Nanoparticulated WO3/NiWO4 Using Cellulose as a Template and Its Application as an Auxiliary Co-Catalyst to Pt for Ethanol and Glycerol Electro-Oxidation.

This work reports the use of cellulose as a template to prepare nanosized WO3 or NiWO4 and its application as a co-catalyst in the electro-oxidation of ethanol and glycerol. Microcrystalline cellulose was hydrolyzed with phosphotungstic acid (H3PW12O40) to prepare the nanocrystalline cellulose template. The latter was air-calcinated to remove the template and obtain nanometric WO3. Tungsten oxide was impregnated with Ni(NO3)2, which was subsequently air-calcinated to obtain the nanometric NiWO4. Elemental analysis confirmed the coexistence of nickel and tungsten, whereas thermal analysis evidenced a high thermal stability for these materials. The X-ray diffractograms displayed crystal facets of WO3 and, when Ni(II) was added, NiWO4. The transmission electron micrographs corroborated the formation of nanosized particles with average particle sizes in the range of 30 to 50 nm. Finally, to apply this material, Pt/WO3-C and Pt/WO3-NiWO4-C were prepared and used in ethanol and glycerol electro-oxidation in an alkaline medium, observing a promotional effect of the oxide and tungstate by reducing the onset potential and increasing the current density. These materials show great potential to produce clean electricity or green hydrogen, contributing to energetic transition.

Polyurethane films formation from microcrystalline cellulose as a polyol and cellulose nanocrystals as additive: Reactions favored by the low viscosity of the source of isocyanate groups used.

To simultaneously form films while synthesizing solvent-free and catalyst-free bio-based polyurethanes, hexamethylene diisocyanate trimer was selected as an isocyanate group source to produce a low-viscosity reaction medium for dispersing high contents of microcrystalline cellulose (MCC, polyol) and cellulose nanocrystals (CNC). Castor oil was used as an additional polyol source. Up to 80 % of the MCC was dispersed, producing a film exhibiting the highest Tg (72 °C), tensile strength (18 MPa), and Young's modulus (522.4 MPa). 12.5 % (30 % MCC) and 7.5 % (50 % MCC) of CNC dispersed in the reaction medium formed films stiffer than their counterparts. All the films exhibited transparency and high crystallinity. The contact angle/zeta potential (ζ) indicated hydrophobic film surfaces. At pH 7.4, ζ suggested that the films interacted with physiological fluids favorably. The films were non-cytotoxic, and the composites exhibited cell growth compared with the control. The reported results, as far as it is known, are unprecedented.

L-lysine and dietary fiber improve the physicochemical properties of sausage without added phosphate and reduced salt levels

The demand for clean label foods has driven research in the meat product sector. The objective of this study was to evaluate the effect on the physicochemical properties of adding L-lysine, wheat fiber (WTF) and microcrystalline cellulose (MCC) in sausage without the addition of sodium tripolyphosphate (STPP) and with reduced salt levels. Eight treatments were produced in total. Three control treatments were: CON1 - 0.5 % sodium tripolyphosphate and 2 % salt; CON2 - without STPP and 2 % salt; CON3 - without STPP and 1 % salt. Five other treatments were carried out without STPP and 1 % of salt: LYS - 0.8 % L-lysine; WTF - 2 % wheat fiber; MCC - 2 % microcrystalline cellulose fiber; LYSWTF - 0.8 % L-lysine and 2 % wheat fiber; LYSMCC - 0.8 % L-lysine and 2 % microcrystalline cellulose fiber. L-lysine and wheat fiber provided good emulsion stability for sausages. L-lysine and MCC increased the yield of the products. Microcrystalline cellulose increased the red color value (a*) of sausages. The intensity of the yellow color value (b*) was significantly affected by the removal of STPP and the reduction of salt levels, but L-lysine and MCC improved this parameter, providing similar results to CON1. Adding of L-lysine and dietary fiber increased hardness in sausages without added STPP and with salt reduction. L-lysine and wheat fiber are promising for reformulating emulsified meat product without phosphate added and with reduced salt levels due to lipid oxidation control and improvement in emulsion stability.

Protection of Mono and Polyunsaturated Fatty Acids from Grapeseed Oil by Spray Drying Using Green Biopolymers as Wall Material.

