X-ray powder diffraction and other analyses of cellulose nanocrystals obtained from corn straw by chemical treatments

Conductive cellulose nanofibers tailored poly(propylene carbonate) island structure and synergistic reinforcement-toughening mechanism of high-performance poly(lactic acid) composites

Biodegradable poly(lactic acid) (PLA) based composites have broad application prospects in replacing common polyester-based composites, but poor toughness and low thermal stability of PLA composites is still unsatisfactory for practical applications. Herein, a new preparation method of PLA composites by doping rigid conductive cellulose nanofibers (CNFene) and tough poly(propylene carbonate) (PPC) to tailor island structure and synergistic reinforcement-toughening mechanism is presented. Moreover, the composite films and paper-based coated beverage straws prepared from these composites has excellent thermal stability, high-strength, and high-toughness. Compared to pure PLA film, the tensile strength, elastic modulus, and elongation at break of the best PLA80P20C3 were increased by 25.3%, 17%, and 17.5 times respectively. And the strength of PLA80P20C3 coated straws reached up to 49.4 MPa, which was 12.7 times higher than untreated paper-based straws and 70% higher than PLA-coated straws. The high-performance PLA-based composites expanded the application areas of bio-packaging and hot drink straws.

Preparation and characterization of cellulose nanocrystal coated with silver nanoparticles with antimicrobial activity by enzyme method

Silver nanoparticles (AgNPs) exhibit broad-spectrum antibacterial activity and serve as effective antimicrobial agents against antibiotic-resistant bacteria. In this study, agricultural waste corn straw was used as the raw material to obtain cellulose nanocrystal (CNC) through enzymatic hydrolysis. The hydrolysate was employed as reducing agents to synthesize CNC-AgNPs. The inhibition effect of CNC-AgNPs on pathogenic microorganisms was analyzed to explore the optimal preparation conditions and antimicrobial mechanisms. XRD, FTIR, and TEM analyses confirmed the presence of silver nanoparticles, with a more uniform particle size of nanoparticles under alkaline conditions. XRD and TGA results showed that silver loading improved the thermal stability of CNC, particularly under pH 11 conditions. pH 4.8-CNC-AgNPs exhibited a sustained antibacterial effect for over 264 h against Escherichia coli and a 96-hour inhibition against Staphylococcus aureus, as well as significant inhibitory effects on the bacterial community in shoe insoles. CNC-AgNPs can be used as additives in composites or as coatings for the composites.

Industrial by-products of tiger nut starch as a source of cellulose nanocrystals for biodegradable packaging materials

The development of eco-friendly, biodegradable nanomaterials is essential for promoting the sustainable utilization of industry by-products from tiger nut starch. This study focuses on the extraction of cellulose nanocrystals (TN-CNC) from tiger nut starch by-products through acid hydrolysis, as well as evaluation of their effects on the characteristics of starch-based biodegradable packaging. The TN-CNC was identified as having a rod-like morphology, exhibiting high crystallinity (CI = 87.2 ± 2.4 %), stable thermal properties (Tonset = 299.1 °C), an average length of 278.4 ± 91.6 nm, and a notable aspect ratio (23.1 ± 8.8). TN-CNC demonstrated compatibility with starch substrates and enhanced the microstructure of natural starch films through self-assembly and the formation of new hydrogen bonds. Incorporating 1.0 % TN-CNC improved the crystallinity of the starch films from 16.2 % to 23.7 %, and increased their thermal stability from 271.8 °C to 289.3 °C. This concentration also significantly increased tensile strength by up to 104.2 %. These findings advocate for the upcycling of tiger nut starch by-products, highlighting their potential in developing high-performance biodegradable packaging materials.

