Derivatized Polysaccharides: Preparation, Characterization, and Application as Bioadhesive Polymer for Drug Delivery

Citric acid crosslinked hydroxyethyl tamarind gum-based hydrogel films: A promising biomaterial for drug delivery

This investigation explored citric acid crosslinked hydroxyethyl tamarind gum hydrogel films as a potential biomaterial for drug delivery. Hydroxyethylation of tamarind gum aimed to improve its solubility, swelling, and crosslinking potential. The synthesized hydroxyethylated tamarind gum (HETG) was comprehensively characterized, revealing the presence of hydroxyethyl groups and increased viscosity in comparison to unmodified tamarind gum. The citric acid crosslinked HETG hydrogel films were developed by esterification-crosslinking mechanism. The films were characterized using instrumental techniques and evaluated for total carboxyl content, mechanical properties, swelling behavior, drug loading, drug release, antibacterial activity, hemocompatibility and in vitro wound healing activity. The presence of ester crosslinks and extent of crosslinking was confirmed through total carboxyl content and instrumental analysis. Varying HETG (2-2.5%w/v) and citric acid (1-1.4 %w/v) concentrations resulted in films with tunable mechanical strength, swelling, and drug loading. The films effectively controlled the release of a water-soluble drug (80.87-99.70 % in 24 h) through a non-Fickian diffusion mechanism. The optimized HETG hydrogel film showed antimicrobial activity, hemocompatibility, and support for cell growth, confirming its biocompatibility and potential for wound healing. Citric acid-crosslinked HETG films appear promising for drug delivery to wounds, meriting further in vivo study.

State-of-the-art progress on tamarind seed polysaccharide (Tamarindus indica) and its diverse potential applications, a review with insight

Tamarind seed polysaccharide (TSP) is a biocompatible, non-ionic polymer with antioxidant properties. Its uses include drug delivery, food industry, and wastewater treatment. TSP has various hydroxy functional groups, one of the most favorable sites for graft copolymerization of different monomers. Hence, various chemical methods for TSP modification were developed to satisfy increasing industrial demand. Of particular interest in scientific community are the methods of graft copolymerization because of their ability to alter the physicochemical properties of TSP, including pH sensitivity and the swelling index, leading to improvements in the adsorption efficiency of hazardous heavy metals and dyes from wastewater effluents. Moreover, in recent years, TSP has been used for controlled drug delivery applications due to its unique advantages of high viscosity, broad pH tolerance, non-carcinogenicity, mucoadhesive properties, biocompatibility, and high drug entrapment capacity. In light of the plethora of literature on the topic, a comprehensive review of TSP-based graft copolymers and unmodified and modified TSP important applications is necessary. Therefore, this review comprehensively highlights several synthetic strategies for TSP-grafted copolymers and discusses unmodified and modified TSP potential applications, including cutting-edge pharmaceutical, environmental applications, etc. In brief, its many advantages make TSP-based polysaccharide a promising material for applications in various industries.

Sustainable production of heavy metal-binding levan by a subarctic permafrost thaw lake Pseudomonas strain 2ASCA

Pseudomonas strain 2ASCA isolated in subarctic Québec, Canada, produced a cell membrane bound levan-type exopolymer (yield 1.17 g/L), after incubation in growth media containing 6 % sucrose (w/v) at temperature of 15 °C for 96 h. The objective of this study was to optimize levan production by varying the growth parameters. Moreover, the polymer's chemical characterization has been studied with the aim of increasing knowledge and leading to future applications in many fields, including heavy metal remediation. Higher levan yields (7.37 g/L) were reached by setting up microbial fermentation conditions based on the re-use of the molasses obtained from sugar beet processing. Spectroscopy analyses confirmed the levan-type nature of the exopolymer released by strain 2ASCA, consisting of a β-(2,6)-linked fructose repeating unit. Gel permeation chromatography revealed that the polymer has a molecular weight of 13 MDa. Scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) showed that the levan sequestered with a strong affinity Cr(III), which has never been previously reported, highlighting an interesting biosorption potential. In addition, SEM analysis revealed the formation of nanoparticles in acidified water solution.

