, which allows greater mobility of the amorphous zone of the polymer chains. In general terms, it was concluded that at higher CNTMW contents, better values were generated in the flexural modulus, maximum flexural stress, elongation modulus, maximum load stress and rupture stress, among other evaluated properties.

Resumo Alguns polímeros têm a propriedade de alterar suas propriedades físicas e químicas finais, adicionando nanopartículas à matriz polimérica para produzir um composto. Esta pesquisa baseia-se na obtenção de composto partir de ácido polilático (PLA) e nanotubos de carbono de paredes múltiplas (MWCNT), amplamente utilizado na indústria de embalagens e dispositivos biomédicos, a fim de expandir seu perfil industrial. Foram desenvolvidas quatro misturas de PLA e MWCNT e o polietilenoglicol (PEG) foi usado como plastificante. Foram avaliadas suas propriedades morfológicas, térmicas, mecânicas, termo-mecânicas, espectroscópicas, ângulo de contato e cristalográficas. Observou-se que os compostos apresentaram degradação térmica em temperaturas abaixo da matriz sem MWCNT, além de aumento no módulo de flexão e tensão em algumas das amostras. Da mesma forma, observou-se que o MWCNT pode aumentar a cristalinidade do material e que, em alguns casos, sua rigidez é aumentada, atuando como um aditivo útil para aplicações de maior tensão mecânica que a matriz. A partir do efeito da adição de PEG nos compostos, determinou-se que o MWCNT não restringe a mobilidade das cadeias poliméricas e ocorre um efeito plastificante, que permite maior mobilidade da zona amorfa das cadeias poliméricas. Em termos gerais, concluiu-se que, com maiores teores de MWCNT, melhores valores foram gerados no módulo de flexão, tensão máxima de flexão, módulo de alongamento, tensão de carga máxima e tensão de ruptura, entre outras propriedades avaliadas.

Radiosensitivity enhancement effect of FePd@CNTs nanocomposites on MCF-7 cells / 中华放射肿瘤学杂志

Objective:To evaluate the radiosensitivity enhancement effect of FePd@CNTs nanocomposites on human breast cancer MCF-7 cells.Methods:FePd@CNTs nanocomposites were synthesized by chemical reduction method. Transmission electron microscope and energy dispersive spectrometer were utilized to characterize the surface morphology and chemical composition of FePd@CNTs nanocomposites. The compatibility of FePd@CNTs nanocomposites with human normal breast epithelial MCF-10A cells was determined by CCK-8 assay. The radiosensitivity enhancement effect of FePd@CNTs nanocomposites on MCF-7 cells was assessed by CCK-8 assay, flow cytometry and clony formation assay.Results:FePd nanospheres were successfully modified on the surface of CNTs by chemical reduction method. FePd@CNTs nanocomposites showed a low toxicity to MCF-10A cells (IC 50=738.3 μg/m), and effectively enhanced the effect of X-ray radiation on MCF-7 cells (sensibilization ratio=1.22). Conclusion:FePd@CNTs nanocomposites exhibit a promising potential for treating breast cancer and enhancing radiosensitivity effect.

Primary culture macrophages from fish as potential experimental model in toxicity studies with multiwalled carbon nanotubes

Multiwalled carbon nanotube (MWCNT) has been broadly used in several sectors of society. This material when exposed to the environment might reach the aquatic animals and cause toxic effects. Here, it was evaluated the MWCNTs toxicity in melanomacrophages primary culture that was submitted to 1 µ gm L-1 MWCNTs for 24 hours. After exposition to MWCNT, 48 and 59% liver and spleen melanomacrophages were healthy, respectively. The control group presented 85% viability. Phagocytosis activity of melanomacrophages was observed by presence of black inclusions in cytoplasm. The findings indicate MWCNT was cytotoxic to melanomacrophages, where its release and effect into aquatic environment must be more studied. Finally, the melanomacrophages present large potential as experimental model for evaluation of carbon-based nanomaterial toxicity.