Native corncob-derived biosorbent with grafted 1,3,4-thiadiazole for enhanced adsorption of palladium in metallurgical wastewater

The reuse of agricultural waste brings significant benefits but still faces a multitude of challenges. In this work, novel precious metal sorbents were constructed by grafting 1,3,4-thiadiazole-2-thiol (MTD) and 2,5-dithiadiazole-1,3,4-thiadiazole (DMTD) onto native corncob, which could rapidly and selectively recover palladium (Pd) from metallurgical wastewater. The characterization of the sorbents by powder X-ray diffraction indicated that introducing MTD or DMTD on native corncob did not alter the crystallinity and inherent structural framework. Corn-2 (grafted with DMTD) exhibited good resistance to various coexisting ions and rapidly extracted Pd from metallurgical wastewater over a minimum of ten cycles. Both Langmuir models and pseudo-second-order kinetic models describe the adsorption process. Rapid and continuous extraction of Pd from metallurgical wastewater was achieved by fixed-bed adsorption on Corn-2 over at least three adsorption-desorption cycles. A fixed-bed column containing 1.0 g of this biosorbent recovered Pd from 3.5 L metallurgical wastewater with a Pd concentration of 8.1 mg/L before exhaustion and achieved a Pd concentration of 1986 mg/L in the eluate. Theoretical calculations and spectroscopic analysis showed that sulfur and nitrogen atoms significantly contribute to the recovery process, and coordination is the primary mechanism for Pd(II) recovery. This study highlights the suitability of cellulose-based adsorbents for the efficient extraction of Pd from metallurgical wastewater and provides valuable insights into resource utilization opportunities for agricultural waste.

Preparation and characterization of a thymol nanoemulsion-loaded multifunctional sustained-release corn straw cellulose nanocrystal/acetylated starch-based aerogel and its application in chilled meat preservation

Chilled meat is prone to microbial contamination during storage, resulting in a shortened shelf life. This study developed multifunctional biodegradable aerogel with water absorption, antibacterial, and sustained release properties as a preservation pad for meat, using corn straw cellulose nanocrystals (CSCNCs) and acetylated starch (AS) as the structural skeleton and thymol (TMO) nanoemulsions as antimicrobials. The effects of different mass ratios of CSCNCs/AS on the morphology, structure, physical properties, and release behavior of aerogels were systematically analyzed. Additionally, their antibacterial properties, biocompatibility, and biodegradability were investigated. The results showed that the aerogels with CSCNC/AS mass ratio of 1:5 had a tailored structure for loading TMO nanoemulsions, as well as excellent water absorption, mechanical properties, and thermal stability. Due to strong hydrogen bonding and a porous structure, the TMO in the aerogels was continuously and uniformly released into high-water-activity and fatty food simulants, mainly controlled by Fickian diffusion. Furthermore, it exhibited superior antibacterial properties and biocompatibility. The application of aerogels for chilled beef preservation extended the shelf life from 8 days to approximately 12 days, which was superior to commercially available preservation pads. Notably, the aerogels exhibited superior biodegradability in soil. Therefore, the prepared aerogel preservation pads showed great potential in preserving chilled meat.

Immobilization of urea on beads based on OPEFB cellulose-alginate via blending to fabricate sustained release fertilizer

Transforming oil palm empty fruit bunches (OPEFB) waste into value-added cellulose as a reinforcement agent for eco-friendly slow-release fertilizer (SRF) composites is a strategy to achieve clean and sustainable production. OPEFB cellulose was isolated by alkalization (10 % w/v NaOH) for 1 h and bleaching (30 % v/v H2O2) for 1.5 h. The treatment increased the cellulose content to 80.88 %, reduced the non-cellulosic component, and improved the fiber crystallinity to 58.40 %. The hydrogel composite was cross-linked by blending urea in an OPEFB cellulose fiber (w/w) (0 %, 0.5 %, and 1 %) and sodium alginate (3 % w/w). Then, the wet beads were freeze-dried to fabricate SRF composites. Each material was evenly dispersed in the matrix, had a porous structure, and could bind total nitrogen up to 20.0 %, confirmed by the Kjeldahl method. Adding cellulose increased crystallinity (significant at 1 % w/w cellulose), decreased bulky density (significant at 0.5 % and 1 % w/w cellulose), increased swelling capacity (significant at 0.5 % w/w cellulose), and water-retention capacity. Reinforced composite with 0.5 % (w/w) cellulose released nitrogen into the soil (Fickian diffusion) following the Higuchi model (R2 = 0.957) with K = 0.0394 and equilibrium at around t1/2 = 1.8 h. Changing SRF composite properties are likely related to the porous structure loaded with urea crystals.

