Cellulose carboxymethyl ether sodium

Carboxymethyl cellulose-based oral delivery systems

For administration of therapeutic agents, the oral route is favored since it is comfortable to patients and also requires a reduced cost. Recently, a considerable amount of work has been reported on carboxymethyl cellulose as oral delivery systems. In contrast to all other polysaccharides having a profile in a pharmacopeia, carboxymethyl cellulose has a hydrophilic character because of its carboxylate groups. These carboxylate groups are responsible for properties such as in situ gellation, bioadhesion, sensitivity to environmental stimuli and controlled drug release. Most of these properties can even be further improved via chemical modifications. In this review, an overview of the carboxymethyl cellulose advantages for oral delivery systems is presented.

Sodium carboxymethyl cellulose-based extrafibrillar demineralization to optimize dentin bonding durability

Objective: To investigate the effects of a sodium carboxymethyl cellulose (SCMC)-based extrafibrillar demineralization conditioner on dentin bonding durability and explore the possible mechanisms.
Methods: The SCMC-based extrafibrillar demineralization conditioner was facilely developed by dissolving SCMC into deionized water at an appropriate concentration. A single layer collagen mineralization/demineralization model was designed to visualize extrafibrillar demineralization in detail. Dentin surfaces of human third molars were conditioned with 3 % SCMC or 37 % phosphoric acid (PA). The morphology, composition, and mechanical properties of conditioned dentin from each group were characterized. To evaluate dentin bonding performance, SCMC- and PA- conditioned dentin were applied with adhesive restoration using the dry-bonding technique. The microtensile bond strength (MTBS), interface nanoleakage, and in situ zymography were measured after 24 h of water storage, 10,000 thermocycles, or one month of collagenase aging. The inhibitory effect of SCMC on recombinant human matrix metalloproteinase-2 (rhMMP-2) and cell toxicity were also investigated.
Results: After SCMC conditioning, both demineralization of extrafibrillar minerals and retention of intrafibrillar minerals were observed in the single layer collagen model and the dentin ultrastructure. The mechanical properties of SCMC-conditioned dentin were largely preserved. Compared with PA, SCMC conditioning produced greater MTBS values and less nanoleakage expression after aging. Endogenous gelatinolytic activity was suppressed in SCMC-conditioned dentin. In addition to being nontoxic, the inhibition of rhMMP-2 by SCMC was confirmed to be dose-dependent.
Significance: From the perspective of minimal intervention, the SCMC-based extrafibrillar demineralization conditioner could improve dentin bonding durability, suggesting a promising strategy to extend the service life of adhesive restorations.

Carboxymethyl cellulose sodium gel: A modified material used to suppress coal dust pollution

To reduce the environmental pollution caused by coal dust, a new type of dust inhibitor with a wide application range, high efficiency, and production simplicity was synthesized by modifying sodium carboxymethylcellulose (CMC-Na) with acrylamide (AM). Through molecular dynamics simulations and experiments, the surfactant composition and concentration were optimized. The experimental results showed that the graft copolymer of CMC-Na and AM (CMC-Na-co-AM) had more pores on the microscopic surface and a unique fiber network structure, which greatly increased its contact area with coal dust. After 14 h of drying at 60 °C, coal samples that were sprayed with the dust suppression agent retained >50% of the water in the spray, which was 9 times greater than the water retention of coal samples sprayed with just water. Additionally, the ability of the dust suppression agent to resist wind erosion was 6 times that of water. The CMC-Na-co-AM dust suppression agent showed that it could effectively inhibit the spread of coal dust under strong winds, offering a solution to the problem of coal dust pollution in coal production and storage.

Key advances of carboxymethyl cellulose in tissue engineering & 3D bioprinting applications

Carboxymethyl cellulose (CMC) is a water-soluble derivative of cellulose and a major type of cellulose ether prepared by the chemical attack of alkylating reagents on the activated non-crystalline regions of cellulose. It is the first FDA approved cellulose derivative which can be targeted for desired chemical modifications. In this review, the properties along with current advances in the physical and chemical modifications of CMC are discussed. Further, CMC and modified CMC could be engineered to fabricate scaffolds for tissue engineering applications. In recent times, CMC and its derivatives have been developed as smart bioinks for 3D bioprinting applications. From these perspectives, the applications of CMC in tissue engineering and current knowledge on peculiar features of CMC in 3D and 4D bioprinting applications are elaborated in detail. Lastly, future perspectives of CMC for wider applications in tissue engineering and 3D/4D bioprinting are highlighted.

Degradation of 2,4-DCP by the immobilized laccase on the carrier of sodium alginate-sodium carboxymethyl cellulose

In this paper, sodium alginate-sodium carboxymethyl cellulose (SA-CMC) composite material was used as a carrier, and sodium alginate-embedded laccase (Lac@SC) was prepared by traditional embedding method. After that, ethylene glycol diglycidyl ether (EGDE) and glutaraldehyde (GLU) were used as cross-linking agents, two different cross-linking-embedded co-immobilized laccases (Lac@SCG and Lac@SCE) were innovatively prepared, respectively, and then these immobilized laccases were characterized by SEM, FT-IR and XRD, and the stability of the three immobilized laccases was explored. In addition, the effects of different factors on the removal of 2,4-DCP by immobilized laccase were studied, and the degradation kinetic models of three immobilized laccases on 2,4-DCP were summarized, the possible degradation pathways of pollutants were also given. Experimental results showed that compared to free laccase, the pH stability, thermal stability and storage stability of immobilized laccase were greatly improved. These immobilized laccases could maintain high activity at pH3~6, 45~55 °C. Lac@SCG had the best storage stability. After 30 days of storage, the relative enzyme activity was still more than 40%. Lac@SC had good reusability, the relative enzyme activity was still more than 50% after 5 uses. In the degradation of 2,4-DCP, all three immobilized laccases showed good performance, when Lac@SCE was at pH5, 35 °C, 25 h, the removal rate of 2,4-DCP could reach 95.2%; When at 45 °C, Lac@SC had the highest degradation rate which reach to 94%; At 45 °C, the degradation rate of Lac@SCG reached 83.2%.