Effects of length and chemical modification on the activation of vascular endothelial cells induced by multi walled carbon nanotubes / 北京大学学报(医学版)

OBJECTIVE@#To investigate the effects of multi-walled carbon nanotubes (MWCNTs) with different length or chemical modification on endothelial cell activation and to explore the role of nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome.@*METHODS@#MWCNTs were characterized by dynamic light scattering (DLS) after being suspended in culture medium. The immortalized mouse cerebral microvascular endothelial cell line b.End3 was treated with short MWCNTs (S-MWCNT, 0.5 to 2 μm), long MWCNTs (L-MWCNT, 10 to 30 μm) and the above long MWCNTs functionalized by carboxyl-(L-MWCNT-COOH), amino-(L-MWCNT-NH2) or hydroxyl-(L-MWCNT-OH) modification. Cytotoxicity of MWCNTs in b.End3 cells was determined by cell counting kit-8 (CCK-8) assay and lactate dehydrogenase (LDH) release assay, and non-toxic low dose was selected for subsequent experiments. Effects of all types of MWCNTs on the endothelial activation of b.End3 were determined by the measurement of vascular cell adhesion molecule-1 (VCAM-1) concentration in cell supernatant and adhesion assay of human monocytic cell line THP-1 to b.End3.To further elucidate the mechanism involved, the protein expressions of nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3(NLRP3) in cells treated with S-MWCNT, L-MWCNT and L-MWCNT-COOH were measured by Western blot.@*RESULTS@#At a higher concentration (125 μg/cm2) and treated for 24 h, all types of MWCNTs significantly inhibited viability of b.End3 cells. At a sub-toxic concentration (6.25 μg/cm2), all types of MWCNTs treated for 12 h significantly induced the activation of b.End3 cells, as evidenced by the elevated VCAM-1 release and THP-1 adhesion. Compared with S-MWCNT, L-MWCNT significantly promoted endothelial cell activation. L-MWCNT and L-MWCNT-COOH activated b.End3 cells to a similar extent. Furthermore, treatment with S-MWCNT, L-MWCNT and L-MWCNT-COOH increased NLRP3 expression in a time-dependent manner at 6.25 μg/cm2. Compared with S-MWCNT, cells treated with L-MWCNT for 4 h and 12 h exhibited significantly increased protein expressions of NLRP3. However, no significant differences were detected in the level of NLRP3 protein in cells treated with L-MWCNT and L-MWCNT-COOH.@*CONCLUSION@#Compared with the surface chemical modification, length changes of MWCNTs exerted more influence on endothelial cell activation, which may be related to the activation of NLRP3 inflammasome. Our study contributes further understanding of the impact of MWCNTs on endothelial cells, which may have implications for the improvement of safety evaluation of MWCNTs.

Compósito odontológico carregado com nanotubos de carbono: caracterização e ensaios biológicos / Dental composite loaded with carbon nanotube: characterization and biological tests

