Particle & Particle Systems Characterization, Feb 6, 2022
In this paper, a localized surface plasmon resonance (LSPR)‐based biosensor, computationally guid... more In this paper, a localized surface plasmon resonance (LSPR)‐based biosensor, computationally guided to detect selectively the four Dengue virus (DENVx) serotypes in seropositive patients, is presented. The behavior of gold nanoparticles in the shape of nanorods is theoretically and numerically studied as a function of induced structural variations, which are experimentally evidenced due to the bio‐interaction between the target analytes and its surface during the detection process. Additionally, with the implementation of the largest Lyapunov exponent, it is possible to calculate the notion of predictability for the experimental results, observing chaotic systems with a very low probability of repetition. Due to the above, when analyzing the recurrence map associated with the obtained resonance curve generated by the LSPR system, the genetic similarity of DENV3/DENV2 and DENV4/DENV1 is evidenced. Finally, the biosensors are validated by analyzing samples of seronegative patients for DENVx and seropositive ones for other Flaviviruses such as Zika virus, Yellow Fever virus, and Saint Louis Encephalitis virus.
Environmental Nanotechnology, Monitoring and Management, Dec 1, 2021
Abstract In recent years, studies using the green chemistry approach for the synthesis of metalli... more Abstract 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.
Particle & Particle Systems Characterization, Mar 1, 2022
In this paper, a localized surface plasmon resonance (LSPR)‐based biosensor, computationally guid... more In this paper, a localized surface plasmon resonance (LSPR)‐based biosensor, computationally guided to detect selectively the four Dengue virus (DENVx) serotypes in seropositive patients, is presented. The behavior of gold nanoparticles in the shape of nanorods is theoretically and numerically studied as a function of induced structural variations, which are experimentally evidenced due to the bio‐interaction between the target analytes and its surface during the detection process. Additionally, with the implementation of the largest Lyapunov exponent, it is possible to calculate the notion of predictability for the experimental results, observing chaotic systems with a very low probability of repetition. Due to the above, when analyzing the recurrence map associated with the obtained resonance curve generated by the LSPR system, the genetic similarity of DENV3/DENV2 and DENV4/DENV1 is evidenced. Finally, the biosensors are validated by analyzing samples of seronegative patients for DENVx and seropositive ones for other Flaviviruses such as Zika virus, Yellow Fever virus, and Saint Louis Encephalitis virus.
Gold nanoparticles enhance antibody-fluorescence detection by flow cytometry reducing the signal ... more Gold nanoparticles enhance antibody-fluorescence detection by flow cytometry reducing the signal to noise ratio and improving cell biology assessments.
Journal of controlled release : official journal of the Controlled Release Society, Jan 8, 2018
Schistosomiasis is an important parasitic disease affecting >207 million people in 76 countrie... more Schistosomiasis is an important parasitic disease affecting >207 million people in 76 countries around the world and causing approximately 250,000 deaths per year. At present, the main strategy adopted for the control of schistosomiasis is the use of safe chemotherapy, such as praziquantel. However, the high rates of reinfection after treatment restrict the use of this treatment approach and assume the need for other forms of control such as vaccination. Sm29 is a protein that is localized in the Schistosoma mansoni tegument of adult worms and schistosomula and is considered a powerful vaccine candidate. Because of the chemical, physical and immunological characteristics of nanoparticles, nanocarriers have received increasing attention. In the field of nanotechnology, gold nanorods are considered potential vaccine carriers. In this study, we bound S. mansoni rSm29 protein to gold nanorods either directly or by cysteamine functionalization. When the worm burden was evaluated, the ...
