Synthesis and Applications of Carboxymethyl Cellulose Hydrogels

Enhanced removal of lead and zinc by a 3D aluminium sulphate-functionalised graphene aerogel as an effective adsorption system

The discharge of heavy metals into the environment has adversely affected the aquatic ecosystem due to their toxic and non-biodegradable nature. In this research, a three-dimensional graphene oxide/carboxymethylcellulose/aluminium sulphate (GOCAS) aerogel was synthesised and evaluated as a novel means for lead and zinc removal. The GOCAS aerogel was prepared via ice-templating of graphene oxide with carboxymethylcellulose and aluminium sulphate as the crosslinking and functionalisation additives. Characterisation of the aerogel by various analytical techniques confirmed the successful integration of the chemical additives. The hydroxyl and sulphate groups in the aerogel were found to participate in the adsorption of both metals. The equilibrium of lead adsorption was found to correlate well to the Freundlich isotherm, while zinc adsorption fitted closely the Langmuir isotherm. The kinetic adsorption behaviour of both metals was best described as pseudo-second-order. The interactive influences of concentration, temperature, contact time and adsorbent dose on the metal removal were explored by a central composite design, and the optimum adsorption capacity for lead was determined to be 138.7 mg/g at a GOCAS dose of 20 mg, initial concentration of 100 mg/L, temperature of 50 °C and contact time of 45 min. The optimum adsorption capacity for zinc was 52.69 mg/g at 30 mg, 65 mg/L, 45 °C and 40 min. Furthermore, regeneration studies with hydrochloric acid eluant were successfully conducted for up to four adsorption-desorption cycles. Overall, this work demonstrates that GOCAS aerogel is a viable nanosorbent for the adsorption of lead and zinc from water systems.

Insight into CMC-PVA-fHNTs Nanocomposite Hydrogel as an Advance Carrier for Cefadroxil Monohydrate: Fabrication and Characterization/Angiogenic Potential Analysis

Controlled drug delivery is a key strategy aimed at reducing both the frequency of therapeutic dosages and potential systemic side effects, particularly in the case of high drug concentrations. The nanocomposite hydrogel systems presented in this study were synthesized by combining carboxymethyl cellulose, polyvinyl alcohol, and (3-aminopropyl)triethoxysilane-functionalized halloysite nanotubes (fHNTs). This hydrogel system is a potential candidate for the controlled release of cefadroxil monohydrate. These hydrogels are analyzed by Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and rheological measurements. Additionally, swelling properties, porosity, hydrophilicity, drug release, and in vitro and in vivo analyses were also evaluated. The observed trends in swelling and drug release demonstrated that the outcomes are dependent on the presence of fHNTs in the hydrogel matrix. Notably, fHNTs-loaded hydrogels displayed sustained drug release patterns. This innovative approach eliminates the need for traditional encapsulation and presents promising and translatable strategies for achieving more effective drug release.

Copper ions reinforced flexible carboxymethylcellulose/polyethyleneimine composite films with enhanced mechanical properties, UV-shielding performance, thermal stability, solvent resistance, and antibacterial activity

A composite film (CMC/PEI) consisting of anionic carboxymethylcellulose (CMC) and cationic polyethyleneimine (PEI) can be easily produced through the solution casting method using self-assembly based on electrostatic interaction and hydrogen bonding. Subsequently, the resulting CMC/PEI polyelectrolyte composite film with a network structure was crosslinked with divalent Cu2+ ions through ionic and coordination bonds, resulting in a strengthened Cu(II)@CMC/PEI film. The composite film was characterized based on its structural, surface, thermal, UV protection, antibacterial, and degradation aspects. The results demonstrated this film has impressive mechanical properties, remarkable solvent resistance, good antibacterial properties, and excellent UV-shielding performance by completely blocking ultraviolet light with wavelengths below 360 nm. These properties can be attributed to the presence of Cu2+ ions and PEI in the film. This work is valuable for the development of novel UV-shielding materials and should contribute to the design of carboxymethylcellulose composite films with desirable properties and exceptional performance.