Emerging nanocellulose from agricultural waste: Recent advances in preparation and applications in biobased food packaging

With the increasing emphasis on sustainability and eco-friendliness, a novel biodegradable packaging materials has received unprecedented attention. Nanocellulose, owing to its high crystallinity, degradability, minimal toxicity, and outstanding biocompatibility, has gained considerable interest in the field of sustainable packaging. This review provided a comprehensive perspective about the recent advances and future development of cellulose nanocrystals (CNCs) and cellulose nanofibers (CNFs). We first introduced the utilization of agricultural waste for nanocellulose production, such as straw, bagasse, fruit byproducts, and shells. Next, we discussed the preparation process of nanocellulose from various agricultural wastes and expounded the advantages and shortcomings of different methods. Subsequently, this review offered an in-depth investigation on the application of nanocellulose in food packaging, especially the function and packaged form of nanocellulose on food preservation. Finally, the safety evaluation of nanocellulose in food packaging is conducted to enlighten and promote the perfection of relevant regulatory documents. In short, this review provided valuable insights for potential research on the biobased materials utilized in future food packaging.

Study of efficient catalytic electrode for hydrogen evolution reaction from seawater based on low tortuosity corn straw cellulose biochar/Mo2C with porous channels

Porosity and channel structure has important effects on the performance of hydrogen evolution reaction (HER) of nanostructured electrocatalysts in acid solution and seawater. Mesopore usually helps to enhance the reaction kinetics and mass transfer, while the macroporous channel structure also affects the electrocatalyst. Traditional graphene materials do not have such structure. Therefore, this paper designs a method to synthesize Mo2C composite nanomaterial in situ on corn straw biochar, inspires by the natural channel structure of conducting water, salt and organic matter in plants. Characteristic characterization shows that the material also has a large number of mesoporous and vertical distribution of large porous channel structure, through the decrease of tortuosity and porosity, ensure the catalyst surface electrolyte transport and hydrogen timely escape, alleviate the process of metal ion precipitation blocking pore channel, so as to improve the rate of hydrogen evolution reaction. The results shows that the overpotential of the catalyst was 48 mV and 251 mV under 10 mA cm-2 acidic electrolyte and simulated seawater electrolyte, respectively. This method provides new ideas for the design of efficient electrocatalysts for seawater decomposition, then the HER performance in alkaline and neutral environments needs to be further explored.

Isolation of cellulose nanofibers from rapeseed straw via chlorine-free purification method and its application as reinforcing agent in carboxymethyl cellulose-based films

In this study, cellulose nanofibers (CNFs) were successfully isolated from rapeseed straw (RS) whose valorization has been rarely investigated to date. A combined bleaching method without chlorine was applied for the purification of cellulose fibers, previously unexplored for RS. Chemical composition analysis and Fourier-transform infrared spectroscopy (FTIR) indicated that the purification method eliminated hemicellulose and reduced lignin content from 24.4 % to 1.8 %. The isolation of CNFs was performed using sulfuric acid hydrolysis under different acid concentrations (55 and 60 % v/v) and hydrolysis times (15, 30, and 45 min). The isolated CNFs were characterized by FTIR, X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The formation of CNFs was confirmed by a significant increase in crystallinity index from 46.45 % of RS to >79.41 % of CNFs, depending on acid concentration and isolation duration. Carboxymethyl cellulose (CMC) films with different contents of CNFs were prepared by casting method. The mechanical properties and cytotoxicity of the prepared films were investigated. The CNFs obtained from RS via a chlorine-free purification method showed promising results for their usage as reinforcement in CMC matrix and film fabrication for various applications such as transdermal medicine and food packaging.

Removal of Natural Organic Matter (NOM) from Aqueous Solutions by Multi-Walled Carbon Nanotube Modification with Magnetic Fe3O4 Nanoparticles

