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Faced with the problem caused by the excessive consumption of plastic packaging, especially those produced with Polyethylene Terephthalate - PET, and most of them have garbage as their final destination, such packaging has become a worrying environmental liability. Their often inadequate disposal promotes the pollution of soils, watercourses, oceans and even the presence of component materials of these packages in the human body, in the form of microplastics, has been observed. As research in the area advances, greater concerns arise, as more problems arising from the excessive use and disposal of plastics are identified. As something needs to be done to remove this liability from the environment, a technology was developed for the production of materials with characteristics similar to 3D graphene, a carbon material with qualities and versatility that allow its wide use in several applications, using PET as carbon precursor. This work presents this production technology with possible variables, the characterization of the materials and potential applications: for the electronics area, as supercapacitors and necessary improvements to validate it, and as an adsorbent for application in the treatment of industrial effluents.

We aimed to optimize the mechanical and biological properties of a conventional methacrylate-based dental polymer by loading it with double- and triple-walled carbon nanotubes as growth (DTWCNTG).A formulation of bisphenol A-glycidyl methacrylate and triethylene glycol dimethacrylate (mass ratio = 2:1) was mixed with DTWCNTG at concentrations of 0.0% (control), 0.001%, 0.005%, and 0.010%. The concentrations were physicochemical and morphologically evaluated, and antibacterial activity was assessed by seeding a Streptococcus mutans strain (ATCC 25175) on the experimental polymeric surfaces. Cellular survival and osteodifferentiation were evaluated in epithelial (HaCat) and preosteoblast cells (MC3T3-E1).The 0.001% DTWCNTG concentration yielded higher compressive strength, elastic modulus, flexural strength, flexural modulus, water sorption, and solubility than the control. The degree of conversion and color did not significantly change with a low amount of DTWCNTG incorporated into the polymer. Antibacterial activity significantly improved when tested on the 0.001% DTWCNTG discs. No groups showed cytotoxicity in a short-term analysis and adding DTWCNTG favored MC3T3-E1 mineralization over the control, particularly in the 0.001% formulation.The micro-addition of 0.001% DTWCNTG confers mechanical resistance, antimicrobial properties, and bioactivity to methacrylate-based polymers without significantly compromising color. Incorporating DTWCNTG improved dental composite properties and could be a biomodified material for minimally invasive procedures.

Nanostructured silica (n-SiO2) synthesized by sol-gel method was used in this work as a support for multi-walled carbon nanotubes (MWCNTs) synthesis by catalytic chemical vapor deposition (CCVD) process. The syntheses were performed using methane as carbon feedstock and without previous catalyst reduction with hydrogen. Three different methods to incorporate the iron-based catalyst on the silica support have been studied to identify its influence on the structural characteristics of the synthesized MWCNTs. Such study aims to develop the production of an advanced hybrid composite with better structural properties to be applied as a strengthener additive in different material matrices. The synthesized hybrid composites were characterized to analyze the MWCNTs quality in terms of morphology, graphitization degree, and thermal stability. Regarding the silica support containing the catalyst, Infrared (FTIR) and X-ray (XRD) analyses showed that no significant differences in terms of chemical composition and crystalline phases have been observed between the analyzed samples regardless of the catalyst incorporation method used. Concerning the hybrid composite, Raman spectroscopy, electron microscopies, and thermal analyses suggested modifications in terms of graphitization degree, morphology, and thermal stability of the MWCNTs. Indeed, the catalyst incorporation method would influence the catalyst/support interaction promoting the deposition of different carbon structures, and the quality of the MWCNTs grown in the hybrid material.

Carbon nanotubes are a promising material to solve the low tensile strength and ductility of Portland cement-based materials. Carbon nanotubes (CNTs) synthesized directly on cement clinker particles can also reduce production costs and help dispersion. In this scenario, this paper analyzes the fresh state rheological behavior, as well as the initial hydration period of blast-furnace slag (Brazilian CP III 40 RS) cement pastes produced with CNTs grown directly on clinker. CP III 40 RS was selected since it is one of the most used cement by the construction industry in Brazil. Cement pastes containing 0.1% and 0.3% of CNTs with respect to cement content were compared with CNT-free pastes. No chemical admixtures were used as a dispersant in all cases. The yield stress, plastic viscosity, temperature profile and evolved accumulated heat during the initial hydration period as well as setting times are the properties investigated. The results show that the addition of CNTs does not alter the rheological behavior of the cement pastes considering the employed concentrations, although the yield stress values were larger. The presence of CNTs in the cement pastes did not change the evolved accumulated heat during the first 72 hours of the hydration period. Resumo Nanotubos de carbono são elementos promissores para melhorar a pequena resistência à tração e a dutilidade de materiais a base de cimento Portland. Nanotubos de carbono (NTC) sintetizados diretamente sobre o clínquer de cimento podem também reduzir custos de produção e melhorar a dispersão destes na matriz. Neste cenário, este artigo analisa o comportamento reológico no estado fresco, bem como o período inicial de hidratação de pastas produzidas com cimento Portland de alto forno (CP III 40 RS) contendo NTC sintetizados diretamente sobre o clínquer. O CP III 40 RS foi selecionado, pois é um dos cimentos mais utilizados pela indústria da construção civil no Brasil. As pastas de cimento contendo 0,1% e 0,3% das NTC em relação a massa de cimento foram comparadas com pastas sem nanotubos. Nenhum aditivo foi usado como dispersante em todos os casos. A tensão de escoamento, a viscosidade plástica, o perfil térmico e o calor acumulado durante o período inicial de hidratação, bem como os tempos de pega são as propriedades investigadas. Os resultados mostram que a adição de NTC não altera o comportamento reológico das pastas de cimento considerando as concentrações empregadas, embora os valores da tensão de escoamento terem sido maiores. A presença de NTC nas pastas de cimento não alterou o calor acumulado durante as primeiras 72 horas do período de hidratação.