One of the most common ways to protect oils is microencapsulation, which includes the use of encapsulating agents. Due to the environmental problems facing humanity, this study seeks to combine green biopolymers (microcrystalline cellulose and whey protein isolate) that function as encapsulating agents for grapeseed oil. Grapeseed oil that is obtained from agro-industrial waste has shown health benefits, including cardioprotective, anticancer, antimicrobial, and anti-inflammatory properties. These health benefits have been mainly associated with monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids. In this sense, it has been observed that grapeseed oil can be easily modified by environmental factors such as oxygen, high temperatures, and light, showing the instability and easy degradation of grapeseed oil. In this study, grapeseed oil was encapsulated using the spray-drying technique to conserve its lipidic profile. Powder recovery of the grapeseed oil microcapsules ranged from 65% to 70%. The encapsulation efficiency of the microcapsules varied between 80% and 85%. The FTIR analysis showed chemical interactions that demonstrate chemisorption between the grapeseed oil and the encapsulating material, while the SEM micrographs showed a correct encapsulation in a spherical shape. Gas chromatography showed that the lipid profile of grapeseed oil is preserved thanks to microencapsulation. Release tests showed 80% desorption within the first three hours at pH 5.8. Overall, whey protein and microcrystalline cellulose could be used as a wall material to protect grapeseed oil with the potential application of controlled delivery of fatty acids microcapsules.

Preparation of microcrystalline cellulose from residual Rose stems (Rosa spp.) by successive delignification with alkaline hydrogen peroxide.

Agricultural residues of Rose flowers (Rosa x hybrida L.) are abundant, cheap, and renewable. These lignocellulosic remains are composed of cellulose, hemicellulose, and lignin. They are an attractive feedstock to produce various value-added products, as microcrystalline cellulose (MCC). The objective of this study was to obtain MCC from residual Rose stems (RS) using a successive alkaline peroxide treatment. X-ray diffraction, Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) were used to determine the degree of crystallinity, structure characteristics, thermal properties, and morphology, respectively, of MCC. The properties of RS-MCC were compared with those of commercial MCC. The degree of crystallinity of RS-MCC was 70.21%. The X-ray diffraction patterns reveal the presence of Type I cellulose. FTIR showed the absence of non-cellulosic components, mainly lignin, present in the amorphous regions of the RS fibers. Results are promising for taking advantage of agricultural residues as a source of MCC, which could be used as a reinforcing agent in polymeric matrices.

Effect of drying methods on the powder and compaction properties of microcrystalline cellulose derived from Gossypium herbaceum

The effect of drying method, a process variable, on the powder and compaction properties of microcrystalline cellulose (MCC) obtained from the partial acid hydrolysis of bleached alpha (α) cellulose content of matured linters of Gossypium herbaceum (GH) was investigated. A portion of the wet MCC obtained was fluid bed dried at 60 ± 1 ºC, inlet air of 30 m3 min-1 for 3 h (coded MCC-GossF). The second portion was lyophilized at - 45 ± 2 ºC for 6 h (coded MCC-GossL). The physicochemical, scanning electron micrographs, X ray diffraction patterns and micromeritic properties of the derived MCCs were determined using standard methods. The cohesiveness and compactibility of the powders were investigated using Kawakita model while the deformation and compressibility pattern were determined using Heckel model. Avicel® PH 102 (AV-102) was used as comparing standard. Ash values of < 2%, pH (6.54 ± 0.23 to 6.58 ± 0.08), degree of polymerization, DP (231.50) was obtained. MCC-GossF had higher moisture content, swellability, better flow indices, and lesser porosity than MCC-GossL. Kawakita model demonstrated good consolidation and compactibility for both powders. Compacts of MCC-GossL were significantly (p < 0.05) harder than those of MCC-GossF. Heckel analysis demonstrated good compressibility and deformation pattern that was comparable with AV-102. Compacts of MCC-GossL had better mechanical and tablet compression properties than MCC-GossF

Formulation development and evaluation of colon targeted delayed release methotrexate pellets for the treatment of colonic carcinoma