Backgroundand Aim. Natural organic matter (NOM) has become one of the most serious environmental problems due to its persistence in aqueous solutions and the risk of carcinogenesis. In this study, the removal efficiencies of real and synthetic humic acid (HA) by multi-walled carbon nanotubes (MWCNTs) coated with iron oxide were evaluated. Materials and Methods. The MWCNs were synthesized and coated with iron oxide. In addition, the effects of pH, contact time, mixing speed, and adsorbent dose on the removal efficiency of NOM by MWCNTs-Fe3O4 were studied. Then, the removal efficiency of NOM from real samples was investigated at optimal conditions. The MWCNT-Fe3O4 was characterized by scanning electron microscopy (SEM) test and X-ray diffraction (XRD), respectively. Data analysis was performed using Minitab software based on the Taguchi method. Results. The results showed that MWCNTs were coated with Fe3O4. The SEM test shows particle (MWCNTs-Fe3O4) size in the range of 48–143 nm, and the particles have uniform spherical shapes. Enix software was used to identify the phase in this sample. The conditions including $\mathrm{p}\mathrm{H}=3$ , mixing speed = 120 rpm, adsorbent dosage = 1.5 g·L−1, and contact time = 90 minutes were selected as optimal for NOM adsorption. The mean removal efficiencies of NOM in synthetic samples at 5, 10, and 20 mg·L−1 concentrations were 86.6%, 84.87%, and 95.41%, respectively. In addition, the mean removal efficiency of NOM in Choghakhor Wetland was 77%. Conclusion. Our findings demonstrated that the MWCNTs-Fe3O4 can be potentially used as an adsorbent for removing natural organic matter (HA) from aqueous solutions.

Cellulose nanocrystals from Siam weed: Synthesis and physicochemical characterization

The use of biomass for the development of environmentally friendly and industrially useful materials is still attracting global interest. Herein, cellulose nanocrystals were prepared from Siam weed. The production steps involved dewaxing the biomass sample, bleaching treatment, alkali treatment and acid hydrolysis. The resulting cellulose nanocrystals were characterized using Fourier transformed infrared (FTIR) spectroscopy, X-ray diffraction (XRD) spectroscopy, thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and dynamic light scattering (DLS) technique. Chemical composition results showed that Siam weed contained 39.6% cellulose, 27.5% hemicellulose, 28.7% lignin and 4.2% extractive. FTIR spectrum confirmed the presence of cellulose and absence of lignin and hemicellulose while XRD analysis revealed that the cellulose nanocrystals have crystallinity index of 66.2% and particle size of 2.2 nm. TGA revealed that thermal stability of raw Siam weed is lower than that of its cellulose nanocrystals due to the presence of the non-cellulosic component with lower temperature of degradation. SEM revealed that degradation of cellulosic chain had occurred. TEM confirmed that the crystal size is in the nanoscale with an average size <100 nm. DLS data revealed a nanocellulose with an average hydrodynamic size of 213 nm and a zeta potential at -9.57 mV.

Recent advancement in isolation, processing, characterization and applications of emerging nanocellulose: A review

The emergence of nanocellulose from various natural resources as a promising nanomaterial has been gaining interest for a wide range application. Nanocellulose serves as an excellent candidate since it contributes numerous superior properties and functionalities. In this review, details of the three main nanocellulose categorised: cellulose nanocrystal (CNC), cellulose nanofibril (CNF), and bacterial nanocellulose (BNC) have been described. We focused on the preparation and isolation techniques to produce nanocellulose including alkaline pre-treatment, acid hydrolysis, TEMPO-mediated oxidation, and enzymatic hydrolysis. The surface modification of nanocellulose through esterification, silylation, amidation, phosphorylation, and carboxymethylation to improve the diverse applications has also been reviewed. Some invigorating perspectives on the applications, challenges, and future directions on the relevant issues regarding nanocellulose are also presented.

Isolation and characterization of cellulose nanofibers from Agave gigantea by chemical-mechanical treatment

Nanocellulose is a renewable and biocompatible nanomaterial that evokes much interest because of its versatility in various applications. This study reports the production of nanocellulose from Agave gigantea (AG) fiber using the chemical-ultrafine grinding treatment. Chemical treatment (alkalization and bleaching) removed non-cellulose components (hemicellulose and lignin), while ultrafine grinding reduced the size of cellulose microfibrils into nanocellulose. From the observation of Transmission Electron Microscopy, the average diameter of nanocellulose was 4.07 nm. The effect of chemical-ultrafine grinding on the morphology and properties of AG fiber was identified using chemical composition, Scanning Electron Microscopy, X-ray Diffraction, Fourier Transform Infrared, and Thermogravimetric Analysis. The bleaching treatment increased the crystal index by 48.3% compared to raw AG fiber, along with an increase in the cellulose content of 20.4%. The ultrafine grinding process caused a decrease in the crystal content of the AG fiber. The crystal index affected the thermal stability of the AG fiber. The TGA results showed that AG fiber treated with bleaching showed the highest thermal stability compared to AG fiber without treatment. The FTIR analysis showed that the presence of CH vibrations from the ether in the fiber. After chemical treatment, the peaks at 1605 and 1243 cm-1 disappeared, indicating the loss of lignin and hemicellulose functional groups in AG fiber. As a result, nanocellulose derived from AG fiber can be applied as reinforcement in environmentally friendly polymer biocomposites.

