JONNATAN JULIVAL DOS SANTOS

JONNATAN JULIVAL DOS SANTOS

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Adsorption of bisphenol-A in aqueous solution using silica nanoparticles obtained from sugarcane ash
2018 - ROVANI, SUZIMARA; SANTOS, JONNATAN J.; CORIO, PAOLA; FUNGARO, DENISE A.
Scientists around the world have searched minimize problems related to the incorrect disposal of solid wastes and water contamination. Brazil, for example, is the largest producer of sugarcane in the world, generates around 3-12 million of tons ash/year or more, and this waste can be transformed into valueadded material. In this study, we tried to solve two problems at the same time, manufacturing an adsorbent material and applies it in the remediation of contaminated water with bisphenol-A (BPA), an endocrine disrupting compounds, which alters plasma sex hormone levels in fishes [1]. The silica nanoparticles were synthetized through the addition of silicate obtained from sugarcane ash in the solution of water/butyl alcohol (1:1) with 2.5% wt. of hexadecyltrimethylammonium bromide under constant stirring. Then, 0.5 mol L-1 H2SO4 solution was added to suspension until pH 4. The nanosilica formed was washed with distilled water, filtered and dried. The silica nanoparticles and BPA adsorbed on silica were characterized by different techniques. The maximum BPA adsorption capacity obtained was 80 mg g-1. From TEM images (Fig. 1A-B) of the silica nanoparticles it is seen that all particles has less than 20 nm. Fig. 1C shows the infrared spectra of samples. The band at 1058 cm-1 is due to the Si–O–Si asymmetric stretching, the band at 965 cm-1 is due to Si-OH bending vibrational absorption, the bands at 799 and 446 cm-1 are due to the Si–O–Si symmetric stretching. The presence of other bands in the blue spectra are attributed of BPA adsorbed on silica nanoparticles, at 554 cm-1 is due to aromatic ring deformation vibration of di-substituted benzenes, at 834 cm-1 is assigned to C-H vibrations out of the plane and at 1512 cm-1 is due to aromatic C=C stretching vibration [2]. The results of characterization of the silica nanoparticles manufactured showed that the material presents potential to be employed as adsorbent for remediation of water contaminated with endocrine disrupting compounds.
Adsorption study of acid orange 8 dye using silica nanoparticles obtained from sugarcane ash
2017 - ROVANI, SUZIMARA; SANTOS, JONNATAN J.; CORIO, PAOLA; FUNGARO, DENISE A.
Developing of new adsorbents becomes a very important need, especially because of the increase of contaminants present in rivers, oceans and any other water body capable of became potable. Biosorbents has a special feature, because they can solve two problems at the same time, once they are prepared from a natural source, giving a utility for wasted materials, and bioremediate a water body, adsorbing contaminants on their surface. In this context, the properties of a biosorbent prepared from sugarcane ash by surfactant mediated synthesis has been studied to the adsorption of acid orange 8 dye, a model molecule, aiming future applications for removal of emerging contaminants of water. According to the results of adsorption kinetic (Fig. 1A), the acid orange 8 dye removal was higher than 89% and 95% in 4 h of contact time for an initial concentration of 200 and 150 mg L-1, respectively. FTIR-ATR analyses (Fig. 1B) indicated the presence of bands: at 799 and 446 cm-1 are due to symmetric stretching of siloxane groups, at 1058 cm-1 is due the Si–O–Si asymmetric stretching, at 2925 cm-1 and 2850 cm-1 are due to the bending of –CH3 and –CH2, respectively, for silica-CTAB sample and additionally, at 1031, 689 and 641 cm-1 are due sulfur groups (S=O), out-of-plane deformation of ring and aromatics groups, respectively, of acid orange 8 dye. In TGA analysis (Fig. 1C), the peak between 150 to 235 °C for silica-CTAB sample has been attributed to the unbound CTAB less stabilized bonding sites on the silica surface due to hydrophobic– hydrophobic interactions of interdigitated CTAB and the peak around 256 °C indicates a stronger bonding of the surfactant to the silica surface due to the electrostatic binding of the ammonium cation head group to the electronegative silica surface [1]. For the silica-CTAB + dye sample, the substitution of the interdigitated CTAB of a second layer by dye was observed by the disappearance of the DTG peak between 150 to 235 °C. The displacement the DTG peak of 256 for 300 °C and appearance of the DTG peak around 435 °C are related to the dye adsorption. These aspects demonstrate the potential of silica nanoparticles obtained from sugarcane ash as new biosorbent for removal of organic compounds, such as, dye from aqueous solution and can be used to alleviate environmental problems.
Surfactant mediated synthesis of silica nanoparticles using sugarcane ash waste as renewable source
2017 - ROVANI, SUZIMARA; SANTOS, JONNATAN J.; CORIO, PAOLA; FUNGARO, DENISE A.
