Carboxymethyl Cellulose Polymer Research Articles

Transient radical species and oxygen colorimetric indicators grounded on phenothiazinium dyes

This study investigates four phenothiazinium dyes including methylene blue (MB) and three analogues containing auxochrome variation 2–4 as oxygen colorimetric indicators prepared by their incorporation into two types of oxygen permeable materials containing: a) polyvinyl alcohol substrate with additional TiO2 photocatalysts (PhOxIn), and b) carboxymethylcellulose polymer matrix containing glucose and KOH (ChOxIn). In vacuum packages where volumetric concentrations of oxygen were below 0.01 %, the leuco forms of the tested phenothiazinum dyes were readily oxidised, initiating the colour turn from white to blue. The redox processes involved were explored by experimental electron paramagnetic resonance EPR and UV–vis spectroscopic methods and further supported by theoretical quantum chemistry. The EPR experiments showed that the chemical oxidation of the leuco-form of the phenothiazinium dyes 1–4 produced transient aminyl radical species with the single electron mainly located at the nitrogen atom of the heterocyclic core. The formation of these transient aminyl species was also perceived by UV–vis spectroscopy, their absorption maxima situated in the 552–592 nm range being also supported by TD-DFT theoretical calculations.

Fabrication and Characterization of Silver Nanoparticle-Doped Chitosan/Carboxymethyl Cellulose Nanocomposites for Optoelectronic and Biological Applications.

The synthesis of nanoparticles using environmentally friendly methods for applications in fields such as food packaging and biomedicine has been gaining increasing attention. Organic-inorganic nanostructures offer opportunities to create innovative materials suitable for use in optoelectronics and biological applications. In this study, we focused on producing nanocomposite films by blending carboxymethyl cellulose (CMC) and chitosan (CS) polymers in equal proportions (50/50 wt %) and adding silver nanoparticles (Ag NPs) through a solution casting process. Our objective was to examine how the introduction of Ag NPs influenced the structural, optical, mechanical, electrical, and antibacterial properties of the virgin CMC/CS composites. XRD patterns of the prepared samples indicated the presence of crystalline Ag phases within the CMC/CS blend. FT-IR spectroscopy showed the primary vibrational peaks associated with CMC and CS, which exhibited reduced intensity after the addition of Ag NPs. The UV absorption of the nanocomposites exhibited a gradual increase and a shift toward longer wavelengths. The electrical properties are enhanced with higher concentrations of Ag NPs. An increase in the content of Ag NPs resulted in a corresponding enhancement of antibacterial activity against both Staphylococcus aureus and Escherichia coli. The CMC/CS-Ag-doped films demonstrated significant enhancements in Young's modulus (Y), tensile stress (σt), and elongation at break (εB). These findings suggest that these nanocomposite films hold promise for potential applications in optoelectronics and biological fields.

Assessing the Utilization of Sawdust in Water-Based Drilling Fluid for Managing Fluid Loss and Enhancing Viscosity

The evaluation of the use of sawdust in drilling fluid formulation is covered in this study. The investigation focused on the physicochemical and rheological properties of water-based mud (WBM) drilling fluids that included four different dosages of sawdust. These properties included yield stress, plastic viscosity, rheological behavior, gel strength, filtration test (API filtrate; American Petroleum Institute), and pH. The sawdust was employed as a substitute for the polymers commonly used in water-based muds (WBMs) to serve either as a viscosifier or as a fluid loss controller. The current study set out to evaluate how sawdust (diameter ≤630 µm) affected the primary characteristics of the drilling muds. Sawdust was utilized in place of carboxymethyl cellulose polymer (CMC) as a viscosifier and polyanionic cellulose polymer (PAC) as a filtrate reducer at several dosages (0, 10, 20, 50, and 100 g/L). It was found that the sawdust dosage and its role had a significant impact on the rheological characteristics of the drilling fluids. At amounts between 20 and 50 g/L, the sawdust was added as a viscosifier to the drilling fluids under study, resulting in a significant improvement in their physicochemical and rheological parameters (yield stress, plastic viscosity, and gel strength). However, the drilling fluids showed extremely high rheological properties and a viscosity that can slow down fluid circulation in the well when 100 g/L of sawdust were used, totally substituting for the polymers.