Confined Chemical Transitions for Direct Extraction of Conductive Cellulose Nanofibers with Graphitized Carbon Shell at Low Temperature and Pressure

Cellulose is the most abundant renewable natural polymer on earth, but it does not conduct electricity, which limits its application expansion. The existing methods of making cellulose conductive are combined with another conductive material or high-temperature/high-pressure carbonization of the cellulose itself, while in the traditional method of sulfuric acid hydrolysis to extract nanocellulose, it is usually believed that a too high temperature will destroy cellulose and lead to experimental failure. Now, based on a new research perspective, by controlling the continuous reaction process and isolating oxygen, we directly extracted intrinsically conductive cellulose nanofiber (CNF) from biomass, where the confined range molecular chains of CNF were converted to highly graphitized carbon at only 90 °C and atmospheric pressure, while large-scale twisted graphene films can be synthesized bottom-up from CNFene suspensions, called CNFene (cellulose nanofiber-graphene). The conductivity of the best CNFene can be as high as 1.099 S/cm, and the generality of this synthetic route has been verified from multiple biomass cellulose sources. By comparing the conventional high-pressure hydrothermal and high-temperature pyrolysis methods, this study avoided the dangerous high-pressure environment and saved 86.16% in energy. These findings break through the conventional notion that nanocellulose cannot conduct electricity by itself and are expected to extend the application potential of pure nanocellulose to energy storage, catalysis, and sensing.

Design and Development of Cellulosic Bionanocomposites from Forestry Waste Residues for 3D Printing Applications

This paper deals with the development of cellulose nanofibres (CNFs) reinforced biopolymers for use in packaging applications. Cellulose nanofibres were extracted from sawdust by a combination of chemical and mechanical treatments. The extracted cellulose nanofibres were chemically modified (fCNFs) and characterised by Fourier Transform Infrared Spectroscopy (FTIR). Bionanocomposites were prepared from biopolymers polylactic acid/polybutylene succinate (PLA/PBS) and cellulose nanofibres by compounding in a twin-screw extruder followed by injection moulding. The developed bionanocomposites were subjected to mechanical and thermal characterisation. As part of product development, CNF-biopolymer pellets were also extruded into filaments which were then 3D printed into prototypes. This work is a successful demonstration of conversion of waste residues into value-added products, which is aligned to the principles of circular economy and sustainable development.

Cellulose nanocrystals in cancer diagnostics and treatment

Cancer is currently a major threat to public health, being among the principal causes of death to the global population. With carcinogenesis mechanisms, cancer invasion, and metastasis remaining blurred, cancer diagnosis and novel drug delivery approaches should be developed urgently to enable management and treatment. A dream break-through would be a non-invasive instantaneous monitoring of cancer initiation and progression to fast-track diagnosis for timely specialist treatment decisions. These innovations would enhance the established treatment protocols, unlimited by evasive biological complexities during tumorigenesis. It is therefore contingent that emerging and future scientific technologies be equally biased towards such innovations by exploiting the apparent properties of new developments and materials especially nanomaterials. CNCs as nanomaterials have undisputable physical and excellent biological properties that enhanced their interest as biomedical materials. This article therefore highlights CNCs utility in cancer diagnosis and therapy. Their extraction, properties, modification, in-vivo/in-vitro medical applications, biocompatibility, challenges and future perspectives are precisely discussed.

