Structure, physicochemical properties, and adsorption performance of the ethyl cellulose/bentonite composite films

Ethyl-Cellulose Nanosponges for Topical Delivery of Simvastatin with Preferential Skin Retention for Wound Healing in a Full-Thickness Wound Rat Model

Novel topical nanosponges were implemented to improve the skin availability of simvastatin (SV) for treating full-thickness wounds while controlling the scarring process. SV exhibits great potential in treating various skin diseases owing to its antibacterial, antioxidant, anti-inflammatory, and immunomodulatory properties. However, its poor oral bioavailability and systemic side effects have hindered its clinical application in dermatology. For the first time, nanosponges were utilized to target injured skin, creating an SV reservoir within the wound bed to enhance therapeutic efficacy while minimizing adverse effects. Herein, SV-loaded ethyl-cellulose nanosponges (SV-NS) were prepared using the emulsion solvent evaporation technique, optimizing organic solvents, SV concentration, and stabilizer concentration. The selected SV-NS (20 mg SV) exhibited nanoporous particles (786.2 ± 50 nm), a specific surface area of 10.3 m2/g, and a total pore volume of 0.016 cm3/g, offering sustained release and enhanced skin retention capacity. In vivo studies on full-thickness rat wounds confirmed that topical SV-NS (5 mg SV, applied every 5 days) significantly accelerated wound closure (P < 0.0001), achieving 76.23 ± 3.20% closure by day 8, a 47% improvement over free SV. Consequently, SV-NS facilitated wound closure exceeding 90% by day 11, whereas free SV required 16 days to attain a comparable level, representing a 31.2% faster healing rate. Histological analysis further revealed that SV-NS promoted optimal epidermal layer formation and well-organized collagen deposition, with collagen expression significantly (P < 0.0001) reaching 59.85 ± 3.17% by day 16. Conclusively, SV-NS enhances SV's dermal availability, improving wound healing and minimizing side effects, demonstrating a promising approach for wound restoration.

Recent progresses in bentonite/lignin or polysaccharide composites for sustainable water treatment

Today, with the growth of the human population, industrial activities have also increased. Different industries such as painting, cosmetics, leather, etc. have broadly developed, and as a result, they also produce a lot of pollutants. These pollutants can enter the environment and pollute water, air, and soil. Organic dyes, nitro compounds, drug residues, pesticides and herbicides are pollutants that should be removed from the environment. Natural polymers or biopolymers are important types of organic materials that are broadly applied for different applications. Among them, polysaccharides and lignin, which are two types of biopolymers, have attracted much consideration owing to their advantages such as biocompatibility, environmental friendly, safety, availability, etc. Polysaccharides include cellulose, gum, starch, alginate (Alg), chitin, and chitosan (CS). On the other hand, bentonite is one of the types of clays, which owing to their properties like large specific surface area, adsorption performance, naturally available, etc., have drawn the interest of many researchers. As a result, the synthesis of a composite including polysaccharide/lignin and bentonite can be very efficient for different applications, especially environmental ones. In this review, we instigated the preparation of these composites as well as the removal performance of them. In fact, we reported recent advancements in the synthesis of lignin- and polysaccharide-bentonite composites for the removal of diverse kinds of contaminants like organic dyes, nitro compounds, and hazardous materials.

Multifunctional bacterial cellulose-bentonite@polyethylenimine composite membranes for enhanced water treatment: Sustainable dyes and metal ions adsorption and antibacterial properties

Developing multifunctional materials for water treatment remains a significant challenge. Bacterial cellulose (BC) holds immense potential as an adsorbent with high pollutant-binding capacity, hydrophilicity, and biosafety. In this study, N-acetylglucosamine was used as a carbon source to ferment BC, incorporating amide bonds in situ. Bentonite, renowned for its adsorption properties, was added to the culture medium, resulting in BC-bentonite composite membranes via a one-step fermentation process. Polyethyleneimine (PEI) was crosslinked with amide bonds on the membrane via glutaraldehyde through Schiff base reactions to enhance the performance of the composite membrane. The obtained membrane exhibited increased hydrophilicity, enhanced active adsorption sites, and enlarged specific surface area. It not only physically adsorbed contaminants through its unique structure but also effectively captured dye molecules (Congo red, Methylene blue, Malachite green) via electrostatic interactions. Additionally, it formed stable complexes with metal ions (Cd²⁺, Pb²⁺, Cu²⁺) through coordination and effectively adsorbed their mixtures. Moreover, the composite membrane demonstrated the broad-spectrum antibacterial activity, effectively inhibiting the growth of tested bacteria. This study introduces an innovative method for fabricating composite membranes as adsorbents for complex water pollutants, showing significant potential for long-term wastewater treatment of organic dyes, heavy metal ions, and pathogens.