Insitu synthesis of gold nanospheres immobilised carboxymethyl cellulose-based conductive hydrogel bioink for 3D bioprinting technology

Electrically conductive bioink (ECB) improves the cellular electrical coupling which increases the propagation of cells in bioprinted 3D scaffolds for developing biomimetic architectures. The preparation of ECB predominantly relies on synthetic organic polymers and inorganic nanomaterials, which have certain limitations such as cytotoxicity, weak mechanical stability, and non-biodegradability. The current study focuses on synthesising an ECB immobilised with gold nanospheres (GNS) within the carboxymethyl cellulose (CMC) polymer to eliminate the drawbacks of ECB preparation. Insitu reduction of gold into stable gold nanoparticles within the CMC hydrogel polymer matrix imparted better conductivity without compromising the bioink properties for 3D bioprinting technology.

The physicochemical properties and molecular docking study of plasticized amphotericin B loaded sodium alginate, carboxymethyl cellulose, and gelatin-based films

Plasticizers are employed to stabilize films by safeguarding their physical stability and avoiding the degradation of the loaded therapeutic drug during processing and storage. In the present study, the plasticizer effect (glycerol) was studied on bioadhesive films based on sodium alginate (SA), carboxymethyl cellulose (CMC) and gelatin (GE) polymers loaded with amphotericin B (AmB). The main objective of the current study was to assess the morphological, mechanical, thermal, optical, and barrier properties of the films as a function of glycerol (Gly) concentration (0.5–1.5 %) using different techniques such as Scanning Electron Microscope (SEM), Texture analyzer (TA), Differential Scanning Calorimeter (DSC), X-Ray Diffraction (XRD), and Fourier Transforms Infrared Spectroscopy (FTIR). The concentration increase of glycerol resulted in an increase in Water Vapor Permeability (WVP) (0.187–0.334), elongation at break (EAB) (0.88–35.48 %), thickness (0.032–0.065 mm) and moisture level (17.5–41.76 %) whereas opacity, tensile strength (TS) (16.81–0.86 MPa), and young's modulus (YM) (0.194–0.002 MPa) values decreased. Glycerol incorporation in the film-Forming solution decreased the brittleness and fragility of the films. Fourier Transform Infrared (FTIR) spectra showed that intermolecular hydrogen bonding occurred between glycerol and polymers in plasticized films compared to control films. Furthermore, molecular docking was applied to predict the binding interactions betweem AmB, CMC, gelatin, SA and glycerol, which further endorsed the stabilizing effects of glycerol in the complex formation between AmB, CMC, SA, and gelatin. The Findings of the current study demonstrated that this polymeric blend could be used to successfully prepare bioadhesive films with glycerol as a plasticizer.

Influence of Battery Electrode Manufacturing Process on Electrode Characteristics and Electrochemical Performance

The numerous battery gigafactory projects show that the Li-ion battery sector is booming. Although groundbreaking technologies such as all-solid-state batteries mobilize a lot of research effort, current Li-ion liquid technology still needs to be updated. Only a few publications are related to electrode manufacturing. However, increasing the active material content, the areal capacity, or the solid slurry content is key to improve the energy density but also the manufacturing costs.The objectives of this thesis work are to understand and improve the preparation of the slurry and the manufacturing process as a whole in order to obtain the best possible performances depending on the material used. Initially, the study is carried out in an aqueous formulation for negative graphite electrodes. Still, it will be extended after that to the positive electrode in an organic formulation. The negative electrode is very interesting from a fundamental study point of view because of its specificities that limit the fast charge operation of the cells with a risk of metallic lithium deposit. This electrode's basic composition, in weight, is 96.5% graphite (90/10 mixture of natural and artificial graphite), 1.3% Na-CMC, 1.7% latex, and 0.5% electronic conductor.Eleven significant parameters were selected thanks to preliminary results and literature outcomes. Their impact is determined by crossing experiences and varying them thanks to a rational approach based on the design of experiments (DOE) methodology. A DOE is carried out to be able to study this large number of parameters with a limited number of trials. Apart from the active material and the mixer used, the parameters are grouped into three categories:- The CMC (CarboxyMethylCellulose) polymer, with the molar mass, the substitution degree, and its content.- The electronic conductors, the content as well as the nature (nanotube, nano-sphere, and platelet)- Electrode properties such as coating speed, porosity, or loading.To determine their influences, characterizations are carried out throughout the electrode coating. The slurries are analyzed by rheology and scanning electron microscopy (SEM). The adhesion of the electrodes and their structuring are measured, with particular attention on the electronic resistivity and tortuosity. Finally, the electrodes obtained are tested by electrochemical cycling at various charging rates.Tortuosity is a particularly sensitive factor in relation to the issue of rapid charge/discharge [1]. The tortuosity is measured by electrochemical impedance in the blocking and symmetric electrode configuration and corresponds to the measurement of the distance traveled by the ions in order to cross an electrode (Figure 1). [2]The results of this wide study will be presented with parameter sensitivity on capacity retention, high charging rate capabilities, or electrode mechanical properties. Interrelations between the parameters will be pointed out. Optimal electrode formulations and designs will be presented to validate the approach.[1] D. Grießl, A. Adam, K. Huber, and A. Kwade, "Effect of the Slurry Mixing Process on the Structural Properties of the Anode and the Resulting Fast-Charging Performance of the Lithium-Ion Battery Cell," J. Electrochem. Soc., vol. 169, no. 2, p. 020531, 2022, doi: 10.1149/1945-7111/ac4cdb.[2] J. Landesfeind, J. Hattendorff, A. Ehrl, W. A. Wall, and H. A. Gasteiger, "Tortuosity Determination of Battery Electrodes and Separators by Impedance Spectroscopy," J. Electrochem. Soc., vol. 163, no. 7, pp. A1373–A1387, 2016, doi: 10.1149/2.1141607jes Figure 1