Green silica from renewable source can be used in very different materials, since addictive for construction materials or polymers to traditional products as glass, silicone rubber as well as source for silicon. Brazil is the world’s largest producer of sugarcane and generates huge amounts of sugarcane ash waste (SAW) which is a rich source of silica. This work investigates a method to produce pure silica nanoparticles from SAW. Initially, sodium silicate was obtained from sugarcane ash waste adapting the methodology published by Alves, et al., 2017. Subsequently, sodium silicate was added to a mixture of water/butyl alcohol (1:1) with 2.5% wt. of hexadecyltrimethylammonium bromide under constant stirring at 60 °C. Then, 0.5 mol L-1 sulfuric acid solution was added slowly to suspension until pH 4 and the resulting gel was aged at 60 °C for 8 h. The aged nanosilica gel was washed with distilled water, filtered and oven dried at 120 °C. The silica nanoparticles were characterized by different techniques. In the Figure 1 can be observed energy dispersive spectra (EDS) and transmission electron microscopy (TEM) images of sugarcane ash waste (A and B) and of silica nanoparticles (C and D). EDS of SAW shows the presence of several different elements (being Si, Fe, Al, P, Cl and S more abundant) and only Si and O were observed after synthesis procedure (Cu signal comes from TEM grid). Transmission electron microscopy image of samples exhibit a drastic alterations of the material size ranging from several micrometers (Fig. 1C) to less than 20 nm (Fig. 1D). The results indicate that was possible to obtain pure silica in a nano- size from waste material to reduce disposal and pollution problems.
Bovine serum albumin conjugated gold-198 nanoparticles as model to evaluate the damage caused by ionizing radiation to biomolecules
2018 - SANTOS, JONNATAN J.; LEAL, JESSICA; DIAS, LUIS A.P.; TOMA, SERGIO H.; CORIO, PAOLA; GENEZINI, FREDERICO A.; KATTI, KATTESH V.; ARAKI, KOITI; LUGAO, ADEMAR B.
Gold nanoparticles (AuNPs) have several applications including in medicine. Considering cancer as one of the most common diseases for men and women, new treatments and more specific and effective drugs, which cause less side effects, have been actively pursued. Among them, gold-198 can be engineered as theranostic agents, working as contrast (exploiting gamma emission) and treatment agents (beta emission). Accordingly, a new procedure for the production of 14 nm diameter radioactive citrate protected gold-198 nanoparticles, that were then conjugated with bovine serum albumin utilizing 3-mercaptopropionic acid directly bound to AuNPs surface as anchoring groups, generating fully dispersible nanoparticles in aqueous media, are described. The effect of gamma and beta radiation on grafted BSA was evaluated by direct irradiation of the corresponding cold material and comparing with the damage caused on BSA grafted gold-198 nanoparticles prepared from a neutron activated gold foil. The investigation by fluorescence and Raman spectroscopy indicated that the damage to BSA chromophore groups is proportional to the dose (from 0.1 to 1 kGy) and that chromophores groups close to the particle surface are more prone to damage. Gold-198 nanoparticles conjugated with bovine serum albumin showed that process is much more localized next to nanoparticles surface since each gold core acts as a punctual radiation source. In short, AuNPs can enhance the damage caused by irradiation of cold nanoparticles and AuNPs@MPA-BSA is a suitable model to probe the effect of gamma and beta emitter on biomolecules. Furthermore, the strategy of diluting the gold-198 with cold gold atoms was shown to be suitable to control the activity of 198AuNPs aiming medical applications, since the damage to BSA was found to be proportional to the relative concentration of gold-198.
Synthesis of high stable gold (198) nanoparticles for radiotherapy
2017 - SANTOS, JONNATAN J.; LEAL, JESSICA; DIAS, LUIS A.P.; TOMA, SERGIO H.; CORIO, PAOLA; ARAKI, KOITI; GENEZINI, FREDERICO A.; KATTI, KATTESH V.; LUGAO, ADEMAR B.
Cancer has become a problem in the last years, is expect be diagnosed more than 500 000 new cases in 2017, only in Brazil, according to Brazilian Cancer Nacional Institute. Among women breast cancer is the most common and among men the most representative is prostate cancer, and although treatments for both cancers have been already developed, new methods more efficient and that causes less damage to the patient are always being searched. Gold nanoparticles (AuNps) have many different applications on chemistry, biology, medicine, etc; their low reactivity and toxicity and high stability become it very interesting for bioapplications, such as drugs delivery and biosensing. In this work, we had developed a new method to prepare 198AuNps, from a leaf of gold bombed by neutrons, adapting Turkevich method, these nanoparticles were modified with bovine serum albumin (BSA) and characterized by multiple techniques, after 30 days (eleven half-life decays). This methodology was capable of generate AuNps with almost 14 nm and Zeta potential higher than -37 mV, very stable. BSA can be used for different applications, like a simple stabilizer or to increase cellular uptaking, but in our case its chromophore groups were utilized to follow damages caused by radiation, as a sensor for radiation damage, a dosimeter. Bellow are presented TEM image, Zeta potential measures and fluorescence spectroscopy of the 198AuNps-BSA samples.