Irradiation of tumor cell lines is a useful way to investigate the effects of ionizing radiation ... more Irradiation of tumor cell lines is a useful way to investigate the effects of ionizing radiation on biological molecules. We designed an easy and reproducible approach for in vitro experimental high dose rate brachytherapy, which was simulated by a Monte Carlo code and dosimetrically characterized by experimental methods to evaluate the correspondence between planned doses and doses absorbed by the cells. This approach is an acrylic platform containing T25 tissue culture flasks and multiwell tissue culture plates. It allows nine parallel needles carrying an 192Ir source to irradiate the adherent cells. The whole system composed of the acrylic platform, tissue culture flasks and 192Ir source tracking was simulated by the Monte Carlo N-Particle transport code (MCNPX). Dosimetric measurements were taken by well ionization chamber and radiochromic films. There was a slight difference, averaging from 2% to 7%, between the MCNPX results and film dosimetry results regarding uniform radiation created by the source arrangement. The results showed different values for planned and measured doses in each cell culture plate, which was attributed to the non-equivalent water material used and to the lack of full scattering coming from the top of the platform. This last contribution was different for each tissue culture plate and an individual dose correction factor was calculated. The dose correction factor must be applied to match the planned dose and the actual doses absorbed by the cells. The designed approach is an efficient tool for in vitro brachytherapy experiments for most commercial cell culture plates.
The zona pellucida (ZP) is a protective barrier of embryonic cells against chemical, physical and... more The zona pellucida (ZP) is a protective barrier of embryonic cells against chemical, physical and biological substances. For this reason, usual transfection methods are not as efficient for mammalian oocytes and embryos as they are for somatic cells. Carbon nanotubes (CNTs) have emerged as a new method for gene delivery and they can be an alternatively used for embryos transfection, but its ability to cross the PZ and mediated gene transfer is still unknown. The aim of the present study was to determine whether multiwall carbon nanotubes (MWNTs) could pass through the PZ and delivery pDNA for in vitro-produced bovine embryos and their effects on apoptosis in bovine blastocysts. Oocytes obtained from ovaries collected at a local slaughterhouse were in vitro matured with TCM 199 (Invitrogen, California, USA) supplemented with 20 μg ml-1 FSH (Sigma, St. Louis, USA) and 10% fetal calf serum (FCS; Invitrogen) in high humidity, under 5% CO2 in air at 38.5°C for 24h. Maturated oocytes were...
Intestinal ischemia is a vascular emergency that arises when blood flow to the intestine is compr... more 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.
AIMS Although excessive fat and caffeine intake are independent risk factors for bone microstruct... more AIMS Although excessive fat and caffeine intake are independent risk factors for bone microstructural and functional disturbances, their association remains overlooked. Thus, we investigated the impact of high-fat diet (HFD) and caffeine alone and combined on serum lipid profile, bone microstructure, micromineral distribution and biomechanical properties. METHODS Forty female C57BL/6 mice were randomized into 4 groups daily treated for seventeen weeks with standard diet (SD) or HFD (cafeteria diet) alone or combined with 50 mg/kg caffeine. KEY FINDINGS The association between HFD and caffeine reduced the weight gain compared to animals receiving HFD alone. Caffeine alone or combined with HFD increases total and HDL cholesterol circulating levels. HFD also reduced calcium, phosphorus and magnesium bone levels compared to the groups receiving SD, and this reduction was aggravated by caffeine coadministration. From biomechanical assays, HFD combined with caffeine increased bending strength and stiffness of tibia, a finding aligned with the marked microstructural remodeling of the cortical and cancellous bone in animals receiving this combination. SIGNIFICANCE Our findings indicated that HFD and caffeine interact to induce metabolic changes and bone microstructural remodeling, which are potentially related to bone biomechanical adaptations in response to HFD and caffeine coadministration.
Nanotechnology is one of the most promising tools for future diagnosis and therapy. Thus, we have... more Nanotechnology is one of the most promising tools for future diagnosis and therapy. Thus, we have produced gold nanoparticles coated with cetuximab at a dose-range from 5 μg up to 200 μg, and prolonged stable nanocomplexes were obtained. The nanocomplexes were characterized by UV-Vis, zeta potential, TEM, fluorometry, infrared regions, XPS and atomic absorption spectrometry. For biological characterization the A431 cell line was used. Cellular uptake, target affinity and cell death were assessed using ICP-OES, immunocytochemistry and flow cytometry, respectively. The immobilization of cetuximab on the AuNPs surfaces was confirmed. The nanocomplex with 24 months of manufacturing promoted efficient EGFR binding and induced tumour cell death due to apoptosis. Significant (p < 0.05) cell death was achieved using relatively low cetuximab concentration for AuNPs coating compared to the antibody alone. Therefore, our results provided robust physicochemical and biological characterization data corroborating the cetuximab-bioconjugate AuNPs as a feasible nanocomplex for biomedical applications.