Facile synthesis of fluorescent carboxymethyl cellulose polymer dots and multi-purpose applications in pH and glucose sensing

Herein, fluorescent carboxymethyl cellulose polymer dots (B-PDs) were synthesized by a straightforward route under mild conditions using ethylenediamine-modified carboxymethyl cellulose (CMC-NH2) and phenylboronic acid as precursors. The B-PDs exhibit a uniform nanoscale size distribution, good water solubility, photostability and excellent fluorescence emission with a high fluorescence quantum yield of 21.6 %. The B-PDs display a reversible fluorescence response with blue emission in acidic solution and green emission in alkaline solution. Moreover, the B-PDs can be designed as an excellent fluorescent sensor for glucose detection. After the addition of glucose, the FL intensity at λex = 388 nm can be enhanced due to the assembly of glucose on the B-PDs based on the reversible reaction between boronic acid and cis-diols through the aggregation-induced enhancement effect (AIE). Two good linear relationships can be obtained between (F-F0)/F0 and the glucose amount ranging from 0 ∼ 0.005 M (R2 = 0.9971) and 0.01 ∼ 1.2 M (R2 = 0.9984), and the detection limit (LOD) was calculated to be 52 μM (3σ/slope). Meanwhile, the proposed probe was successfully utilized to analyze glucose in human urine samples (recovery: 97.9–104.1 %, RSD: 2.64–4.23 %) by the standard addition method, indicating good feasibility as a practical platform for sensing.

Immobilization of hydrochar in cellulose beads for eradicating paracetamol from synthetic and sewage water

Sodium carboxymethyl cellulose polymer was used as a support matrix in immobilizing activated hydrochar derived from bamboo using hydrothermal carbonization. The structural and textural morphology of the beads were studied using FTIR, XRD, SEM/EDS, BET and TGA. Activated hydrochar showed a rough surface with irregular spherical shaped structure. Various oxygenated functional groups in composite beads and activated hydrochar were identified that assist in interaction with PARA pollutant. TGA analysis showed weight loss at three stages 200 °C, 365 °C and 710 °C that leads to complete disintegration of composite beads. BET analysis showed a variation in the surface area between activated hydrochar and beads which could be due to air drying process. Batch adsorption test was conducted for investigating the efficiency of beads in removing PARA from water. Pseudo-second order and Langmuir isotherm fitted the best highlighting chemical mode of adsorption with homogenous interaction on the adsorbent surface. 48.12 mg g−1 was the maximum adsorption capacity estimated from sorption between beads and PARA. For practical applications beads were effectively used in reducing COD levels of PARA spiked sewage water with the defined experimental parameters. Ethanol would be effectively used as regenerating solvent in recycling the beads for the betterment of cost reduction. The activated hydrochar immobilized cellulose beads would be successfully applied as adsorbent in removing target pollutants from water thereby reducing the hurdles faced with respect to fine particles in water treatment.

