The impact of synthetic bone grafting for tissue regeneration: an in vivo study

Aims: This study aimed to examine the biological response of synthetic nanocomposite material on canine mandibular bone. Methods: Nine healthy adult male local breed dogs aged 12 to 18 months and weighing 10.2 to 15.2 kg were used in the study. Based on healing intervals of 1 and 2 months, the dogs were divided into 2 groups. Each group had 3 subgroups with 3 dogs each. The division was based on the grafting material used to fill the created defect: an empty defect (Control-ve), Beta-Tricalcium Phosphate, and nanocomposite (Beta-Tricalcium Phosphate and nanosilver 1%) . Surgery started after the dogs were anaesthetized. The surgical procedure began with a 5 cm parallel incision along the mandible's lower posterior border. After exposing the periosteum, a three 5mm-diameter, 5-mmdeep critical-size holes were made, 5mm between each one. Each group's grafting material had independent 3 holes. The defects were covered with resorbable collagen membranes followed by suturing of the mucoperiosteal flap. Results: Total densitometric analysis showed no significant differences between groups at 1-month intervals, with the nanocomposite group having a higher mean rank (165.66± 31.21) in comparison to other groups while at 2 months intervals that there was a highly significant difference between three groups as the P-value was (0.000) with the nanocomposite group having a higher mean rank (460.66± 26.40). Conclusions: In the current study, the use of nanocomposites improved osteoconductivity by accelerating new bone formation. Moreover, the encorporation of nanosilver enhanced growth factor activity. These attributes make nanocomposites a promising material for enhancing the bone healing process

Antibacterial copper sulfide/graphene oxide nanosheets composite film promotes angiogenic and osteogenic differentiation in vitro / 中华创伤骨科杂志

Objective:To investigate whether the antibacterial copper sulfide (CuS)/graphene oxide (GO) nanosheets composite film can promote angiogenesis and osteogenesis in vitro. Methods:GO and CuS/GO nanosheets were synthesized and mixed into polyvinyl alcohol (PVA)/carboxymethyl cellulose (CMC) hydrogel films. The study was conducted in 4 groups: PVA/CMC/GO, PVA/CMC/CuS/GO, PVA/CMC (only PVA/CMC-based film) and blank control (no material). The PVA/CMC, PVA/CMC/GO and PVA/CMC/CuS/GO films were characterized by electron scanning microscopy and energy dispersive spectrometer. The biocompatibility of different films (PVA/CMC/CuS/GO films with concentrations of CuS/GO nanotablets of 0, 50, 100, 200, 400, and 800 μ g/mL) was evaluated by CCK-8, live/dead cell staining, and hemolysis test. The angiogenesis was evaluated by cell migration and tube forming test in vitro. Alkaline phosphatase and alizarin red staining were used to evaluate osteogenesis in vitro, and the expression of osteogenic genes was measured by immunofluorescence staining and RT-qPCR. In addition, the bacterial plate counting method and bacteriostatic circle method were used to evaluate the antibacterial activity of films. Results:In the PVA/CMC/GO and PVA/CMC/CuS/GO groups, the surface of the PVA/CMC-based film was smooth and flat whereas the nanosheets composite films were irregularly flaky and convex. The biosafety experiments showed that the PVA/CMC-based film composited with GO or CuS/GO nanosheets at the concentration of 100 μg/mL had good biocompatibility. The results of angiogenesis in vitro showed that the migration ratio of HUVEC cells in the PVA/CMC/CuS/GO group was significantly better than those in the PVA/CMC/GO, PVA/CMC and control groups ( P<0.001). In the experiment of tube forming area and length, the PVA/CMC/CuS/GO group was significantly better than the PVA/CMC/GO, PVA/CMC and control groups ( P<0.001). The osteogenic differentiation in vitro displayed that the alkaline phosphatase and alizarin red staining of MC3T3-E1 cells in the PVA/CMC/CuS/GO group were significantly better than those in the PVA/CMC/GO, PVA/CMC and control groups ( P<0.001). In addition, the fluorescence intensity of immunofluorescence staining in alkaline phosphatase and type Ⅰcollagen on MC3T3-E1 cells, and the mRNA expression levels of osteogenic related genes including alkaline phosphatase, bone morphogenetic protein 2, osteocalcin and osteopontin in the PVA/CMC/CuS/GO group were significantly higher than those in the PVA/CMC/GO, PVA/CMC and control groups ( P<0.001). The antibacterial assay showed that the PVA/CMC/CuS/GO group had a significantly greater antibacterial activity and a significantly larger inhibition zone against Gram-positive bacteria and Gram-negative bacteria than the PVA/CMC/GO, PVA/CMC and control groups ( P< 0.001). Conclusions:PVA/CMC films composited with GO or CuS/GO nanosheets demonstrate ideal biocompatibility and antibacterial properties which promote angiogenesis and osteogenic differentiation in vitro. In particular, antibacterial PVA/CMC/CuS/GO composite films with the coupling function of angiogenesis and osteogenesis are expected to provide a new strategy for infectious bone defects.

