RESUMO
Breast cancer is the most commonly diagnosed type of cancer among the female population worldwide. It is a disease with a high incidence and geographic distribution that negatively impacts global public health and deleteriously affect the quality of life of cancer patients. Among the new approaches, cancer immunotherapy is the most promising trend in oncology by stimulating the host's own immune system to efficiently destroy cancer cells. Recent evidence has indicated that iron oxide nanoparticles can promote the reprograming of M2 into M1 macrophages with anti-tumor effects in the tumor microenvironment. Thus, the aim of the present work was to evaluate the ability of polyaniline-coated maghemite (Pani/γ-Fe2O3) nanoparticles to modulate human macrophages in 2D monolayers and 3D multicellular breast cancer models. It was observed that Pani/γ-Fe2O3 NPs re-educated IL-10-stimulated macrophages towards a pro-inflammatory profile, decreasing the proportion of CD163+ and increasing the CD86+ proportion in 2D models. NPs were successfully taken-up by macrophages presented in the 3D model and were also able to induce an increasing in their CD86+ proportion in triple MCTs model. Overall, our findings open new perspectives on the use of Pani/γ-Fe2O3 NPs as an immunomodulatory therapy for macrophage reprogramming towards an anti-tumor M1 phenotype, providing a new tool for breast cancer immunotherapies.
Assuntos
Neoplasias da Mama , Nanopartículas , Humanos , Feminino , Neoplasias da Mama/terapia , Neoplasias da Mama/patologia , Macrófagos Associados a Tumor/patologia , Qualidade de Vida , Nanopartículas Magnéticas de Óxido de Ferro , Microambiente TumoralRESUMO
We describe the preparation of a membrane composed of polypyrrole-polystyrene (PPy-PS) and its application in DNA extraction. We adopted the electrospinning technique to prepare polystyrene (PS) membranes, which we used as substrates for incorporating polypyrrole chains through an in situ chemical procedure. As a model system, we initially investigated the use of PPy-PS membranes for the extraction of salmon sperm DNA from aqueous solutions. These studies have shown that the PPy-PS membrane has a maximum adsorption capacity of 236.0 mg of DNA per gram of PPy after 30 min of exposure to a DNA solution (100 mg/L). We incorporated the PPy-PS membranes into centrifugation columns, which we used to carry out experiments for extracting and purification of DNA from curly lettuce leaves. The protocol was initially optimized by first examining the most appropriate concentration of the three components of the lysis buffer (Tris/HCl, NaCl, and EDTA-Na). We then investigated the most adequate volumes of the concentrated surfactant solution (SDS 20%) and that used in the protein and polysaccharide precipitation step (5 M potassium acetate, pH 6.3), factors that directly influence the quality and quantity of the fraction of DNA obtained. For curly lettuce leaves, both in their mature and young stages, the yield and purity of the DNA purified using the PPy-PS membrane were comparable to those obtained using a commercial kit. In both cases, the collected DNA samples presented excellent integrity and quality. These results are suggestive that these composite membranes are competitive with the commercial kits available for the extraction and purification of DNA from plants.
RESUMO
Cancer immunotherapy is the most promising trend in oncology, focusing on helping or activating the patient's immune system to identify and fight against cancer. In the last decade, interest in metabolic reprogramming of tumor-associated macrophages from M2-like phenotype (promoting tumor progression) to M1-like phenotypes (suppressing tumor growth) as a therapeutic strategy against cancer has increased considerably. Iron metabolism has been standing out as a target for the reprogramming of tumor-associated macrophages to M1-like phenotype with therapeutic purposes against cancer. Due to the importance of the iron levels in macrophage polarization states, iron oxide nanoparticles can be used to change the activation state of tumor-associated macrophages for a tumor suppressor phenotype and as an anti-tumor strategy.
Assuntos
Nanopartículas , Neoplasias , Humanos , Imunoterapia , Macrófagos , Nanopartículas Magnéticas de Óxido de Ferro , Neoplasias/tratamento farmacológico , Macrófagos Associados a TumorRESUMO
In 2016, the Zika virus (ZIKV) infection became a major public health problem, after the discovery that an alarming increase in the number of Brazilian newborns with microcephaly could be associated with the occurrence of this viral disease during the pregnancy of their mothers. The urgent need for simple diagnostic methods that allow rapid screening of suspected cases has stimulated the search for low-cost devices capable of detecting specific sequences of nucleic acids. The present work describes the development of nanostructured films formed by bilayers of conjugated polymers for rapid detection of the presence of Zika virus DNA, via fluorescence methods. For this, we initially deposited alternating layers of polyaniline (PANI) and polypyrrole (PPY) on the surface of polyethylene terephthalate (PET) sheets. The films obtained were then characterized by SEM, UV-Vis, ATR-FTIR, and contact angle measurements. For their use as quenchers for the diagnosis of Zika, a single DNA strand-specific for ZIKV was labeled with a fluorophore (FAM-ssDNA). We determined the time required for the saturation of the interaction between probe FAM-ssDNA and the film (180 min) and the time for the maximal hybridization between FAM-ssDNA and target DNA to occur (60 min). The detection limits were estimated as 345 pM and 278 pM for the PET/PPY-PANI and PET/PANI-PPY hybrid films, respectively. The simplicity of the procedure, coupled with the fact that a positive/negative response can be obtained in less than 60 min, suggests that the proposal of using these polymeric bilayer films is a promising methodology for the development of rapid molecular diagnostic tests.
