Cellulose can be broken down into fermentable sugars by using the fungus Trichoderma reesei or by using acid to convert them first into sugars and then into gas. The gut of termites also can be utilized for this purpose. Further, a group of bacteria collectively referred to as methanogens have the ability to digest cellulose and produce carbon di oxide and methane, which is further processed.
One group of such bacteria called methanobacteria grow anaerobically on cellulosic matter and degrade it to produce methane.
They are also found in the rumen of cattle and the dung of cattle. As is seen from this, it is quite easy to obtain a substrate for biogas production especially by using waste cellulosic material. Therefore, it is important that to utilize even the apparent waste material to ensure a reduction in wastage and optimum usage of its potential [ 34 , 35 ]. Cellulose has numerous applications in the field of pharmaceuticals and food technology.
Modifying the structure of cellulose with other chemical groups results in the production of structures that have better bio-compatibility, flexibility, stability, emulsifying effects. Further, cellulose being indigestible by human beings, tend to have zero calorific value and can thus have been added in food to serve several purposes.
Compounds like HPMC, sodium carboxymethyl cellulose, hydroxyethyl cellulose and others are commonly utilized in the pharmaceutical industry and food technology industry. Some of these uses are enumerated below:. HPMC is widely utilized in the pharmaceutical industry not only because it is safe and nontoxic but also because it does not get engrossed orally and does not upsurge the energy of foods. It is utilized as a film-forming agent, thickener, blocker, sustained-release agent, blending agent and suspending agent in many dosage forms, thus forming the numerous pharmaceutical preparation consistently discrete, tough short of being wrecked due to sustained release effects or steady emulsion without stratification.
It is regularly used as a matrix, adhesives, frame ingredients, the film creating material or in the creation of sustained or controlled release microcapsules and pellets [ 36 ]. It used as an emulsion stabilizer in injections, adhesion and film-forming materials which have proved to be effective in controlling wound infections and can reduce postoperative oedema and wound stimulation phenomena.
Animal experiments have shown that sodium carboxymethyl cellulose is a safe and reliable carrier of anticancer drugs [ 37 ]. In ice cream, frozen milk drinks, it is added as a stabilizer to extend the storage life and improve the overflow property. It is also used as the stabilizer of beer foam. Due to its unique physical and chemical properties and its behaviour in water, it is today being increasingly used a food additive to improve the bulk and fibre content of foods without having a major impact on the flavour of the food.
Since it is indigestible by humans, it has no caloric value and is thus used in excessive amounts in diet foods to create a sensation of fullness both physical and physiology without having consumed too many calories. It is also widely used an emulsifier and a thickening agent in whipped cream, sauces and ice cream [ 38 ].
Cellulose, with its properties, as discussed in previous sections of this manuscript, is extensively used in the field of biomedicine and pharmaceuticals.
The cost of several pharmaceutical products is extremely high due to production factors such as high cost, difficulty in procuring the material, complicated processing steps etc. These problems can be remedied by the use of cellulose, which is found abundantly in nature.
The most productive use of cellulose would be the utilization of plant based waste materials which are produced in bulk by many industries such as the sugar production industry as well as in minor quantities by households. The applications highlighted below could be brought to mainstream commercial use with the appropriate optimization techniques and novel modifications to the various steps of the production and processing of cellulosic material.
Solid dosage forms including pills, tablets, granules, pellets, microcapsules and spherules can be coated, usually with the aim to protect the drug from adverse environmental factors such as humidity, oxygen, enzymatic or acidic degradation. Coating may also be used to facilitate drug delivery systems with altered release mechanisms such as delayed release, extended release, step-by-step release, pulsatile release and sustained release.
Derivatives of cellulose such as esters and ethers are also extensively used as coating materials. Many attempts are being made to reduce the price of the final product by experimenting with various starting materials and test conditions [ 39 ]. From the advent of novel drug delivery systems, cellulose based models seemed like strong candidates due to their projected benefits.
Since then various advances have been made with the aim to bring its use to common practice. There are still many hurdles to cross before this becomes a reality. Cellulose based drug delivery is an important step in green and sustainable pharmacy which focuses on toxicity reduction, biodegradability and less hazardous synthesis with respect to drugs and drug delivery systems. A very brief overview of the primary ways in which it is used is provided here.
Cellulose nanocrystals CNCs have the potential to acquire a negative charge during hydrolysis. This coupled with their large surface area allow them to bind ionizable drugs such as tetracycline and doxorubicin permitting optimum dosing control.
Sites for surface modification for multiple chemicals are provided by the multitude of surface hydroxyl groups. This is used in case of non-ionized or hydrophobic drugs which do not generally bind to cellulose.
The open pore structure and high surface area of CNC based aerogels provide increased drug loading capacity and drug bioavailability. Extremely porous aerogel scaffolds were reported to attain sustained drug release [ 40 ]. Cellulose derivatives have also been researched in terms of drug delivery. For instance, cellulose acetate has been successfully used in several HIV drugs, five flavonoids, one pain reliever and two antibiotics among others.