Electrochemical sensor for anti-doping in athletes / Sensor eletroquímico para anti-doping em atletas / Sensor electroquímico para antidoping en deportistas

ABSTRACT Introduction: Several athletes use steroids such as nandrolone aiming at muscle hypertrophy and performance gain. The current research focused on developing a GO-TiO2 nanostructure as an electrochemical sensor for detecting Nandrolone (ND) like doping agents. Objective: Develop a graphene oxide and carbon paste-modified TiO2 nanocomposite electrode (TiO2-GO/CPE) as an electrochemical biosensor for the detection of anabolic steroids in the urine of athletes. Methods: The hydrothermal approach was employed to make GO-TiO2 nanocomposites, while the modified Hummers approach was used to make GO nanofilaments. Results: The interaction of TiO2 nanostructures with GOES resulted in the anchoring of TiO2 nanoparticles on the surface of GO nanowires, as demonstrated by structural investigations of the generated nanocomposite using SEM. The DPV approach was used to investigate the electrochemical properties of an anabolic steroid sensor, which revealed a stable and selective response to anabolic steroids and superior performance to previously reported anabolic steroid sensors. Conclusion: RSD values ranged from 3.20% to 4.45%, indicating that the developed electrochemical anabolic steroid sensor can be used as a viable detection technique to identify anabolic steroids in human biological fluids. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMO Introdução: Vários atletas fazem uso de esteróides como nandrolone visando a hipertrofia muscular e ganho de performance. A pesquisa atual se concentrou no desenvolvimento de uma nanoestrutura GO-TiO2 como um sensor eletroquímico para detecção de Nandrolone (ND) como agente dopante. Objetivo: Desenvolver um eletrodo de nanocomposto de óxido de grafite e pasta de carbono modificado (TiO2-GO/CPE) como um biossensor eletroquímico para a detecção de esteróides anabólicos na urina de atletas. Métodos: A abordagem hidrotérmica foi empregada para fazer nanocompósitos de GO-TiO2, enquanto a abordagem Hummers modificada foi usada para fazer nanofilamentos de GO. Resultados: A interação das nanoestruturas de TiO2 com GOES resultou na ancoragem de nanopartículas de TiO2 na superfície dos nanofilamentos de GO, como demonstrado pelas investigações estruturais do nanocomposto gerado usando SEM. A abordagem DPV foi utilizada para investigar as propriedades eletroquímicas de um sensor de esteróides anabólicos, que revelou uma resposta estável e seletiva aos esteróides anabólicos, bem como um desempenho superior ao dos sensores de esteróides anabólicos anteriormente relatados. Conclusão: Os valores de RSD variaram de 3,20% a 4,45%, indicando que o sensor de esteróides anabolizantes eletroquímicos desenvolvido pode ser usado como uma técnica de detecção viável para identificar esteróides anabolizantes em fluidos biológicos humanos. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción: Varios atletas hacen uso de esteroides como la nandrolona con el objetivo de hipertrofia muscular y aumento de rendimiento. La presente investigación se centró en el desarrollo de una nanoestructura de GO-TiO2 como sensor electroquímico para la detección de nandrolona (ND) como agente dopante. Objetivo: Desarrollar un electrodo de nanocompuesto de óxido de grafito y pasta de carbono modificado (TiO2-GO/CPE) como biosensor electroquímico para la detección de esteroides anabólicos en la orina de atletas. Métodos: Se empleó el enfoque hidrotérmico para hacer nanocompuestos de GO-TiO2, mientras que el enfoque de Hummers modificado se utilizó para hacer nanofilamentos de GO. Resultados: La interacción de las nanoestructuras de TiO2 con el GOES dio lugar al anclaje de las nanopartículas de TiO2 en la superficie de los nanofilamentos de GO, tal y como demostraron las investigaciones estructurales del nanocompuesto generado mediante SEM. El enfoque de DPV se utilizó para investigar las propiedades electroquímicas de un sensor de esteroides anabólicos, que reveló una respuesta estable y selectiva a los esteroides anabólicos, así como un rendimiento superior a los sensores de esteroides anabólicos reportados anteriormente. Conclusión: Los valores de RSD oscilaron entre el 3,20% y el 4,45%, lo que indica que el sensor electroquímico de esteroides anabólicos desarrollado puede utilizarse como una técnica de detección viable para identificar esteroides anabólicos en fluidos biológicos humanos. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