Gold nanorods (GNRs) are increasingly being studied for diagnostic and therapeutic purposes. Green synthesis based methods with natural compounds as additives stand out as a hope in terms of better synthesis methodology, with advantages of producing potentially less toxic and, perhaps, biologically active GNRs due to influence of natural additives used during synthesis. Exploring green chemistry using different natural phenolic compounds, the present work reveals different in vitro activity of GNRs evaluated against different parasites that causes skin infectious diseases compared to GNRs produced by convencional seed mediated method. This approach brings advantages in producing active GNRs, with ease calling, less cytotoxic and with a better selectivity index (SI) than GNRs synthesized by conventional seed mediated synthesis, opening new possibilities for therapies. Natural compounds used in green syntheses were gallic acid (GA), resveratrol (RSV) and a purified fraction of the hydroalcoholic extract of Stryphnodendron obovatum. GNRs exhibited great activity against Leishmania braziliensis, and the dermatophytes Tricophyton rubrum, T. interdigitale and Microsporum gypseum. The anti-Leishmania and antidermatophytic activity of GNRs reinforce the applicability of GNRs in biomedical field and the influence of synthesis method in biological activity, showing benefits related to the seedless synthesis with natural compounds. In addition, these preliminary results indicate the possibility of exploring at maximum the physical and chemical properties of GNRs in addition to the biological activity itself, such as the development of topical antiparasitic formulations for association with phototherapy.

Carboxylated Multi-wall Carbon Nanotube (MWCNT-COOH) presents unique properties due to nanoscale dimensions and permits a broad range of applications in different fields, such as bone tissue engineering and regenerative medicine. However, the cytocompatibility of MWCNT-COOH with human stem cells is poorly understood. Thus, studies elucidating how MWCNT-COOH affects human stem cell viability are essential to a safer application of nanotechnologies. Using stem cells from the human exfoliated deciduous teeth model, we have evaluated the effects of MWCNT-COOH on cell viability, oxidative cell stress, and DNA integrity. Results demonstrated that despite the decreased metabolism of mitochondria, MWCNT-COOH had no toxicity against stem cells. Cells maintained viability after MWCNT-COOH exposure. MWCNTCOOH did not alter the superoxide dismutase activity and did not cause genotoxic effects. The present findings are relevant to the potential application of MWCNT-COOH in the tissue engineering and regenerative medicine fields. Made available in DSpace on 2021-10-31T02:05:41Z (GMT). No. of bitstreams: 1 Cytocompatibility-carboxylated.pdf: 1212719 bytes, checksum: 3a765d7e9612a0daa32979125140b553 (MD5) Previous issue date: 2021 Online ahead of print.

Hydroxyapatite (HAP), the main mineral component of bone and tooth enamel, has become an important biomaterial in orthopedic and dental applications. However, its low fracture toughness, poor tensile strength and wear resistance make it not suitable to be used in bone tissue engineering applications, the improvement of mechanical properties of HAP using different additives being still a great challenge. Nowadays, the most used additives for reinforcement are graphene oxide (GO) and single- or multi-walled carbon nanotubes (MWCNTs). The present study reports their successful incorporation of MWCNTs and GO (0.5, 1.0 and 2.0 wt%) into the HAP matrix. The prepared HAP-based nanocomposites (NCs) were characterized by X-ray diffraction, laser diffraction, scanning and transmission electron microscopy, thermal analysis and Raman spectroscopy. Moreover, the UV–Vis spectroscopy was used to investigate the desorption properties of obtained NCs by using ibuprofen, one of the most common prescribed analgesic nonsteroidal anti-inflammatory drugs. It was found that CNTs addition does not have a major influence on desorption efficiency, while the addition of GO evidenced an increase in desorption efficiency over time for all the studied NCs.

Due to the influence of its superficial physical parameters on the interaction with catalyst, mesoporous silica is commonly referred as suitable support to grow carbon nanotubes (CNTs) by catalytic chemical vapor deposition (CCVD) method. Faced with the various possibilities of applying nanostructured SiO2/CNTs composites, this work aims to evaluate and clarify the influence of the silica mesoporosity and morphology on the quality and amount of CNTs produced by CCVD process. Five different nanostructured silicas (n-SiO2) were produced by sol-gel method. Basically, four silica samples were synthesized with the addition of an acidic catalyst and one with a basic catalyst. Thermogravimetric analysis, Raman spectroscopy, transmission electron microscopy and scanning electron microscopy were used to characterize the silica supports and the as-grown CNTs produced in this work. The obtained results show differences in the morphology of the synthesized CNTs according to the physical properties of each n-SiO2. The mesoporous silica structure, due to different pore size distribution and volume, affected the interaction between the support and the catalyst, and, consequently, the quality and amount of the synthesized multi-walled carbon nanotubes (MWCNTs). Silica supports with either high mesopore volume, or high mesopore size, provide the highest quantities of as-grown CNTs materials. However, in terms of quality of as-grown CNTs, the supports with lower mesopores volume were more adequate to the MWCNTs synthesis. Nevertheless, the presence of pores with compatible size may have allowed an improved anchorage of catalyst particles inside these pores favoring the growth of CNTs with good quality.

The optical and morphological properties of resveratrol were investigated. This nontoxic fluorescent natural material, emitting in the visible blue light, was used as an optical marker, enabling the enhancement of the image contrast coming from relief pictures marked on challenging surfaces. By applying appropriated imaging softwares, this marker was verified to be very useful in the latent fingerprint recognition deposited on different wood surface types, mainly those with high level of roughness, where conventional forensic materials do not allow effective fingerprint image visualization.