Assuntos
Complicações Infecciosas na Gravidez , Infecção por Zika virus , Zika virus , Condutividade Elétrica , Feminino , Humanos , Recém-Nascido , Polímeros , Gravidez , Complicações Infecciosas na Gravidez/virologia , Pirróis , Zika virus/genética , Infecção por Zika virus/diagnósticoRESUMO
We report the synthesis and characterization of a new hybrid magnetic composite formed by the enveloping of magnetic iron oxide nanoparticles (γ-NP) with chains of the conductive polymer PEDOT, and its use for the efficient separation of DNA molecules from complex biological samples, allowing the high yield separation of a pure and high-quality DNA fraction. The successful formation of the γ-NP/PEDOT composite was confirmed by Fourier transform infrared spectroscopy, scanning electron microscopy, UV visible spectroscopy (UV-Vis), and magnetic hysteresis loop measurements. The nanocomposites showed an excellent capacity of DNA adsorption (Qe â¼ 248 mg/g) in a model system consisting of salmon sperm DNA. When the γ-NP/PEDOT was used in protocols to extract the DNA from complex samples, the corresponding yield was in the range of 6.4 µg (blood) and 7.3 µg (bacteria), as evaluated quality by UV-Vis, PCR analysis, and electrophoresis assays. We also established that the captured DNA does not need to be detached from the nanocomposite for use as seeding material in PCR amplification experiments. These results and the simplicity of the protocols indicate that the γ-NP/PEDOT composite is a promising DNA absorbent, being competitive with the commercially available magnetic purification kits.
Assuntos
Nanocompostos , Compostos Bicíclicos Heterocíclicos com Pontes , DNA/genética , Polímeros , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
We report the preparation of flexible polystyrene/polypyrrole (PS/PPy) mats and their successful use as a resistive humidity sensor. These composite membranes were prepared by first obtaining PS films through the electrospinning technique, and then incorporating PPy chains by an in situ chemical polymerization of the pyrrole monomer. The PS fibers were homogeneously distributed, with diameters that obeyed a normal distribution with an average value of (1.04 ± 0.12) µm. The deposition of conducting PPy chains on the surface of the PS fibers was confirmed after characterizing the PS/PPy mats by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), contact angle measurements, and electrochemical impedance spectroscopy (EIS). When used as humidity sensors, the PS/PPy mats exhibited a sensor response of 128.6%, with fast response ((54.9 ± 3.5)s) and recovery times ((76.8 ± 11.1)s), and stable response under different humidity conditions over several days. These performance characteristics compare favorably to those of previous resistive humidity sensors discussed in the literature.
Assuntos
Polímeros , Pirróis , Umidade , PoliestirenosRESUMO
We report the preparation of poly(3,4-ethylene dioxythiophene) (PEDOT)-modified polyvinylidene fluoride electrospun fibers and their use as a novel adsorbent material for the removal of the anionic dye Methyl Orange (MO) from aqueous media. This novel adsorbent material can be used to selectively remove MO on a wide pH range (3.0-10.0), with a maximum capacity of 143.8 mg/g at pH 3.0. When used in a recirculating filtration system, the maximum absorption capacity was reached in a shorter time (20 min) than that observed for batch mode experiments (360 min). Based on the analyses of the kinetics and adsorption isotherm data, one can conclude that the predominant mechanism of interaction between the membrane and the dissolved dye molecules is electrostatic. Besides, considering the estimated values for the Gibbs energy, and entropy and enthalpy changes, it was established that the adsorption process is spontaneous and occurs in an endothermic manner. The good mechanical and environmental stability of these membranes allowed their use in at least 20 consecutive adsorption/desorption cycles, without significant loss of their characteristics. We suggest that the physical-chemical characteristics of PEDOT make these hybrid mats a promising adsorbent material for use in water remediation protocols and effluent treatment systems.