Effect of High-Energy Milling on the Dissolution of Anti-HIV Drug Efavirenz in Different Solvents

The anti-HIV drug efavirenz (EFV) displays low and variable bioavailability because of its poor aqueous solubility. Ball milling is a simple and cost-effective alternative to traditional micronization to improve the solubility and dissolution rate of EFV. A multibody dynamics model was employed to optimize the milling process parameters, while the motion of the balls in the mill jar was monitored in operando. This led to a better understanding of the milling dynamics for efficient comminution and enhancement of EFV dissolution. The variability of results for different EFV batches was also considered. Depending on the EFV batch, there were intrinsic differences in how the milling affected the dissolution behavior and inhibition of HIV-1 infection. High-energy grinding is more effective on EFV materials containing an amorphous fraction; it helps to remove agglomeration and enhances dissolution. Polyvinylpyrrolidone (PVP) addition improves the dissolution by forming a hydrophilic layer on the EFV surface, thereby increasing the drug wettability. Polymorphism also affects the quality, dosage, and effectiveness of the drug. The mechanical stress effect and PVP addition on the EFV polymorphic transformation were monitored by X-ray powder diffraction, while the residual of ground EFV was collected after dissolution, analyzed by scanning electron microscopy, and provided insights into the morphological changes.

Methane production from wheat straw pretreated with CaO2/cellulase

There are various lignocellulosic biomass pretreatments that act as attractive strategies to improve anaerobic digestion for methane (CH₄) generation. This study proposes an effective technique to obtain more CH₄via the hydrothermal coupled calcium peroxide (CaO₂) co-cellulase pretreatment of lignocellulosic biomass. The total organic carbon in the hydrolysate of samples treated with 6% CaO₂ and 15 mg enzyme per g-cellulose was 7330 mg L⁻¹, which represented an increase of 92.39% over the total organic carbon value of samples hydrolyzed with the enzyme alone. The promotion of the anaerobic digestion of wheat straw followed this order: hydrothermal coupled CaO₂ co-cellulase pretreatment > hydrothermal coupled CaO₂ pretreatment > enzymatic pretreatment alone > control group. The sample treated with 6% CaO₂ and 15 mg enzyme per g-cellulose gave the highest CH₄ production with a CH₄ yield of 214 mL g⁻¹ total solids, which represented an increase of 64.81% compared to the control group. The CH₄ yield decreased slightly when the amount of added cellulase exceeded 15 mg enzyme per g-cellulose.

This work reports methane production from wheat straw pretreated with CaO₂/cellulase.

Effects of magnesium carbonate concentration and lignin presence on properties of natural cellulosic Cissus quadrangularis fiber composites

Cissus quadrangularis biodegradable natural cellulosic fibers comprehensively characterized to assess their potential as reinforcing materials in polymer composites. Initially, the Cissus quadrangularis fibers were chemically treated with 5% Sodium hydroxide (NaOH) and 5% magnesium carbonate (MgCO₃) to improvise the properties of the fiber. The mechanical test result shows that chemically treated 5% MgCO₃ fiber show that 4% and 24% improved tensile strength compared to NaOH and untreated ones. The cellulose crystallinity of the treated fiber got increased as the amorphous constituents removed. Further, 5% MgCO₃ treatment removed a larger amount of amorphous hemicellulose, lignin, and other impurities present on the fiber surface. Secondly, the composites were fabricated at different combination of MgCO₃ (5%, 10%, 15%), plasticizer (5%, 7.5%, 10%), and fiber volume (20%, 25% and 30%) with L9 Taguchi orthogonal array approach. Based on the results, 5% MgCO₃, 5% plasticizer, and 30% fiber volume showed significant improvement in Young's modulus, tensile, and flexural strength of 8%, 27%, and 16% respectively. Moreover, there was no notable improvement observed on impact strength for both treated (15.91 KJ/m²) and untreated (13.98 KJ/m²) fiber. The scanning electron microscopy (SEM) micrographs used to examine the interface bonding between fiber and the matrix.

Hydrophobic Modification of Cellulose Nanocrystals from Bamboo Shoots Using Rarasaponins

Because of their hydrophilic tendencies, the modification of cellulose nanocrystals (CNCs) is needed for applying them as a hydrophobic drug carrier. Previous studies have investigated several modification agents, such as cetyltrimethylammonium bromide. Natural surfactants, such as rarasaponins (RSs), are suitable to avoid human health and environmental issues. In this work, RSs were attached onto CNCs from bamboo shoots to enhance their hydrophobicity. The initial RS concentration and the operating temperature were studied to obtain the best conditions for the modification process, which had significances (p-value < 5%) toward the amount of RSs linked on the CNCs (q) as the response. A q as high as 203.81 ± 0.98 mg/g was obtained at an initial RS concentration of 2000 mg/L and an operating temperature of 30 °C. The curcumin uptake on CNCs-RSs reached 12.40 ± 0.24%, while it was slowly released until approximately 78% in 3 days.