Polydopamine-Modified Carboxymethyl Cellulose as Advanced Polysulfide Trapping Binder

The search for a high-energy-density alternative to lithium-ion batteries has led to great interest in the lithium sulfur battery (LSB). However, poor cycle lifetimes and coulombic efficiencies (CEs) due to detrimental lithium polysulfide (LiPS) shuttling has hindered its widespread adoption. To address this challenge, a modified sodium carboxymethyl cellulose (CMC) polymer with integrated dopamine moieties and polydopamine nanoparticles was created through a facile one-pot dopamine (DOP) amidation reaction to strengthen noncovalent interactions with LiPSs and mitigate the shuttling effect. The resulting CMC-DOP binder improved electrode wettability, adhesion, and electrochemical performance. Compared to LSBs with a standard CMC binder, CMC-DOP 5:1 (with a 5:1 weight ratio of CMC to dopamine precursor) improves the specific capacity at cycle 100 by 38% to 552 mAh g−1 and CE from 96.8 to 98.9%. LSBs show good stability, even after 500 cycles. Post-mortem electrochemical impedance spectroscopy (EIS) and energy-dispersive spectroscopy (EDS) studies confirmed the effectiveness of the CMC-DOP in confining LiPS in the cathode. This simple but effective nature-inspired strategy promises to enhance the viability of LSBs without using harmful chemicals or adding excess bulk.

Rheological insights on Carboxymethyl cellulose hydrogels

Hydrogels are copiously studied for tissue engineering, drug delivery, and bone regeneration owing to their water content, mechanical strength, and elastic behaviour. The preparation of stable and mechanically strengthened hydrogels without using toxic crosslinkers and expensive approaches is immensely challenging. In this study, we prepared Carboxymethyl cellulose based hydrogels with different polymer concentration via a less expensive physical crosslinking approach without using any toxic crosslinkers and evaluated their mechanical strength. In this hydrogel system, the carbopol concentration was fixed at 1 wt/v% and the Carboxymethyl cellulose concentration was varied between 1 and 5 wt/v%. In this hydrogel system, Carbopol serves as the crosslinker to bridge Carboxymethyl cellulose polymer through hydrogen bonds. Rheological analysis was employed in assessing the mechanical properties of the prepared hydrogel, in particular, the viscoelastic behaviour of the hydrogels. The viscoelastic nature and mechanical strength of the hydrogels increased with an increase in the Carboxymethyl cellulose polymer concentration. Further, our results suggested that gels with Carboxymethyl cellulose concentration between 3 wt/v % and 4 wt/v % with yield stresses of 58.83 Pa and 81.47 Pa, respectively, are potential candidates for use in transdermal drug delivery. The prepared hydrogels possessed high thermal stability and retained their gel network structure even at 50 °C. These findings are beneficial for biomedical applications in transdermal drug delivery and tissue engineering owing to the biocompatibility, stability, and mechanical strength of the prepared hydrogels.

Multi-characteristic tannic acid-reinforced polyacrylamide/sodium carboxymethyl cellulose ionic hydrogel strain sensor for human-machine interaction

Big data and cloud computing are propelling research in human-computer interface within academia. However, the potential of wearable human-machine interaction (HMI) devices utilizing multiperformance ionic hydrogels remains largely unexplored. Here, we present a motion recognition-based HMI system that enhances movement training. We engineered dual-network PAM/CMC/TA (PCT) hydrogels by reinforcing polyacrylamide (PAM) and sodium carboxymethyl cellulose (CMC) polymers with tannic acid (TA). These hydrogels possess exceptional transparency, adhesion, and remodelling features. By combining an elastic PAM backbone with tunable amounts of CMC and TA, the PCT hydrogels achieve optimal electromechanical performance. As strain sensors, they demonstrate higher sensitivity (GF = 4.03), low detection limit (0.5 %), and good linearity (0.997). Furthermore, we developed a highly accurate (97.85 %) motion recognition system using machine learning and hydrogel-based wearable sensors. This system enables contactless real-time training monitoring and wireless control of trolley operations. Our research underscores the effectiveness of PCT hydrogels for real-time HMI, thus advancing next-generation HMI systems.