Assuntos
Poluentes Químicos da Água , Adsorção , Compostos Azo , Compostos Bicíclicos Heterocíclicos com Pontes , Concentração de Íons de Hidrogênio , Cinética , Polímeros , Polivinil , TermodinâmicaRESUMO
Phosphate ions perform a variety of functions in metabolic processes and are essential for all living organisms. The determination of the concentration of phosphate ions is useful in clinical diagnosis of various diseases as an inadequate phosphate level could lead to many health problems. In the search for a cost-effective method of fast monitoring, we investigated the use of cobalt ferrite nanoparticles (CoFeNPs) in the selective recognition of phosphate ions dissolved in aqueous media and more complex samples, such as human blood serum. We prepared these NPs by a chemical coprecipitation route and subjected them to annealing at 600 °C for 1 h. The successful formation of the NPs was confirmed by Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, and hysteresis loop measurements. The NPs exhibited a ferrimagnetic behavior, a spinel-type crystalline structure, and hexagonal shape in the nanoscale range. We demonstrated that CoFeNPs containing immobilized fluorescent-labeled single-chain DNA (ssDNA*) probes can be applied for the fast selective detection of phosphate ions dissolved in a liquid medium. We have explored the fact that phosphate groups can displace ssDNA* probes attached to the nanoparticles, therefore causing a perceptible change in the fluorescence signal of the supernatant liquid. This detection method has been tested for the sensing of phosphate ions present both in aqueous solutions and in biological samples, with excellent selectivity and a low limit of detection (â¼1.75 nM).
RESUMO
The human papillomavirus (HPV) is one of the main sexually transmitted pathogens that infect the anogenital epithelium and mucous membranes. HPV genotypes can be classified as high and low oncogenic risk, with infection by the former resulting in cervical cancer in approximately 100 % of the cases. In this work, we developed an ultrasensitive electrochemical biosensor for the detection and identification of different HPV genotypes. A nanostructured platform based on a matrix of polyaniline (PANI) containing gold nanoparticles (AuNps) was designed for the chemical immobilization of a DNA probe capable of recognizing different HPV types. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and atomic force microscopy (AFM) were used to characterize the genosensor. The impedimetric responses indicate that the proposed sensor was able to detect HPV (types 6, 11, 16, 31, 33, 45, and 58) in cervical specimens (cDNA samples). We obtained different profiles of electrochemical responses for the high and low-risk HPV genotypes. By adopting a three-dimensional quantitative analysis of impedance response variables, it was possible to identify the existence of a pattern of association for samples of high oncogenic risk, which may lead to the differential diagnosis of HPV. The biosensor demonstrated an excellent analytical performance for the detection of HPV genotypes with high sensibility and selectivity. The genosensor exhibited a linear range of response in the 1 pg µL-1 to 100 pg µL-1 range. Besides, a limit of detection (LOD) of 2.74 pg µL-1 and 7.43 pg µL-1 was obtained for HPV11 and HPV16, respectively, with regression coefficients of 99.88 % and 99.47 %. Thus, the proposed sensor may serve as a good prognostic indicator for patients infected with papillomavirus.
Assuntos
Alphapapillomavirus/isolamento & purificação , Técnicas Biossensoriais/métodos , Colo do Útero/virologia , Nanopartículas Metálicas/química , Infecções por Papillomavirus/diagnóstico , Alphapapillomavirus/genética , Colo do Útero/patologia , DNA Viral/isolamento & purificação , Diagnóstico Diferencial , Estudos de Viabilidade , Feminino , Técnicas de Genotipagem/métodos , Ouro/química , Humanos , Limite de Detecção , Nanopartículas Metálicas/ultraestrutura , Microeletrodos , Microscopia de Força Atômica , Sondas Moleculares/química , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/virologia , Prognóstico , Neoplasias do Colo do Útero/prevenção & controle , Neoplasias do Colo do Útero/virologiaRESUMO
We describe the use of a hybrid magnetic nanocomposite (HMNC) for the extraction and purification of plasmid DNA (pDNA) from Escherichia coli aqueous solutions. The HMNC, which was synthesized via emulsion polymerization, was characterized by transmission electron microscopy, scanning electron microscopy, UV-Vis spectroscopy, Fourier transform infrared spectroscopy, dynamic light scattering and magnetic measurements. The results confirmed the incorporation of polyaniline (Pani) in its conducting form onto a core formed by the magnetic iron oxide, with the hybrid particles presenting an average size of (95⯱â¯30) nm and a saturation magnetization of 30 emu/g. The yield, purity and quality of the pDNA purified by using the Pani HMNC were evaluated by UV-Vis spectroscopy, agarose gel electrophoresis, and Polymerase Chain Reaction (PCR), respectively. An average yield of ~6.9⯵g was obtained in the DNA extraction process, with the collected material presenting a good purity (a â³260/280 ratio in the 1.68-1.82 range) and an excellent quality, as confirmed by subsequent PCR assays. Hence, this HMNC appears as a promising material for use in pDNA purification protocols, and we suggest that this novel HMNC-based methodology can be of general interest and find widespread application in different biomedical procedures.