Homogenous isolation of individualized bacterial nanofibrillated cellulose by high pressure homogenization

Cellulose Dissolution, Modification, and the Derived Hydrogel: A Review

The cellulose-based hydrogel has occupied a pivotal position in almost all walks of life. However, the native cellulose can not be directly used for preparing hydrogel due to the complex non-covalent interactions. Some literature has discussed the dissolution and modification of cellulose but has yet to address the influence of the pretreatment on the as-prepared hydrogels. Firstly, the "touching" of cellulose by derived and non-derived solvents was introduced, namely, the dissolution of cellulose. Secondly, the "conversion" of functional groups on the cellulose surface by special routes, which is the modification of cellulose. The above-mentioned two parts were intended to explain the changes in physicochemical properties of cellulose by these routes and their influences on the subsequent hydrogel preparation. Finally, the "reinforcement" of cellulose-based hydrogels by physical and chemical techniques was summarized, viz., improving the mechanical properties of cellulose-based hydrogels and the changes in the multi-level structure of the interior of cellulose-based hydrogels.

Purification and Immobilization of Superoxide Dismutase Obtained from Saccharomyces cerevisiae TBRC657 on Bacterial Cellulose and Its Protective Effect against Oxidative Damage in Fibroblasts

Superoxide dismutase (SOD) is an essential enzyme that eliminates harmful reactive oxygen species (ROS) generating inside living cells. Due to its efficacities, SOD is widely applied in many applications. In this study, the purification of SOD produced from Saccharomyces cerevisiae TBRC657 was conducted to obtain the purified SOD that exhibited specific activity of 513.74 U/mg with a purification factor of 10.36-fold. The inhibitory test revealed that the purified SOD was classified as Mn-SOD with an estimated molecular weight of 25 kDa on SDS-PAGE. After investigating the biochemical characterization, the purified SOD exhibited optimal activity under conditions of pH 7.0 and 35 °C, which are suitable for various applications. The stability test showed that the purified SOD rapidly decreased in activity under high temperatures. To overcome this, SOD was successfully immobilized on bacterial cellulose (BC), resulting in enhanced stability under those conditions. The immobilized SOD was investigated for its ability to eliminate ROS in fibroblasts. The results indicated that the immobilized SOD released and retained its function to regulate the ROS level inside the cells. Thus, the immobilized SOD on BC could be a promising candidate for application in many industries that require antioxidant functionality under operating conditions.

Simulated elephant colon for cellulose extraction from sugarcane bagasse: An effective pretreatment to reduce chemical use

Sugarcane bagasse (SCB) is an abundant by-product from sugar production and promising biomass for cellulose extraction. Simulated elephant colon pretreatment (SEP) to reduce chemical use in cellulose extraction from SCB was investigated using elephant dung as fermentation inoculum. The 16S rRNA gene sequences showed microorganisms in elephant dung that corresponded to metabolites during pretreatment. Organic acid accumulation in the fermentation broth was confirmed by the presence of lactic, acetic, propionic and butyric acids. Lignin peroxidase, manganese peroxidase and xylanase detected during the pretreatment enhanced lignin removal. The SEP fiber showed increased cellulose content, while lignin content decreased with reduced bleaching time from 7 to 5 h and high whiteness and crystallinity indices. Lignin removal was also confirmed by Fourier transform infrared spectroscopy. Scanning electron microscopy revealed increasing internal surface area through opening up the fiber structure. SEP offered an efficient and promising approach for cellulose fiber extraction with reduced use of chemicals for the bleaching process.

Lignocellulosic Biomass Waste-Derived Cellulose Nanocrystals and Carbon Nanomaterials: A Review

Rapid population and economic growth, excessive use of fossil fuels, and climate change have contributed to a serious turn towards environmental management and sustainability. The agricultural sector is a big contributor to (lignocellulosic) waste, which accumulates in landfills and ultimately gets burned, polluting the environment. In response to the current climate-change crisis, policymakers and researchers are, respectively, encouraging and seeking ways of creating value-added products from generated waste. Recently, agricultural waste has been regularly appearing in articles communicating the production of a range of carbon and polymeric materials worldwide. The extraction of cellulose nanocrystals (CNCs) and carbon quantum dots (CQDs) from biomass waste partially occupies some of the waste-recycling and management space. Further, the new materials generated from this waste promise to be effective and competitive in emerging markets. This short review summarizes recent work in the area of CNCs and CQDs synthesised from biomass waste. Synthesis methods, properties, and prospective application of these materials are summarized. Current challenges and the benefits of using biomass waste are also discussed.

Improved water dispersion and bioavailability of coenzyme Q10 by bacterial cellulose nanofibers

The purpose of this study was to investigate the potential of bacterial cellulose nanofiber suspension (BCNs) as stabilizer in anti-solvent precipitation and its effect on improving bioavailability of coenzyme Q10. Bacterial cellulose (BC) was hydrolyzed by sulfuric acid followed by the oxidation with hydrogen peroxide to prepare BCNs. The suspension of BCNs-loaded CoQ10 (CoQ10-BCNs) were prepared by antisolvent precipitation. The zeta potential of CoQ10-BCNs was about -36.01 mV. The properties of CoQ10, BCNs and CoQ10-BCNs were studied by scanning electron microscopy, transmission electron microscope, Fourier-transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry and thermo gravimetric analysis. The crystallinity of CoQ10 decreased in CoQ10-BCNs compared with the raw CoQ10, and CoQ10-BCNs have good physicochemical stability. In oral bioavailability studies, the area under curve (AUC) of CoQ10-BCNs was about 3.62 times higher than the raw CoQ10 in rats.