In vitro evaluation of drying supports and adhesive polymers as adjuvants for biocontrol of Diplodia seriata by Trichoderma harzianum and Clonostachys rosea

Grapevine trunk diseases (GTDs) can cause large losses in vineyards. Diplodia seriata is an important GTD pathogen in Chile. Development and use of bioprotectors is a complementary alternative to the use of agrochemicals for disease management. To produce bioformulations for management of D. seriata, additives could be used to maintain viability and survival of biocontrol agents, such as Trichoderma harzianum and Clonostachys rosea. Effects of drying supports (inulin, maltodextrin, lactose, or talc) and adhesive polymers (carboxymethylcellulose, Aloe vera gel, or chitosan) were assessed on D. seriata conidium viability and mycelium development of T. harzianum and C. rosea, and for their biocontrol capacity against D. seriata. T. harzianum and C. rosea cultured in Potato Dextrose Agar containing inulin (at 10% w/v) maltodextrin (10% w/v), lactose (6% w/v), or talc (4% w/v), or the adhesive polymers carboxymethylcellulose (0.5% w/v), Aloe vera gel (0.5% w/v), or chitosan (1.5% w/v), maintained their biocontrol activity against D. seriata. These additives did not enhance D. seriata development. Therefore, these preparations, at the respective indicated concentrations, can be included in bioformulations for management of disease caused by this pathogen.

Experimental analysis of tribological performance of base ficus carica vegetable oil with different polymers as additives using four ball tribometer

The need to use vegetable lubricants has been driven by the widespread concern for environmental issues, especially in industries that overuse petroleum lubricants. This research examined the tribological characteristics of vegetable-based lubricants by adding additives such as ethylene–vinyl acetate (EVA) and Eichhornia crassipes carboxymethyl cellulose (EC-CMC) polymers to study the viscometric response of the lubricants. The test was conducted using four ball-tester, and analyzed in terms of coefficient of friction (COF), wear scar diameter (WSD), and wear scar rate, respectively. The results showed that with the addition of each additive enhanced the tribological properties significantly but yielded poor results with 0.5% additives for both samples. The characterization investigation showed that ficus carica (Fig) oil responded effectively to the addition of various additives when conducted thermogravimetric analysis (TGA) and Fourier transform infrared (FT-IR) spectroscopy. Under 100 kg load and speed of 1200 rpm, base Fig lubricant yielded a higher COF of 0.193, while blended EVA and EC-CMC gave lower COF of 0.161 and 0.171, while the lowest wear scar diameter was with 1.5 wt% EVA (0.39 mm) and 1 wt% EVA (0.41 mm), respectively. Comparing all the lubricants under 1500 rpm, the base Fig lubricant yielded 0.317, while 1.5 wt% EVA, 1.5 wt% EC-CMC, SEA 5W 30 gives COF of 0.287, 0.263, and 0.239, respectively. The study revealed that the reduction in the COF and wear scar diameter was due to the formation of the film by the included additive.

Investigating the tunable properties of double blended nanocomposite films exposed to direct Nd:YAG laser beam

Detailed characterization for double blended nanocomposite films of PVP (Polyvinylpyrrolidone)/CMC (carboxy-methyl cellulose) polymer blends doped with SnO2 and ZnS nanoparticles based on different proportional concentrations (1-x)SnO2 -x ZnS (x = 0, 0.25, 0.5, 0.75, 1) has been represented. Nanoparticles were synthesized based on the sol-gel technique, while nanocomposite films were prepared using the casting technique. The crystalline structures for both nanoparticles and nanocomposite films before and after laser exposure have been discussed by the x-ray technique. Fourier transform infrared spectroscopic technique (FTIR) revealed variations in the vibrational bands intensities and locations under the effect of both laser exposure and nanoparticles. The morphological features of the studied samples have been discussed through SEM (Scanning Electron Microscope) images. The optical properties (linear-nonlinear) of nanocomposite films have been discussed in details using UV–Vis spectroscopy technique. The refractive index has been calculated based on different proposed models. Similarities in the refractive index values have been observed. The effect of direct laser beam exposure on the estimated values of energy gap Eg has been represented in details. Eg values showed a reduction from 5.1 eV (for undoped films) to 4.8 eV (for laser exposed doped films). Nanocomposite films fully doped with 100% zinc sulphide nanoparticles exhibited the lowest Eg value (4 eV). Linear and nonlinear optical parameters confirmed the dominant effect of direct laser exposure compared with the particle size effect.

