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1.
Bile acid sequestrants: a review of mechanism and design.
Feng, Y, Li, Q, Ou, G, Yang, M, Du, L
The Journal of pharmacy and pharmacology. 2021;(7):855-861
Abstract
OBJECTIVE Bile acid sequestrants (BAS) are used extensively in the treatment of hypercholesterolaemia. This brief review aimed to describe the design and evaluation of three types of BAS: amphiphilic copolymers, cyclodextrin/poly-cyclodextrin and molecular imprinted polymers. The mechanisms underlying the action of BAS are also discussed. KEY FINDINGS BAS could lower plasma cholesterol, improve glycemic control in patients with type 2 diabetes and regulate balance energy metabolism via receptors or receptor-independent mediated mechanisms. Different types of BAS have different levels of ability to bind to bile acids, different stability and different in-vivo activity. CONCLUSIONS A growing amount of evidence suggests that bile acids play important roles not only in lipid metabolism but also in glucose metabolism. The higher selectivity, specificity, stability and in-vivo activity of BAS show considerable potential for lipid-lowering therapy.
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Nano-cellulose reinforced starch bio composite films- A review on green composites.
Bangar, SP, Whiteside, WS
International journal of biological macromolecules. 2021;:849-860
Abstract
Plastic-based food packaging is generating a serious environmental problem by accumulating large amounts of plastic in the surroundings. Ecological and health concerns are driving research efforts for developing biodegradable films. There are few alternatives that could reduce the environmental impact; one of them is to substitute petroleum-based plastic with starch-based film. Starch has remarkable properties, including biodegradability, sustainability, abundancy, and capable of being modified or blended with other polymers. However, low mechanical strength and low water resistance restrict its application in food packaging. Nanocellulose isolated from lignocellulosic fibers has attracted tremendous interest in the field of science due to high crystallinity and mechanical strength, unique morphology along with abundancy, renewability, and biodegradability. Therefore, nano cellulose as a reinforcer proved to be a good option for fabricating biocomposites for food packaging. The current review will give a critical snapshot of the potential application of nanocellulose in food packaging and discuss new challenges and opportunities for starch biocomposites enriched with nano cellulose.
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3.
Cello-oligosaccharides production from lignocellulosic biomass and their emerging prebiotic applications.
Ávila, PF, Silva, MF, Martins, M, Goldbeck, R
World journal of microbiology & biotechnology. 2021;(5):73
Abstract
Cello-oligosaccharides (COS) are linear oligosaccharides composed of β-1,4-linked glucopyranose units. They comprise a group of important new oligosaccharides of significant interest and potential applications in the pharmaceutical, food, chemical, and feed industries, currently emerging as potential prebiotic compounds. COS from lignocellulosic biomass, specifically the agro-industrial residues and by-products of the forestry industry, constitute a new attractive process that imposes the sustainable use of biomass resources. Two main strategies have been used for the production of COS: acid-based and enzyme-based cellulose hydrolysis. The latter has been considered more attractive due to the use of milder reaction conditions and less production of monomers. This review summarizes that although COS is emerging as a potential prebiotic with also other potential applications, there is a lack of information regarding the large-scale production, which could be associated with the recalcitrant nature of cellulose compared to other polysaccharides, which hinders the hydrolysis of its dense network.
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4.
Engineering of Saccharomyces cerevisiae for efficient fermentation of cellulose.
Oh, EJ, Jin, YS
FEMS yeast research. 2020;(1)
Abstract
Conversion of lignocellulosic biomass to biofuels using microbial fermentation is an attractive option to substitute petroleum-based production economically and sustainably. The substantial efforts to design yeast strains for biomass hydrolysis have led to industrially applicable biological routes. Saccharomyces cerevisiae is a robust microbial platform widely used in biofuel production, based on its amenability to systems and synthetic biology tools. The critical challenges for the efficient microbial conversion of lignocellulosic biomass by engineered S. cerevisiae include heterologous expression of cellulolytic enzymes, co-fermentation of hexose and pentose sugars, and robustness against various stresses. Scientists developed many engineering strategies for cellulolytic S. cerevisiae strains, bringing the application of consolidated bioprocess at an industrial scale. Recent advances in the development and implementation of engineered yeast strains capable of assimilating lignocellulose will be reviewed.
