Natural Rubber Latex Biomaterials in Bone Regenerative Medicine

Natural rubber latex (NRL) is a white and milky solution that exudes from Hevea brasiliensis bark when perforated, and it has been appointed as a new promising biomaterial. NRL has been proven to be a very biocompatible material, and several new biomedical applications have been proposed. NRL has been proven to stimulate angiogenesis, cellular adhesion and formation of extracellular matrix, besides promoting replacement and regeneration of tissue. NRL also can be used as an occlusive membrane for guided bone regeneration (GBR) with promising results. Therefore, the aim of this chapter is to review NRL studies and to present NRL membrane as a promising biomembrane for use in bone trauma and injury

New flexible and transparent solution-based germanium-sulfide polymeric materials

New flexible and transparent materials based on germanium sulfide were obtained using GeCl4 and 1,3-propanedithiol as precursors. These materials have transparency in the ultraviolet-visible (UV-Vis) spectral region (about 70%), thermal stability up to 200 degrees C and glass transition located at temperatures below 0 degrees C (-37 degrees C, -56 degrees C and -59 degrees C) as shown by differential scanning calorimetry (DSC) curves. Scanning electron microscopy (SEM) images showed that the polymer is homogeneous and presents formation of crystals in some regions of the surface. These polymers also exhibit Ge-S bonds in its structure, as can be observed through Fourier transform infrared (FTIR) (bands at 399, 401, 432 and 470 cm(-1)) and Raman (peaks at 361 and 430 cm(-1)) spectroscopies, and the diffraction patterns X-rays, which suggest the formation of a mixture of GeS2 and GeO2 phases (also confirmed through energy-dispersive X-ray analysis). The coupled thermogravimetric analysis / Fourier transform infrared (TG/FTIR) technique was used to investigate the degradation of the sample. Taken together, the results of these characterizations suggest optical applications, and usability at low temperatures.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Natural-rubber-based flexible microfluidic device

The fabrication of flexible devices is of great interest owing to their eco-friendliness, economic prospects, feasibility, and wide range of applications in biocompatible diagnostic devices and flexible labs-on-chips. Therefore, this paper reports a new method developed to fabricate natural-rubber-based microfluidic devices (NRMDs) for optical and electrochemical applications. Furthermore, we provide a detailed protocol that will allow further study using NRMDs for the development of different lab-on-a-chip platforms. Microchannels were successfully replicated in NRMDs through casting of latex collected from trees of Hevea Brasiliensis into an acrylic moulding template. NRMDs combined both flexibility and transparency, the latter of which is an important characteristic for application in spectroscopic measurements in the visible range. When two flexible carbon fiber (FCF) electrodes were inserted into the NRMD, the device stated to work as a flexible electrochemical microcell. FCF electrodes showed a fast response to reach the stationary current immediately after the [Fe(CN)(6)](4-/3-) concentration was changed. High reversibility in the cleaning process was also confirmed when the microdevice was cleaned several times. Electronic spectroscopy was used to evaluate the absorption band of potassium ferricyanide and results showed that NRMD is very efficient for spectroscopic analysis in flow. NRMDs with different formats and configurations were evaluated. The findings show that natural rubber is a robust and versatile promising material for building microfluidic labs-on-chips.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Pyrolysis and combustion of pulp mill lime sludge

Thermal degradation and gaseous products evolving from pyrolysis and combustion of pulp mill lime sludge were investigated using Thermogravimetric Analysis in conjunction with Fourier Transform Infrared Analysis (TG-FTIR). The materials were studied in temperatures ranging from 25 to 1000 degrees C. The addition of calcium carbonate caused a decrease in S-containing compounds that evolved from the sludge combustion. The temperature range for decomposition by pyrolysis is higher than for decomposition by combustion. FTIR spectra of the gases evolved show considerable amounts of CO(2), in addition to HNCO and CH(4) absorptions. NH(3) gas was not detected, and sulfur and nitrogen-containing gases only developed in insignificant amounts. The sludge combustion presents two maxima pattern, determined by the CO(2) and H(2)O evolution, that could be associated to the flaming of volatile matter - for the first maximum followed by a glowing of the fixed carbon - for the second maximum. Results show that pulp mill lime sludge can be used as an alternative energy source if pollutant gases and heat expended from dewatering are carefully managed. (C) 2008 Elsevier B.V. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Thermal inkjet printing of polyaniline on paper