Hydroxypropyl methylcellulose has been used in oral drug delivery formulations [ 41 ]. Scaffolds are materials that have been engineered to cause desirable cellular interactions to contribute to the formation of new functional tissues for medical purposes by providing the microenvironment required by cells to proliferate, migrate and differentiate. It contributes the geometrical basis and building blocks to provide cell attachment.
Gluconacetobacter xylinus sourced nanocellulose is an emerging biomaterial for this purpose. Bacterial nanocellulose has a very high affinity for water and therefore displays properties similar to those of hydrogels which provides an ideal environment to host cells. Studies have confirmed that human smooth muscle cells, bone forming osteoblasts and fibroblasts and human embryonic kidney cells can grow in the presence of bacterial cellulose scaffolds.
The main challenge in the production of these scaffolds seems to be biodegradability as the cellulose, the enzyme required to breakdown cellulose is not present in humans. This property was reported to be enhanced by periodate oxidation [ 42 ]. BNC is specifically nondegradable under physiological conditions and has been shown to be biocompatible. These properties further impart durable mechanical properties and long-term chemical stability which make it an exciting candidate for application in this field: Cardiovascular implants: Bacterial cellulose has an important application in artificial blood vessels.
Compared to the material generally used for vascular grafts, these materials show less thrombosis and occlusion. Heparin hybridized bacterial nanocellulose scaffolds with anticoagulant properties have potential use in vascular tissue engineering.
Potential use of BC in the production of heart valve replacements has been explored [ 43 , 44 ]. Bone and connective tissue repair: Nanocellulose are promising materials for the culture of various cells including osteoblasts and chondroblasts indicating that they have potential for bone tissue regeneration and healing.
A membrane of BC and hydroxyapatite was developed as biomaterial for potential bone regeneration, which delivered prone growth of osteoblast cells, high level of alkaline phosphatase activity and greater bone nodule formation. It was also found that HAp crystals are partially substituted with carbonate resembling natural bones [ 45 , 46 , 47 ].
From the chapter we can conclude that cellulose is a highly versatile polymer which is easy to manufacture and extract. Its application in multiple fields has been discussed above. With increasing population, demand and technological innovations, renewable energy is gradually becoming imperative aspect of resource conservation and overall environmental health.
Although various other polymers can be utilized for consumables, biomedical and pharmaceutical applications, the marked advantage of cellulose is that it is a biodegradable and environmentally friendly material. Altmetric -. Citations Cited By. This article is cited by publications. Kelcilene B. Teodoro, Rafaela C. Sanfelice, Fernanda L. Migliorini, Adriana Pavinatto, Murilo H. Facure, Daniel S. ACS Sensors , 6 7 , Gorbacheva, Sergey O. Chemical Reviews , 17 , ACS Energy Letters , 5 7 , The Journal of Physical Chemistry C , 27 , Biomacromolecules , 20 7 , Carson Meredith, Yulin Deng.
ACS Omega , 4 1 , Review on Electromechanical Coupling Properties of Biomaterials. Dunlop , and Jiayin Yuan. The Journal of Physical Chemistry B , 20 , Deringer , Ulli Englert , and Richard Dronskowski.
Biomacromolecules , 17 3 , Mehebub Alam and Dipankar Mandal. Reppert , Christina M. Biochemistry , 54 49 , Chemical Reviews , 14 , Mahadeva , Konrad Walus , and Boris Stoeber. Hoeger , Orlando J. Rojas , Ilona Peszlen , Joel J. Pawlak , and Perry N. ACS Macro Letters , 1 7 , Gimenez , J. Paper-Based Photoconductive Infrared Sensor. The Journal of Physical Chemistry C , 38 , Biomacromolecules , 12 9 , Langmuir , 27 13 , McMillan , and Vladimir Dmitriev. Biomacromolecules , 12 6 , Electrospun Fullerenol-Cellulose Biocompatible Actuators.
The Journal of Physical Chemistry C , 41 , Biomacromolecules , 11 8 , Rayon is an important fiber made out of cellulose and has been used for textiles since the beginning of the 20th century. The major combustible component of non-food energy crops is cellulose, with lignin second. Cellulose is a straight chain polymer: unlike starch, no coiling occurs, and the molecule adopts an extended rod-like conformation.
In microfibrils , the multiple hydroxyl groups on the glucose residues hydrogen bond with each other, holding the chains firmly together and contributing to their high tensile strength. This strength is important in cell walls, where they are meshed into a carbohydrate matrix , conferring rigidity to plant cells. In contrast to starch , cellulose is also much more crystalline. Given a cellulose-containing material, the portion that does not dissolve in a Cellulose can be assayed using a method described by Updegraff in , where the fiber is dissolved in acetic and nitric acid , and allowed to react with anthrone in sulfuric acid.
The resulting coloured compound is assayed spectrophotometrically at a wavelength of approximately nm. In addition, cellulose is represented by the difference between acid detergent fiber ADF and acid detergent lignin ADL. In vascular plants cellulose is synthesized at the plasma membrane by rosette terminal complexes RTC's. In nature, cellulose is found as fibers made of the several cellulose polymers. In wood and plants, the fibers create a network, in which the fibers are attached to each other by mechanical forces and hydrogen bonds.
A number of commercial products have been developed and are manufactured from cellulose.
0コメント