Green electrochemical sensors based on ionic liquid nanocomposites for detection of environmental pollutants

Industrialization and globalization have caused a huge burden on the limited natural resources, which releases various environmental pollutants such as toxic metal ions and pesticides. World Health Organisation (WHO) has set a maximum permissible limit for these toxic pollutants in water, above which, it is unsuitable for drinking purpose. There are various techniques available for the determination of such pollutants like ICP-MS, HPLC, FAAS etc. that are costly, cumbersome, and time consuming. Whereas, electrochemical sensors are portable, fast and can perform multi-analyte sensing. Electrochemical sensor can be made selective by fabricating with nanocomposites having different functional groups. Nowadays, trend of utilizing greener materials in research field is being highly appreciated in accordance with the principles of green chemistry for the application and development of electrochemical sensors. Ionic liquids having non-volatility, low toxicity, wide potential window, high electrochemical stability and conductivity have shown sustainable electrochemical sensing applications. Nanocomposite of these ionic liquids as a sensing platform have been extensively used in electrochemical detection of various pollutants. This work provides a literature survey of different ionic liquid nanocomposite based sensing platform for electrochemical detection of toxic pesticides and heavy metals. They have demonstrated good sensitivity with detection limit below WHO guidelines.

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.

One-pot synthesis of silver nanocomposites from Achyranthes aspera: An eco-friendly larvicide against Aedes aegypti L

Objective: To formulate silver nanocomposites from Achyranthes aspera leaf extracts and evaluate its larvicidal activity against Aedes aegypti. Methods: The silver nanocomposites were synthesized from Achyranthes aspera leaf extracts. The process was optimized and traced through UV-visible and photon correlation spectroscopy. The larvicidal potential of silver nanocomposites of Achyranthes aspera leaf extracts was assessed against the early fourth instars of Aedes aegypti and three non-target organisms. Furthermore, the most effective and eco-safe nanocomposite was characterized by different biophysical techniques including scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform-infrared spectroscopy (FT-IR). Results: The formulated silver nanocomposites exhibited efficient larvicidal efficacy against Aedes aegypti. Bioassay with silver nanocomposites formulated using different AgNO 3 concentrations (3, 4, and 5 mM) revealed respective LC

One-pot synthesis of silver nanocomposites from Achyranthes aspera: An eco-friendly larvicide against Aedes aegypti L

