Carboxymethylation of cashew tree exudate polysaccharide

Synthesis and Characterization of Superhigh Moisturizing Carboxymethyl Tamarind Xyloglucan and Its Potential Application in Cosmetics

Carboxymethyl tamarind xyloglucan (CMTXG) was synthesized by xyloglucan with sodium chloroacetate in 50% ethanol. The effects of carboxymethylation on the structure and properties of xyloglucan were studied, and its application potential in cosmetics was evaluated. The results showed that carboxymethylation increased the molecular weight, enhanced water solubility and stability, decreased apparent viscosity, and promoted xyloglucan's application in cosmetics. The CMTXG with moderate substitution (CMT-M) exhibited superior hygroscopic and moisturizing effects, indicating that CMTXG does not need to pursue high degree of substitution. The moisturizing rate of CMT-M was 81.08% after 12 h, surpassing that of sodium hyaluronate (55.79%) and glycerin (59.52%). The CMT-M exhibited enhanced antioxidant and antibacterial activity after modification. Toxicity assessment indicated that CMT-M can improve the long-term tolerance of larvae zebrafish. Furthermore, the CMT-M cream demonstrated a long-term moisturizing effect compared to commercial creams. The research findings are expected to provide an effective bioactive moisturizer candidate for the daily chemical industry.

Cashew gum as future multipurpose biomacromolecules

The review highlights significant advances in delivery systems, with an emphasis on the use of cashew gum (CG), a natural polysaccharide extracted from Anacardium occidentale L., recognized for its remarkable biodegradability and versatility. CG has a wide range of applications spanning sectors such as food, pharmaceuticals, agriculture, and biotechnology. This study examines research focused on the extraction, purification, and chemical modifications of CG, as well as its combination with other biopolymers to enhance physicochemical and mechanical properties. These strategies aim to optimize the gum's characteristics, allowing for the creation of innovative materials with improved performance, expanding its potential applications. This review aims to provide a comprehensive overview of recent research trends, focusing on the utilization of CG as a polymeric component in the development of biomaterials with diverse applications.

pH-responsive IPN beads of carboxymethyl konjac glucomannan and sodium carboxymethyl cellulose as a controlled release carrier for ibuprofen

The convergence of polymer and pharmaceutical sciences has advanced drug delivery systems significantly. Carbohydrate polymers, especially carboxymethylated ones, offer versatile benefits for pharmaceuticals. Interpenetrating polymer networks (IPNs) combine synthetic and natural polymers to enhance drug delivery. The study aims to develop IPN beads using sodium carboxymethyl cellulose (SCMC) and carboxymethyl konjac glucomannan (CMKGM) for controlled release of ibuprofen (IB) after oral administration. Objectives include formulation optimization, characterization of physicochemical properties, evaluation of pH-dependent swelling and drug release behaviors to advance biocompatible and efficient oral drug delivery systems. The beads were analyzed using SEM, FTIR, DSC, and XRD techniques. Different ratio of polymers (CMKGM:SCMS) and crosslinker concentrations (2&4 %w/v) were used, significantly impacting bead size, swelling, drug encapsulation, and release characteristics. DSC results indicated higher thermal stability in IPN beads compared to native polymers. XRD revealed IB dispersion within the polymer matrix. IPN beads size ranged from 580 ± 0.56 to 324 ± 0.27 μm, with a nearly spherical shape. IPN beads exhibited continuous release in alkaline conditions (pH 7.4) and minimal release in acidic media (pH 1.2). These findings suggest that the formulated IPN beads can modulate drug release in both acidic and alkaline environments, potentially mitigating the gastric adverse effects often associated with oral administration of IB.

Antimicrobial activity of nanoparticles based on carboxymethylated cashew gum and epiisopiloturine: In vitro and in silico studies

Epiisopiloturine (EPI) is a compound found in jaborandi leaves with antiparasitic activity, which can be enhanced when incorporated into nanoparticles (NP). Cashew Gum (CG), modified by carboxymethylation, is used to produce polymeric nanomaterials with biological activity. In this study, we investigated the antimicrobial potential of carboxymethylated CG (CCG) NP containing EPI (NPCCGE) and without the alkaloid (NPCCG) against bacteria and parasites of the genus Leishmania. We conducted theoretical studies, carboxymethylated CG, synthesized NP by nanoprecipitation, characterized them, and tested them in vitro. Theoretical studies confirmed the stability of modified carbohydrates and showed that the EPI-4A30 complex had the best interaction energy (-8.47 kcal/mol). CCG was confirmed by FT-IR and presented DSabs of 0.23. NPCCG and NPCCGE had average sizes of 221.94 ± 144.086 nm and 247.36 ± 3.827 nm, respectively, with homogeneous distribution and uniform surfaces. No NP showed antibacterial activity or cytotoxicity to macrophages. NPCCGE demonstrated antileishmanial activity against L. amazonensis, both in promastigote forms (IC50 = 9.52 μg/mL, SI = 42.01) and axenic amastigote forms (EC50 = 6.6 μg/mL, SI = 60.60). The results suggest that nanostructuring EPI in CCG enhances its antileishmanial activity.