Methylene blue-covered superparamagnetic iron oxide nanoparticles combined with red light as a novel platform to fight non-local bacterial infections: A proof of concept study against Escherichia coli

Currently, antimicrobial photodynamic therapy (APDT) is limited to the local treatment of topical infections, and a platform that can deliver the photosensitizer to internal organs is highly desirable for non-local ones; SPIONs can be promising vehicles for the photosensitizer. This work reports an innovative application of methylene blue (MB)-superparamagnetic iron oxide nanoparticles (SPIONs). We report on the preparation, characterization, and application of MB-SPIONs for antimicrobial photodynamic therapy. When exposed to light, the MB photosensitizer generates reactive oxygen species (ROS), which cause irreversible damage in microbial cells. We prepare SPIONs by the co-precipitation method. We cover the nanoparticles with a double silica layer - tetraethyl orthosilicate and sodium silicate - leading to the hybrid material magnetite-silica-MB. We characterize the as-prepared SPIONs by Fourier transform infrared spectroscopy, powder X-ray diffraction, and magnetic measurements. We confirm the formation of magnetite using powder X-ray diffraction data. We use the Rietveld method to calculate the average crystallite size of magnetite as being 14 nm. Infrared spectra show characteristic bands of iron‑oxygen as well as others associated with silicate groups. At room temperature, the nanocomposites present magnetic behavior due to the magnetite core. Besides, magnetite-silica-MB can promote ROS formation. Thus, we evaluate the photodynamic activity of Fe₃O₄-silica-MB on Escherichia coli. Our results show the bacteria are completely eradicated following photodynamic treatment depending on the MB release time from SPIONs and energy dose. These findings encourage us to explore the use of magnetite-silica-MB to fight internal infections in preclinical assays.

Improvement in the Oral Bioavailability and Efficacy of New Ezetimibe Formulations-Comparative Study of a Solid Dispersion and Different Micellar Systems

Ezetimibe (EZ) is a poorly water-soluble drug with low bioavailability. Strategies such as solid dispersions (SD) and micellar systems (MS) were developed to identify the most effective drug delivery formulations with the highest oral bioavailability, and to improve their lipid-lowering effect. The EZ formulations were prepared with different proportions of Kolliphor^® RH40 as a surfactant (1:0.25, 1:0.5 and 1:0.75) and croscarmellose as a hydrophilic carrier. These excipients, and the addition of microcrystalline cellulose during the production process, led to significant improvements in the dissolution profiles of MS. Powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) revealed an amorphous form of ezetimibe with different semicrystalline states of microcrystalline cellulose for MS-I (1:0.75) and MS-II (1:0.75). Pharmacokinetic analysis after administration of MS-II (1:0.75) demonstrated a 173.86% increase in maximum plasma concentration (C_max) and a 142.99% increase in oral bioavailability compared to EZ raw material (EZ-RM). Efficacy studies with the micellar system MS-II (1:0.75) in rats with hyperlipidemia showed that total cholesterol, triglycerides and high-density lipoprotein were reduced to normal levels and revealed improvements in low-density lipoprotein, aspartate and alanine aminotransferase. The improvement in the dissolution rate with micellar systems increases bioavailability and enhances the anti-hyperlipidemic effect of EZ.

Effects of rice straw structure on chaetoglobosin A production by Chaetomium globosum CGMCC 6882

As the most abundant macromolecules in nature, lignocelluloses are served as a promising and renewable source for sustainable production of high value chemical compounds. In present work, extrusion pretreatment with 23% (w/w) distilled water, 2% (w/w) glycerol and 1 g/L NaHCO₃ as moisture agent, not only reduced the particle size, crystallinity and component contents (cellulose, hemicelluloses and lignin) of rice straw, but also effectively enhanced chaetoglobosin A yield and degradation rate of rice straw by C. globosum CGMCC 6882. Meanwhile, mycelial biomass of C. globosum CGMCC 6882 increased from 2.9 g/L to 7.0 g/L, mycelia growth time reduced by 2 days and chaetoglobosin A titer increased from 108.4 mg/L to 270.2 mg/L, representing an increase of 149.3%. Furthermore, degradation rate of rice straw by C. globosum CGMCC 6882 increased from 28.93% to 65.38%. This work provides a good guidance for production of chaetoglobosin A from lignocelluloses.