Objective: To formulate silver nanocomposites from Achyranthes aspera leaf extracts and evaluate its larvicidal activity against Aedes aegypti.Methods: The silver nanocomposites were synthesized from Achyranthes aspera leaf extracts. The process was optimized and traced through UV-visible and photon correlation spectroscopy. The larvicidal potential of silver nanocomposites of Achyranthes aspera leaf extracts was assessed against the early fourth instars of Aedes aegypti and three non-target organisms. Furthermore, the most effective and eco-safe nanocomposite was characterized by different biophysical techniques including scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform-infrared spectroscopy (FT-IR). Results: The formulated silver nanocomposites exhibited efficient larvicidal efficacy against Aedes aegypti. Bioassay with silver nanocomposites formulated using different AgNO3 concentrations (3, 4, and 5 mM) revealed respective LC50 values of 37.570, 6.262 and 1.041 μg/mL; 5.819, 1.412 and 0.489 μg/mL; and 5.519, 1.302 and 0.267 μg/mL after 24, 48 and 72 h. The silver nanocomposites with 4 mM AgNO3 were selected for characterization. SEM and TEM analysis revealed spherical, poly-dispersed structure with varied diameters of 1-25 nm. The XRD analysis established the crystalline and face-centred-cubic structure of silver nanocomposites with the maximum peak at a 2θ value of 37.42°. The EDX pattern showed the presence of Ag, O and C in the nanocomposites in their order of weight％. The FT-IR displayed visibly distinct peaks in different ranges demonstrating the intricacy of silver nanocomposites. In addition, the lethal concentrations of silver nanocomposites of Achyranthes aspera leaf extracts against Aedes aegypti larvae were non-toxic to non-target organisms including Gambusia affinis, Daphnia magna and Moina macrocopa. Conclusions: Silver nanocomposites synthesized with leaf extract of Achyranthes aspera provide a cost-effective and eco-safe alternative to conventional insecticides, and can be utilized as a potent mosquito nano-larvicide.

Nanotechnology for Combating Microbial Contamination of Water

El agua es una necesidad universal que ha sido reportada por las Naciones Unidas (ONU) y la Organización Mundial de la Salud (OMS) como una prioridad. Existe una necesidad apremiante de acceso gratuito al agua potable para las poblaciones de los países en desarrollo. Además, las fuentes de agua de los países desarrollados también requieren atención debido a la presencia de un alto nivel de contaminantes emergentes. Por lo tanto, la nanotecnología parece ser una herramienta poderosa que podría usarse como sensores, filtros, superficies antibacterianas y nanoantimicrobianos. En esta revisión, hemos discutido la aplicación de las nanopartículas y los nanocompuestos para el tratamiento de aguas y aguas residuales. Además, el impacto de las nanopartículas libres como contaminantes emergentes en las plantas de tratamiento de agua, así como en las aguas subterráneas, merece más estudios.

The water is a universal need that has been reported by the United Nations (UN) and World Health Organization (WHO) as a priority. There is a pressing need for free access to drinking water for populations from developing countries. Furthermore, the water sources of developed countries also require attention due to the presence of a high level of emergent contaminants. Therefore, nanotechnology appears to be a powerful tool that could be used as sensors, filters, antibacterial surfaces, and nanoantimicrobials. In this review, we have discussed the application of nanoparticles and nanocomposites for water and wastewater treatment. Moreover, the impact of free-nanoparticles as emergent contaminants in water treatment plants as well as groundwater warrants further studies.

Response of green synthesized drug blended silver nanoparticles against periodontal disease triggering pathogenic microbiota

