Nanocrystalline cellulose extracted from bast fibers: Preparation, characterization, and application

Cellulose nanofibers produced from spaghetti squash peel by deep eutectic solvents and ultrasonication

In this study, the cellulose nanofibers (CNFs) derived from spaghetti squash peel (SSP) were prepared using a novel approach involving deep eutectic solvent (DES) pretreatment coupled with ultrasonication. Molecular dynamics (MD) simulations revealed that the number of hydrogen bonds influences the viscosity and density of DES systems, and experimental viscosity (ηexp) confirmed consistency with the computed viscosity (ηMD) trends. After DES pretreatment and ultrasonication, the cellulose content of ChCl/oxalic acid (ChCl/OA) CNF (35.63%) and ChCl/formic acid (ChCl/FA) (32.46%) is higher than ChCl/Urea CNF (28.27%). The widths of ChCl/OA CNF, ChCl/FA CNF, and ChCl/Urea CNF were 19.83, 11.34, and 18.27 nm, respectively, showing a network-like fiber distribution. Compared with SSP (29.76%) and non-ultrasonic samples, the crystallinity index of ChCl/OA CNF, ChCl/FA CNF, and ChCl/Urea CNF was improved by ultrasonication. The thermal decomposition residue of ChCl/OA CNF (25.54%), ChCl/FA CNF (18.54%), and ChCl/Urea CNF (23.62%) was lower than that of SSP (29.57%). These results demonstrate that CNFs can be prepared from SSP via DES pretreatment combined with ultrasonication. The lowest viscosity observed in the formic acid DES group (ηexp of 18 mPa·s), the ChCl/FA CNF exhibits excellent stability (Zeta potential of -37.6 mV), which can provide a promising prospect for utilization in biomass by-products and applications in the materials field.

Biopolymer-Based Nanosystems: Potential Novel Carriers for Kidney Drug Delivery

Kidney disease has become a serious public health problem throughout the world, and its treatment and management constitute a huge global economic burden. Currently, the main clinical treatments are not sufficient to cure kidney diseases. During its development, nanotechnology has shown unprecedented potential for application to kidney diseases. However, nanotechnology has disadvantages such as high cost and poor bioavailability. In contrast, biopolymers are not only widely available but also highly bioavailable. Therefore, biopolymer-based nanosystems offer new promising solutions for the treatment of kidney diseases. This paper reviews the biopolymer-based nanosystems that have been used for renal diseases and describes strategies for the specific, targeted delivery of drugs to the kidney as well as the physicochemical properties of the nanoparticles that affect the targeting success.

Cellulose nanocrystalline from biomass wastes: An overview of extraction, functionalization and applications in drug delivery

Cellulose nanocrystals (CNC) have been extensively used in various fields due to their renewability, excellent biocompatibility, large specific surface area, and high tensile strength. Most biomass wastes contain significant amounts of cellulose, which forms the basis of CNC. Biomass wastes are generally made up of agricultural waste, and forest residues, etc. CNC can be produced from biomass wastes by removing the non-cellulosic components through acid hydrolysis, enzymatic hydrolysis, oxidation hydrolysis, and other mechanical methods. However, biomass wastes are generally disposed of or burned in a random manner, resulting in adverse environmental consequences. Hence, using biomass wastes to develop CNC-based carrier materials is an effective strategy to promote the high value-added application of biomass wastes. This review summarizes the advantages of CNC applications, the extraction process, and recent advances in CNC-based composites, such as aerogels, hydrogels, films, and metal complexes. Furthermore, the drug release characteristics of CNC-based material are discussed in detail. Additionally, we discuss some gaps in our understanding of the current state of knowledge and potential future directions of CNC-based materials.

Challenges associated with cellulose composite material: Facet engineering and prospective

Cellulose is the most abundant polysaccharide on earth. It has a large number of desirable properties. Its low toxicity makes it more useful for a variety of applications. Nowadays, its composites are used in most engineering fields. Composite consists of a polymer matrix and use as a reinforcing material. By reducing the cost of traditional fibers, it has an increasing demand for environment-friendly purposes. The use of these types of composites is inherent in moisture absorption with hindered natural fibers. This determines the reduction of polymer composite material. By appropriate chemical surface treatment of cellulose composite materials, the effect could be diminished. The most modern and advanced techniques and methods for the preparation of cellulose and polymer composites are discussed here. Cellulosic composites show a reinforcing effect on the polymer matrix as pointed out by mechanical characterization. Researchers tried their hard work to study different ways of converting various agricultural by-products into useful eco-friendly polymer composites for sustainable production. Cellulose plays building blocks, that are critical for polymer products and their engineering applications. The most common method used to prepare composites is in-situ polymerization. This help to increase the yields of cellulosic composites with a significant enhancement in thermal stability and mechanical properties. Recently, cellulose composites used as enhancing the incorporation of inorganic materials in multi-functional properties. Furthermore, we have summarized in this review the potential applications of cellulose composites in different fields like packaging, aerogels, hydrogels, and fibers.