Gellan gum-based bi-polymeric hydrogel scaffolds loaded with Rosuvastatin calcium: A useful tool for tendon tissue regeneration

Statins have been long used in tissue engineering, besides their marketed hypolipidemic benefits. The aim of this research was to sustain the release of rosuvastatin calcium from bi-polymeric hydrogel scaffolds. A bi-polymer blend technique was used to enhance the mechanical properties of the fabricated hydrogels. Briefly, hydrogels were prepared via crosslinking gellan gum as the main polymer together with a secondary polymer in the presence of Ca2+. The fabricated hydrogels were assessed in terms of % swelling capacity, hydrolytic degradation and % drug released to determine the most efficient carrier system. The selected hydrogel exhibited a swelling capacity of 131.45±1.49 % following 3 weeks in an aqueous environment with a % weight loss of 15.73±1.86 % after 4 weeks post-equilibrium in aqueous medium. The results ensure a proper window for adequate drug diffusion and nutrient exchange. Sustained release was attained where 94.61±2.77 % of rosuvastatin was released at the 4-week mark. Later, FT-IR and DSC, were carried out and suggested the successful crosslinking and formation of new matrix. SEM images demonstrated the porous surface of the hydrogel while a Young's modulus of 888.558±73.549 kPa indicated the suitability of the hydrogel for soft tissue engineering. In-vivo testing involved implanting the selected hydrogel at precisely surgical cuts in the Achilles tendon of male Wistar Albino rats. Upon visual and microscopic evaluation, enhanced rates of fibrous tissue formation, vascularization and collagen expression were clearly noticed in the treatment group.

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.

Structure-property relationships of epoxy functionalized enoate ester-based tailored hybrid gels doped with different polysaccharides

Natural polymer-based cryogenically structured hybrid gels as support matrices were prepared by constructing synergistic multiple interactions among copolymer poly(2-hydroxyethyl methacrylate-co-glycidyl methacrylate) and different polysaccharides; hyaluronic acid (HyA), dextrin (Dex), maltodextrin (MDex), carboxymethyl cellulose (CMC) and xanthan gum (XG). Great improvement in thermal stability was achieved in the presence of CMC and MDex. In the as-prepared state, the highest modulus is observed in HyA-doped hydrogels, while in the swollen-state, CMC-doped hydrogels have a greater modulus. Hybrid cryogels showed higher swelling than hybrid hydrogels in all cases, while maximum swelling was obtained in HyA-doped hybrid cryogels. Solvent selection methodology based on solvent/polymer interaction was presented using 16 solvents with various solubility parameters. The PHG/XG network exhibited a more gradual swelling, whereas water uptake of hybrids doped with Dex and MDex were more pronounced dependent on temperature. The adsorption capacity of hybrid cryogels for methyl orange (MO) is both higher and faster compared to hydrogels, while a decrease in the adsorption capacity of hybrid cryogels at equilibrium was observed in the order of MDex > Dex > XG > CMC > HyA. This study provides a perspective on cryogenically structured hybrid material design by comparatively presenting the effectiveness of different polysaccharides that can be used for MO adsorption in water purification assemblies.

Polymeric Hydrogels for Intervertebral Disc Replacement/Integration: Playing with the Chemical Composition for Tuning Shear Behavior and Hydrophilicity

Damages to the intervertebral disc (IVD) due to improper loading or degeneration result in back pain, which is a common disease affecting an increasing number of patients. Different strategies for IVD remediation have been developed, from surgical treatment to disc replacement, by using both metallic and non-metallic materials. Hydrogels are very attractive materials due to their ability to simulate the properties of many soft tissues; moreover, their chemical composition can be varied in order to assure performances similar to the natural disc. In particular, for the replacement of the IVD outer ring, namely, the anulus fibrosus, the shear properties are of paramount importance. In this work, we produced hydrogels through the photo-induced crosslinking of different mixtures composed of two hydrophilic monofunctional and difunctional polymers, namely, poly(ethyleneglycol) methyl ether methacrylate (PEGMEMA) and poly(ethyleneglycol) dimethacrylate (PEGDMA), together with a hydrophobic molecule, i.e., tert-butyl acrylate (tBA). By changing the ratio among the precursors, we demonstrated the tunability of both the shear properties and hydrophilicity. The structural properties of hydrogels were studied by solid-state nuclear magnetic resonance (NMR). These experiments provided insights on both the structure and molecular dynamics of polymeric networks and, together with information obtained by differential scanning calorimetry (DSC), allowed for correlating the physical properties of the hydrogels with their chemical composition.