Nanotubos de carbono (NTC) são materiais promissores ao melhoramento de compósitos odontológicos. Entretanto, a homogeneização e o comprometimento estético dessas associações ainda são um desafio. Além disso, até o momento, não foram exploradas composições capazes de induzir respostas teciduais endógenas de reparo. Neste sentido, este estudo teve como objetivo incorporar duas concentrações de NTC de paredes múltiplas (NTCPM), as growth, numa rede polimérica de metilmetacrilato no intuito de investigar as propriedades químicas, mecânicas e biológicas desse novo biomaterial. Produziu-se uma formulação Bis-GMA e TEGDMA (2:1) com 0%; 0,001%; ou 0,01% de NTCPM. Os compósitos foram caracterizados por meio de termogravimetria, espectroscopia no infravermelho com refletância total atenuada (FTIR-ATR), microscopia eletrônica de varredura (MEV). Testes de compressão, flexão, sorção-solubilidade (norma ISO 4049:2009), estabilidade de cor, grau de conversão, e microdureza foram aplicados aos diferentes grupos experimentais. Finalmente, ensaios antimicrobianos em S. mutans (ATCC 25175) (suspensão e biofilme) e ensaios em queratinócitos (HaCat) (citotoxicidade) e pré-osteoblastos (MC3T3) (citotoxicidade/diferenciação) foram utilizados para avaliação de citocompatibilidade e bioatividade. Utilizou-se luz LED (470 nm e 800 mW/cm2) para fotoativar os monômeros. De acordo com ANOVA seguido pelo post-hoc de Tukey, adotando um nível de significância de 5%, a resistência à compressão foi significativamente maior no grupo 0,001% (125,66 MPa) que no grupo controle (46,94 MPa). A resistência flexural foi significativamente maior no grupo 0,001% (51,74 MPa) quando comparado ao grupo 0,1%. Não houve variação nos valores de sorção, solubilidade e estabilidade de cor entre os grupos avaliados. O grau de conversão foi menor nos grupos com NTCPM quando comparado com o grupo controle, e a microdureza Knoop menor na concentração 0,001% quando comparada aos demais grupos. O exame superficial mostrou maior formação de aglomerados de nanotubos nas amostras mais concentradas. O grupo contendo 0,001% NTCPM apresentou atividade antibiofilme quando comparado com o grupo controle e 0,01%. Todas as concentrações apresentaram citotoxicidade nas HaCat após 7 dias, mas a incorporação de NTCPM favoreceu a mineralização de MC3T3 em relação ao controle. Concluiu-se que tanto as propriedades mecânicas como as biológicas apresentaram melhoras com a adição de baixa concentração de NTCPM (0,001%). A adição de 0,001% de NTCPM parece promissora para incorporação em compósitos odontológicos.

Carbon nanotubes (CNT) are candidates for the improvement of dental composites. However, the homogenization and aesthetic commitment of CNT' addition are still a challenge. Moreover, heretofore, there is no study investigating compositions capable of inducing tissue responses towards repair. In this sense, this study aimed to incorporate two concentrations of multiple walls CNT (MWCNT), as growth, in a polymeric network. The chemical, mechanical, and biologicals properties of this experimental biomaterials were assessed. A Bis-GMA and TEGDMA (2:1) base was produced with 0%; 0.001%; or 0.01% MWCNT. The composites were assessed using thermogravimetry, infrared spectroscopy with attenuated total reflectance (FTIR-ATR), scanning electron microscopy (SEM), and were also subjected to compression, bending, sorption-solubility tests in accordance with ISO 4049 :2009, color stability, degree of conversion, microhardness and also to antimicrobial assays in S. aureus (ATCC 25193) (halo formation), S. mutans (ATCC 25175) (biofilm adhesion) and biological assays in keratinocytes (HaCat ) (cytotoxicity) and pre-osteoblasts (MC3T3) (differentiation). LED light (470 nm and 800 mW / cm2) was used to light-cure the monomers. According to ANOVA followed by Tukey's post-hoc, adopting a significance level of 5%, the compressive strength was significantly higher for the 0.001% group (125.66 MPa) than control (46.94 MPa). Flexural strength was also more significant in the 0.001% (51.74 MPa) group than the 0.1% group. There was no significant difference in the values of sorption and solubility and color stability between the evaluated groups. The degree of conversion was lower in the groups with NTCPM when compared to the control group, however the Knoop microhardness was higher in the group with the highest concentration of NTCPM and lower in the group with the lowest concentration when compared to the control group. Despite not showing bacterial inhibition halo formation in any of the groups, the groups containing NTCPM showed a decrease in biofilm adhesion when compared to the control group. All groups shown cytotoxicity on HaCat, but the addition of MWCNT favored MC3T3 mineralization over control. It was concluded that both mechanical and biological properties improved with the addition of low concentration of MWCNT (0.001%). The addition of 0.001% MWCNT looks promising for incorporation in dental composites.

Effect of Addition of Graphene and Carbon Nanotubes on Flexural Strength of Polymethylmethacrylate- A Comparative In-Vitro Study.