Microscopic understanding of the supramolecular interaction in enhanced oil recovery

The researchers found that supramolecular polymers have great application potential in improving oil recovery in medium and high permeability reservoirs, especially supramolecular polymers based on host–guest interaction. This study employed quantum chemical calculations and molecular dynamics simulations to investigate the interaction between adamantane and cyclodextrin molecular monomers, as well as the self-assembly mechanism of their modified carboxymethylcellulose in an aqueous solution. The study found that the interaction between adamantane and cyclodextrin molecular monomers is obvious, and the interaction is mainly van der Waals interaction rather than electrostatic interaction. The simulation results for molecular dynamics indicate that modified carboxymethylcellulose polymers follow an assembly mechanism summarized as “node-reinforcement-cement”. In this mechanism, modified molecules interact closely with each other, forming a “node”. The supramolecular polymer then unfolds around the node, creating a “reinforcement bar”. Finally, the addition of water molecules acts as “cement” to form a supramolecular hydrogel. Our research reveals the mechanism of supramolecular self-assembly at the molecular level, which provides a theoretical basis for the next step in the design of new supramolecular polymers.

The influence of molecular weight of cellulose on the properties of carboxylic acid crosslinked cellulose hydrogels for biomedical and environmental applications

Hydrogels a three-dimensional network structure of hydrophilic polymers have gained significant interest in the field of biomedicine due to its high-water absorption properties and its resemblance to the native extracellular matrix. However, the hydrogel's physicochemical properties are important in its ability to serve as a matrix in biomedical applications. The variations in the molecular weight of polymers in the preparation of crosslinked hydrogels may alter the properties. Different molecular weight carboxymethyl cellulose polymers were employed in this work to determine the effect of molecular weight on the physicochemical parameters of the hydrogel's crosslinking reaction. For this study, two distinct molecular weight carboxymethyl cellulose (CMC) polymers (Mw, 250,000 and 700,000) and various concentrations of crosslinker solution were used. The hydrogels were prepared through a chemical crosslinking reaction combining CMC and citric acid, which results in the formation of an ester bond between the two polymer chains. The crosslinking reaction is confirmed by Fourier transform infrared spectroscopy and total carboxyl content analysis. According to the physicochemical, thermal, and mechanical analysis, we have identified that 7 %, 9 % and 10 % citric acid showed the most promising hydrogels and found 7CMC hydrogel had superior quality. In vitro results demonstrated that the citric acid crosslinked CMC had excellent hemocompatibility and cytocompatibility.

Kinetic Study for Janus Green Dye Adsorption from Aqueous Solutions Using Iraqi Bauxite Clay and its Composite

Clays are considered important natural materials in the field of water purification, including bauxite clay (BAU) and its prepared and activated composite (BAU/CMC-AC) with carboxymethyl cellulose polymer. The ad-sorbent surfaces are characterized by FTIR and XRD techniques. The adsorp-tion of green janus (JG) from an aqueous solution with bauxite and its compo-site were studied under the influence of different conditions of the weight and size of adsorbed surface particles, contact time and temperature. The results were found to be: contact time (90, 45) min for maximum quantity adsorbed of (JG) dye on bauxite and its composite respectively. The experimental data were tested on pseudo 1st- and 2nd-order kinetic models. It was shown to apply more with the pseudo-2nd order kinetic model for both adsorbents. It also showed that the highest removal percentage were (78%, 88.5 %) for the bauxite surface and its composite (BAU, BAU/CMC-AC) at the preferred temperature

Design of Phage-Cocktail–Containing Hydrogel for the Treatment of Pseudomonas aeruginosa–Infected Wounds

Recently, the treatment of infected wounds has become a global problem due to increased antibiotic resistance in bacteria. The Gram-negative opportunistic pathogen Pseudomonas aeruginosa is often present in chronic skin infections, and it has become a threat to public health as it is increasingly multidrug resistant. Due to this, new measures to enable treatment of infections are necessary. Treatment of bacterial infections with bacteriophages, known as phage therapy, has been in use for a century, and has potential with its antimicrobial effect. The main purpose of this study was to create a phage-containing wound dressing with the ability to prevent bacterial infection and rapid wound healing without side effects. Several phages against P. aeruginosa were isolated from wastewater, and two polyvalent phages were used to prepare a phage cocktail. The phage cocktail was loaded in a hydrogel composed of polymers of sodium alginate (SA) and carboxymethyl cellulose (CMC). To compare the antimicrobial effects, hydrogels containing phages, ciprofloxacin, or phages plus ciprofloxacin were produced, and hydrogels without either. The antimicrobial effect of these hydrogels was investigated in vitro and in vivo using an experimental mouse wound infection model. The wound-healing process in different mouse groups showed that phage-containing hydrogels and antibiotic-containing hydrogels have almost the same antimicrobial effect. However, in terms of wound healing and pathological process, the phage-containing hydrogels performed better than the antibiotic alone. The best performance was achieved with the phage-antibiotic hydrogel, indicating a synergistic effect between the phage cocktail and the antibiotic. In conclusion, phage-containing hydrogels eliminate efficiently P. aeruginosa in wounds and may be a proper option for treating infectious wounds.