Preparation of Cellulose Nanocrystals by Synergistic Action of Ionic Liquid and Recyclable Solid Acid under Mild Conditions

Cellulose nanocrystals (CNCs) are nanoscale particles made from cellulose. They have many unique properties such as being lightweight, stiff, and renewable, making them promising for a variety of applications in a wide range of industries, including materials science, energy storage, and biomedicine. In this paper, a two-stage (swelling-SA-catalyzed) method including IL pretreatment and solid acid hydrolysis process was developed to extract CNCs with high purity and good thermal stability from microcrystalline cellulose (MCC). In the first stage, the swelling of MCC in ionic liquid was studied with the assistance of ultrasonication, and it was found that the amorphous regions became more disordered while the crystalline areas were selectively retained under the conditions of 30 min of reaction time, 45 °C of temperature, 2% of ionic liquid water content and 1:4 mass ratio of cellulose to ionic liquid. CNCs were extracted using solid acid hydrolysis, with a 45 wt% solid acid to cellulose ratio and a 5.0 h hydrolysis process at 45 °C. The morphology, crystallinity, surface characteristics and thermo stability of the sample were characterized by atomic force microscopy (AFM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA), respectively. Results demonstrated the highly thermostable CNCs were successful extracted with rodlike shape of 300 ± 100 nm in length and 20 ± 10 nm in width. Solid acid recovery and reuse were also studied, revealing a promising candidate that can reduce the environmental impact associated with chemical products.

Organized mineralized cellulose nanostructures for biomedical applications

Cellulose is the most abundant naturally-occurring polymer, and possesses a one-dimensional (1D) anisotropic crystalline nanostructure with outstanding mechanical robustness, biocompatibility, renewability and rich surface chemistry in the form of nanocellulose in nature. Such features make cellulose an ideal bio-template for directing the bio-inspired mineralization of inorganic components into hierarchical nanostructures that are promising in biomedical applications. In this review, we will summarize the chemistry and nanostructure characteristics of cellulose and discuss how these favorable characteristics regulate the bio-inspired mineralization process for manufacturing the desired nanostructured bio-composites. We will focus on uncovering the design and manipulation principles of local chemical compositions/constituents and structural arrangement, distribution, dimensions, nanoconfinement and alignment of bio-inspired mineralization over multiple length-scales. In the end, we will underline how these cellulose biomineralized composites benefit biomedical applications. It is expected that this deep understanding of design and fabrication principles will enable construction of outstanding structural and functional cellulose/inorganic composites for more challenging biomedical applications.

Strategic developments in the drug delivery of natural product dihydromyricetin: applications, prospects, and challenges

Dihydromyricetin (DHM) is an important natural flavonoid that has attracted much attention because of its various functions such as protecting the cardiovascular system and liver, treating cancer and neurodegenerative diseases, and anti-inflammation effect, etc. Despite its great development potential in pharmacy, DHM has some problems in pharmaceutical applications such as low solubility, permeability, and stability. To settle these issues, extensive research has been carried out on its physicochemical properties and dosage forms to produce all kinds of DHM preparations in the past ten years. In addition, the combined use of DHM with other drugs is a promising strategy to expand the application of DHM. However, although invention patents for DHM preparations have been issued in several countries, the current transformation of DHM research results into market products is insufficient. To date, there is still a lack of deep research into the pharmacokinetics, pharmacodynamics, toxicology, and action mechanism of DHM preparations. Besides, preparations for combined therapy of DHM with other drugs are scarcely reported, which necessitates the development of dosage forms for this application. Apart from medicine, the development of DHM in the food industry is also of great potential. Due to its multiple effects and excellent safety, DHM preparations can be developed for functional drinks and foods. Through this review, we hope to draw more attention to the development potential of DHM and the above challenges and provide valuable references for the research and development of other natural products with a similar structure-activity relationship to this drug.

Cellulose Nanocrystals (CNCs) and Its Modified Form from Durian Rind as Dexamethasone Carrier

In this study, CNCs were extracted from durian rind. Modification to CNCs with saponin was conducted at 50 °C for one h. CNCs and CNCs-saponin were employed as dexamethasone carriers. Modification to CNCs using saponin did not change the relative crystallinity of CNCs. CNCs' molecular structure and surface chemistry did not alter significantly after modification. Both nanoparticles have surface charges independently of pH. Dexamethasone-released kinetics were studied at two different pH (7.4 and 5.8). Higuchi, Ritger-Peppas, first-order kinetic and sigmoidal equations were used to represent the released kinetic data. The sigmoidal equation was found to be superior to other models. The CNCs and CNCs-saponin showed burst release at 30 min. The study indicated that cell viability decreased by 30% after modification with saponin.