Drug delivery using reduction-responsive hydrogel based on carboxyethyl-succinoglycan with highly improved rheological, antibacterial, and antioxidant properties

The development of exopolysaccharide-based polymers is gaining increasing attention in various industrial biotechnology fields for materials such as thickeners, texture modifiers, anti-freeze agents, antioxidants, and antibacterial agents. High-viscosity carboxyethyl-succinoglycan (CE-SG) was directly synthesized from succinoglycan (SG) isolated from Sinorhizobium meliloti Rm 1021, and its structural, rheological, and physiological properties were investigated. The viscosity of CE-SG gradually increased in proportion to the degree of carboxyethylation substitution. In particular, when the molar ratio of SG and 3-chloropropionic acid was 1:100, the viscosity was significantly improved by 21.18 times at a shear rate of 10 s-1. Increased carboxyethylation of SG also improved the thermal stability of CE-SG. Furthermore, the CE-SG solution showed 90.18 and 91.78 % antibacterial effects against Escherichia coli and Staphylococcus aureus and effective antioxidant activity against DPPH and hydroxyl radicals. In particular, CE-SG hydrogels coordinated with Fe3+ ions, which improved both viscosity and rheological properties, while also exhibiting reduction-responsive drug release through 1,4-dithiothreitol. The results of this study suggest that SG derivatives, such as CE-SG, can be used as functional biomaterials in various fields such as food, cosmetics, and pharmaceutical industries.

Gastroprotective activity and physicochemical analysis of carboxymethylated gum from Anadenanthera colubrina

Biotechnological advancements require the physicochemical alteration of molecules to enhance their biological efficacy for the effective treatment of gastric ulcers. The study aimed to produce a polyelectrolytic compound from red angico gum (AG) by carboxymethylation, evaluate its physicochemical characteristics and investigate gastric protection against ethanol-induced ulcers. AG and carboxymethylated angico gum (CAG) were characterized by Fourier transform infrared spectroscopy, determination of the degree of substitution and gel permeation chromatography (GPC) and 13C NMR techniques. The results demonstrated that the modification of the polymer was satisfactory, presenting conformational changes e improving the interaction with the gastric mucosa. AG and CAG reduced macroscopic and microscopic damage such as edema, hemorrhage and cell loss caused by exposure of the mucosa to alcohol. Both demonstrated antioxidant activity in vitro, and in vivo, pretreatment with gums led to the restoration of superoxide dismutase and glutathione levels compared to the injured group. Concurrently, the levels of malondialdehyde and nitrite decreased. Atomic force microscopy showed that CAG presented better conformational properties of affinity and protection with the gastric mucosa compared to AG in the acidic pH. Based on our findings, it is suggested that this compound holds promise as a prospective product for future biotechnological applications.

Study on Synergistic Effects of Nanohydroxyapatite/High-Viscosity Carboxymethyl Cellulose Scaffolds Stimulated by LIPUS for Bone Defect Repair of Rats

