Synthesis of partially hydrolyzed graft copolymer (H-partially carboxymethylated guar gum-g-methacrylic acid): A superabsorbing material

Carboxymethylated Gums and Derivatization: Strategies and Significance in Drug Delivery and Tissue Engineering

Natural polysaccharides have been widely exploited in drug delivery and tissue engineering research. They exhibit excellent biocompatibility and fewer adverse effects; however, it is challenging to assess their bioactivities to that of manufactured synthetics because of their intrinsic physicochemical characteristics. Studies showed that the carboxymethylation of polysaccharides considerably increases the aqueous solubility and bioactivities of inherent polysaccharides and offers structural diversity, but it also has some limitations that can be resolved by derivatization or the grafting of carboxymethylated gums. The swelling ratio, flocculation capacity, viscosity, partition coefficient, metal absorption properties, and thermosensitivity of natural polysaccharides have been improved as a result of these changes. In order to create better and functionally enhanced polysaccharides, researchers have modified the structures and properties of carboxymethylated gums. This review summarizes the various ways of modifying carboxymethylated gums, explores the impact that molecular modifications have on their physicochemical characteristics and bioactivities, and sheds light on various applications for the derivatives of carboxymethylated polysaccharides.

Characterization of Microwave-Controlled Polyacrylamide Graft Copolymer of Tamarind Seed Polysaccharide

The main objective of the study was to prepare tamarind seed polysaccharide grafted copolymers of polyacrylamide (TSP-g-Am) using a 3² factorial design. Tamarind seed polysaccharide (TSP) was extracted, and grafted copolymer of TSP was prepared using polyacrylamide as copolymer and ceric ammonium nitrate as initiator. Various batches (F1-F9) of TSP-g-Am were prepared, among which F1 showed highest grafting efficiency; hence, the prepared TSP-g-Am (F1) was evaluated for grafting efficiency, conversion, effect of initiator and further characterized using SEM analysis, contact angle determination, DSC analysis, swelling index, swelling and deswelling, and chemical resistance. The contact angle of TSP was found to be 81 ± 2, and that of TSP-g-Am (F1) was found to be 74 ± 2, which indicates that the wetting ability of the grafted copolymer was less than that of the native polymer. The results of thermal analysis indicated that TSP-g-Am had a more stable molecular structure than TSP. The morphology of the grafted polymer was observed from SEM images, and it was observed that the particles was asymmetrical. Antimicrobial activity was also found in the grafted copolymer. The present study concludes that the TSP-g-Am showed an excellent performance in thermal stability and swelling capacity compared with TSP. The detailed structural characteristics, as well as the excellent thermal stability and swelling capacities, will make it beneficial to use the synthesised copolymer as a precursor for the production of large-scale eco-friendly advanced materials with a wide range of applications, acting as a stabiliser, thickener, binder, release retardant, modifier, suspending agent, viscosity enhancer, emulsifying agent, or carrier for novel drug delivery systems in oral, buccal, colon, and ocular systems, and in nanofabrication and wound dressing, and it is also becoming an important part of food, cosmetics, confectionery, and bakery.

Recent advances in guar gum based drug delivery systems and their administrative routes

Guar gum-based drug carrier systems have gained attention for the delivery of various therapeutic agents via different administration routes for attaining controlled and sustained release. Guar gum offers a safe and effective system for drug delivery due to its natural occurrence, easy availability, biocompatibility, and biodegradability, besides simple and mild preparation techniques. Furthermore, the possibility of using various routes such as oral, buccal, transdermal, intravenous, and gene delivery further diversify guar gum applications in the biomedical field. This review delineates the recent investigation on guar gum-based drug carrier systems like hydrogels, nanoparticles, nanocomposites, and scaffolds along with their related delivery routes. Also, the inclusion of data of the loading and subsequent release of the drugs enables to explore the noble and improved drug targeting therapies.

RETRACTED: A review on biomacromolecular hydrogel classification and its applications

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief and Author. The work included substantial parts copied without attribution from a prior work by Varaprasad et al (2017): https://doi.org/10.1016/j.msec.2017.05.096

Chemical Modifications of Guar Gum for Drug Delivery Applications: A Review

Guar gum is a natural excipient extracted from the plant seed of Cyamopsis tetragonolobus, belonging to the Leguminosae family. In the pharmaceutical industries, it contributes an important role due to its non-toxicity, ease of availability, biodegradability and eco-friendly nature. The major constituents of guar gum is galactomannan which is composed of D-galactose anhydride and mannose anhydride. Hydroxyl groups present in galactomannan can be modified by carboxymethylation, grafting or cross-linking with other excipients for developing modified polymers having desirable properties. Guar gum is commonly used as a suspending, emulsifying, stabilizing, gelling and thickening agent in various dosage forms. The guar gum derivatives are also useful in controlling the drug release from the pharmaceutical dosage forms. In this review, different aspects of synthesis of guar gum derivatives and its applications in various drug delivery systems is described.

