Cellulose is the most abundant biopolymer on Earth, found in trees, waste from agricultural crops and other biomass The fibres that comprise cellulose can be broken down into building blocks, known as fibrillated cellulose, of varying, controllable dimensions that extend to the nanoscale Fibrillated cellulose is harvested from renewable resources, so its sustainability potential combined with its other functional properties (mechanical, optical, thermal and fluidic, for example) gives this nanomaterial unique technological appeal Here we explore the use of fibrillated cellulose in the fabrication of materials ranging from composites and macrofibres, to thin films, porous membranes and gels We discuss research directions for the practical exploitation of these structures and the remaining challenges to overcome before fibrillated cellulose materials can reach their full potential Finally, we highlight some key issues towards successful manufacturing scale-up of this family of materials

Developing fibrillated cellulose as a sustainable technological material.

Highly open porous biodegradable poly(L-lactic acid) ¿PLLA scaffolds for tissue regeneration were fabricated by using ammonium bicarbonate as an efficient gas foaming agent as well as a particulate porogen salt. A binary mixture of PLLA-solvent gel containing dispersed ammonium bicarbonate salt particles, which became a paste state, was cast in a mold and subsequently immersed in a hot water solution to permit the evolution of ammonia and carbon dioxide within the solidifying polymer matrix. This resulted in the expansion of pores within the polymer matrix to a great extent, leading to well interconnected macroporous scaffolds having mean pore diameters of around 300-400 microm, ideal for high-density cell seeding. Rat hepatocytes seeded into the scaffolds exhibited about 95% seeding efficiency and up to 40% viability at 1 day after the seeding. The novelty of this new method is that the PLLA paste containing ammonium bicarbonate salt particles can be easily handled and molded into any shape, allowing for fabricating a wide range of temporal tissue scaffolds requiring a specific shape and geometry.

A Novel Fabrication Method of Macroporous Biodegradable Polymer Scaffolds Using Gas Foaming Salt as Porogen Additive

Over the past few years, nanocellulose (NC), cellulose in the form of nanostructures, has been proved to be one of the most prominent green materials of modern times. NC materials have gained growing interests owing to their attractive and excellent characteristics such as abundance, high aspect ratio, better mechanical properties, renewability, and biocompatibility. The abundant hydroxyl functional groups allow a wide range of functionalizations via chemical reactions, leading to developing various materials with tunable features. In this review, recent advances in the preparation, modification, and emerging application of nanocellulose, especially cellulose nanocrystals (CNCs), are described and discussed based on the analysis of the latest investigations (particularly for the reports of the past 3 years). We start with a concise background of cellulose, its structural organization as well as the nomenclature of cellulose nanomaterials for beginners in this field. Then, different experimental procedures for the production of nanocelluloses, their properties, and functionalization approaches were elaborated. Furthermore, a number of recent and emerging uses of nanocellulose in nanocomposites, Pickering emulsifiers, wood adhesives, wastewater treatment, as well as in new evolving biomedical applications are presented. Finally, the challenges and opportunities of NC-based emerging materials are discussed.

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Nanocellulose: From Fundamentals to Advanced Applications

Renewable and sustainable biobased materials: An assessment on biofibers, biofilms, biopolymers and biocomposites

Poly-γ-glutamic acid (γ-PGA) is a naturally occurring biopolymer made up of repeating units of l-glutamic acid, d-glutamic acid or both. γ-PGA can exhibit different properties (conformational states, enantiomeric properties and molecular mass). Owing to its biodegradable, non-toxic and non-immunogenic properties, it has been used successfully in the food, medical and wastewater industries. Amongst other novel applications, it has the potential to be used for protein crystallization, as a soft tissue adhesive and a non-viral vector for safe gene delivery. This review focuses on the production, properties and applications of γ-PGA. Each application of γ-PGA utilizes specific properties attributed to various forms of γ-PGA. As a result of its growing applications, more strains of bacteria need to be investigated for γ-PGA production to obtain high yields of γ-PGA with different properties. Many medical applications (especially drug delivery) have exploited α-PGA. As γ-PGA is essentially different from α-PGA (i.e. it does not involve a chemical modification step and is not susceptible to proteases), it could be better utilized for such medical applications. Optimization of γ-PGA with respect to cost of production, molecular mass and conformational/enantiomeric properties is a major step in making its application practical. Analyses of γ-PGA production and knowledge of the enzymes and genes involved in γ-PGA production will not only help increase productivity whilst reducing the cost of production, but also help to understand the mechanism by which γ-PGA is effective in numerous applications.