Despite the self-healing capacity of bone, the regeneration of critical-size bone defects remains a major clinical challenge. In this study, nanohydroxyapatite (nHAP)/high-viscosity carboxymethyl cellulose (hvCMC, 6500 mPa·s) scaffolds and low-intensity pulsed ultrasound (HA-LIPUS) were employed to repair bone defects. First, hvCMC was prepared from ramie fiber, and the degree of substitution (DS), purity, and content of NaCl of hvCMC samples were 0.91, 99.93, and 0.017%, respectively. Besides, toxic metal contents were below the permissible limits for pharmaceutically used materials. Our results demonstrated that the hvCMC is suitable for pharmaceutical use. Second, nHAP and hvCMC were employed to prepare scaffolds by freeze-drying. The results indicated that the scaffolds were porous, and the porosity was 35.63 ± 3.52%. Subsequently, the rats were divided into four groups (n = 8) randomly: normal control (NC), bone defect (BD), bone defect treated with nHAP/hvCMC scaffolds (HA), and bone defect treated with nHAP/hvCMC scaffolds and stimulated by LIPUS (HA-LIPUS). After drilling surgery, nHAP/hvCMC scaffolds were implanted in the defect region of HA and HA-LIPUS rats. Meanwhile, HA-LIPUS rats were treated by LIPUS (1.5 MHz, 80 mW cm-2) irradiation for 2 weeks. Compared with BD rats, the maximum load and bone mineral density of HA-LIPUS rats were increased by 20.85 and 51.97%, respectively. The gene and protein results indicated that nHAP/hvCMC scaffolds and LIPUS promoted the bone defect repair and regeneration of rats significantly by activating Wnt/β-catenin and inhibiting OPG/RANKL signaling pathways. Overall, compared with BD rats, nHAP/hvCMC scaffolds and LIPUS promoted bone defect repair significantly. Furthermore, the research results also indicated that there are synergistic effects for bone defect repair between the nHAP/hvCMC scaffolds and LIPUS.

Influence of Reduction with NaBH4 and HCl in Obtaining Amino Derivatives of Cashew Gum and Cytotoxic Profile

Tree-exuded gums are natural polymers that represent an abundant raw material in the food and pharmaceutical industries. The cashew gum can be obtained by exudation of trees of the genus Anacardium, a native species of the Brazilian northeast; its polymer consists of monosaccharide units propitious to the action of chemical reactions that tend to improve their intrinsic characteristics among them, as the degree of hydro-solubility. The objective of this work was to modify the exudate gum of Anacardium occidentale (cashew gum (CG)) through an amine reaction. The modification was confirmed by Nuclear Magnetic Resonance (¹H NMR), infrared spectroscopy (FTIR), gel permeation chromatography (GPC), zeta potential, and thermogravimetric analysis (TG). In addition, the chemical modification altered the molar mass and surface charge of the CG, and the amino group binding to the CG polymers was confirmed by FTIR spectra. In addition, cytotoxicity tests were performed where cell viability was estimated by an MTT assay on RAW 264.7 macrophages. Through these tests, it was found that the amine caused an increase in the thermal stability of the amino compounds and did not present cytotoxic potential at concentrations below 50.0 mg/L.

Effect of Acyl Chain Length on Hydrophobized Cashew Gum Self-Assembling Nanoparticles: Colloidal Properties and Amphotericin B Delivery

Given its many potential applications, cashew gum hydrophobic derivatives have gained increasing attraction in recent years. We report here the effect of acyl chain length on hydrophobized cashew gum derivatives, using acetic, propionic, and butyric anhydrides on self-assembly nanoparticle properties and amphotericin B delivery. Nanoparticles with unimodal particle size distribution, highly negative zeta potential, and low PDI were produced. Butyrate cashew gum nanoparticles presented smaller size (<~100 nm) than acetylated and propionate cashew gum nanoparticles and no cytotoxicity in murine fibroblast cells was observed up to 100 µg/mL for loaded and unloaded nanoparticles. As a proof of concept of the potential use of the developed nanoparticle as a drug carrier formulation, amphotericin B (AmB) was encapsulated and fully characterized in their physicochemical, AmB association and release, stability, and biological aspects. They exhibited average hydrodynamic diameter lower than ~200 nm, high AmB efficiency encapsulations (up to 94.9%), and controlled release. A decrease in AmB release with the increasing of the anhydride chain length was observed, which explains the differences in antifungal activity against Candida albicans strains. An excellent storage colloidal stability was observed for unloaded and loaded AmB without use of surfactant. Considering the AmB delivery, the acyl derivative with low chain length is shown to be the best one, as it has high drug loading and AmB release, as well as low minimum inhibitory concentration against Candida albicans strains.

A review on challenges and issues with carboxymethylation of natural gums: The widely used excipients for conventional and novel dosage forms

Diverse properties of natural gums have made them quite useful for various pharmaceutical applications. However, they suffer from various problems, including unregulated hydration rates, microbial degradation, and decline in viscosity during warehousing. Among various chemical procedures for modification of gums, carboxymethylation has been widely studied due to its simplicity and efficiency. Despite the availability of numerous research articles on natural gums and their uses, a comprehensive review on carboxymethylation of natural gums and their applications in the pharmaceutical and other biomedical fields is not published until now. This review outlines the classification of gums and their derivatization methods. Further, we have discussed various techniques of carboxymethylation, process of determination of degree of substitution, and functionalization pattern of substituted gums. Detailed information about the application of carboxymethyl gums as drug delivery carriers has been described. The article also gives a brief account on tissue engineering and cell delivery potential of carboxymethylated gums.