Particle & Particle Systems Characterization, Feb 6, 2022
In this paper, a localized surface plasmon resonance (LSPR)‐based biosensor, computationally guid... more In this paper, a localized surface plasmon resonance (LSPR)‐based biosensor, computationally guided to detect selectively the four Dengue virus (DENVx) serotypes in seropositive patients, is presented. The behavior of gold nanoparticles in the shape of nanorods is theoretically and numerically studied as a function of induced structural variations, which are experimentally evidenced due to the bio‐interaction between the target analytes and its surface during the detection process. Additionally, with the implementation of the largest Lyapunov exponent, it is possible to calculate the notion of predictability for the experimental results, observing chaotic systems with a very low probability of repetition. Due to the above, when analyzing the recurrence map associated with the obtained resonance curve generated by the LSPR system, the genetic similarity of DENV3/DENV2 and DENV4/DENV1 is evidenced. Finally, the biosensors are validated by analyzing samples of seronegative patients for DENVx and seropositive ones for other Flaviviruses such as Zika virus, Yellow Fever virus, and Saint Louis Encephalitis virus.
Environmental Nanotechnology, Monitoring and Management, Dec 1, 2021
Abstract In recent years, studies using the green chemistry approach for the synthesis of metalli... more Abstract 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.
Particle & Particle Systems Characterization, Mar 1, 2022
In this paper, a localized surface plasmon resonance (LSPR)‐based biosensor, computationally guid... more In this paper, a localized surface plasmon resonance (LSPR)‐based biosensor, computationally guided to detect selectively the four Dengue virus (DENVx) serotypes in seropositive patients, is presented. The behavior of gold nanoparticles in the shape of nanorods is theoretically and numerically studied as a function of induced structural variations, which are experimentally evidenced due to the bio‐interaction between the target analytes and its surface during the detection process. Additionally, with the implementation of the largest Lyapunov exponent, it is possible to calculate the notion of predictability for the experimental results, observing chaotic systems with a very low probability of repetition. Due to the above, when analyzing the recurrence map associated with the obtained resonance curve generated by the LSPR system, the genetic similarity of DENV3/DENV2 and DENV4/DENV1 is evidenced. Finally, the biosensors are validated by analyzing samples of seronegative patients for DENVx and seropositive ones for other Flaviviruses such as Zika virus, Yellow Fever virus, and Saint Louis Encephalitis virus.
Gold nanoparticles enhance antibody-fluorescence detection by flow cytometry reducing the signal ... more Gold nanoparticles enhance antibody-fluorescence detection by flow cytometry reducing the signal to noise ratio and improving cell biology assessments.
Journal of controlled release : official journal of the Controlled Release Society, Jan 8, 2018
Schistosomiasis is an important parasitic disease affecting >207 million people in 76 countrie... more Schistosomiasis is an important parasitic disease affecting >207 million people in 76 countries around the world and causing approximately 250,000 deaths per year. At present, the main strategy adopted for the control of schistosomiasis is the use of safe chemotherapy, such as praziquantel. However, the high rates of reinfection after treatment restrict the use of this treatment approach and assume the need for other forms of control such as vaccination. Sm29 is a protein that is localized in the Schistosoma mansoni tegument of adult worms and schistosomula and is considered a powerful vaccine candidate. Because of the chemical, physical and immunological characteristics of nanoparticles, nanocarriers have received increasing attention. In the field of nanotechnology, gold nanorods are considered potential vaccine carriers. In this study, we bound S. mansoni rSm29 protein to gold nanorods either directly or by cysteamine functionalization. When the worm burden was evaluated, the ...
Irradiation of tumor cell lines is a useful way to investigate the effects of ionizing radiation ... more Irradiation of tumor cell lines is a useful way to investigate the effects of ionizing radiation on biological molecules. We designed an easy and reproducible approach for in vitro experimental high dose rate brachytherapy, which was simulated by a Monte Carlo code and dosimetrically characterized by experimental methods to evaluate the correspondence between planned doses and doses absorbed by the cells. This approach is an acrylic platform containing T25 tissue culture flasks and multiwell tissue culture plates. It allows nine parallel needles carrying an 192Ir source to irradiate the adherent cells. The whole system composed of the acrylic platform, tissue culture flasks and 192Ir source tracking was simulated by the Monte Carlo N-Particle transport code (MCNPX). Dosimetric measurements were taken by well ionization chamber and radiochromic films. There was a slight difference, averaging from 2% to 7%, between the MCNPX results and film dosimetry results regarding uniform radiation created by the source arrangement. The results showed different values for planned and measured doses in each cell culture plate, which was attributed to the non-equivalent water material used and to the lack of full scattering coming from the top of the platform. This last contribution was different for each tissue culture plate and an individual dose correction factor was calculated. The dose correction factor must be applied to match the planned dose and the actual doses absorbed by the cells. The designed approach is an efficient tool for in vitro brachytherapy experiments for most commercial cell culture plates.