Enhanced adsorption of Pb2+ by the oxygen-containing functional groups enriched activated carbon

Lead is one of the primary pollutants found in water and poses significant toxicity risks to humans; thus, it is necessary to investigate techniques for removing it economically and efficiently. In order to enhance the removal capacity of Pb2+, coconut shell-based activated carbon (AC) was modified with introducing oxygen-containing functional groups (OFGs) via nitric acid (HNO3) or hydrogen peroxide (H2O2) modification in this study. The characterization results show that after oxidation treatment, the content of OFGs increased, and the textural properties of the samples do not change significantly. This indicates that the modification conditions used in this study effectively introduced OFGs while avoiding the adverse effects on physical adsorption ability of AC caused by oxidation treatment. The Pb2+ adsorption capacities of the AC modified with 10 M HNO3 and 30 wt.% H2O2 were 4.26 and 3.64 times that of the pristine AC, respectively. The experimental data can be well fitted using the Langmuir isotherm model and the Elovich kinetic model, suggesting that the adsorption of Pb2+ on AC belongs to single-layer adsorption, and chemical adsorption dominates the adsorption process. In summary, the hydrothermal-assisted HNO3/H2O2-modified coconut shell-based AC shows great potential in efficiently removing Pb2+ from solutions, offering a solution for utilizing coconut shell waste.

Cellulose nanocrystals intercalated clay biocomposite for rapid Cr(VI) removal

The application of bentonite (Bt) as an adsorbent for heavy metals has been limited due to its hydrophobicity and insufficient surface area. Herein, we present cellulose nanocrystal (CNC) modified Bt composite (CNC@Bt) with enhanced efficiency for Cr(VI) removal. CNC@Bt exhibited an increased specific surface area and a porous structure, while maintaining the original crystal structure of Bt. This was achieved through a synergistic function of ion exchange, hydrogen bonding, electrostatic interactions, and steric hindrance. The adsorption of Cr(VI) by CNC@Bt followed the pseudo-second-order kinetic and Langmuir isotherm adsorption model. Moreover, the process was endothermic and spontaneous. At an initial Cr(VI) concentration of 20 mg/L and pH = 4.0, 10 g/L CNC@Bt achieved a removal rate of 92.7%, and the adsorption capacity was 1.85 mg/g, significantly higher than bare Bt (37.9% and 0.76 mg/g). The removal efficiency remained consistently above 80% over a wide pH range, indicating the potential practical applicability of CNC@Bt. With its fast adsorption rate, pH adaptability, and stable performance, CNC@Bt presents promising prospects for the rapid treatment of Cr-contaminated wastewater.

Simple, One-Pot Method for Preparing Transparent Ethyl Cellulose Films with Good Mechanical Properties

In this research, ethyl cellulose films were prepared by a simple, easy, controlled one-pot method using either ethanol or ethyl lactate as solvents, the films being formed at 6 °C. Titanium dioxide nanoparticles were incorporated to improve the oxygen transmission and water vapour transmission rates of the obtained films. This method used no plasticizers, and flexible materials with good mechanical properties were obtained. The resulting solvent-free and transparent ethyl cellulose films exhibited good mechanical properties and unique free-shapable properties. The obtained materials had similar properties to those reported in the literature, where plasticizers were incorporated into ethyl cellulose films with an elastic modulus of 528 MPa. Contact angles showed the hydrophobic nature of all the prepared materials, with contact angles between 80 and 108°. Micrographs showed the smooth surfaces of the prepared samples and porous intersections with honeycomb-like structures. The oxygen and water vapor transmission rates were the lowest for the ethyl cellulose films prepared in ethyl lactate, these being 615 cm³·m⁻²·day⁻¹ and 7.8 gm⁻²·day⁻¹, respectively, showing that the films have promise for food packaging applications.