Utilization of Waste Textile Cotton by Synthesizing Sodium Carboxymethyl Cellulose: An Approach to Minimize Textile Solid Waste

This research uses waste textile cotton (WTC) from the textile industry as a raw material to synthesize sodium carboxymethyl cellulose (CMC) by adapting a modified etherification methodology. Yields of technical CMC (TCMC), semipurified CMC (SPCMC), and purified CMC (PCMC) were $3.45\pm 0.17$  g, $2.49\pm 0.08$  g, and $1.51\pm 0.016$  g, respectively, per gram of cotton waste. Degree of substitution (DS) values of PCMC, SPCMC, and TCMC was $0.998\pm 0.007$ , $0.79\pm 0.031$ , and $0.561\pm 0.029$ , respectively. For PCMC, SPCMC, and TCMC, the purity of the prepared different grades of CMC was $98.59\pm 0.12$ %, $78.56\pm 1.93$ %, and $61.59\pm 2.31$ %, respectively. Fourier transform infrared spectroscopy (FTIR) peak values were 3437 cm-1, 1609 cm-1, and 1427 cm-1, proving WTC conversion to CMC. Furthermore, $2\theta$ values of X-ray diffraction (XRD) peaks were 9.7 and 20.5, confirming the transformation of WTC to CMC as well. Thermogravimetric analysis (TGA) and scanning electron microscope (SEM) have been assessed to define CMC’s thermal stability and morphology, respectively.

Comparison of the Physicochemical Properties of Carboxymethyl Agar Synthesized by Microwave-Assisted and Conventional Methods

The microwave-assisted carboxymethylation of agar to improve its physicochemical properties was investigated. Microwave power, reaction time, and temperature, ethanol concentration, and amounts of chloroacetic acid and sodium hydroxide were assessed for their effects on synthetic yield and degree of substitution (DS). All factors were positively correlated with DS within a certain range. Using optimized conditions, samples with different DS were prepared, and the physicochemical properties of unmodified and carboxymethyl agars prepared by microwave and conventional methods were compared. Carboxymethylation significantly changed the physicochemical properties of the agar, improving gel transparency and reducing dissolution temperature, gel strength, gel hardness, molecular weight, and molecular size; DS was the key factor. Specifically, higher DS values resulted in greater changes. The microwave-assisted method significantly shortened the reaction time and preserved molecular weight, gel strength, and texture hardness of the agar. Therefore, as an environmentally friendly method, microwave-assisted synthesis shows great promise for producing carboxymethyl agar.

Waste Materials as a Resource for Production of CMC Superabsorbent Hydrogel for Sustainable Agriculture

Waste materials are receiving more attention as concerns about the future of our planet increase. Cellulose is the most common substance in agricultural waste. Agricultural wastes containing cellulose are misplaced resources that could be reused in various fields for both environmental and economic benefits. In this work, 32 different kinds of waste are investigated for chemical modification in order to obtain carboxymethyl cellulose for the production of a superabsorbent hydrogel that can be applied in agriculture. A brief literature review is provided to help researchers wishing to obtain carboxymethyl cellulose by carboxymethylation starting with waste materials. We also provide details about methods to obtain as well as verify carboxymethylation. Carboxymethyl cellulose (CMC), as a constituent of cellulosic water and superabsorbent hydrogels with applications in agriculture, is described. Superabsorbent hydrogels with CMC are able to absorb huge amounts of water and are biodegradable.

Bioactive Carbohydrate Polymers-Between Myth and Reality

Polysaccharides are complex macromolecules long regarded as energetic storage resources or as components of plant and fungal cell walls. They have also been described as plant mucilages or microbial exopolysaccharides. The development of glycosciences has led to a partial and difficult deciphering of their other biological functions in living organisms. The objectives of glycobiochemistry and glycobiology are currently to correlate some structural features of polysaccharides with some biological responses in the producing organisms or in another one. In this context, the literature focusing on bioactive polysaccharides has increased exponentially during the last two decades, being sometimes very optimistic for some new applications of bioactive polysaccharides, notably in the medical field. Therefore, this review aims to examine bioactive polysaccharide, taking a critical look of the different biological activities reported by authors and the reality of the market. It focuses also on the chemical, biochemical, enzymatic, and physical modifications of these biopolymers to optimize their potential as bioactive agents.