Visceral leishmaniasis (VL) is a systemic parasitic disease that leads to high rates of morbidity and mortality in humans worldwide. There is a great need to develop new drugs and novel strategies to make chemotherapy for this disease more efficacious and well tolerated. Recent reports on the immunomodulatory effects and the low toxicity of the spherical carbon nanostructure fullerol led us to investigate in vitro and in vivo antileishmanial activity in free and encapsulated forms in liposomes. When assayed against intramacrophagic Leishmania amastigotes, fullerol showed a dose-dependent reduction of the infection index with IC50 of 0.042 mg/mL. When given daily by i.p. route for 20 days (0.05 mg/kg/d) in a murine model of acute VL, fullerol promoted significant reduction in the liver parasite load. To improve the delivery of fullerol to the infection sites, liposomal formulations were prepared by the dehydration-rehydration method. When evaluated in the acute VL model, liposomal fullerol (Lip-Ful) formulations given i.p. at 0.05 and 0.2 mg/kg with 4-days intervals were more effective than the free form, with significant parasite reductions in both liver and spleen. Lip-Ful at 0.2 mg/kg promoted complete parasite elimination in the liver. The antileishmanial activity of Lip-Ful was further confirmed in a chronic model of VL. Lip-Ful was also found to induce secretion of pro-inflammatory TNF-α, IFN-γ and IL-1β cytokines. In conclusion, this work reports for the first time the antileishmanial activity of fullerol and introduces an innovative approach for treatment of VL based on the association of this nanostructure with liposomes.

The investigation of the effects of three essential oils (EOs) from Taxandria fragrans (FRA), Melaleuca alternifolia (TTO) and Boswellia serrata (IF), alone and combined with ketoconazole (KTZ), and their functionalised gold nanoparticles (AuNP) against Trichophyton interdigitale both in vitro and in vivo indicated that EOs presented activity against T. interdigitale. The combination of EOs and KTZ was antagonistic. FRA, TTO, gold nanoparticles capped with T. fragrans (AuNPFRA) and gold nanoparticles capped with M. alternifolia (AuNPTTO) presented antidermatophytic activity in vivo, with the capacity to reduce fungal burden and to preserve tissue architecture; however, combination treatment with KTZ increased fungal burden and caused tissue damage. The combination of EO with KTZ exhibited antagonistic activity and was histologically harmful. In contrast, FRA, TTO, AuNPFRA and AuNPTTO are promising treatments for dermatophytosis.

High-quality double- and triple-walled carbon nanotubes have been synthesized using Fe−Co catalysts supported on aluminum flake powder. The diameters and lengths of the obtained nanotubes are in the ranges of 3–8 nm and 150–300 μm, respectively, and the specific surface area were quoted as 600 m2/g. The yield of the nanotubes synthesis relative to the initial weight of the catalyst is in the order of 1200%, with 70% of the resulting material consisting of thin carbon nanotubes with less than 6 nm of outer diameter and carbon purity of greater than 90%. Our results indicate that the use of aluminum as catalyst support have a profound effect in the formation of the metal nanoparticles. In addition to boost the reduction the catalyst precursors, the high chemical reactivity of metallic aluminum drives the thermal formation of an oxide layer on the Al surface that suppresses the diffusion and aggregation of catalyst nanoparticles. As a result, a simple impregnation method can be adopted to produce catalyst nanoparticles with narrow size distribution that are suitable for the growth of few wall carbon nanotubes at high yield and large scale.

In recent years, studies using the green chemistry approach for the synthesis of metallic nanoparticles (Nps) have been increasingly explored. Gold Nps (GNps) produced from natural compounds, such as hydroalcoholic extracts or essential oils from plants, can have greater stability, monodispersion, faster and more efficient synthesis, and can be an interesting alternative to conventional synthesis. In this work the seedless synthesis of gold nanorods (GNRs) using resveratrol (RSV), gallic acid (GA) and a fraction of the hydroalcoholic extract of Stryphnodendron obovatum was explored. The main objective was to characterize their stability and surface chemistry to demonstrate the natural products presence. Characterizations were made by Ultaviolet-Visible Absorption Spectrophotometry (UV–vis), Transmission Electron Microscopy (TEM), Zeta Potential, Fourier Transform Infrared Spectroscopy (FTIR) and X-Ray Photoelectron Spectroscopy (XPS). The results showed that the natural compounds used in the synthesis of GNRs favor the production of more stable particles, in addition to remaining anchored on its surface which reinforces, and allows us to suggest, several applications in the biomedical area of the GNRs thus produced.

Neglected for years, Zika virus (ZIKV) has become one of the most relevant arboviruses in current public health. The recent Zika fever epidemic in the Americas generated a worldwide alert due to the association with diseases such as Guillain-Barré syndrome and congenital syndromes. Among the pathogenesis of ZIKV, recent studies suggest that oxidative stress plays an important role during infection and that compounds capable of modulating oxidative stress are promising as therapeutics. Furthermore, so far there are no specific and efficient antiviral drug or vaccine available against ZIKV. Thus, fullerol was evaluated in the context of infection by ZIKV, since it is a carbon nanomaterial known for its potent antioxidant action. In this study, fullerol did not alter cell viability at the concentrations tested, proving to be inert, beyond to presenting high antioxidant power at low concentrations. ZIKV infection of human glioblastoma increased the production of reactive oxygen species by 60% and modulated the Nrf-2 pathway activity negatively. After treatment with fullerol, both conditions were restored to baseline levels. Additionally, fullerol was able to reduce viral production by up to 90%. Therefore, our results suggest that fullerol as a promising candidate in the control of ZIKV infections, presenting both antioxidant and antiviral action.