The zona pellucida (ZP) is a protective barrier of embryonic cells against chemical, physical and... more The zona pellucida (ZP) is a protective barrier of embryonic cells against chemical, physical and biological substances. For this reason, usual transfection methods are not as efficient for mammalian oocytes and embryos as they are for somatic cells. Carbon nanotubes (CNTs) have emerged as a new method for gene delivery and they can be an alternatively used for embryos transfection, but its ability to cross the PZ and mediated gene transfer is still unknown. The aim of the present study was to determine whether multiwall carbon nanotubes (MWNTs) could pass through the PZ and delivery pDNA for in vitro-produced bovine embryos and their effects on apoptosis in bovine blastocysts. Oocytes obtained from ovaries collected at a local slaughterhouse were in vitro matured with TCM 199 (Invitrogen, California, USA) supplemented with 20 μg ml-1 FSH (Sigma, St. Louis, USA) and 10% fetal calf serum (FCS; Invitrogen) in high humidity, under 5% CO2 in air at 38.5°C for 24h. Maturated oocytes were...
Intestinal ischemia is a vascular emergency that arises when blood flow to the intestine is compr... more 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.
AIMS Although excessive fat and caffeine intake are independent risk factors for bone microstruct... more AIMS Although excessive fat and caffeine intake are independent risk factors for bone microstructural and functional disturbances, their association remains overlooked. Thus, we investigated the impact of high-fat diet (HFD) and caffeine alone and combined on serum lipid profile, bone microstructure, micromineral distribution and biomechanical properties. METHODS Forty female C57BL/6 mice were randomized into 4 groups daily treated for seventeen weeks with standard diet (SD) or HFD (cafeteria diet) alone or combined with 50 mg/kg caffeine. KEY FINDINGS The association between HFD and caffeine reduced the weight gain compared to animals receiving HFD alone. Caffeine alone or combined with HFD increases total and HDL cholesterol circulating levels. HFD also reduced calcium, phosphorus and magnesium bone levels compared to the groups receiving SD, and this reduction was aggravated by caffeine coadministration. From biomechanical assays, HFD combined with caffeine increased bending strength and stiffness of tibia, a finding aligned with the marked microstructural remodeling of the cortical and cancellous bone in animals receiving this combination. SIGNIFICANCE Our findings indicated that HFD and caffeine interact to induce metabolic changes and bone microstructural remodeling, which are potentially related to bone biomechanical adaptations in response to HFD and caffeine coadministration.
Nanotechnology is one of the most promising tools for future diagnosis and therapy. Thus, we have... more Nanotechnology is one of the most promising tools for future diagnosis and therapy. Thus, we have produced gold nanoparticles coated with cetuximab at a dose-range from 5 μg up to 200 μg, and prolonged stable nanocomplexes were obtained. The nanocomplexes were characterized by UV-Vis, zeta potential, TEM, fluorometry, infrared regions, XPS and atomic absorption spectrometry. For biological characterization the A431 cell line was used. Cellular uptake, target affinity and cell death were assessed using ICP-OES, immunocytochemistry and flow cytometry, respectively. The immobilization of cetuximab on the AuNPs surfaces was confirmed. The nanocomplex with 24 months of manufacturing promoted efficient EGFR binding and induced tumour cell death due to apoptosis. Significant (p < 0.05) cell death was achieved using relatively low cetuximab concentration for AuNPs coating compared to the antibody alone. Therefore, our results provided robust physicochemical and biological characterization data corroborating the cetuximab-bioconjugate AuNPs as a feasible nanocomplex for biomedical applications.
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Papers by Luiz Orlando Ladeira