Colonic carcinoma is one of the most common internal malignancies and is the second leading cause of deaths in United States. Methotrexate (MTX) is a drug of choice in the treatment of colon cancer. The aim of the present research work was to develop and characterize colon targeted pellets of MTX for treatment of colonic carcinoma. The product and process parameters were optimized by screening methods. Pellets were prepared by extrusion spheronization using microcrystalline cellulose (MCC) as spheronizing aid and ethyl cellulose (EC) as release retardant in different ratio. Based on the physical appearance, sphericity and % in vitro drug release, batch P17 containing EC: MCC (3:7) was optimized for core pellets. The site specificity was obtained by screening the coating polymers and by coating the core pellets with EudragitS100. The 32 full factorial design was applied in which airflow rate (X1) and coating time (X2) were the independent parameters and physical appearance (Y1) and time taken for 100% drug release (Y2) were selected as the dependent variables. From the results obtained, 6min of coating time and 60cm3/min airflow rate was optimized. The batch B5 showed appropriate physical appearance and % in vitro drug release upto 17hr indicating sustained release property. The ex-vivo studies performed on rat colon indicated a significant relation with the in vitro drug release. The drug release followed Higuchi's model indicating the diffusion pattern of drug release from the matrix of pellets. Thus, the coated pellets can be a good candidate for site specific delivery of MTX to colon by decreasing the gastric irritation and thus to improve bioavailability.

Escherichia coli expressing endoglucanase gene from Thai higher termite bacteria for enzymatic and microbial hydrolysis of cellulosic materials

Background: Endoglucanase plays a major role in initiating cellulose hydrolysis. Various wild-type strains were searched to produce this enzyme, but mostly low extracellular enzyme activities were obtained. To improve extracellular enzyme production for potential industrial applications, the endoglucanase gene of Bacillus subtilis M015, isolated from Thai higher termite, was expressed in a periplasmic-leaky Escherichia coli. Then, the crude recombinant endoglucanase (EglS) along with a commercial cellulase (Cel) was used for hydrolyzing celluloses and microbial hydrolysis using whole bacterial cells. Results: E. coli Glu5 expressing endoglucanase at high levels was successfully constructed. It produced EglS (55 kDa) with extracellular activity of 18.56 U/mg total protein at optimal hydrolytic conditions (pH 4.8 and 50°C). EglS was highly stable (over 80% activity retained) at 40­50°C after 100 h. The addition of EglS significantly improved the initial sugar production rates of Cel on the hydrolysis of carboxymethyl cellulose (CMC), microcrystalline cellulose, and corncob about 5.2-, 1.7-, and 4.0-folds, respectively, compared to those with Cel alone. E. coli Glu5 could secrete EglS with high activity in the presence of glucose (1% w/v) and Tween 80 (5% w/v) with low glucose consumption. Microbial hydrolysis of CMC using E. coli Glu5 yielded 26 mg reducing sugar/g CMC at pH 7.0 and 37°C after 48 h. Conclusions: The recombinant endoglucanase activity improved by 17 times compared with that of the native strain and could greatly enhance the enzymatic hydrolysis of all studied celluloses when combined with a commercial cellulase.

Optimized pH-responsive film based on a eutectic mixture-plasticized chitosan.

Chitosan (CS, 2g/100mL)/curcumin 1g/100mL in acetic acid aqueous solution were used to prepare films to be used as food indicator. Microcrystalline cellulose (MCC) and a eutectic mixture (DES) were incorporated as reinforcing and plasticizing agents, respectively. The MCC content (133 mas%) and DES composition (7.93 mass%), based on CS dry mass, were optimized. The properties of the DES-plasticized film were compared to those for the unplasticized and glycerol (G)-plasticized CS films. The DES-plasticized film presented initial temperature of thermal decomposition at 267.7°C, dynamic glass transition at 149.3°C, water vapor permeability of 7.21×10-10gs-1m-1Pa-1, water solubility of 3.07% and stress at break of 20.1MPa. The incorporation of MCC contributed to increase the crystallinity of the composite films. Colorimetric tests, carried out in aqueous environments for the DES-plasticized film, revealed accentuated color changes, mainly at pHs higher than pH 8.

Nanocrystalline cellulose extracted from pine wood and corncob.

The extraction of nanocrystalline cellulose from agro-residues is an interesting alternative to recover these materials. In the present study, nanocrystalline cellulose was extracted from pine wood and corncob. In addition, microcrystalline cellulose was used as a reference to compare results. Initially, the lignocellulosic residues were submitted to delignification pre-treatments. At the end of the process, the bleached fibre was submitted to acid hydrolysis. Additionally, microparticles were obtained from the spray-drying of the nanocrystalline cellulose suspensions. The nanocrystalline cellulose yield for the pine wood was 9.0-% of the value attained for the microcrystalline cellulose. For the corncob, the value was 23.5-%. Therefore, complementary studies are necessary to improve the yield. The spray-dried microparticles showed a crystallinity index of 67.8-% for the pine wood, 70.9-% for the corncob and 79.3-% for the microcrystalline cellulose. These microparticles have great potential for use in the production of polymer composites processed by extrusion.