Hydrogels with silver nanoparticles for wound treatment
2017 - OLIVEIRA, MARIA J.A.; SANTOS, JONNATAN J.; TOMA, SERGIO H.; ALCANTARA, MARA T.S.; VASQUEZ, PABLO A.V.; ARAKI, KOITI; LUGAO, ADEMAR B.
In recent years, the study and preparation of nanoparticles have attracted considerable interest for both fundamental and applied research. In biomedical area, silver nanoparticles have been a vast field of study, although antimicrobial properties have originated from their medical application since 19th century. Since silver has had several uses and its enormous potential for the treatment of injuries. Silver-containing topcoats are an excellent option for topical microbial combat on wounds that present infection, as well as being an essential tool for controlling bacterial load. Among these coatings are the hydrogel dressings with silver nanoparticles that have broad spectrum of antimicrobial action. In vitro studies have demonstrated bactericidal activity in strains of antibiotic resistant microorganisms. The objective of this work is characterize hydrogels with silver nanoparticles, prepared using polyvinylpyrrolidone (PVP), carboxymethylcellulose (CMC), used to treat wounds. A gamma radiation source cobalt-60 was used to crosslink the hydrogels, sterilize and form the silver nanoparticles simultaneously. Irradiation is recognized as a very viable tool because there is no need to add possibly harmful primers or crosslink that are difficult to remove. The results showed uniform distribution of the nanoparticles on the surface of the hydrogels, making it feasible for topical application.
Radiation-induced "one pot" synthesis for cell therapies
2017 - LUGAO, ADEMAR B.; FAZOLIN, GABRIELA N.; VARCA, GUSTAVO H.C.; SANTOS, JORGE G.; BARROS, JANAINA; FUCASE, TAMARA; SANTOS, JONNATAN J.; LEAL, JESSICA; GRASSELLI, MARIANO; KATTI, KATTESH V.
The dream of Marie Curie lab’s expressed by Regaud and Lacassagne in 1927 was to administer radiations with penetration range of molecular dimensions to the organism and selectively fixed in the protoplasm of cells one seeks to destroy. Gold nanoparticles can be employed as a radiation sensitizer by utilizing mainly Auger effect and photoelectrons. Auger electrons are released in large numbers with low kinetic energy therefore these electrons damage cells over a very short range: less than the size of a single cell, on the order of nanometers. Gold-198 is a beta and gamma emitter can be employed for therapy as well as diagnostic. The radioactive properties of gold include: Au (βmax=0.96 MeV; t1/2 = 2.7 days) and Au (βmax =0.46 MeV; t1/2 = 3.14 days), making it a strong candidate for theranostics. However, Gold or Gold-198 need to internalize selectively in tumor cells. Conjugation with proteins and peptides can make them very selective. While radioactive nanoparticles can offer a much higher dose payload than ions for therapy and diagnostic, in addition to the huge surface to bind targeting species presented by the nanoparticles, functionalization with proteins may potentially increases the particle uptake by tumors or tissues. Albumin and Papain features a set of characteristics that assure applications as natural drug carriers with particular attractive properties in oncology. Albumin may be easily crosslinked and engineered towards loading of large number of hydrophobic molecules as well as hydrophilic ones. They can be bound in a reversible way and the delivery controlled by endogenous mechanism. Alternatively to conventional systems, albumin can be crosslinked by radiation in such way that dialdehydes or toxic chemicals are totally avoided . Conjugation of such materials with sugars, peptides, antibodies, proteins among others is routinely used nowadays for targeting. The main purpose of this work was the development of one pot in situ synthesis of radioactive gold 198 nanoparticle encapsulated by albumin for application in cancer Theranostics. While crosslinked albumin may provide a nontoxic coating on AuNPs with a controllable hydrodynamic diameter, conventional AuNP can be activated by nuclear reactor to produce AuNP. The gamma or beta radiation originated from the gold nanoparticle was used to crosslink the Albumin layer. The use of a radioactive particle able to emit radiation for crosslinking of the Albumin layer and simultaneous theranostic application was tried for the first time. The elegant procedure and simplicity of the production process combined with the properties of Au and the safety of AuNP/BSA make this new particle an exciting advancement in cancer therapy and diagnosis. Gold conjugated protein nanoparticles and protein nanoparticles itself were also produced in an radiation induced one pot process. Crosslinking and protein damage werea cessed by different techniques.
Sugarcane biomass ash as a renewable source of nanosilica
2017 - ROVANI, SUZIMARA; SANTOS, JONNATAN J.; CORIO, PAOLA; FUNGARO, DENISE A.