Reviews on mechanisms of in vitro antioxidant, antibacterial and anticancer activities of water-soluble plant polysaccharides

Degenerative diseases such as cancer and cardiovascular diseases, and antimicrobial resistance are becoming prominent health problems needing utmost public health attention. Curative interventions such as the use of pharmaceutical drugs and alternative plant medicines are increasingly being explored. Plant polysaccharides have gained attention for their promising bioactivities such as antioxidant, antimicrobial and anticancer activities. Bioactive plant polysaccharides are also being preferred for their relatively few side effects compared to conventional pharmaceuticals. The elucidation of the bioactive potential of plant polysaccharides in disease treatment entails an understanding of the factors that determine their biofunctional properties using functional and mechanistic assays. This review summarizes the literature on the composition, structural, functional, and mechanistic determinations of the antioxidant, anticancer and antimicrobial activities of plant polysaccharides. The outcome of this review highlights the leading trends in the elucidation of the antioxidant, anticancer and antimicrobial activities of plant polysaccharides and underscores the promising health benefits of plant polysaccharides.

Recent Developments of Carboxymethyl Cellulose

Carboxymethyl cellulose (CMC) is one of the most promising cellulose derivatives. Due to its characteristic surface properties, mechanical strength, tunable hydrophilicity, viscous properties, availability and abundance of raw materials, low-cost synthesis process, and likewise many contrasting aspects, it is now widely used in various advanced application fields, for example, food, paper, textile, and pharmaceutical industries, biomedical engineering, wastewater treatment, energy production, and storage energy production, and storage and so on. Many research articles have been reported on CMC, depending on their sources and application fields. Thus, a comprehensive and well-organized review is in great demand that can provide an up-to-date and in-depth review on CMC. Herein, this review aims to provide compact information of the synthesis to the advanced applications of this material in various fields. Finally, this article covers the insights of future CMC research that could guide researchers working in this prominent field.

Synthesis, characterization and fabrication of sodium carboxymethyl-okra-gum-grafted-polymethacrylamide into sustained release tablet matrix

The objective of the present study was to modify okra gum (Abelmoschus esculentus) by carboxymethylation and subsequent graft-copolymerization, characterize and fabricate into sustained-release tablet matrix. Firstly, okra gum was carboxymethylated using sodium hydroxide and monochloroacetic acid followed by grafting with polymethacrylamide employing synergistic combination of free-radical-initiator and microwave-irradiation. The FTIR, NMR, elemental analysis and viscosity study corroborate the formation of sodium-carboxymethyl-okra gum-grafted-polymethacrylamide copolymer (SCMOG-g-PMA). The maximum degree of carboxymethyl-substitution (DCS) and % grafting (%G) were found to be 0.604 ± 0.011 and 644.1, respectively. Water-uptake-capacity was found to increase by 3.5 fold. The tablet formulation of diclofenac sodium with SCMOG-g-PMA (DCS 0.604 and 423.4% G) showed to exhibit excellent sustained-release capacity with 90% drug-release at 11.7 h and similarity-factor of 72.0. The toxicity and biodegradability study also exhibited the bio-compatible and biodegradable nature of the copolymer, which might make the copolymer suitable for sustained-release drug delivery systems as smart semi-synthetic biopolymer.

Carboxymethylation of (1 → 6)-α-dextran from Leuconostoc spp.: Effects on microstructural, thermal and antioxidant properties

The carboxymethylated (1 → 6)-α-dextran (CM-dex) was synthesized by introducing carboxymethyl groups at different degrees of substitution (DS). The resulting dex1-1, dex2-1, dex3-1, and dex4-1 products had degrees of substitution of 0.57, 0.78, 1.13, and 1.25, respectively. The dex3-1 showed the highest glass transition temperature (T_g) of 215.96 °C, whereas T_g of pure dextran was 149.83 °C. TGA results indicated that the residual loss was reduced along with the increase of DS in the high-temperature region (450-600 °C). Besides, the CM-dex had stronger scavenging capacity against OH radicals but lower scavenging capacity for DPPH (1,1-diphenyl-2-picrylhydrazyl) radicals compared to that of pure dextran. The carboxymethylation of (1 → 6)-α-dextran will extend the applications for modified dextran.