Intestinal ischemia is a vascular emergency that arises when blood flow to the intestine is compromised. Reperfusion is necessary to restore intestinal function but might lead to local and systemic inflammatory responses and bacterial translocation, with consequent multiple organ dysfunction syndrome (MODS). During reperfusion occurs production of reactive oxygen species. These species contribute to intestinal injury through direct toxicity or activation of inflammatory pathways. Fullerol is a nanacomposite which has been shown to act as reactive oxygen species and reactive nitrogen species (RNS) scavengers. Thus, our aim was to evaluate whether Fullerol confer anti-inflammatory activity during intestinal ischemia and reperfusion (IIR). Intestinal ischemia was induced by total occlusion of the superior mesenteric artery. Groups were treated with vehicle or Fullerol 10 min before reperfusion. Mice were euthanized after 6 h of reperfusion, and small intestines were collected for evaluation of plasma extravasation, leukocyte influx, cytokine production and histological damage. Bacterial translocation to the peritoneal cavity and reactive oxygen and nitrogen species production by lamina propria cells were also evaluated. Our results showed that treatment with Fullerol inhibited bacterial translocation to the peritoneal cavity, delayed and decreased the lethality rates and diminished neutrophil influx and intestinal injury induced by IIR. Reduced severity of reperfusion injury in Fullerol-treated mice was associated with blunted reactive oxygen and nitrogen species production in leukocytes isolated from gut lamina propria and decreased production of pro-inflammatory mediators. Thus, the present study shows that Fullerol is a potential therapy to treat inflammatory bowel disorders associated with bacterial translocation, such as IIR.

For the first time, patterned growth of boron nitride nanostructures (BNNs) is achieved by thermal chemical vapor deposition (TCVD) technique at 1150 °C using a mixture of FeS/Fe2O3 catalyst supported in alumina nanostructured, boron amorphous and ammonia (NH3) as reagent gas. This innovative catalyst was synthesized in our laboratory and systematically characterized. The materials were characterized by X-ray diffraction (XRD), Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), Thermogravimetric analysis (TGA), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The X-ray diffraction profile of the synthesized catalyst indicates the coexistence of three different crystal structures showing the presence of a cubic structure of iron oxide and iron sulfide besides the gamma alumina (γ) phase. The results show that boron nitride bamboo-like nanotubes (BNNTs) and hexagonal boron nitride (h-BN) nanosheets were successfully synthesized. Furthermore, the important contribution of this work is the manufacture of BNNs from FeS/Fe2O3 mixture.

Gold nanostructures of two different shapes (spheres and rods) were synthesized to form a colloidal hybrid system with 5,10,15,20-tetrakis(N-methylpyridinium-4-yl)porphyrin tosylate salt (H2TM4PyP(OTs)4) (POR) for applications in photodynamic therapy (PDT) using light in the visible spectral range. Electron paramagnetic resonance (EPR) experiments in combination with spin trapping were used for the detection of reactive oxygen species (ROS) and evaluation of the efficiency of these novel hybrid systems as photosensitizers. It is shown that the hybrid system consisting of gold nanorods (AuNR) and porphyrin (POR) is by far more efficient than its isolated components. This enhanced efficiency is explained by a synergetic effect between the AuNR and the porphyrin, wherein a rapid energy transfer from the former to the latter produces a large amount of singlet oxygen followed by its conversion into hydroxyl radicals. The mechanism was investigated using different spin traps and different ROS inhibitors. On the other hand, spherical gold nanoparticles (AuNP) do not show this synergetic effect. The synergetic effect for gold nanorods/POR hybrid is attributed to a larger field enhancement close to the gold nanorod surface in addition to the electrostatic attraction between the components of the hybrid system.

It has been reported that carbon nanotubes (CNTs) serve as nucleation sites for the deposition of bone matrix and cell proliferation. Here, we evaluated the effects of multi-walled CNTs (MWCNTs) on bone repair of rat tibiae. Furthermore, because sodium hyaluronate (HY) accelerates bone restoration, we associated CNTs with HY (HY-MWCNTs) in an attempt to boost bone repair. The bone defect was created by a 1.6-mm-diameter drill. After 7 and 14 days, tibiae were processed for histological and morphometric analyses. Immunohistochemistry was used to evaluate the expression of vascular endothelial growth factor (VEGF) in bone defects. Expression of osteocalcin (OCN), bone morphogenetic protein-2 (BMP-2), and collagen I (Col I) was assessed by real-time PCR. Histomorphometric analysis showed a similar increase in the percentage of bone trabeculae in tibia bone defects treated with HY and HY-MWCNTs, and both groups presented more organized and thicker bone trabeculae than nontreated defects. Tibiae treated with MWCNTs or HY- MWCNTs showed a higher expression of VEGF. Treatment with MWCNTs or HY-MWCNTs increased the expression of molecules involved in the bone repair process, such as OCN and BMP-2. Also, HY- and MWCNT-treated tibiae had an increased expression of Col I. Thus, it is tempting to conclude that CNTs associated or not with other materials such as HY emerged as a promising biomaterial for bone tissue engineering.

In this work, we characterize nor-β-lapachone-loaded (NβL-loaded) microcapsules prepared using an emulsification/solvent extraction technique. Features such as surface morphology, particle size distribution, zeta potential, optical absorption, Raman and Fourier transform infrared spectra, thermal analysis data, drug encapsulation efficiency, drug release kinetics and in vitro cytotoxicity were studied. Spherical microcapsules with a size of 1.03 ± 0.46 μm were produced with an encapsulation efficiency of approximately 19%. Quantum DFT calculations were also performed to estimate typical interaction energies between a single nor-β-lapachone molecule and the surface of the microparticles. The NβL-loaded PLGA microcapsules exhibited a pronounced initial burst release. After the in vitro treatment with NβL-loaded microcapsules, a clear phagocytosis of the spheres was observed in a few minutes. The cytotoxic activity against a set of cancer cell lines was investigated.