Heat polymerized denture base resins are a popular choice in prosthodontics for fabrication of partial or complete dentures, cranioplasts, hybrid implant prosthesis, and maxillofacial prosthetics. The wide utility of these materials can be attributed to their favourable mechanical properties. Despite the popularity gained by them, clinicians often encounter suboptimal flexural strength resulting in frequent fracture of the fabricated prosthesis. The purpose of this study was to compare the flexural strength (FS) of Polymethylmethacrylate (PMMA) modified using micro-additions of Multi-Walled Carbon Nanotubes (MWCNT) and Graphene Oxide (GO) as fillers respectively with PMMA having no micro-additions.METHODSThis is an in-vitro comparative study. Sixty samples of PMMA were divided in three groups of 20 each containing: Group 1: no micro additions (control group), Group 2: 0.5 wt% MWCNT in monomer of PMMA resin, Group 3: 0.5 wt% GO in monomer of PMMA resin. MWCNT and Graphene oxide were dispersed in Methylmethacrylate (monomer) respectively by ultrasonic agitation. Monomer and polymer were mixed in the ratio of 1:3. The samples were heat polymerised. Finished samples were subjected to 3-point bending test for checking their flexural strength. The results were statistically compared using one-way ANOVA followed by post hoc Bonferroni corrected paired T test for inter-group comparisons.RESULTSThe highest mean Flexural Strength of 36.5 MPa was recorded in Group 2 (MWCNT) followed by 31.55 MPa in Group 1 (control) and the least 29.72 MPa in Group 3 (Graphene Oxide) respectively. Intergroup comparisons revealed significant difference between Group 1 (control) & Group 2 (MWCNT) with “p=0.011” and between Group 2 (MWCNT) & Group 3 (Graphene Oxide) with “p<0.001”. However, no significant difference was found between Group 1 (control) and Group 3 (Graphene Oxide) with “p= 0.803”.CONCLUSIONSThe addition of 0.5 wt% MWCNT to PMMA is an easy, effective and economical step towards increasing the flexural strength and thus, decreasing the incidence of prosthesis fracture, when compared to 0.5 wt% graphene oxide or no micro additions.

Acid-functionalized single-walled carbon nanotubes alter epithelial tight junctions and enhance paracellular permeability

The T(EB4)Nta, T(IBj5)Nta, and T(B362i)NtA strains were constructed by introgressing the insertionaltranslocations EB4, IBj5, and B362i from Neurospora crassa into the related species N. tetrasperma. Theprogeny from crosses of T(IBj5)Nta and T(B362i)NtA with opposite mating-type derivatives of the standard N.tetrasperma strain 85 exhibited a unique and unprecedented transmission ratio distortion (TRD) that disfavoredhomokaryons produced following alternate segregation relative to those produced following adjacent-1 segregation. The TRD was not evident among the [mat A ? mat a] dikaryons produced following either segregation. Further, crosses of the T(IBj5)Nta and T(B362i)NtA strains with the Eight spore (E) mutant showed anunusual ascus phenotype called ‘max-4’. We propose that the TRD and the max-4 phenotype are manifestations of the same Bateson-Dobzhansky-Muller incompatibility (BDMI). Since the TRD selects against 2/3 ofthe homokaryotic progeny from each introgression cross, the BDMI would have enriched for the dikaryoticprogeny in the viable ascospores, and thus, paradoxically, facilitated the introgressions.

Target-specific gene delivery in plant systems and their expression: Insights into recent developments

High-yielding Indian cotton varieties are not amenable for regeneration and transformation because they arerecalcitrant in nature. In this work, we have developed Narasimha (NA1325) cotton variety by introducing threeCrygenes driven by three different promoters conferring insect resistance. The meristematic region of embryo axisexplants were infected and co-cultivated with Agrobacterium tumefacience (LBA4404) harbouring pMDC100vector with three Cry gene cassettes (a-globulin : Cry2Ab, DECaMV35s : Cry1F and nodulin : Cry1Ac) with Npt IIas a selectable marker gene. Out of 1010 embryo axes explants infected, 121 (T0) regenerated under two rounds ofkanamycin selection medium. About 2551 T1 seeds were collected from 111 T0 plants and these seeds screened againwith kanamycin at seedling stage. The transgenic plants were characterized by PCR, real time quantitative PCR,lateral flow strip protein assay and insect bioassay. Out of 145 kanamycin resistant plants (T1), twelve showedamplification of all four transgenes: Npt II, Cry2Ab, Cry1F and Cry1Ac through PCR with expected amplicons as395, 870, 840 and 618 bp, respectively. Further, lateral flow strip test revealed Cry1F and Cry1Ac proteinsaccumulated in 12 plants, whereas Cry2Ab protein was detected in eight only. The transcripts of all three Cry geneswere accumulated significantly higher in transgenic plants at T2 generation. The transgenic lines showed effectiveresistance against Helicoverpa armigera and Spodoptera litura larvae. The T2 line L-3 exhibited highest percentageof insect mortality, in which transcripts of all cry genes were accumulated higher than other plants. The transgeniccotton plants carrying triple Cry genes could be an excellent germplasm resource for the breeders for introgressions.

