Cassava biopolymer polyamide hydrogel accelerates healing of induced skin woundsin rats / Hidrogel de biopolímero de poliamido de mandioca acelera o processo de cicatrização em feridas cutâneas induzidas em ratos

This study aimed to macroscopically and microscopically evaluate the healing of skin wounds induced in rats by topical application of cassava polyamide biopolymer hydrogel. In total, 32 rats were used and divided into four groups (n= 8): negative control - saline solution; positive control - use of commercial ointment; experimental group - I - ointment + cassava hydrogel; experimental group - II - cassava hydrogel. A 1cm2 wound induced on the animals dorsum was treated and evaluated. At day 21 post-operation, the animals were sacrificed by anesthetic overdose, and then 1cm2 of cicatricial skin from the wound region was collected. The material was cut to evaluate healing. In the macroscopic evaluation, complete healing was observed at the end of 21 days. Re-epithelialization was observed histologically; the connective tissue in the negative control, positive, and experimental - I groups was characterized by an abundance of collagen fibers, fibroblasts, and blood vessels. In experimental group - II additional healing was observed, as evidenced by the arrangement of collagen fibers and fibroblasts, and the reduction of neoformed vessels. Thus, we concluded that the hydrogel can assist in healing skin wounds, especially in the remodeling phase.(AU)

O objetivo deste estudo foi avaliar macro e microscopicamente a cicatrização de feridas cutâneas induzidas em ratos, a partir da aplicação tópica do hidrogel de biopolímero de poliamido de mandioca. Trinta e dois ratos foram divididos em quatro grupos (n= 8): controle negativo, tratado com solução salina; controle positivo, com pomada comercial; grupo experimental - I, com pomada + hidrogel de mandioca; grupo experimental - II, com hidrogel de mandioca. Feridas induzidas de 1cm 2 no dorso dos animais foram tratadas e avaliadas em intervalos de três a quatro dias. No 21º dia do pós-operatório, os animais foram mortos por aprofundamento anestésico, em seguida foi coletado 1cm 2 de pele da região cicatricial. O material foi cortado, corado pelas técnicas de hematoxilina-eosina e azocarmine-G, para avaliação da cicatrização. Na avaliação macroscópica, foi observada cicatrização completa no final do período de 21 dias. Histologicamente, observou-se reepitelização, o tecido conjuntivo no grupos controle negativo, positivo e experimental - I se caracterizou pela abundância de fibras colágenas, fibroblastos e vasos sanguíneos. No grupo experimental - II, a cicatrização sugere avanço de etapas, evidenciado pelo arranjo das fibras colágenas, pela redução de fibroblastos e dos vasos neoformados. Assim, foi possível concluir que o hidrogel de biopolímero de amido de mandioca pode auxiliar na cicatrização de feridas cutâneas, principalmente na fase de remodelação.(AU)

Evaluation of Pb (II) biosorption utilizing sugarcane bagasse colonized by Basidiomycetes.

The contamination of water resources by metallic ions is a serious risk to public health and the environment. Therefore, a great emphasis has been given to alternative biosorption methods that are based on the retention of aqueous-solution pollutants; in the last decades, several agricultural residues have been explored as low-cost adsorbent. In this study, the ability of Pb (II) biosorption using sugarcane bagasse modified by different fungal species was evaluated. The presence of carbonyl, hydroxyl, and carboxyl groups in the biosorbent was observed by spectroscopy in the infrared region. By scanning electron microscopy, changes in the morphology of modified material surfaces were observed. The highest adsorption capacity occurred at pH 5.0, while the shorter adsorbate-adsorbent equilibrium was at 20 min, and the system followed the pseudo-second-order model. The maximum biosorption in isotherms was found at 58.34 mg g(-1) for modified residue by Pleurotus ostreatus U2-11, and the system followed the Langmuir isotherm. The biosorption process was energetically spontaneous with low desorption values. This modification showed great potential for filters to remove Pb (II) and provide the preservation of water resources and animal health.

Iron translocation in Pleurotus ostreatus basidiocarps: production, bioavailability, and antioxidant activity.

Translocation of minerals from substrate to mushrooms can change the medicinal characteristics, commercial value, and biological efficiency of mushroom. In the present study, we demonstrated that addition of iron to the substrate reduces the yield of Pleurotus ostreatus mushroom. The biological efficiency of the mushroom varied from 36.53% on the unsupplemented substrate to 2.08% for the substrate with 500 mg/kg iron added. The maximum iron concentration obtained for mushroom was 478.66 mg/kg (dry basis) and the maximum solubility in vitro was 293.70 mg/kg (dry basis). Iron translocation increased the ash and protein content, reduced antioxidant activity, and enhanced the aroma and flavor characteristics of the mushroom. However mushroom has higher amounts of iron than vegetables like collard greens, it is not feasible to use mushrooms as the only dietary source of iron. The study also indicated that because of more bioaccumulation of iron in mycelium than in the mushroom, mycelium and not mushroom, could be a better alternative as a non-animal iron source.

Assessment of chemically modified sugarcane bagasse for lead adsorption from aqueous medium.

This study evaluated the adsorption capacity of chemically modified sugarcane bagasse with citric acid (B-CA), sodium hydroxide (B-S) and citric acid and sodium hydroxide (B-CAS) for Pb2+ ion adsorption in aqueous medium. Infrared spectroscopy (FT-IR) was used to characterise the materials, where the chemical modification was confirmed by the presence of carboxylate groups created at 1,730 cm(-1) peak. All assays related to Pb2+ ion adsorption onto adsorbent, i.e. equilibrium time between Pb2+ ions and adsorbate (24 h), as well as Pb2+ ion concentration, were performed in batch system. The initial and final Pb2+ ion concentration after shaking time was determined by Flame Atomic Absorption Spectrometry (FAAS). Isotherm adsorptions were applied to Langmuir and Freundlich linear models and maximum adsorption capacity (MAC) of materials towards Pb2+ ions was calculated in function of modifications. A significant improvement regarding Pb2+ ion adsorption after the bagasse treatment with citric acid, in which MAC was 52.63 mg g(-1), was observed. The adsorptions followed the behaviour described by the Langmuir linear model and its kinetics follow the behaviour described by the pseudo-second-order equation.