Objective: Evidences for microorganisms to predominate periodontal disease, alteration of human pathogenshifted microbiota by Erythrina fusca, and antimicrobial response potentiation by ecofriendly silvernanoparticles (AgNPs) intended present study to perform green synthesis of AgNPs and evaluate againstperiodontal disease triggering pathogenic microbiota.Material and Methods: Present study involved green synthesis of AgNPs using Erythrina fusca leavesaqueous extract (EFLAE), followed by optimization, characterization, stability, and evaluation of antimicrobialpotential of biosynthetic AgNPs against periodontitis causing pathogenic human microflora (Pseudomonasaeruginosa, Escherichia coli, Streptococcus pyogenes, and Staphylococcus aureus).Results: The AgNPs green synthesis success was based on brown coloration and surface plasmon resonancesignal at 433 nm. UV-Visible spectrometry driven optimization determined 5 mM AgNO3 concentration, 1:9EFLAE and AgNO3 volumetric ratio, pH 7, 60°C temperature, and 2 hours’ time as parametric requirementsfor AgNPs biosynthesis. Stability studies revealed signal appearance between 415 and 424 nm supportingAgNPs stability. Characterization studies recognized shifted and broadened Fourier transformed infrared bandsof AgNPs revealing silver capping by biochemical moieties of EFLAE; AgNPs size below 32 nm in fieldemission scanning electron microscopic micrograph; X-ray diffraction signals at 38.95, 44.97, 64.92, and78.97 representing 111, 200, 220, and 311 AgNPs silver cubic structure planes; and elemental silver 83.66%,carbon 11.87%, and oxygen 4.47% in energy-dispersive X-ray spectrum. Optimized and characterized biogenicAgNPs, when evaluated against periodontal disease-causing pathogenic microflora using well diffusion method,exhibited maximum inhibitory zone (in mm) against Bacillus cereus (13 and 18), followed by P. aeruginosa (11and 19), E. coli (10 and 18), and S. pyogenes (9 and 15) in 50 and 100 µg/ml administered dose.Conclusion: Present study concludes that biogenic AgNPs synthesized using EFLAE possess high inhibitionpotential against periodontitis triggering pathogens (E. coli, B. cereus, S. pyogenes, and P. aeruginosa) ofmicrobiota, and recommends EFLAE as potential source for AgNPs green synthesis

Mechanical Characteristics of (TiO2-ZnO)/PMMA Nanocomposites for Dentures

Mechanical properties (impact strength, compressive strength and flexural strength) have been studied for (Polymethyl-methacrylate (PMMA)) polymer reinforced with nano (TiO2+ZnO) (0 v%, 1 v%, 2 v%, 3 v%, 4 v% and 5 v%). Ultrasonic dispersion technique was used to prepare the nanocomposites samples, follow with cold casting technique using Teflon molds standard conditions. Charpy impact instrument was used to measure the impact strength, the compressive strength of each sample which was tested in newton units using digital compression tester (TinusOlsen: H50KT, England), while flexural strength can be found from mathematical formulas which depend on the impact strength, compressive strength and flexural strength. Results show that values increase in 1 v%, then decrease alternately by (2 v%, 3 v%, 4 v%, and 5 v%), while 0 v% is the less value of volume fraction of fillers. Young modules values increase alternately by the volume fraction of fillers until 2 v%, while if it is higher and lower than 2 v% it decreases the modulus of elasticity.

Nanocomposites combined with molecular imaging in hyperthermia and its application of oral squamous cell carcinoma / 中国介入影像与治疗学

Tumor hyperthermia has become a new method of nanomedical therapy with low toxicity and high cure rate in recent years. Local hyperthermia, especially combined with surgery, radiotherapy or chemotherapy, is effective in the treatment of malignant tumors, such as oral squamous cell carcinoma, but still has some problems in following fields,included the control of heat dose, the screening of targeted therapeutic area, the differentiation of normal cells from cancer cells and so on. With the development of nanotechnology, multifunctional nano-composites have been introduced into the local hyperthermia of head and neck cancer. Targeting cancer cells with molecular imaging and simultaneous therapy through local hyperthermia can effectively improve the accuracy of treatment, and prolong the survival of patients. The advancements of nano-composites combined with molecular imaging technology and the application for tracking oral squamous cell carcinoma in hyperthermia were reviewed in this article.