Detection of Rutin in Sophorae Immaturus Flos with Electrochemical Sensor Assembled with Gold Nanoparticles/Nafion/Multi-wall Carbon Nanotube / 中国实验方剂学杂志

Objective::A new-type electrochemical sensor was developed by electrodepositing gold nanoparticle on the surface of glassy carbon electrode (GCE) modified by Nafion-multi-wall carbon nanotube (MWNTs) by the potentiostatic method, and used for the detection of rutin in practical samples. Method::The electrochemical properties of the sensor in potassium ferricyanide-potassium ferrocyanide system were studied by electrochemical impedance spectroscopy and cyclic voltammetric method, in order to explore the electrochemical performance of the sensor. The electrochemical behavior of rutin on the surface of the sensor was studied by the cyclic voltammetric method, and the factors affecting the performance of the sensor were optimized. The content of rutin was determined by differential pulse voltammetric methods. Result::The optimized conditions were -0.25 V of the deposition potential of gold nanoparticle, 20 s of the deposition time, pH 3.0, and 6 μL of 1 g·L-1 carbon nanotube. Under the conditions, a good linear relationship between reduction peak current and rutin concentration was obtained from 5.0 ×10-9 to 7.0 ×10-7 mol·L-1, and the detection limit was 3.6×10-9 mol·L-1. Conclusion::The developed sensor has a good electrical conductivity and stability, and is highly sensitive and simple for the detection of rutin, with a low detection limit. It has been successfully applied to the detection of rutin in Sophorae Immaturus Flos with the recoveries between 97.6%and 104.4%, which provides a new method for the determination of rutin and a new idea for the quality control of Chinese medicinal materials.

TGA/Chemometrics addressing innovative preparation strategies for functionalized carbon nanotubes / 药物分析学报

In this work, functionalized carbon nanotubes (CNTs) using two polyamine polymers, polyethyleneimine (PEI) and polyamidoamine dendrimer (PAMAM), were investigated by thermal analysis in order to address preparation strategies to obtain low cytotoxic compounds with the ability to conjugate micro-RNAs and, at the same time, to transfect efficiently endothelial cells. Thermogravimetric analysis (TGA) was coupled to chemometrics as a novel analytical strategy to characterize functionalized CNTs from different preparation conditions. In particular, two starting materials were considered:very small CNTs and carboxylated CNTs (CNT-COOH) in order to examine the affinity with polymers. Chemometrics permitted to compare results from TGA and to investigate the effect of a number of factors affecting the synthesis of coated nanotubes including a different amount of involved polymer and the time required for the suspension for a satisfactory and reproducible preparation procedure. The results demonstrated the effectiveness of TGA as a tool able to address synthesis of coated CNTs to be employed as efficient drug delivery vectors in biomedical applications.

Biomimetic carbon nanotubes for neurological disease therapeutics as inherent medication

Nowadays, nanotechnology is revolutionizing the approaches to different fields from manufacture to health. Carbon nanotubes (CNTs) as promising candidates in nanomedicine have great potentials in developing novel entities for central nervous system pathologies, due to their excellent physicochemical properties and ability to interface with neurons and neuronal circuits. However, most of the studies mainly focused on the drug delivery and bioimaging applications of CNTs, while neglect their application prospects as therapeutic drugs themselves. At present, the relevant reviews are not available yet. Herein we summarized the latest advances on the biomedical and therapeutic applications of CNTs and for neurological diseases treatments as inherent therapeutic drugs. The biological mechanisms of CNTs-mediated bio-medical effects and potential toxicity of CNTs were also intensely discussed. It is expected that CNTs will exploit further neurological applications on disease therapy in the near future.