Cancer-Associated Fibroblasts (CAFs) contribute to tumour progression and have received significant attention as a therapeutic target. These cells produce growth factors, cytokines and chemokines, stimulating cancer cell proliferation and inhibiting their apoptosis. Recent advances in drug delivery have demonstrated a significant promise of iron oxide nanoparticles in clinics as theranostic agents, mainly due to their magnetic properties. Here, we designed superparamagnetic iron oxide nanoparticles (SPIONs) to induce apoptosis of human fibroblasts. SPIONs were synthesized via co-precipitation method and coated with sodium citrate (SPION_Cit). We assessed the intracellular uptake of SPIONs by human fibroblast cells, as well as their cytotoxicity and ability to induce thermal effects under the magnetic field. The efficiency and time of nanoparticle internalization were assessed by Prussian Blue staining, flow cytometry and transmission electron microscopy. SPIONs_Cit were detected in the cytoplasm of human fibroblasts 15 min after in vitro exposure, entering into cells mainly via endocytosis. Analyses through Cell Titer Blue assay, AnnexinV-fluorescein isothiocyanate (FITC) and propidium iodide (PI) cellular staining demonstrated that concentrations below 8 × 10−2 mg/mL of SPIONs_Cit did not alter cell viability of human fibroblast. Furthermore, it was also demonstrated that SPIONs_Cit associated with alternating current magnetic field were able to induce hyperthermia and human fibroblast cell death in vitro, mainly through apoptosis (83.5%), activating caspase 8 (extrinsic apoptotic via) after a short exposure period. Collectively these findings suggest that our nanoplatform is biocompatible and can be used for therapeutic purposes in human biological systems, such as inducing apoptosis of CAFs.

Aim This study determined the optimum gamma irradiation dosage to sterilize sodium hyaluronate (HY), single-walled carbon nanotubes (SWCNT), multi-walled carbon nanotubes (MWCNT) and CNT functionalized with HY (HY-SWCNT and HY-MWCNT), evaluated the structural integrity of the materials and assessed whether sterilized materials kept biological properties without affecting renal function. Main methods Materials were submitted to dosages of 100 gγ to 30 Kgγ and plated onto agar mediums for colony forming units (CFUs) counting. Sterilized samples were inoculated with 107 Bacillus clausii, submitted again to gamma irradiation, and plated in agar mediums for CFUs counting. Scanning electron microscope was used for structural evaluation of sterilized materials. Tooth sockets of rats were treated with sterilized materials for bone formation assessment and renal function of the animals was analyzed. Key findings The optimum gamma dosage for sterilization was 250 gγ for HY and 2.5 Kgγ for the other materials without meaningful structural changes. Sterilized materials significantly increased bone formation (p Significance Gamma irradiation efficiently sterilized HY, SWCNT, MWCNT, HY-SWCNT and HY-MWCNT without affecting structural aspects while maintaining their desirable biological properties.

Anaplasmosis is one of the most prevalent tick-borne diseases of cattle caused by Anaplasma marginale. MSP1a surface protein has been shown to be involved in eliciting immunity to infected cattle. Carbon nanotubes (CNTs) has been increasingly highlighted due to their needle like structure, which contain multiple attachment sites for biomolecules and may interact with or cross biological membranes, increasing antigen availability to immune system. Here, we have successfully designed a nanocomplex of a synthetic peptide noncovalently attached to multiwalled CNT (MWCNT). Peptide comprising the core motif of the MSP1a was efficiently adsorb onto the nanoparticle surface. The MWCNT-Am1 nanocomplex exhibited high stability and good dispersibility and in vivo immunization showed high levels of IgG1 and IgG2a, followed by increased expression of pro-inflammatory and anti-inflammatory cytokines. This is a proof-of-concept of a nanovaccine that was able to generate a strong immune response compared to the common antigen-adjuvant vaccine without the nanoparticles.

Made available in DSpace on 2019-10-04T11:57:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-04-01 Instituto Nacional de Ciencia e Tecnologia Nanomaterial de Carbono Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Given the increasing use of carbon nanotubes (CNT) in several industries and technological applications, it is essential to perform in vivo toxicological studies with these nanomaterials to evaluate their potential ecotoxicity. Dopamine (DA) and serotonin (5HT) are key neurotransmitters for brain functions and behavioral responses. Determination of DA and 5HT were performed in brain samples from zebrafish Danio rerio exposed i.p. to single-walled CNT (SWCNT), besides analyzing acetylcholinesterase (AChE) and ectonucleotidases activity, lipid peroxidation and total antioxidant capacity. Results showed that treatment with SWCNT increased between 3 and 6-fold the concentration of DA and 5HT (p < 0.05). Similarly, a significant reduction (p < 0.05) in AChE activity was observed in the brains of SWCNT exposed zebrafish when compared to the control groups. Cholinergic, serotonergic, and dopaminergic systems, through AChE activity and serotonin and dopamine levels, respectively were affected by SWCNT in the zebrafish brain. Alterations in these neurotransmitters can potentially affect several physiological and behavioral that they control. Univ Fed Rio Grande FURG, ICB, Av Italia Km 8 S-N,Cx P 474, BR-96200970 Rio Grande, RS, Brazil Univ Fed Rio Grande FURG, ICB, Progmma Posgrad Ciencias Fisiol FAC, Rio Grande, RS, Brazil Rede Nanotoxicol MCTI CNPq, Brasilia, DF, Brazil Inst Nacl Ciencia & Tecnol Nanomat Carbono CNPq, Belo Horizonte, MG, Brazil Fac Biociencias PUCRS INCT TM CNPq, Porto Alegre, RS, Brazil Univ Estadual Paulista, Sao Jose Do Rio Preto, SP, Brazil Univ Fed Rio Grande do Sul, Porto Alegre, RS, Brazil Univ Fed Minas Gerais, Belo Horizonte, MG, Brazil Univ Estadual Paulista, Sao Jose Do Rio Preto, SP, Brazil CNPq: 421701/2017-0