Rheological properties of soy protein isolate – carboxymethyl flaxseed gum mixed dispersions under large amplitude oscillatory shear

Carboxymethyl flaxseed gum (CMFG) is developed in our laboratory by modifying flaxseed gun through carboxymethylation. The aim of this study is to reveal the rheological properties of soy protein isolate – carboxymethyl flaxseed gum (SPI-CMFG) mixed dispersion in realistic processing conditions by conducting large amplitude oscillatory shear (LAOS) test, with consideration of concentration and degree of substitution (DS) of CMFG. Results showed that increasing CMFG concentration significantly increased storage moduli (Gʹ), loss moduli (Gʺ), and the apparent viscosity of all SPI-CMFG mixed dispersions. LAOS test illustrated that the dispersions experienced a transition from LAOS type IV to type III after increasing the concentration of CMFG, while the behavior converted from LAOS type I to type III by increasing DS. Fourier transform rheology (FTR) exhibited that increasing the concentration or DS of CMFG both induced a conversion from “soft sphere” to “hard sphere” behavior. The strain-stiffening ratio S and the shear-thickening ratio T demonstrated, that all SPI-CMFG dispersions experienced a similar conversion from strain stiffening to strain softening, and from shear thinning to shear thickening behaviors by increasing the concentration of CMFG. Nevertheless, the mixed dispersions presented shear thickening behaviors when DS was no more than 0.520 in the whole range of strain, while a conversion from shear thinning to shear thickening behavior occurred, when DS reached at 0.755 and 0.973.

Self-assembling cashew gum-graft-polylactide copolymer nanoparticles as a potential amphotericin B delivery matrix

Amphotericin B is an antibiotic used in the treatment of fungal disease and leishmania; however, it exhibits side effects to patients, hindering its wider application. Therefore, nanocarriers have been investigated as delivery systems for amphotericin B (AMB) in order to decrease its toxicity, besides increase bioavailability and solubility. Amphiphilic copolymers are interesting materials to encapsulate hydrophobic drugs such as AMB, hence copolymers of cashew gum (CG) and l-lactide (LA) were synthesized using two different CG:LA molar ratios (1:1 and 1:10). Data obtained revealed that copolymer nanoparticles present similar figures for particle sizes and zeta potentials; however, particle size of encapsulated AMB increases if compared to unloaded nanoparticles. The 1:10 nanoparticle sample has better stability although higher polydispersity index (PDI) if compared to 1:1 sample. High amphotericin (AMB) encapsulation efficiencies and low hemolysis were obtained. AMB loaded copolymers show lower aggregation pattern than commercial AMB solution. AMB loaded nanoparticles show antifungal activities against four C. albicans strains. It can be inferred that cashew gum/polylactide copolymers have potential as nanocarrier systems for AMB.

Preparation and characterization of carboxymethyl cashew gum grafted with immobilized antibody for potential biosensor application

This report details the design of carboxymethylated cashew gum (CG) as a platform for antibody (Ab) immobilization, which can then be used as a biosensor for bacteria detection. The CG was isolated and characterized, followed by conversion to carboxymethyl cashew gum (CMCG). The CMCG film was a viable support for antibody immobilization; it was electrodeposited on gold surface using the cyclic voltammetry technique, applying a potential sweep from -1.0 V to 1.3 V with a scan rate of 50 mV s^-1 and 10 scans. The COOH groups on the surface of the film were critical in promoting Ab bonding. The immobilization of the Ab was mediated by protein A (PrA) for recognition of the antigen. Voltammetry studies were used to monitor the antibody immobilization. Finally, the analytical response of the CMCG-PrA-Ab system was evaluated with the chronoamperometry technique and was found to detect Salmonella Typhimurium bacteria rapidly and efficiently.

Antibacterial application of natural and carboxymethylated cashew gum-based silver nanoparticles produced by microwave-assisted synthesis

This study presents a green synthesis route to silver nanoparticles (AgNPs) stabilized with cashew gum (CG) or carboxymethylated cashew gum (CCG) using microwave-assisted synthesis and evaluates their antibacterial activity. The antimicrobial activity was measured by determining the minimum inhibitory concentration (MIC) with Staphylococcus aureus and Escherichia coli. In both cases of the presence of CG and CCG, it was found that higher pH lead to more efficient conversion of silver nitrate to AgNPs with well dispersed, spherical and stable particles as well as low crystallinity. CCG-capped AgNPs were slightly smaller (137.0 and 96.3 nm) than those coated with non-modified gum (144.7 and 100.9 nm). The samples presented promising antibacterial activity, especially on Gram-negative bacteria, resulting in significant membrane damage on treated bacteria in comparison to the untreated control, observed by atomic force microscopy. Thus, a quick and efficient synthesis route was applied to produce CGAgNPs and CCGAgNPs with antimicrobial potential.

