Organic acids and protein compounds causing the photoluminescence properties of natural rubber membranes and the quenching phenomena from Au nanoparticle incorporation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estimating the concentration of gold nanoparticles incorporated on natural rubber membranes using multi-level starlet optimal segmentation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Investigation of the dielectric relaxation processes in PbZr0.65Ti0.35O3-BaFe12O19 multiferroic ceramic composites

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of fiber orientation on the shear behavior of glass fiber/epoxy composites

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Production and characterization of natural rubber-Ca/P blends for biomedical purposes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Natural-rubber-based flexible microfluidic device

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Processing and characterization of ablative composites used in rocket motors

The main objective of this research work was to obtain two formulations of ablative composites. These composites are also known as ablative structural composites, for applications in atmospherically severe conditions according to the high-temperature, hot gaseous products flow generated from the burning of solid propellants. The formulations were manufactured with phenolic resin reinforced with chopped carbon fiber. The composites were obtained by the hot compression molding technique. Another purpose of this work was to conduct the physical and chemical characterization of the matrix, the reinforcements and the composites. After the characterization, a nozzle divergent of each formulation was manufactured and its performance was evaluated through the rocket motor static firing test. According to the results found in this work, it was possible to observe through the characterization of the raw materials that phenolic resins showed peculiarities in their properties that differentiate one from the other, but did not exhibit significant differences in performance as a composite material for use in ablation conditions. Both composites showed good performance for use in thermal protection, confirmed by firing static tests (rocket motor). Composites made with phenolic resin and chopped carbon fiber showed that it is a material with excellent resistance to ablation process. This composite can be used to produce nozzle parts with complex geometry or shapes and low manufacturing cost.

Protocylindrocorpus brasiliensis n. sp. (Diplogastroidea: Cylindrocorporidae) associated with the ambrosia beetle, Euplatypus parallelus (f.) (Curculionidae: Platypodinae) in para rubber trees (Hevea brasiliensis)

Protocylindrocorpus brasiliensis n. sp. (Diplogastroidea: Cylindrocorporidae) is described from reproductive stages removed from galleries of the ambrosia beetle, Euplatypus parallelus (F.) (Curculionidae: Platypodinae) in Para rubber trees (Hevea brasiliensis) in Brazil. This is the first record of the genus Protocylindrocorpus from the Neotropics. Males of P. brasiliensis are quite striking because their long spicules extend up to 72% of their total body length. The adults exhibit conspecific agglutination where they congregate in a slimy substance that serves to maintain them in a coherent group for mating. Some of the adults were infected by fungal and protozoan pathogens, implying that disease plays a role in regulating natural populations. The discovery of P. brasiliensis provides new information on nematode structure, behavior, and ecology.

Evaluation of modified silica nanoparticles in carboxylated nitrile rubber nanocomposites

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Structural and functional characterization of barium zirconium titanate/epoxy composites

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of stryphnodendron sp. release using natural rubber latex membrane as carrier

Natural rubber latex from Hevea brasiliensis has interesting characteristics related to this work such as: it is easy to manipulate, low cost, can stimulate the natural angiogenesis, is a biocompatible material and presents high mechanical resistance. The aim of this study was to develop a novel sustained delivery system for Stryphnodendron sp. based on Natural Rubber Latex (NRL) membranes and to study the Stryphnodendron sp. delivery system behavior. Stryphnodendron sp., commonly known as barbatimao is extensively used in folk medicine for the treatment of diarrhoea, gynaecological problems and for healing wounds. The stem bark of this species is mentioned in the Brazilian Pharmacopeia with a content of at least 20% of tannins. Previous studies showed significant cicatrizant properties, anti-inflammatory activity and gastric anti-ulcerogenic effects for the stem bark crude extract. One possible way to accelerate the tissue repair process, it was incorporated the Stryphnodendron sp. extract in NRL membranes. Stryphnodendron sp extract was incorporated into the NRL, by mixing it in solution for in vitro protein delivery experiments. Results show that the NRL membrane can release Stryphnodendron sp. for up to 49.89% of its Stryphnodendron sp. content for up 400 h. The kinetics of the extract release could be fitted with double exponential function, with two characteristic times of 0.78 and 133.22 h. In this study, we demonstrated that the induced angiogenesis provided by NRL membranes combined with a controlled release of extract is relevant for biomedical applications.

Casearia sylvestris Swartz Extract Release Using Natural Rubber Latex Biomembranes as Carrier

The Natural Rubber Latex (NRL) from Hevea brasiliensis has shown promise in biomedical applications due to its low cost, easy handling, mechanical properties and biocompatibility, being used for bone regeneration and wound healing due to its natural stimulus to angiogenesis. The aim of this work was to incorporate Casearia sylvestris Sw. extract in NRL biomembranes and study its release behavior. The complex membrane-extract has as object of study a new approach of using C. sylvestris extract in the treatment of wounds, for possessing antiseptic activity, anti-inflammatory and analgesic properties. The C. sylvestris species (Salicaceae), popularly known as "guaçatonga", presents great distribution and is used in folk medicine as antiulcer, wound healing, anti-snake venom, properties which have been proven and related to clerodane diterpenes (casearins A-X). The release rate of C. sylvestris compounds from extract-membrane complex was monitored and analyzed using the method of optical spectroscopy (UV-VIS). The release varied with temperature ranging from 14 to 33 days, releasing more than 90%, with an interesting and promising biomedical application, such as wound healing and burns.

Natural rubber latex: Study of a novel carrier for Casearia sylvestris swartz delivery

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ciprofloxacin Release Using Natural Rubber Latex Membranes as Carrier

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Bacterial cellulose-hydroxyapatite composites with osteogenic growth peptide (OGP) or pentapeptide OGP on bone regeneration in critical-size calvarial defect model

This study aimed to evaluate the potential of bacterial cellulose-hydroxyapatite (BC-HA) composites associated with osteogenic growth peptide (OGP) or pentapeptide OGP(10–14) in bone regeneration in critical-size calvarial defects in mice. In this study, the BC-HA, BC-HA-OGP, and BC-HA-OGP(10–14) membranes were analyzed at 3, 7, 15, 30, 60, and 90 days. In each period, the specimens were evaluated by micro-computed tomography (µCT), descriptive histology, gene expression of bone biomarkers by qPCR and VEGFR-2 (vascular endothelial growth factor) quantification by ELISA. Three days post-operative, Runx2, Tnfrsf11b and Bglap bone biomarkers were upregulated mainly by BC-HA OGP and BC-HA OGP(10–14) membranes, suggesting an acceleration of the osteoblast differentiation/activity with the use of these biomaterials. At 60 and 90 days, a high percentage of bone formation was observed by µCT for BC-HA and BC-HA OGP(10–14) membranes. High expression of some bone biomarkers, such as Alpl, Spp1, and Tnfrsf11b, was also observed for the same membranes on days 60 and 90. In conclusion, the BC-HA membrane promoted a better bone formation in critical-size mice calvarial defects. Nevertheless, incorporation of the peptides at the concentration of 10−9 mol L−1 did not improve bone regeneration potential in the long-term.