Poly-γ-glutamic acid: production, properties and applications.

Commercial application of cellulose nano-composites - A review.

Microalgae offer fascinating highlights to be enable them as elective raw material for different applications through bio-refining process. They have special capacities to use them for biotechnology oriented applications. In this way, this review examines to grow the extent of incorporating microalgae along with different other biorefinery applications to upgrade their maintainability. The utilization of microalgae as animal and fish feed, manures, pharmaceutical, cosmeceutical, environmental and other biotechnological applications are altogether assessed. It additionally features the boundaries, openings, improvements, what's more, probabilities of expanding the extent of microalgae through techno-economic analysis. This review infers that subsidizing supported research and a move of microalgal research objective from biofuels generation to bio-refinery co-items can ensure them as valuable resource. In addition, innovation joining is inescapable to bypass the expense of biomass handling of microalgae. It is anticipated that this review would be useful to decide the future job of microalgae in bio-refinery applications.

Microalgae – A green multi-product biorefinery for future industrial prospects

Process optimization for the production of cellulose nanocrystals from rice straw derived α-cellulose

Superior effect on thermal, mechanical and optical properties of cellulose acetate nanocomposite (CA) films has been established by its fabrication with rice straw derived cellulose nanofibers (RS CNFs) as nano filler. The ratio of CA/RS CNF were optimized (2, 5, 7.5 and 10 wt % of CNF) through solvent casting method, their effect on the thermal, mechanical and optical properties of the nanocomposite films were observed. Better crystallinity index (92%) and lower lignin content of RS CNF (up to 5 wt % loading) enhanced tensile strength to 65 MPa and Young’s modulus up to 2.5 GPa of CA film. The improvement of thermal and optical properties were understood by the enhancement in thermal stability and transparency through TGA and UV–Vis spectrophotometer respectively in higher loading of CNFs. The improvised CA nanocomposite film with RS CNFs keeps better future and promise in packaging and logistic industries as superior to commercial CA films.

Fabrication of cellulose acetate nanocomposite films with lignocelluosic nanofiber filler for superior effect on thermal, mechanical and optical properties

Natural statin like lovastatin which is mainly produced by Aspergillus terreus strains is an inhibitor of HMG-CoA reductase, an enzyme involved in the biosynthetic pathway of cholesterol. The mechanism involved in controlling plasma cholesterol levels is the reversible competitive inhibition of HMG-CoA which binds to the HMG-CoA reductase due to the structural homology between the β-hydroxyacid form of the statins and the HMG-CoA intermediate formed. Mainly Lovastatin are produced industrially by liquid submerged fermentation which decreases the production cost compared to costs of chemical synthesis. Lovastatin application part is in various field like management of hypercholesterolaemia, cholesterol lowering actions, reduce the prevalence of Alzheimer’s and renal disease etc. This review deals with the structure, properties, biosynthetic pathway, submerged fermentation, applications and side effects of lovastatin.

Saswata Goswami

Papers

Commercial application of cellulose nano-composites - A review.

Microalgae – A green multi-product biorefinery for future industrial prospects

Process optimization for the production of cellulose nanocrystals from rice straw derived α-cellulose

Fabrication of cellulose acetate nanocomposite films with lignocelluosic nanofiber filler for superior effect on thermal, mechanical and optical properties

A review on lovastatin and its production