Use of seed gums from Tamarindus indica and Cassia fistula as controlled-release agents

Most seed gums have been widely used in oral and topical pharmaceutical formulations, cosmetics, and food products because of their hydrophilic properties. Gums from Tamariudus indica and Cassia fistula seeds were chemically modified by carboxymethylation to improve their functionalities. The objective of the present study was to characterize  and evaluate crude and carboxymethylated gums from T. indica and C. fistula seeds to achieve the controlled-release of diclofenac sodium (DS) in matrix tablet form. Both crude and carboxymethylated gums were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The results revealed that the gums were successfully modified by carboxymethylation and that the modified gums were amorphous in structure and had better flow properties. The carboxymethylated gums from both plant seeds did not exhibit cytotoxicity at concentrations lower than 0.5 mg/ml. All gum samples used as polymeric controlled-release agents were formulated into DS matrix tablets. Hardness and thickness tests were conducted as in-process tests. Drug content estimation and in vitro drug release studies were carried out to evaluate the matrix tablets. Increasing the concentration of gums increased compression time and hardness while it reduced the thickness. Furthermore, the results fitted well with the Korsmeyer–Peppas model. Moreover, the DS tablets were found to release the drug by super case II transport (relaxation).  In summary, the carboxymethylated gum from T. indica and C. fistula seeds is an excellent, naturally sourced gum with high physicochemical and functional qualities, and can potentially be used in pharmaceutical applications as a disintegrant, diluent, and drug release-controlling agent.

Acetylation Modification Improves Immunoregulatory Effect of Polysaccharide from Seeds of Plantago asiatica L

The current study was conducted to investigate effects of acetylated Plantago asiatica L. polysaccharides (Ac-PLCPs) on their immunoregulatory activities in bone-marrow-derived dendritic cells (DCs) model. Influences of natural Plantago asiatica L. crude polysaccharide (PLCP) and Ac-PLCPs on inducing phenotypic and functional maturation on DCs were determined. The results showed that Ac-PLCPs with degree of substitution (DS) from 0.06 to 0.1 could not only stimulate the expression of surface molecules major histocompatibility complex class II (MHC II), cluster of differentiation 86 (CD86), and CD80 on DCs (P<0.01) but also increase the secretion of cytokine IL-12p70 (P<0.01). The endocytosis activity of DCs was attenuated by Ac-PLCPs treatment (P<0.01), while the mRNA expressions of chemokine receptors CCR7 and CXCR4 in DCs were significantly increased (P<0.01). Besides, DCs treated with the Ac-PLCPs showed extremely strong T cell proliferation stimulating activity (P<0.01). These data showed that Ac-PLCPs had higher maturation-stimulating activity on DCs than PLCP, which indicated that acetylation modification improved the immunoregulatory effect of PLCP.

Novel pH-responsive and self-assembled nanoparticles based on Bletilla striata polysaccharide: preparation and characterization

In this investigation, innovative pH-sensitive and amphiphilic nanoparticles (NPs) were synthesized by grafting histidine (His, pH sensitive molecule) and stearic acid (SA, hydrophobic segment) onto the polysaccharides of Bletilla striata (BSP). The His-SA-BSP was able to self-assemble into NPs with pH sensitivity. The acidic conditions could trigger the imidazole ionization and reverse the surface charge, while the electrostatic repulsion wrecked the structure and drove the NPs to a swollen state, as revealed by dynamic light scattering (DLS), transmission electron microscopy (TEM), and critical micelle concentration (CMC) analyses. By increasing the degree of substitution (DS) of His, the NPs showed improved pH sensitivity. The NPs could accelerate Doxorubicin (Dox) release to a remarkably greater extent (3-fold) at pH 5 than at pH 7.4. The CCK-8 assay demonstrated a good biocompatibility of the NPs towards different cell lines and a specific inhibition effect of Dox-loaded NPs against tumor cells. Furthermore, the NPs showed the improved cellular uptake of Dox towards MCF-7 by fluorescence microscopy and flow cytometry. Therefore, the new His-SA-BSP showed potential applications in drug nanocarrier systems.

In this investigation, innovative pH-sensitive and amphiphilic nanoparticles (NPs) were synthesized by grafting histidine (His, pH sensitive molecule) and stearic acid (SA, hydrophobic segment) onto the polysaccharides of Bletilla striata (BSP).