The development of organic devices requires the fabrication of thin films, and inkjet printing has been shown to be a suitable method to reach this goal. This work describes the printing process and characterisation of polyaniline (PANI) printed on bond and photographic papers using a desktop inkjet thermal printer. To enable printing, a solution composed by PANI, n-methyl-2-pyrrolidone, ethylene glycol, alcohol and water must be prepared. PANI is printed on bond and photographic paper and then doping of PANI is performed by hydrochloric acid vapour exposure. Micro-Raman spectroscopy showed that PANI printed on paper keeps its basic characteristics. The results from electrical measurements showed that the surface resistivity of the printed PANI samples decreases by increasing the printing number, i.e. the number of layers that were deposited, and depends slightly on the paper type. A stretched semicircle followed by a linear upward tail, attributed to Warburg impedance combined with other intrinsic mechanisms of PANI on porous media, are always present on the Cole-Cole plots obtained for doped-PANI on bond paper. It was shown that these parameters significantly change with the relative humidity, opening the possibility to apply PANI/paper-based devices as humidity sensors. (C) 2012 Elsevier B.V. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Monitoramento das propriedades térmicas das borrachas naturais de novos clones: IAC 301 e IAC 303

A borracha natural (BN) de três clones de seringueira [Hevea brasiliensis (Willd. exAdr. de Juss. Muell.-Arg.)] de um período de sete meses foi obtida por coagulação do látex com solução de ácido acético a 10% e seca a 65°C. As curvas TG-DTG foram utilizadas para monitorar as propriedades térmicas da BN. Os resultados indicaram pequenas variações entre clones e coletas, exceto no valor de Tf-T0, indicando que o clone IAC 301 sofre degradação mais rápida durante o processo termo degradação da BN seca. Não houve diferenças significativas nos valores de Tg entre clones e coletas.Natural rubber (NR) tapped from three clones of the rubber tree [Heveabrasiliensis (Willd. ex Adr. de Juss. Muell.-Arg.)] over a seven month period was obtained by coagulation of lattices with 10% acid acetic and dried at 65 °C. TG-DTG curves were used to monitor thermal properties of NR. The TG-DTG results indicated very small differences among the clones and tappings, except in the value of Tf-T0, which indicated that the IAC 301 clone suffered the fastest thermal degradation, during decomposition of the dried, raw NR. There was no significant difference in Tg values among clones and tappings

Formulation additives on formation of films isolated from ethylcellulose. Physicochemical and morphological studies

Neste trabalho foram produzidos filmes isolados de etilcelulose em base aquosa (Surelease®) contendo os aditivos α-GOS (α-glucoligossacarídeo) e/ou Tween® 80, os quais foram obtidos sobre placas de Teflon® pelo método de casting process. Os filmes foram caracterizados pelas seguintes análises: Calorimetria diferencial de varredura (DSC), termogravimetria (TG), espectroscopia na região do infravermelho (FTIR-ATR) e microscopia eletrônica de varredura (MEV). As análises de DSC e TG evidenciaram que os aditivos de formulação não influenciaram na estabilidade térmica dos filmes de Surelease®. Pelas análises das micrografias obtidas por MEV, os filmes apresentaram características morfológicas homogê- neas e ausência de separação de fase. Isto também foi verificado através dos espectros de FTIR-ATR os quais confirmaram haver somente mistura física entre os componentes dos filmes.In this work were developed free films from Surelease®, additives α-GOS (alfa-glucooligosaccharide) and/or Tween® 80 in aqueous solution. It was obtained by Teflon plates “casting” process. The free films were characterized by thermal analysis (DSC and TGA), infrared spectroscopy (FTIR-ATR) and scanning electron microscopy (SEM). DSC and TG analysis showed that the additives do not influenced in the thermal stability of Surelease® films. SEM analysis observed homogeneous morphological characteristics and phase detachment absence. FTIR-ATR spectra were used to confirm the physical mixture between the components of films.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Formulation additives on formation of films isolated from ethylcellulose. Physicochemical and morphological studies

Neste trabalho foram produzidos filmes isolados de etilcelulose em base aquosa (Surelease®) contendo os aditivos α-GOS (α-glucoligossacarídeo) e/ou Tween® 80, os quais foram obtidos sobre placas de Teflon® pelo método de casting process. Os filmes foram caracterizados pelas seguintes análises: Calorimetria diferencial de varredura (DSC), termogravimetria (TG), espectroscopia na região do infravermelho (FTIR-ATR) e microscopia eletrônica de varredura (MEV). As análises de DSC e TG evidenciaram que os aditivos de formulação não influenciaram na estabilidade térmica dos filmes de Surelease®. Pelas análises das micrografias obtidas por MEV, os filmes apresentaram características morfológicas homogê- neas e ausência de separação de fase. Isto também foi verificado através dos espectros de FTIR-ATR os quais confirmaram haver somente mistura física entre os componentes dos filmes.In this work were developed free films from Surelease®, additives α-GOS (alfa-glucooligosaccharide) and/or Tween® 80 in aqueous solution. It was obtained by Teflon plates “casting” process. The free films were characterized by thermal analysis (DSC and TGA), infrared spectroscopy (FTIR-ATR) and scanning electron microscopy (SEM). DSC and TG analysis showed that the additives do not influenced in the thermal stability of Surelease® films. SEM analysis observed homogeneous morphological characteristics and phase detachment absence. FTIR-ATR spectra were used to confirm the physical mixture between the components of films.Colegio de Farmacéuticos de la Provincia de Buenos Aire