Evaluation of the Effectiveness of an Innovative Polycomponent Formulation on Adult and Aged Human Dermal Fibroblasts

Skin aging is a dynamic process that determines structural alterations in ECM and reduction in dermal fibroblasts. The recent availability on the market of an innovative polycomponent formulation (KARISMA Rh Collagen® FACE, K) containing noncrosslinked high-molecular-weight hyaluronic acid (HMW-HA), a human recombinant polypeptide of collagen-1 alpha chain, and carboxymethyl cellulose (CMC), attracted our scientific interest in evaluating its biomolecular effects on human dermal adult and aged fibroblasts. After treatment with increasing K concentrations, cell proliferation, collagen I, prolyl 4-hydroxylase (P4HA1), an essential protein in collagen biosynthesis, and α-SMA levels were assessed. The fibroblast contractility, TGF-β1 levels, and oxidative stress markers were also evaluated. K formulation exposure led to a significant and dose-dependent increase in the proliferation and migration of adult fibroblasts. Of note, the K exposure counteracted the H2O2-induced aging by promoting cell proliferation, reducing β-galactosidase activity, and neutralizing the aging-associated oxidative damage. Moreover, an increase in collagen I, P4HA1, α-SMA, TGF-β1 levels, and improved contractility of adult and aged fibroblasts were observed after treatment. Overall, our results show evidence that the K treatment is efficacious in improving biological functions in adult fibroblasts and suppressing the biomolecular events associated with H2O2-induced cellular aging, thus supporting the regenerative and bio-revitalizing action of the K formulation helpful in preventing or treating skin aging.

Advanced applications of strontium-containing biomaterials in bone tissue engineering

Strontium (Sr) and strontium ranelate (SR) are commonly used therapeutic drugs for patients suffering from osteoporosis. Researches have showed that Sr can significantly improve the biological activity and physicochemical properties of materials in vitro and in vivo. Therefore, a large number of strontium containing biomaterials have been developed for repairing bone defects and promoting osseointegration. In this review, we provide a comprehensive overview of Sr-containing biomaterials along with the current state of their clinical use. For this purpose, the different types of biomaterials including calcium phosphate, bioactive glass, and polymers are discussed and provided future outlook on the fabrication of the next-generation multifunctional and smart biomaterials.

Micro-/Nano-Carboxymethyl Cellulose as a Promising Biopolymer with Prospects in the Agriculture Sector: A Review

The increase in the population rate has increased the demand for safe and quality food products. However, the current agricultural system faces many challenges in producing vegetables and fruits. Indiscriminate use of pesticides and fertilizers, deficiency of water resources, short shelf life of products postharvest, and nontargeted delivery of agrochemicals are the main challenges. In this regard, carboxymethyl cellulose (CMC) is one of the most promising materials in the agriculture sector for minimizing these challenges due to its mechanical strength, viscosity, wide availability, and edibility properties. CMC also has high water absorbency; therefore, it can be used for water deficiency (as superabsorbent hydrogels). Due to the many hydroxyl groups on its surface, this substance has high efficacy in removing pollutants, such as pesticides and heavy metals. Enriching CMC coatings with additional substances, such as antimicrobial, antibrowning, antioxidant, and antisoftening materials, can provide further novel formulations with unique advantages. In addition, the encapsulation of bioactive materials or pesticides provides a targeted delivery system. This review presents a comprehensive overview of the use of CMC in agriculture and its applications for preserving fruit and vegetable quality, remediating agricultural pollution, preserving water sources, and encapsulating bioactive molecules for targeted delivery.