Natural biodegradable polymers based nano-formulations for drug delivery: A review

Nanomedicines are now considered as the new-generation medication in the current era mainly because of their features related to nano size. The efficacy of many drugs in their micro/macro formulations is shown to have poor bioavailability and pharmacokinetics after oral administration. To overcome this predicament, use of natural/synthetic biodegradable polymeric nanoparticles (NPs) have gained prominence in the field of nanomedicine for targeted drug delivery to improve biocompatibility, bioavailability, safety, enhanced permeability, better retention time and lower toxicity. For drug delivery, it is essential to have biodegradable nanoparticle formulations for safe and efficient transport and release of drug at the intended site. Moreover, depending on the target organ, a suitable biodegradable polymer can be selected as the drug-carrier for target specific as well as for sustained drug delivery. The aim of this review is to present the current status and scope of natural biodegradable polymers as well as some emerging polymers with special characteristics as suitable carriers for drug delivery applications. The most widely preferred preparation methods are discussed along with their characterization using different analytical techniques. Further, the review highlights significant features of methods developed using natural polymers for drug entrapment and release studies.

Guar gum and its composites as potential materials for diverse applications: A review

Naturally occurring polymers are currently of prime importance among which polysaccharides occupies superior position due to their easy availability, eco- friendly and non-toxic nature. Guar gum, one of the naturally occurring polymer, is a galactomannan acquired by ground endosperm of Cyamopsis tetragonolobus or Cyamopsis psoraloides. It belongs to the family leguminosae. Presence of large number of hydroxyl groups increases its H- bonding ability when dissolved in water that enhance the viscosity and gelling properties of the guar gum solution. Based upon these properties, guar gum is used in several industries such as textile, food, petrochemical, mining and paper for varied applications. It is used as suspending, emulsifying, gelling and stabilising agent in the conventional dosage forms. Last few decades have marked the increase in development of various composites of guar gum that have intrinsic utilization in various fields. Immobilization of guar gum with the others not only enhances its properties but also enriches its utilization in numerous fields for diverse applications such as water purification, drug delivery, pharmaceutical, cosmetic and food industries, etc. Guar gum derivatives are found to have therapeutic importance in certain physiological disorders also. In this review article, we have summarized various possible composites of guar gum and their most probable applications in different fields.

A One Pot Method for Preparing an Antibacterial Superabsorbent Hydrogel with a Semi-IPN Structure Based on Tara Gum and Polyquaternium-7

An antibacterial superabsorbent polymer was prepared by graft polymerization of acrylic acid onto tara gum polysaccharide, by adding N,N-dimethyl-N-2-propenyl-2-propen-1-aminium chloride and a polymer with 2-propenamide (polyquaternium-7, PQ7) as an antibacterial agent. The effects of the amount of PQ7 in the hydrogel on its swelling ratio were investigated and maximum swelling ratios of 712 g/g and 68 g/g, in distilled water and 0.9 wt % NaCl solution were attained with 0.5 g PQ7 per gram of tara gum. The superabsorbent hydrogel was characterized by using Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy and thermal gravimetric analysis. The results showed that poly (acrylic acid) was successfully grafted onto tara gum and a three-dimensional network structure formed with PQ7 chains penetrated in the networks. The antibacterial properties of these superabsorbent hydrogels against Staphylococcus aureus and Escherichia coli improved with increasing PQ7 content. This study demonstrates a method of preparing novel functional superabsorbent hydrogels.

Gellan gum-g-N-vinyl-2-pyrrolidone: synthesis, swelling, metal ion uptake and flocculation behavior

The synthesis of graft copolymer (gellan gum-g-N-vinyl-2-pyrrolidone) is carried out in nitrogen atmosphere using potassium bromate and silver as redox system. The reaction conditions for maximum grafting have been optimized by varying the reaction variables, including the concentration of N-vinyl-2-pyrrolidone (12.0 × 10(--2) to 28 × 10(--2) mol dm(-3)), potassium bromate (6 × 10(-3) to 22 × 10(-3) mol dm(-3)), silver (2.4 × 10(-3)to 5.6 × 10(-3) mol dm(-3)), sulphuric acid (2.0 × 10(-3) to 10 × 10(-3) mol dm(-3)), gellan gum (0.6-1.4 g dm(-3)) along with time duration (60 to 180 min) and temperature (30-50 °C).Water swelling capacity, metal ion sorption and flocculation studies of synthesized graft copolymer have been performed with respect to the parent polymer. The graft copolymer has been characterized by FTIR spectroscopy and thermogravimetric analysis.