This study synthesized and characterized a nanohybrid composed of graphene oxide (GO) functionalized with sodium hyaluronate (HY) (GO-HY), evaluated its effect in vitro and determined its osteogenic potential in vivo. The synthesized nanohybrid was analyzed by Scanning electron microscopy (SEM), Raman spectrometry, Thermogravimetry, Fourier-transform infrared (FTIR) spectroscopy and X-ray diffraction. MC3T3-E1 cell viability was assessed by MTT assay in 48 and 72 h. Bone defects were created in tibia of 40 Wistar rats and filled with blood clot (control), 1% HY, GO (50, 100 and 200 μg/mL) and the nanohybrid (50, 100 and 200 μg/mL). After 7 and 14 days, histomorphometric analysis was carried out to assess osteogenic potential of the nanohybrid. Immunohistochemical analysis evaluated the expression of vascular endothelial growth factor (VEGF) in bone defects. Thermogravimetric analysis, Raman and FTIR spectrometry confirmed the functionalization of GO with HY by covalent bonds. Five μg/mL concentrations of the nanohybrid did not alter the viability of the MC3T3-E1 cells. Histomorphometric analysis demonstrated that the nanohybrid at 100 μg/mL significantly accelerated the bone repair in tibia of rats when compared to controls (p 0.01). Immunohistochemical analysis showed a significantly less intense VEGF expression in tibia treated with the nanohybrid when compared to controls (p 0.05). The nanohybrid composed of GO functionalized with HY was able to induce the acceleration of the tissue regeneration process in bone defects created in the tibia of rats. This novel nanohybrid is a promising material for the field of bone tissue engineering.

Irinotecan is a useful chemotherapeutic agent for the treatment of several solid tumors. However, this therapy is associated with side effects, including leukopenia and mucositis. Reactive oxygen species (ROS) activate inflammatory pathways and contribute to Irinotecan-induced mucositis. Fullerol is a nanocomposite with anti-oxidant properties that may reduce tissue damage after inflammatory stimuli. In this paper, the effects of Fullerol and mechanisms of protection were investigated in a model of Irinotecan-induced mucositis. Mucositis was induced by an injection of Irinotecan per 4 days in C57BL/6. Fullerol or a vehicle was injected every 12h. On day 7, the intestines were removed to evaluate histological changes, leukocyte influx, and the production of cytokines and ROS. Irinotecan therapy resulted in weight loss, an increased clinical score and intestinal injury. Treatment with Fullerol attenuated weight loss, decreased clinical score and intestinal damage. Irinotecan also induced increased ROS production in enterocytes, oxidative stress, IL-1β production, neutrophil and eosinophil influx in the ileum. Fullerol treatment decreased production of ROS in the enterocytes, oxidative stress, IL-1β production, neutrophil and eosinophil influx in the ileum. Irinotecan therapy also induced leukopenia in an ROS-dependent manner because leukopenia reverted in WT mice treated with Fullerol or Apocynin or in Gp91phox(-/-) mice. Mice treated with Irinotecan presented less melanoma tumor growth compared to the control group. Fullerol does not interfere in the anti-tumor action of Irinotecan. Fullerol has a great pharmacology potential to decreases the severity of mucositis and of leukopenia during chemotherapy treatment.

Although used in medical applications for centuries, the development of nanotechnology has shed new light in the plethora of possible medical and biological applications using gold-based nanostructures. Gold nanostructures are stable and relatively inert in biological systems, leading to low reatogenicity, biocompatibility and general lack of toxicity. Allied to that, gold nanoparticles present optical and electronic properties that have been exploited in a range of biomedical applications. In this review we discuss biologically relevant properties of gold nanoparticles and how they are used in some biomedicine fields, especially those involving biosensing of biological analytes – including viruses and antibodies against them, cancer therapies, and antigen delivery, including viral antigens – as part of nonclassic vaccine strategies.

Osteoporosis is a degenerative disease associated with excessive bone resorption, a natural process performed by osteoclasts. In turn, osteoclast maturation is critically regulated by the receptor activator of nuclear factor kB ligand (RANKL), its signalling receptor (RANK), and its decoy receptor osteoprotegerin (OPG). The critical role of the protein triad, RANK–RANKL–OPG, in osteoclastogenesis has made their binding an important target for the rational development of drugs against osteoporosis. Based on this, we have performed a quantum biochemistry investigation of the binding between RANKL and its decoy receptor, OPG, in order to analyse the individual contributions of all amino acid residues involved in the complex formation, providing a deeper understanding of the inhibition process. The role of specific residues in the RANKL–OPG binding was evaluated through quantum biochemistry computations performed within the molecular fractionation with conjugate caps (MFCC) methodology, and inter-residue binding energies were calculated within the framework of density functional theory (DFT). Our simulations, considering water effects (implicit and explicit) and the role of the dielectric constant background, attested the major importance of site II, when compared to site I, over OPG binding and functionality, mainly through interactions performed by the tripeptide OPG core, I94–E95–F96. The obtained results also explain (i) the impact of a specific OPG mutation (F96L) on Paget's disease development; (ii) how some pioneers proposed that peptides efficiently inhibit the RANKL–OPG complex, acting as promising drugs for the treatment of osteoporosis. In conclusion, our quantum biochemistry approach provides a solid base that allows important insights into peptide and drug design for the treatment of osteoporosis based on RANKL–OPG binding inhibition.

Multiwalled carbon nanotubes (MWCNTs), nanographene oxide (NGO), and gold nanorods (NRs) can be functionalized and complexed to DNA to promote efficient gene delivery to Nile tilapia spermatogonial stem cells inducing less cell death than electroporation and the commercial reagents tested. Therefore, nanomaterials can contribute to achieve fish transgenesis.