Comparison of Calcium Oxide and Calcium Peroxide Pretreatments of Wheat Straw for Improving Biohydrogen Production

Wheat straw was pretreated with either CaO₂ or CaO to improve biohydrogen production. Both CaO and CaO₂ pretreatments improved the biodegradability of the wheat straw. CaO pretreatment raised the H₂ yield by between 48.8 and 163.9% at CaO contents ranging from 2 to 4%. The highest H₂ yield [144 mL/g total solid (TS)] was obtained at 121 °C and 6% CaO. In addition, the highest H₂ yield from wheat straw pretreated at the same temperature and dosage of CaO₂ was 71.8 mL/g TS, which was higher than that of the control group (43.2 mL/g TS), with hot water (121 °C) treatment. Considering pretreatment costs and H₂ production potential, CaO was a better pretreatment agent than CaO₂.

Preparation of microcrystalline cellulose from residual Rose stems (Rosa spp.) by successive delignification with alkaline hydrogen peroxide

Agricultural residues of Rose flowers (Rosa x hybrida L.) are abundant, cheap, and renewable. These lignocellulosic remains are composed of cellulose, hemicellulose, and lignin. They are an attractive feedstock to produce various value-added products, as microcrystalline cellulose (MCC). The objective of this study was to obtain MCC from residual Rose stems (RS) using a successive alkaline peroxide treatment. X-ray diffraction, Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) were used to determine the degree of crystallinity, structure characteristics, thermal properties, and morphology, respectively, of MCC. The properties of RS-MCC were compared with those of commercial MCC. The degree of crystallinity of RS-MCC was 70.21%. The X-ray diffraction patterns reveal the presence of Type I cellulose. FTIR showed the absence of non-cellulosic components, mainly lignin, present in the amorphous regions of the RS fibers. Results are promising for taking advantage of agricultural residues as a source of MCC, which could be used as a reinforcing agent in polymeric matrices.

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.

Isolation and Characterization of Nanocellulose with a Novel Shape from Walnut (Juglans Regia L.) Shell Agricultural Waste

Herein, walnut shell (WS) was utilized as the raw material for the production of purified cellulose. The production technique involves multiple treatments, including alkaline treatment and bleaching. Furthermore, two nanocellulose materials were derived from WS by 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) oxidation and sulfuric acid hydrolysis, demonstrating the broad applicability and value of walnuts. The micromorphologies, crystalline structures, chemical functional groups, and thermal stabilities of the nanocellulose obtained via TEMPO oxidation and sulfuric acid hydrolysis (TNC and SNC, respectively) were comprehensively characterized. The TNC exhibited an irregular block structure, whereas the SNC was rectangular in shape, with a length of 55-82 nm and a width of 49-81 nm. These observations are expected to provide insight into the potential of utilizing WSs as the raw material for preparing nanocellulose, which could address the problems of the low-valued utilization of walnuts and pollution because of unused WSs.

An insight into nanocellulose as soft condensed matter: Challenge and future prospective toward environmental sustainability

Nanocellulose, a structural polysaccharide that has caught tremendous interests nowadays due to its renewability, inherent biocompatibility and biodegradability, abundance in resource, and environmental friendly nature. They are promising green nanomaterials derived from cellulosic biomass that can be disintegrated into cellulose nanofibrils (CNF) or cellulose nanocrystals (CNC), relying on their sensitivity to hydrolysis at the axial spacing of disordered domains. Owing to their unique mesoscopic characteristics at nanoscale, nanocellulose has been widely researched and incorporated as a reinforcement material in composite materials. The world has been consuming the natural resources at a much higher speed than the environment could regenerate. Today, as an uprising candidate in soft condensed matter physics, a growing interest was received owing to its unique self-assembly behaviour and quantum size effect in the formation of three-dimensional nanostructured material, could be utilised to address an increasing concern over global warming and environmental conservation. In spite of an emerging pool of knowledge on the nanocellulose downstream application, that was lacking of cross-disciplinary study of its role as a soft condensed matter for food, water and energy applications toward environmental sustainability. Here we aim to provide an insight for the latest development of cellulose nanotechnology arises from its fascinating physical and chemical characteristic for the interest of different technology holders.