Color stability of nanohybrid composite resins in drinks

Aim: The objective of this study was to evaluate the effects of solutions on the color stability of nanohybrid composite resins. Methods: The experimental sample consisted of 90 composite specimens (Beautifil II; Z350XT; Premisa), divided into three subgroups (n=10) according to the solutions (matte tea; lemon flavor isotonic drink; artificial saliva). The specimens were immersed in the solutions (5 mL/specimen) while stirring for 5 minutes, four times a day, with 1-hour intervals, repeated for 15 days. The color of the specimens was analyzed before (baseline) and after the 15th day of cycling using the CIELAB system. Data were analyzed using the two-way analysis of variance (ANOVA) and Tukey's test (α=5%). Results: Different behaviors were observed among resins. Beautifil II presented the highest color change (∆E=4.18) and less color stability, statistically different from the others (p<.05). The solutions also presented different behaviors. The lemon flavor isotonic drink (∆E=3.95) promoted the highest color change, statistically different from saliva (∆E=2.75; p<.05). The interaction between Beautifil II and isotonic drink became even more evident and significant (p<.05). Conclusion: The isotonic drink is the solution that most affected the resins, and Beautifil II presents the worst color stability

Advances in application of environment-responsive smart probes in tumor therapy / 肿瘤

With the development of medical nanotechnology, scientists have found that nanoparticle drug delivery system can improve the accumulation of anti-tumor drugs inside the tumor and reduce the damage to normal tissues, so as to increase the treatment effect while decrease its side effect. In recent years, the nanoparticle drug delivery system has been gradually developing towards intellectualization, and various smart probes which are stimuli-responsive and sensitive to microenvironment of tumor have been designed. Those probes can be divided into two categories: internal (including pH, enzyme, and redox) and external (including light, temperature, ultrasound, and magnetic field) environment-responsive probes. In this paper, the latest research progress in the two kinds of environment-responsive smart probes in the field of tumor therapy is reviewed, and the further research direction is also prospected.

Progress in antitumor nano-drug carrier / 肿瘤

As a global public health problem, the incidence of malignant tumors is increasing year by year. With the development of nanotechnology and tumor molecular biology, there are many growing researches related to small molecular nano-targeted antitumor drugs. Relying on the nano-drug delivery system, the small molecular nano-targeted drugs have some advantages. On the one hand, the nano-drug delivery system can increase the stability, bioavailability and targeting of drugs. On the other hand, the nano-drug delivery systems also have better degradability. This review focuses on the three common antitumor nano-drug carrier systems (including liposome drug delivery system, polymer micellar loading system and inorganic nano-ion carrier system), and discusses their preparation methods, research status and the condition of going on sale.

Ultrasensitive electrochemical determination of metronidazole based on polydopamine/carboxylic multi-walled carbon nanotubes nanocomposites modified GCE / 药物分析学报

An ultrasensitive electrochemical sensor based on polydopamine/carboxylic multi-walled carbon nano-tubes (MWCNTs-COOH) nanocomposites modified glassy carbon electrode (GCE) was presented in this work, which has been developed for highly selective and highly sensitive determination of an anti-microbial drug, metronidazole. The preparation of polydopamine/MWCNTs―COOH nanocomposites/GCE sensor is simple and possesses high reproducible, where polydopamine can be coated on the surface of MWCNTs―COOH via a simple electropolymerization process. Under optimized conditions, the proposed sensor showed ultrasensitive determination for metronidazole with a wide linear detection range from 5 to 5000μmol/dm3 and a low detection limit of 0.25μmol/dm3 (S/N = 3). Moreover, the proposed sensor has been successfully applied for the quantitative determination of metronidazole in real drug samples. This work may provide a novel and effective analytical platform for determination of me-tronidazole in application of real pharmaceutical and biological samples analysis.