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5.
Applications of Cellulose-based Materials in Sustained Drug Delivery Systems.
Sun, B, Zhang, M, Shen, J, He, Z, Fatehi, P, Ni, Y
Current medicinal chemistry. 2019;(14):2485-2501
Abstract
Bio-compatible, bio-degradable, and bio-available excipients are of critical interest for drug delivery systems. Cellulose and its derivative-based excipients have been well studied due to their green/natural and unique encapsulation/binding properties. They are often used in controlled/sustained drug delivery systems. In these applications, cellulose and its derivatives function generally can modify the solubility/gelling behavior of drugs, resulting in different mechanisms for controlling the release profiles of drugs. In this paper, the current knowledge in the structure and chemistry of conventional cellulose derivatives, and their applications in drug delivery systems are briefly reviewed. The development of innovative cellulose-based materials, including micro-cellulose (MC) and nano-cellulose (NC) in the applications of sustained drug delivery, is also discussed.
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Bacterial cellulose skin masks-Properties and sensory tests.
Pacheco, G, de Mello, CV, Chiari-Andréo, BG, Isaac, VLB, Ribeiro, SJL, Pecoraro, É, Trovatti, E
Journal of cosmetic dermatology. 2018;(5):840-847
Abstract
BACKGROUND Bacterial cellulose (BC) is a versatile material produced by microorganisms in the form of a membranous hydrogel, totally biocompatible, and endowed with high mechanical strength. Its high water-holding capacity based on its highly porous nanofibrillar structure allows BC to incorporate and to release substances very fast, thus being suitable for the preparation of skincare masks. AIMS The preparation and characterization of cosmetic masks based on BC membranes and active cosmetics. METHODS The masks were prepared by the simple incorporation of the cosmetic actives into BC membranes, used as a swelling matrix. The masks were characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM), sensory tests, and skin moisture tests on volunteers. RESULTS The results of sensory tests revealed the good performance of BC, being considered effective by the panel of volunteers, specially for adhesion to the skin (7.7 at the score scale), and improvement of the skin moisture (the hydration effect increased 76% in 75% of the volunteers that used vegetable extract mask formulation [VEM]), or a decrease in skin hydration (80% of the volunteers showed 32.6% decrease on skin hydration using propolis extract formulation [PEM] treatment), indicating the BC nanofiber membranes can be used to skincare applications. CONCLUSION The results demonstrate the BC can be used as an alternative support for cosmetic actives for skin treatment.
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7.
[Optimization of Nasal Drug Absorption from Powder Formulations: The Feasibility of Controlling Drug Absorption by the Use of Pharmaceutical Excipients].
Tanaka, A
Yakugaku zasshi : Journal of the Pharmaceutical Society of Japan. 2018;(12):1467-1472
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Abstract
Nasal application of powder formulations has garnered attention because of its significant potential for systemic drug delivery. Because a powder drug must first diffuse from the formulation and dissolve in the nasal cavity fluid before transepithelial permeation, dissolution and diffusion are distinct but important factors for nasal drug absorption. Since the formulation is directly administered onto the nasal mucosal surface, the effect of excipients on drug absorption may be significant. Therefore, the influence of excipients on nasal drug absorption was evaluated. Three types of hydroxypropyl cellulose (HPC) [HPC (SL), HPC (M), and HPC (H)], lactose, and sodium chloride (NaCl) were used as excipients. Warfarin (WF), piroxicam (PXC), sumatriptan (STP), and norfloxacin (NFX) were selected as model drugs. HPC (M) enhanced the absorption of PXC, while both HPC (M) and HPC (H) enhanced the absorption of STP. All three HPCs failed to enhance the absorption of WF. An increase in the polymerization degree of HPCs decreased the diffusion of drugs in HPC solutions, but prolonged their nasal retention. Lactose and NaCl increased the fluid volume on the nasal mucosal surface by increasing the osmotic pressure, thereby enhancing the nasal absorption of PXC and NFX; however, lactose and NaCl accelerated the nasal clearance of these. These results indicate that nasal drug absorption from powder formulations can be controlled by excipients.