Biosensor design using an electroactive label-based aptamer to detect bisphenol A in serum samples

Protein–protein interactions (PPIs) are important for the study of protein functions and pathways involved in differentbiological processes, as well as for understanding the cause and progression of diseases. Several high-throughput experimental techniques have been employed for the identification of PPIs in a few model organisms, but still, there is a huge gapin identifying all possible binary PPIs in an organism. Therefore, PPI prediction using machine-learning algorithms hasbeen used in conjunction with experimental methods for discovery of novel protein interactions. The two most popularsupervised machine-learning techniques used in the prediction of PPIs are support vector machines and random forestclassifiers. Bayesian-probabilistic inference has also been used but mainly for the scoring of high-throughput PPI datasetconfidence measures. Recently, deep-learning algorithms have been used for sequence-based prediction of PPIs. Severalclustering methods such as hierarchical and k-means are useful as unsupervised machine-learning algorithms for theprediction of interacting protein pairs without explicit data labelling. In summary, machine-learning techniques have beenwidely used for the prediction of PPIs thus allowing experimental researchers to study cellular PPI networks.

Research developments for using of carbon nanotubes in pesticide residues detection and their application prospects in traditional Chinese medicines / 中国中药杂志

Pesticides are one of the main exogenous harmful residues in traditional Chinese medicines( TCMs),and the potential safety problems caused by pesticides affect the sustained and healthy development of TCMs. Carbon nanotubes( CNTs) possessed unique structure and properties,and widely used in analytical chemistry and other areas. In this review,the structure of CNTs and preparation method of composite material were summed up. Then,the application of CNTs in the pre-treatment technique of pesticides residues such as solid-phase extraction,solid phase micro-extraction,dispersive solid-phase extraction,matrix solid phase dispersion for detection of pesticides in different matrices were discussed in detail. In addition,the characteristics of pesticides in TCMs and maximum levels of pesticide residues in TCMs were investigated. Finally,the development and problems of CNTs in the determination of pesticide residues in TCMs were prospected.

Development of a microcomposite with single-walled carbon nanotubes and Nd2O3 for determination of paracetamol in pharmaceutical dosage by adsorptive voltammetry / 药物分析学报

This study presents for the first time a new composite of carbon paste (CP), single-walled carbon na-notubes (SWCNTs) and Nd2O3 (NdOX). This versatile composite (NdOX-SWCNT/CPE) was applied to the oxidation of paracetamol (PCM). The newly formed surface was characterized by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The re-sults showed greater conductivity and a higher surface area for the composite than those of the carbon paste alone. Moreover, the anodic peak currents for PCM increased from 1.6 to 3.6 mA with CPE and NdOX-SWCNT/CPE, indicating an increase of nearly 51.0％ for the anodic peak current. On the other hand, the anodic peak potentials shifted from 0.67 to 0.57 V. The detection limits were 0.05 mmol/L with NdOX-SWCNT/CPE and 0.50 mmol/L with SWCNT/CPE. The relative standard deviations (RSDs) were 1.5％(n =7). The accuracy and interference of the methods were evaluated with a urine chemistry control spiked with known quantities of PCM, uric acid, dopamine, ascorbic acid, caffeine, acetylsalicylic acid, tartrazine, sunset yellow, allure red, rutin, morin and metal ions. Finally, the novelty and usefulness of the composite were evaluated to quantify PCM in pharmaceutical dosage forms such as tablets, powders and syrups for children.