Novel Zn-doped CuO nanocomposites inhibit tumor growth in vitro and in vivo:role of reactive oxygen species-dependent apoptosis and autophagy cross-linked by NF-kappaB pathway / 中国药理学与毒理学杂志

OBJECTIVE Zn-doped CuO nanocomposites (nZn-CuO NPs) are novel nanoparticles synthesized by sonochemical method.This study aimed to further investigate the antitumor effects and mechanism of nZn-CuO NPs, as well as the exact mechanism of reactive oxygen species (ROS) on nZn-CuO NPs-induced death using N-acetylcysteine (NAC). METHODS The antitumor effects of nZn-CuO NPs were evaluated by MTS assay and orthotopic transplantation tumor model in nude mice. The effects of nZn-CuO NPs with or without NAC on ROS production, DNA damage, apoptosis, mitochondrial damage, autophagy, lysosome impairment, and ER and Golgi stress were determined. Also,western blot was used to detect apoptosis and autophagy related proteins,as well as NF-κB pathway related proteins. RESULTS nZn-CuO NPs significantly inhibit tumor growth both in vitro and in vivo. nZn-CuO NPs were able to cause cytotoxicity, ROS production, DAN damage mitochondrial damage, apoptosis, and autophagy, and NAC can attenuate them. Further studies showed that nZn-CuO NPs induced changes of apoptosis, autophagy and NF-κB pathway related proteins, and NAC can restore them. CONCLUSION Overall, our data demonstrated that nZn-CuO NPs could inhibit tumor growth both in vitro and in vivo by ROS-dependent regulation of apoptosis and autophagy, which might be cross-linked by NF-κB pathways.

Ação cicatrizante da nanopartícula de prata com norbixina em queimaduras / Healing action of silver nanoparticle with norbixin on burns

Introdução: A queimadura é uma injúria que altera a integridade da pele, decorrente de traumas térmicos. Dentre os compostos não convencionais utilizados na cicatrização de feridas estão a norbixina e as preparações com prata. Objetivo: avaliar a ação cicatrizante da nanopartícula de prata associada à norbixina em queimaduras de Mus musculus. Métodos: Inicialmente, preparou-se uma solução nanoprata/norbixina e a partir desta obteve-se o gel teste. Posteriormente dividiu-se os animais em 3 grupos, sendo negativo (sem tratamento), positivo (sulfadiazina de prata) e teste (gel teste). Nestes animais houve a indução das queimaduras. No 7º e 14º dia realizou-se a eutanásia e os tecidos lesionados foram coletados para análise microscópica. Resultado: Verificou-se potencial vantagem do grupo teste em relação ao negativo e igualdade comparada ao positivo. Conclusão: A nanopartícula de prata associada à norbixina representa uma fonte alternativa para a cicatrização de queimaduras. (AU)

Introduction: Burning is an injury that alters the integrity of the skin, due to thermal trauma. Among the non-conventional compounds used in wound healing are norbixin and silver preparations. Objective: to evaluate the cicatrizing action of silver nanoparticle associated with norbixina in Mus musculus burns. Methods: Initially, a nanoprata / norbixin solution was prepared and from this solution the test gel was obtained. Afterwards the animals were divided into 3 groups, being negative (without treatment), positive (silver sulfadiazine) and test (gel test). In these animals, there was the induction of burns. On the 7th and 14th day, euthanasia was performed and the injured tissues were collected for microscopic analysis. Result: There was a potential advantage of the test group in relation to negative and equality compared to positive. Conclusion: The silver nanoparticle associated with norbixin represents an alternative source for the healing of burns. (AU)

Preparación y Caracterización de Nanocompositos Quitosano-Cobre con Actividad Antibacteriana para aplicaciones en Ingeniería de Tejidos / Preparation and characterization of Copper Chitosan Nanocomposites with Antibacterial Activity for Applications in Tissue Engineering

RESUMEN: El presente trabajo describe la preparación de nanocompositos formulados a partir de quitosano (QS)/nanopartículas de cobre (nCu) con características antibacterianas y aplicación potencial en ingeniería de tejidos. Para ello, se prepararon nanocompositos mediante mezclado en solución asistido con ultrasonido con el objetivo de incrementar la dispersión de la carga nanométrica en el biopolímero. El análisis de FTIR demostró que la presencia de nCu en la matriz de QS favorece la interacción del nCu con los grupos amino/hidroxilo de la molécula del QS. Se determinó mediante UV-Vis que los nanocompositos QS/nCu presentan absorción asociada con la presencia de nanopartículas y la posible liberación de iones Cu2+ en medio líquido. Mediante AFM se determinó que el QS hidratado forma una malla con microporos, que puede favorecer la penetración de bacterias en el nanocomposito y su interacción con las nCu. Finalmente, se determinó el efecto antibacteriano del material al contacto con la bacteria Staphylococcus aureus, en donde se presenta una actividad antibacteriana superior al 90% entre los 90 y 180 min de interacción. Dichos resultados sugieren que es posible obtener nanomateriales antibacterianos biocompatibles para su posible aplicación en ingeniería tisular.