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8.
Chloroplasts as Cellular Factories for the Cost-effective Production of Cellulases.
Khan, MO, Mehmood, MA, Mukhtar, Z, Ahmad, N
Protein and peptide letters. 2018;(2):129-135
Abstract
Chloroplasts are vital photosynthetic organelles in plant cells that carry out several important cellular functions including synthesis of amino acids, fatty acids, and lipids and metabolism of nitrogen, starch, and Sulphur to sustain the homeostasis in plants. These organelles have got their own genome, and related genetic machinery to synthesize required proteins for various plant functions. Genetic manipulations of the chloroplast genome for different biotech applications has been of great interest due to desired features including the availability of operonal mode of gene expression, high copy number, and maternal mode of inheritance (in the most field crops). Their capacity to often express transgenes at high levels make it a cost-effective platform for the production of foreign proteins, particularly high-value targets of industrial importance, at large scale. This article reviews briefly the research work carried out to produce cellulolytic enzymes in higher plant chloroplasts. The challenges and future opportunities for the same are also discussed.
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Sticking to cellulose: exploiting Arabidopsis seed coat mucilage to understand cellulose biosynthesis and cell wall polysaccharide interactions.
Griffiths, JS, North, HM
The New phytologist. 2017;(3):959-966
Abstract
The cell wall defines the shape of cells and ultimately plant architecture. It provides mechanical resistance to osmotic pressure while still being malleable and allowing cells to grow and divide. These properties are determined by the different components of the wall and the interactions between them. The major components of the cell wall are the polysaccharides cellulose, hemicellulose and pectin. Cellulose biosynthesis has been extensively studied in Arabidopsis hypocotyls, and more recently in the mucilage-producing epidermal cells of the seed coat. The latter has emerged as an excellent system to study cellulose biosynthesis and the interactions between cellulose and other cell wall polymers. Here we review some of the major advances in our understanding of cellulose biosynthesis in the seed coat, and how mucilage has aided our understanding of the interactions between cellulose and other cell wall components required for wall cohesion. Recently, 10 genes involved in cellulose or hemicellulose biosynthesis in mucilage have been identified. These discoveries have helped to demonstrate that xylan side-chains on rhamnogalacturonan I act to link this pectin directly to cellulose. We also examine other factors that, either directly or indirectly, influence cellulose organization or crystallization in mucilage.
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10.
Regulation of cellulose synthesis in response to stress.
Kesten, C, Menna, A, Sánchez-Rodríguez, C
Current opinion in plant biology. 2017;:106-113
Abstract
The cell wall is a complex polysaccharide network that provides stability and protection to the plant and is one of the first layers of biotic and abiotic stimuli perception. A controlled remodeling of the primary cell wall is essential for the plant to adapt its growth to environmental stresses. Cellulose, the main component of plant cell walls is synthesized by plasma membrane-localized cellulose synthases moving along cortical microtubule tracks. Recent advancements demonstrate a tight regulation of cellulose synthesis at the primary cell wall by phytohormone networks. Stress-induced perturbations at the cell wall that modify cellulose synthesis and microtubule arrangement activate similar phytohormone-based stress response pathways. The integration of stress perception at the primary cell wall and downstream responses are likely to be tightly regulated by phytohormone signaling pathways in the context of cellulose synthesis and microtubule arrangement.