The Rietveld method as a tool to quantify the amorphous amount of microcrystalline cellulose.

With the use of X-ray powder diffraction data and the Rietveld method, we verified that both microcrystalline cellulose PH-101 and PH-102 presented differences in the crystallinity degree. The results revealed these samples are semicrystalline in nature and via Rietveld refinements, it was possible, adding a known amount of an internal standard of corundum to the samples, to perform quantitative phase analyses, which allowed us to determine the amorphous amount of the studied samples: 63.7(11) wt % in microcrystalline cellulose PH-101 and 51.0(11) wt % in microcrystalline cellulose PH-102. An important contribution of this work refers to the attempt of using this simple method, permitting to evaluate the degree of crystallinity of microcrystalline cellulose.

Development of tablets containing semipurified extract of guaraná (Paullinia cupana)

This study evaluated the technological feasibility of producing a semipurified extract of guaraná (Paullinia cupana Kunth, Sapindaceae) in tablet form, using a direct-compression process. Maltodextrin and gum arabic were used to produce the extract microparticles, in order to protect the microparticles against such factors as temperature, oxidation, and humidity. Using pharmacopoeial methodologies, technological and physicochemistry tests (determination of residual moisture, of bulk and tapped density, Hausner ratio, compressibility and compactibility index, appearance, mean weight, hardness, friability, disintegration time, determination of EPA amount in tablets and in vitro release profile) were conducted. The formulation containing 200 mg of microparticles, 170 mg microcrystalline cellulose, and 10 mg lactose gave the best results in terms of hardness (116 N), friabilility (0.28%), mean weight (0.3821 g), and disintegration time (25 min) for a tablet designed for oral administration. The results met pharmacopoeial specifications, and the tablets are suitable for oral administration.

Evaluation of several microcrystalline celluloses obtained from agricultural by-products.

Microcrystalline cellulose (MCCI) has been widely used as an excipient for direct compression due to its good flowability, compressibility, and compactibility. In this study, MCCI was obtained from agricultural by-products, such as corn cob, sugar cane bagasse, rice husk, and cotton by pursuing acid hydrolysis, neutralization, clarification, and drying steps. Further, infrared spectroscopy (IR), X-ray diffraction (XRD), optical microscopy, degree of polymerization (DP), and powder and tableting properties were evaluated and compared to those of Avicel PH101, Avicel PH102, and Avicel PH200. Except for the commercial products, all materials showed a DP from 55 to 97. Particles of commercial products and corn cob had an irregular shape, whereas bagasse particles were elongated and thick. Rice and cotton particles exhibited a flake-like and fiber-like shape, respectively. MCCI as obtained from rice husk and cotton was the most densified material, while that produced from corn cob and bagasse was bulky, porous, and more compressible. All products had a moisture content of less than 10% and yields from 7.4% to 60.4%. MCCI as obtained from bagasse was the most porous and compressible material among all materials. This product also showed the best tableting properties along with Avicel products. Likewise, all MCCI products obtained from the above-mentioned sources showed a more rapid disintegration time than that of Avicel products. These materials can be used as a potential source of MCCI in the production of solid dosage forms.

A quantitative study of the influence of coprocessing of binders on the mechanical properties of paracetamol tablets

A 2³ factorial experimental design has been used to quantitatively study individual and interaction effects of the nature of binder (N), concentration of binder (C) and the applied pressure (P) on two mechanical properties, namely, tensile strength (TS) and brittle fracture index (BFI), of paracetamol tablets. The factorial design was also used to study the quantitative effects of coprocessing of binders on the mechanical properties. The results obtained from this study suggest that the nature (i.e. plastic/elastic) and ratio of binders coprocessed together alter the influence of C and P on TS and BFI.

Utilizou-se planejamento experimental fatorial 2³ para estudar, quantitativamente, os efeitos individuais e de interação da natureza do ligante (N), concentração do ligante (C) e a pressão aplicada (P) em duas propriedades mecânicas, como forças de ruptura (TS) e índice de fragilidade (BFI) de comprimidos de paracetamol. O planejamento fatorial foi, também, empregado para estudar os efeitos quantitativos do coprocessamento de ligantes nas propriedades mecânicas. Os resultados obtidos desse trabalho sugerem que a natureza (plástica/elástica) e a proporção de ligantes coprocessados, juntas, alteram a influência de C e P em TS e em BFI.