ABSTRACT: The Present work describes the preparation of nanocomposites based on chitosan (QS)/copper nanoparticles (nCu) with antibacterial properties and potential application in tissue engineering. For this purpose, nanocomposites were prepared by solution blending with ultrasound assisted, aiming to increase the nanoparticles dispersion in the biopolymer. FTIR analyses demonstrates that nCu supported in QS increase their interaction of nanoparticles with amine/hydroxyl groups of QS molecule. UV-Vis analyses demonstrates that QS/nCu nanocomposites have an absorption signal associated with the presence of nanoparticles and the possible Cu2+ ions release in liquid media. AFM analyses shown that hydrated QS form a mesh with micro pores, improving the bacterial penetration and the direct contact with nCu. This behavior was corroborated by antibacterial assays, where QS/nCu nanocomposites shown an antibacterial activity higher than 90% between 90-180 minutes of interaction. Our results suggest that is possible to obtain combined antibacterial/biocompatible nanomaterials with potential application in tissue engineering.

Enhanced bioactive properties of BiodentineTM modified with bioactive glass nanoparticles

Abstract Objective To prepare nanocomposite cements based on the incorporation of bioactive glass nanoparticles (nBGs) into BiodentineTM (BD, Septodent, Saint-Maur-des-Fosses Cedex, France) and to assess their bioactive properties. Material and Methods nBGs were synthesised by the sol-gel method. BD nanocomposites (nBG/BD) were prepared with 1 and 2% nBGs by weight; unmodified BD and GC Fuji IX (GIC, GC Corporation, Tokyo, Japan) were used as references. The in vitro ability of the materials to induce apatite formation was assessed in SBF by X-ray diffraction (XRD), attenuated total reflectance with Fourier transform infrared spectroscopy (ATR-FTIR), and scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis. BD and nBG/BD were also applied to dentine discs for seven days; the morphology and elemental composition of the dentine-cement interface were analysed using SEM-EDX. Results One and two percent nBG/BD composites accelerated apatite formation on the disc surface after short-term immersion in SBF. Apatite was detected on the nBG/BD nanocomposites after three days, compared with seven days for unmodified BD. No apatite formation was detected on the GIC surface. nBG/BD formed a wider interfacial area with dentine than BD, showing blockage of dentine tubules and Si incorporation, suggesting intratubular precipitation. Conclusions The incorporation of nBGs into BD improves its in vitro bioactivity, accelerating the formation of a crystalline apatite layer on its surface after immersion in SBF. Compared with unmodified BD, nBG/BD showed a wider interfacial area with greater Si incorporation and intratubular precipitation of deposits when immersed in SBF.

The study of 5-Hydroxytryptamine 2B receptor-nanodisc self-assembling and its ligand binding activity / 中国医师杂志

Objective To explore the application of nanodisc in functional and drug discovery research of G protein-coupled receptor (GPCR).Methods The purified recombinant 5-Hydroxytryptamine 2B receptor (5-HT2BR) was reconstituted into nanodisc complex.Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and size exclution chromatography were performed to evaluate the reconstitution reaction,followed by the use of surface plasmon resonance to validate the ligand-binding activity of 5-HT2BR after reconstitution.Results 5-HT2B R was effectively self-assembled into nanodisc while maintained its binding activity toward the antagonist SB204741.Conclusions The presented study provided potential application of 5-HT2B R-nanodisc for the development of subtype-selective drugs against 5-HT2B R and the fundamental of utilizing nanodisc for GPCR structural and functional studies as well as drug discovery.