Carbon nanotubes:Evaluation of toxicity at biointerfaces / 药物分析学报

Carbon nanotubes (CNTs) are a class of carbon allotropes with interesting properties that make them productive materials for usage in various disciplines of nanotechnology such as in electronics equip-ments, optics and therapeutics. They exhibit distinguished properties viz., strength, and high electrical and heat conductivity. Their uniqueness can be attributed due to the bonding pattern present between the atoms which are very strong and also exhibit high extreme aspect ratios. CNTs are classified as single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) on the basis of number of sidewalls present and the way they are arranged spatially. Application of CNTs to improve the performance of many products, especially in healthcare, has led to an occupational and public exposure to these nanomaterials. Hence, it becomes a major concern to analyze the issues pertaining to the toxicity of CNTs and find the best suitable ways to counter those challenges. This review summarizes the toxicity issues of CNTs in vitro and in vivo in different organ systems (bio interphases) of the body that result in cellular toxicity.

Design and characterization of nanocarriers loaded with Levofloxacin for enhanced antimicrobial activity; physicochemical properties, in vitro release and oral acute toxicity

Inorganic and carbon based nanomaterials are widely used against several diseases, such as cancer, autoimmune diseases as well as fungi and bacteria colonization. In this work, Santa Barbara Amorphous mesoporous silica (SBA), Halloysite Nanotubes (HNTs) and Multiwalled Carbon Nanotubes (CNTs) were loaded with fluoroquinolone Levofloxacin (LVF) to be applied as antimicrobial agents. The prepared via adsorption nanocarriers were characterized by Fourier-Transformed Spectroscopy, Scanning Electron Microscopy as well as High Pressure liquid Chromatography. In vitro release studies were carried out using Simulated Body Fluid at 37oC and data analyzed by various kinetic models showing slow dissolution over 12-24 hours. Antimicrobial studies showed improved antibacterial activity against Escherichia coli, Enterococcus faecalis, Listeria monocytogenes, Staphylococcus aureus, and Staphylococcus epidermidis compared to neat nanomaterials. CNTs were found to be the most promising candidates for LVF delivery and they were chosen to be further studied for their acute oral toxicity and histopathological examination using C57/Black mice. Histological examination depicted that drug loading did not affect mice organs morphology as well as hepatocyte degeneration, central vein degeneration and parenchymal necrosis scores. To conclude, the prepared nanomaterials present significant characteristics and can act as antimicrobial drug carriers; CNTs found to be safe candidates when orally fed to mice.

XPS of carbon nanostructures obtained by underwater arc discharge of graphite electrodes / XPS de nanoestructuras de carbono obtenidas por descarga de arco de electrodos de grafito sumergidos en agua

Abstract Carbon nanostructures, obtained by underwater arc discharge of graphite electrodes, were studied by X-Ray Photoelectron Spectroscopy (XPS). It was observed that the spectra of the samples taken from the floating part of the synthesis products, composed basically by Carbon nano-onions (CNO), present differences with those obtained from the precipitate, which contains a mixture of CNOs and multi-walled Carbon Nanotubes (MWCNT). These differences are related with the presence of atoms of carbon located in orbitals with different degree of hybridization (sp2-sp3), which in turn is related to the diverse grade of curvature of the planes of carbon in the nanostructures present in the samples. The obtained results indicate that XPS can be an important element in the characterization of the products obtained by the above-mentioned method of synthesis.

Resumen Se utilizó la Espectroscopia Fotoelectrónica de Rayos X (XPS) para estudiar nanoestructuras de carbono obtenidas por descarga de arco de electrodos de grafito sumergidos en agua. Se observó que los espectros de las muestras tomadas de la fracción flotante de los productos de la síntesis, compuestas básicamente por nano-cebollas de carbono (CNO), presentan diferencias con los de las muestras obtenidas del precipitado, que contiene una mezcla de CNOs y nano-tubos de carbono de capas múltiples (MWCNT). Estas diferencias están asociadas con la presencia de átomos de carbono localizados en orbitales con diferente grado de hibridación (sp2-sp3), lo que a su vez se relaciona con las diferentes curvaturas de los planos de carbono en las nanoestructuras presentes en la muestras. Los resultados obtenidos indican que XPS puede ser un elemento importante en la caracterización de los productos obtenidos por el citado método de síntesis.