Nanocelluloses: Sources, Pretreatment, Isolations, Modification, and Its Application as the Drug Carriers

The 'Back-to-nature' concept has currently been adopted intensively in various industries, especially the pharmaceutical industry. In the past few decades, the overuse of synthetic chemicals has caused severe damage to the environment and ecosystem. One class of natural materials developed to substitute artificial chemicals in the pharmaceutical industries is the natural polymers, including cellulose and its derivatives. The development of nanocelluloses as nanocarriers in drug delivery systems has reached an advanced stage. Cellulose nanofiber (CNF), nanocrystal cellulose (NCC), and bacterial nanocellulose (BC) are the most common nanocellulose used as nanocarriers in drug delivery systems. Modification and functionalization using various processes and chemicals have been carried out to increase the adsorption and drug delivery performance of nanocellulose. Nanocellulose may be attached to the drug by physical interaction or chemical functionalization for covalent drug binding. Current development of nanocarrier formulations such as surfactant nanocellulose, ultra-lightweight porous materials, hydrogel, polyelectrolytes, and inorganic hybridizations has advanced to enable the construction of stimuli-responsive and specific recognition characteristics. Thus, an opportunity has emerged to develop a new generation of nanocellulose-based carriers that can modulate the drug conveyance for diverse drug characteristics. This review provides insights into selecting appropriate nanocellulose-based hybrid materials and the available modification routes to achieve satisfactory carrier performance and briefly discusses the essential criteria to achieve high-quality nanocellulose.

Pectin-microfibrillated cellulose microgel: Effects on survival of lactic acid bacteria in a simulated gastrointestinal tract

Using high pressure microfluidization, we prepared micro-fibrillated soybean cellulose (MFSC) and analyzed its morphology and structure. MFSC was then incorporated into low-methoxyl pectin (PC) to coat lactic acid bacteria (LAB) by ionotropic gelation, and the effects of PC-MFSC microgel on LAB survival in a simulated gastrointestinal tract were investigated. Particle size analysis showed that the MFSC particle size decreased significantly with increasing jet pressure. Transmission electron microscopy analysis indicated that many cellulosic microfibers appeared at 150 MPa. Infrared spectroscopy and X-ray diffraction analysis revealed that the crystal structure changed from β-cellulose I type to II type with increasing jet pressure, but excessive pressure (200 MPa) damaged the crystalline structure of MFSC. Scanning microscopy indicated that cellulosic microfibers not only promoted a compact pectin gel morphology but also adhered to and coated the LAB in the pectin gel. MFSC-150 stabilized the pectin gel network, preventing the weakening of the gel under low pH conditions. Compared with other PC-MFSCs, PC-MFSC-150 microgel significantly decreased LAB susceptibility to gastrointestinal juice and increased the viability of LAB.

Vegetable Additives in Food Packaging Polymeric Materials

Plants are the most abundant bioresources, providing valuable materials that can be used as additives in polymeric materials, such as lignocellulosic fibers, nano-cellulose, or lignin, as well as plant extracts containing bioactive phenolic and flavonoid compounds used in the healthcare, pharmaceutical, cosmetic, and nutraceutical industries. The incorporation of additives into polymeric materials improves their properties to make them suitable for multiple applications. Efforts are made to incorporate into the raw polymers various natural biobased and biodegradable additives with a low environmental fingerprint, such as by-products, biomass, plant extracts, etc. In this review we will illustrate in the first part recent examples of lignocellulosic materials, lignin, and nano-cellulose as reinforcements or fillers in various polymer matrices and in the second part various applications of plant extracts as active ingredients in food packaging materials based on polysaccharide matrices (chitosan/starch/alginate).

Optimization of cellulose nanocrystals from bamboo shoots using Response Surface Methodology

Cellulose-based advanced materials, such as cellulose nanocrystals (CNC), have high potential application for drug delivery system. In this study, the CNC were produced from bamboo shoots using acid hydrolysis process. The delignification of bamboo shoots was conducted using alkali and hydrogen peroxide pretreatment processes. The operating condition of the production of CNC from bamboo shoots was optimized using Response Surface Methodology (RSM) based on the yield and crystals recovery as the responses. The optimum CNC yield of 50.67 ± 0.74% with a crystals recovery of 77.99 ± 1.14% was obtained at the sulfuric acid concentration of 54.73 wt% and a temperature of 39 °C from the optimization based on the yield. This optimization has been validated to confirm the accuracy.

Optimization of bacterial nanocellulose fermentation using recycled paper sludge and development of novel composites

In this work, recycled paper sludge (RPS), composed of non-recyclable fibres, was used as a carbon source for bacterial nanocellulose (BNC) production. The biomass was enzymatically hydrolysed with Cellic CTec 2 to produce a sugar syrup with 45.40 g/L glucose, 1.69 g/L cellobiose and 2.89 g/L xylose. This hydrolysate was used for the optimization of BNC fermentation by static culture, using Komagataeibacter xylinus ATCC 700178, through response surface methodology (RSM). After analysis and validation of the model, a maximum BNC yield (5.69 g/L, dry basis) was obtained using 1.50% m/v RPS hydrolysate, 1.0% v/v ethanol and 1.45% m/v yeast extract/peptone (YE/P). Further, the BNC obtained was used to produce composites. A mixture of an amino-PolyDiMethylSiloxane-based softener, polyethyleneglycol (PEG) 400 and acrylated epoxidized soybean oil (AESO), was incorporated into the BNC membranes through an exhaustion process. The results show that BNC composites with distinct performances can be easily designed by simply varying the polymers percentage contents. This strategy represents a simple approach towards the production of BNC and BNC-based composites.