Bioengineered Water-Responsive Carboxymethyl Cellulose/Poly(vinyl alcohol) Hydrogel Hybrids for Wound Dressing and Skin Tissue Engineering Applications.

The burden of chronic wounds is growing due to the increasing incidence of trauma, aging, and diabetes, resulting in therapeutic problems and increased medical costs. Thus, this study reports the synthesis and comprehensive characterization of water-responsive hybrid hydrogels based on carboxymethyl cellulose (CMC) and poly(vinyl alcohol) (PVA) using citric acid (CA) as the chemical crosslinking agent, with tunable physicochemical properties suitable to be applied as a wound dressing for soft tissue engineering applications. They were produced through an eco-friendly process under mild conditions. The hydrogels were designed and produced with flexible swelling degree properties through the selection of CMC molecular mass (Mw = 250 and 700 kDa) and degree of functionalization (DS = 0.81), degree of hydrolysis of PVA (DH > 99%, Mw = 84-150 kDa) associated with synthesis parameters, CMC/PVA ratio and extension of chemical crosslinking (CA/CMC:PVA ratio), for building engineered hybrid networks. The results demonstrated that highly absorbent hydrogels were produced with swelling degrees ranging from 100% to 5000%, and gel fraction from 40% to 80%, which significantly depended on the concentration of CA crosslinker and the presence of PVA as the CMC-based network modifier. The characterizations indicated that the crosslinking mechanism was mostly associated with the chemical reaction of CA carboxylic groups with hydroxyl groups of CMC and PVA polymers forming ester bonds, rendering a hybrid polymeric network. These hybrid hydrogels also presented hydrophilicity, permeability, and structural features dependent on the degree of crosslinking and composition. The hydrogels were cytocompatible with in vitro cell viability responses of over 90% towards model cell lines. Hence, it is envisioned that this research provides a simple strategy for producing biocompatible hydrogels with tailored properties as wound dressings for assisting chronic wound healing and skin tissue engineering applications.

Production and Characterization of Bio‐based Sponges Reinforced with Hypericum perforatum oil (St. John′s Wort Oil) via Pickering Emulsions for Wound Healing Applications

AbstractHypericum perforatum oil (HPO) was known as Saint John′s wort oil which has antibacterial properties for medicinal applications. (topically to heal wounds). In this study, Pickering sponges containing HPO have been stabilized using β‐cyclodextrin (β‐CD) natural substance while Polyvinyl alcohol/sodium carboxymethyl cellulose (PVA/CMC) polymer matrices. The β‐CD/HPO inclusion complexes were added to the PVA/CMC sponges in various ratios (1 : 1, 1 : 4, and 1 : 8) and morphological, thermal and physical properties of sponges were investigated based on the ratios. SEM images revealed all Pickering PVA/CMC/HPO sponges has good porosity and PVA/CMC sponges containing (1 : 8 w/v) of β‐CD/HPO indicated the highest porosity. Furthermore, existence of HPO in the sponges were confirmed by FT‐IR analysis. Similarly, thermal stability is increased as the β‐CD/HPO increased. Contact angle value rise from 12.7° to 89.9° as HPO concentration increased, and this value is the ideal hydrophobicity for the skin. Antibacterial efficiency showed good antibacterial activities of Pickering sponges containing the highest amount of HPO (1 : 8 w/v of β‐CD/HPO) against Gram (−) (Escherichia coli), and Gram (+) (Staphylococcus aureus, P. aeruginosa) bacteria with 13–17 mm zone inhibition diameter. All samples showed biocompatibility, and the material with the lowest amount of HPO (1 : 1 w/v of β‐CD/HPO) having the best biocompatibility. The increase in the HPO amount in Pickering sponges caused a decrease in mechanical properties. As a result, the resulting PVA/CMC/HPO Pickering sponges can be utilized in wound dressing applications owing to their imroved antibacterial activity results.