Synthesis of Carboxymethyl Flaxseed Gum and Study of Nonlinear Rheological Properties of Its Solutions

Flaxseed gum (FG) was carboxymethylated by reacting it with monochloroacetic acid (MCA). The effects of concentrations of NaOH and MCA, reaction temperature and reaction time, on the degree of substitution (DS) were investigated. Reaction between the FG and MCA at NaOH and MCA concentrations of 0.06 g/mL and 0.08 g/mL, respectively, at 70 °C for 60 min produced carboxymethyl flaxseed gum (CMFG) with a DS of 0.969. Carboxymethylation of FG increased its solubility and light transmittance in water. The nonlinear rheological properties of CMFG solutions were studied using large amplitude oscillatory shear (LAOS) tests, Fourier transform (FT) rheology and Chebyshev stress decomposition methods. The different nonlinear rheological behaviors observed were related to the microstructures of the CMFG solutions as a function of concentration and DS.

The derivatization and antitumor mechanisms of polysaccharides

At present, the polysaccharide antitumor research is focused on how to further improve the antitumor activity of polysaccharides. The structural modification of polysaccharides can enhance their antitumor activity to a certain extent. The antitumor mechanisms of polysaccharide derivatives mainly contain the inducing apoptosis of tumor cells, effecting on the cycle of tumor cells, enhancing the antioxidant activity of organism, activating the body's immune response and inhibiting the tumor angiogenesis. Herein, the common methods of polysaccharide modification, such as sulfation, carboxymethylation, phosphorylation and acetylation, were summarized. At the same time, the effects of chemical modification of polysaccharides on their antitumor mechanisms and activity were analyzed and discussed.

Effect of carboxymethylation on rheological and drug release characteristics of Terminalia catappa gum

The carboxymethylation of galactomannans, arabinogalactans, arbinoxylan, etc is known to modify solubility, swelling index, rheological behaviour, powder characteristics, etc. Therefore, an attempt had been made to study the effect of carboxymethylation on Terminalia catappa (TC) gum. For this, modified Williamson synthesis reaction was utilized employing Quality by Design (QbD) approach. Grafting of carboxymethyl group on Terminalia catappa was confirmed by ATR-FTIR, H¹NMR and DSC analyses. The rheological attributes revealed that the carboxymethylation of TC lowers the viscosity, enhance thermal stability (high activation energy), disentanglement was near to re-entanglement, and weak gelling characteristic. However, the soluble fluconazole loaded gel formulation of CMTC showed diffusion based kinetic model indicating good reservoir for effective application on skin/tissue surfaces.

Fragrant films on the basis of potato starch

New fragrant and biodegradable starch-based films have been obtained. These films were prepared by the method of the outpour into the Teflon mould of the starch composition containing such fragrant compounds as: eugenol or α-pinene. For characterizing the final products the following properties were taken into account: the solubility in water, the absorbance of moisture from air and the length of release of the fragrant compound. The obtained starch-based films were characterized by the relatively long time of release the fragrant compound and also by the good absorbance of moisture from air. Taking into account the properties of the obtained films, they can find applications in production of appliances used in the bioactive cleaning of air. The prototype of such a product was presented in this work. The presented studies show the potential of applying these materials in the future, and thus these examinations should be developed.

Development and characterization of seed gums from Tamarindus indica and Cassia fistula as disintegrating agent for fast disintegrating Thai cordial tablet

Crude seed gum and their carboxymethyl derivatives from Tamarindus indica and Cassia fistula seeds were developed and characterized to apply as the pharmaceutical disintegrant in fast disintegrating Thai cordial tablet. The chemical structure of crude gum was chemically modified via carboxymethylation. Degree of substitution (DS) of carboxymethylated gums was determined. Carboxymethylated gums with minimum and maximum DS values were chosen for further application. IR absorption spectra of gum samples were observed to verify their chemical structure changes. In physical properties, the intrinsic viscosity and swelling property of all gum samples were evaluated. The results showed that carboxymethylated gums had higher intrinsic viscosity than those of crude gum. Moreover, they could swell and be soluble in cold water better than those of crude gums. In conclusion, the modified gums from both plants could provide higher hardness and be better used than that crude gums for fast disintegrating Thai cordial tablet. However, this is a preliminary assessment to expressing pharmaceutical application possibility of these gums as disintegrants, diluents and drug release controlling agents.