The objectives of this study were to assess the effects of hyaluronic acid (HY), multi-walled carbon nanotubes (MWCNT), and MWCNT functionalized with HY (HY-MWCNT) on the resolution of neutrophilic inflammation in the pleural cavity of LPS-challenged mice and to assess the influence of these materials in the inflammatory process of bone repair of tooth sockets of rats. C57Bl/6 mice were intra-pleurally injected with HY, MWCNT, HY-MWCNT, phosphate-buffered saline (PBS), or LPS. The animals were euthanized after 8 and 24 h, and cells were harvested for total and differential cell counting. The tooth sockets of Wistar rats were filled with HY, MWCNT, HY-MWCNT, or blood clot (control). After 1, 3, and 7 days, histological and morphometric analyses evaluated the number of cell nuclei and blood vessels, and bone trabeculae formation in the sockets. Myeloperoxidase (MPO) activity quantified neutrophil accumulation in the sockets. HY, MWCNT, and HY-MWCNT increased neutrophilic recruitment at 8 h and reduced the inflammatory process at 24 h in the pleural cavity. Histological and morphometric analyses and MPO activity showed no significant differences in the recruitment of inflammatory cells in the tooth sockets. HY increased the number of blood vessels, and HY and HY-MWCNT increased bone trabeculae formation at 7 days of tooth extraction. HY, MWCNT, and HY-MWCNT resolved the neutrophilic inflammation in the pleural cavity of the mice. However, these materials did not modulate the inflammatory process in the early stages of bone repair of the tooth sockets, thereby excluding this action as a possible mechanism by which these biomaterials accelerate bone repair. HY-MWCNT is capable of accelerating bone repair/regeneration without affecting the inflammatory phase during the bone healing process.

Multi-walled carbon nanotubes (MWCNTs) have been incorporated in cementitious composites and important results in terms of rheological and mechanical performance have been obtained. Despite the current MWCNT dispersion procedures found in the literature, MWCNT synthesized directly on clinker is an alternative route to employ this nanomaterial in cementitious composites. It is also much more compatible with the procedures used by the construction industry. Based on this scenario, this study presents results in terms of rheological behavior, hydration process and mechanical strength of cement pastes (with a water/cement ratio of 0.4), produced with MWCNTs synthesized directly on clinker. The percentage of MWCNTs was equal to 0.15 and 0.30% with respect to cement content (bwoc). A reference paste without MWCNTs was also produced for comparison. In terms of the rheological behavior, the cement pastes with MWCNTs showed adequate performance for the application. It was also verified that MWCNTs promoted an increase in the cement hydration rate, reducing the initial setting time and changing the hydration period. This was most evident when the MWCNT rate was increased from 0.15 to 0.30% bwoc. With respect to compressive and tensile strength, the pastes with MWCNTs showed gains of 28% and 43% respectively at the age of 28 days for the 0.15% carbon nanotube content.

We perform ultrafast pump-probe spectroscopy of plasmonic structures beyond the perturbative excitation regime. As a prototypical system we choose gold nanorods dispersed in water, which display both longitudinal and transverse plasmon resonances. A broadband investigation reveals a complex scenario for the saturation of the transient optical response as a function of the pump fluence, with strong dependence on the probe wavelength. In particular, we observed stronger saturation effects for the high energy transverse plasmonic resonance as compared to the low energy longitudinal one. This behavior is well captured by a three-temperature model and is understood in terms of the nonlinearity of the Fermi-smearing mechanism, presiding over the optical nonlinearity of noble metal nanomaterials. Our results highlight a universal saturation dynamics in the transient optical response of plasmon-enhanced photonic structures excited by intense light beams, with potential impact on many applications, from the all-optical modulation of light to photovoltaics and photocatalysis.

Graphene and its derivatives, due to a wide range of unique properties that they possess, can be used as starting material for the synthesis of useful nanocomplexes for innovative therapeutic strategies and biodiagnostics. Here, we summarize the latest progress in graphene and its derivatives and their potential applications for drug delivery, gene delivery, biosensor and tissue engineering. A simple comparison with carbon nanotubes uses in biomedicine is also presented. We also discuss their in vitro and in vivo toxicity and biocompatibility in three different life kingdoms (bacterial, mammalian and plant cells). All aspects of how graphene is internalized after in vivo administration or in vitro cell exposure were brought about, and explain how blood–brain barrier can be overlapped by graphene nanomaterials.

Nanodiamonds (NDs), multiwalled carbon nanotubes (MWCNTs) and gold nanorods (NRs) can be functionalized to promote gene delivery to hard-to-transfect cells with higher transfection efficiency than cationic lipids, and inducing less cell death.

Nanoscale engineered plasmonic materials that can efficiently sustain surface enhanced Raman scattering (SERS) have been strongly pursued for high sensitivity molecular detection. In this work, we report the production of gold nanorod/graphene oxide (GNR/GO) nanocomposites by a simple, one-pot process whereby GNR are formed directly onto the GO flakes in solution by UV light irradiation. The proposed method is easily scalable and results in GNRs with low dispersion in size and aspect ratio of ∼3. The GNR/GO hybrids were deposited in glass by filtration yielding homogenous films that were systematically tested as SERS active substrates. Raman spectroscopy mapping revealed that the tested substrates present spatially homogenous and reproducible SERS responses. Analysis of Raman spectroscopy by using a model molecule (cresyl violet perchlorate) indicates that the produced substrates can provide very large SERS enhancement factors (∼106) and very low molecular detection limits (10−11 M).

Cement pastes and mortars were prepared incorporating carbon nanotubes (CNTs) and nanofibers (CNFs) synthesized directly on ground clinker and silica fume. Setting times of the cement paste...

A gold nanoparticles functionalization experiment was conducted in a biotechnology summer course at UFOP as a model for the introduction of the laboratory practice in nanotechnology for postgraduate courses in the areas of chemistry and biotechnology. The gold nanorods were synthesized by the seed method and then, functionalized with anti-IL-6 antibodies using the reagents EDAC/NHS and polyethyleneimine (PEI). This nanocompound was tested against the binding with the specific antigen (IL-6) and changes in the longitudinal plasmon absorption spectrum showed the coupling efficiency, which was also verified by the decrease in zeta potential. The experiment was satisfactory, with a positive feedback from participants, and could be implemented in nanotechnology practical classes from postgraduate courses, as a way for improve education in the emergent area of nanobiotechnology.

Multi-walled carbon nanotubes (MWCNTs) have potential applications in the industrial, agricultural, pharmaceutical, medical, and environmental remediation fields. However, many uncertainties exist regarding the environmental implications of engineered nanomaterials. This study examined the effect of the MWCNTs on metabolic status and morphology of filamentous green microalgae Klebsormidium flaccidum. Appropriate concentrations of MWCNT (1, 50, and 100 μg mL-1) were added to a microalgal culture in the exponential growth phase and incubated for 24, 48, 72, and 96 h. Exposure to MWCNT led to reductions in algal growth after 48 h and decreased on cell viability for all experimental endpoints except for 1 µg mL-1 at 24 h and 100 µg mL-1 after 72 h. At 100 µg mL-1, MWCNTs induced reactive oxygen species (ROS) production and had an effect on intracellular adenosine triphosphate (ATP) content depending on concentration and time. No photosynthetic activity variation was observed. Observations by scanning transmission electron microscopy showed cell damage. In conclusion, we have demonstrated that exposure to MWCNTs affects cell metabolism and microalgal cell morphology. To our best knowledge, this is the first case in which MWCNTs exhibit adverse effects on filamentous green microalgae K. flaccidum. These results contribute to elucidate the mechanism of MWCNT nanotoxicity in the bioindicator organism of terrestrial and freshwater habitats.

This paper analyzes the influence of carbon nanotubes (CNTs) on the rheological and mechanical properties of cement slurries used in oil wells. CNTs were grown directly onto the cement clinker by chemical vapor deposition. Cement pastes containing 0.1% and 0.3% of CNT bwoc were compared with CNT-free slurries. Lignosulfonate (0.2% bwoc) was used as dispersant in all cement slurries. Compressive and tensile strength were evaluated at the ages of 48 h and 7 days. The results show that the addition of CNTs does not alter the rheological behavior and stability of the cement slurries considering the dispersant and concentrations employed. On the other hand, the presence of CNTs in the cement slurries increases the tensile strength by approximately 15% at 48 h and 7 days of aging for 0.1% CNT bwoc.

The infrared (IR) and Raman spectra of the osteoporosis drug alendronate in the monosodium trihydrate alendronate crystal were measured. In order to interpret them, density functional theory (DFT) calculations for the solvated alendronate molecule were performed following the structural features revealed by X-ray data. A comparison between the DFT-calculated IR and Raman of the converged species and the measured spectra unveils relevant phosphate group signatures in the 400–1400 cm−1 wavenumber range, especially IR absorption bands at 1015, 1049, 1067, 1131, 1177, and 1235 cm−1, which were related to CP and OP bond length stretching, and Raman lines at 449, 661, and 969 cm−1, involving phosphate scissors and bond length vibrations. A comparison with experimental data of alendronate incorporated into hydroxyapatite (HAP) indicates that, for wavenumbers below 1500 cm−1, the interaction of alendronate with HAP does not affect significantly the alendronate vibrational spectra, while for the 1600–3000 cm−1 interval the interaction with HAP changes the normal mode wavenumbers by about −100 cm−1. Copyright © 2014 John Wiley & Sons, Ltd.

Biomaterial matrices are being developed that mimic the key characteristics of the extracellular matrix, including presenting adhesion sites and displaying growth factors in the context of a viscoelastic hydrogel. This review focuses on two classes of materials: those that are derived from naturally occurring molecules and those that recapitulate key motifs of biomolecules within biologically active synthetic materials. We also discussed some of the most significant biological features of the ECM, and several engineering methods currently being implemented to design and tune synthetic scaffolds to mimic these features. Understanding the cell-protein-material interaction is fundamental for developing more powerful tools in tissue engineering and regenerative medicine strategies. The design of model substrates including the presence of well-defined properties (chemistry, topography, stiffness) and even the gradient of these properties in three dimensional environments must lead in the near future to learn more about the specific roles of protein adsorption and the very dynamic process related to the cell fate of synthetic substrates: cell adhesion, matrix reorganisation, deposition and degradation at the cell-material interface. These materials will open new doors to biosurgical therapeutics in tissue engineering and regenerative medicine.

The transient optical response of gold nanorods is investigated beyond the perturbative regime. Ultrafast pump-probe spectroscopy and semiclassical modeling of hot electrons reveal a universal mechanism presiding over the saturation of nonlinear plasmonic effects.

In this letter, we study the electronic structure and optical properties of the active medicinal component γ -aminobutyric acid (GABA) and its cocrystals with oxalic (OXA) and benzoic (BZA) acid by means of the density functional theory formalism. It is shown that the cocrystallization strongly weakens the zwitterionic character of the GABA molecule leading to striking differences among the electronic band structures and optical absorption spectra of the GABA crystal and GABA:OXA, GABA:BZA cocrystals, originating from distinct sets of hydrogen bonds. Calculated band widths and Δ -sol band gap estimates indicate that both GABA and GABA:OXA, GABA:BZA cocrystals are indirect gap insulators.