Leucaena leucocephala succinate based polyelectrolyte complexes for colon delivery of synbiotic in management of inflammatory bowel disease

Polyelectrolyte complexes (PECs) formed by the interaction between oppositely charged polymers have emerged as promising carriers for accomplishing colon-specific release. In this study, we have explored the potential of polyelectrolyte complexes between a succinate derivative of Leucaena leucocephala galactomannan and cationic guar gum for colon delivery of synbiotic. The PECs were prepared using a polyelectrolyte complexation method and characterized. The PECs exhibited excellent stability, with high encapsulation efficiency for both probiotics (95.53 %) and prebiotics (83.33 %). In vitro studies demonstrated enhanced survivability and proliferation of the encapsulated probiotics in the presence of prebiotics (93.29 %). The SEM images revealed a smooth and firm structure with reduced number of pores when both prebiotic and probiotic were encapsulated together. The treatment with synbiotic PECs in acetic acid induced IBD rats significantly relieves colitis symptoms as was evident from colon/body ratio, DAI score and histopathology studies. An increase in the protein and reduced glutathione levels and reduction in superoxide dismutase activity was observed in colitic rats that received synbiotic treatment as compared to colitic rats. Overall, this study highlights the potential of Leucaena leucocephala succinate-cationic guar gum PECs as a promising system for colon-specific synbiotic delivery, with implications for improved gut health and the treatment of various gastrointestinal disorders.

Modification of chicha gum: Antibacterial activity, ex vivo mucoadhesion, antioxidant activity and cellular viability

The aim of the present work was to modify the exuded gum of Sterculia striata tree by an amination reaction. The viscosity and zero potential of the chicha gum varied as a function of pH. The modification was confirmed by X-ray diffraction (XRD), infrared spectroscopy (FTIR), size exclusion chromatography (SEC), zeta potential, thermogravimetric analysis (TG), and differential scanning calorimetry (DSC). Furthermore, the chemical modification changed the molar mass and surface charge of the chicha gum. In addition, the gums were used in tests for ex vivo mucoadhesion strength, antibacterial activity against the standard strain of Staphylococcus aureus (ATCC 25923), inhibitory activity of α-glucosidase, antioxidant capacity, and viability of Caco-2 cells. Through these tests, it was found that amination caused an increase in the mucoadhesive and inhibitory activity of chicha gum against the bacterium Staphylococcus aureus. In addition, the gums (pure and modified) showed antioxidant capacity and an inhibitory effect against the α-glucosidase enzyme and did not show cytotoxic potential.

Preparation, characterization and release studies of folic acid from inulin conjugates

Folic acid a synthetic form of folate, is the oxidized form of folate which acts as a coenzyme in one carbon transfer reactions required in the biosynthesis of DNA and RNA and its deficiency could be related to diseases such as neural tube defects, Alzheimer's disease, pregnancy complications and cancer. Inulin is a polydisperse polysaccharide comprising mostly of fructosyl fructose units. An oxidized derivative of this inulin was prepared and used as a complexing agent for folic acid to obtain a polysaccharide bound folic acid conjugate. The aldehyde content and degree of oxidation of the oxidized inulin were determined by acid-base titrations. All the products were characterized by sophisticated spectroscopic and thermal methods of analysis. Release studies of folic acid from conjugates were carried out in different pH media and the results demonstrate the pH-sensitive behavior of the inulin-based delivery system towards the controlled release of folic acid.

Candidate Polyurethanes Based on Castor Oil (Ricinus communis), with Polycaprolactone Diol and Chitosan Additions, for Use in Biomedical Applications

Polyurethanes are widely used in the development of medical devices due to their biocompatibility, degradability, non-toxicity and chemical versatility. Polyurethanes were obtained from polyols derived from castor oil, and isophorone diisocyanate, with the incorporation of polycaprolactone-diol (15% w/w) and chitosan (3% w/w). The objective of this research was to evaluate the effect of the type of polyol and the incorporation of polycaprolactone-diol and chitosan on the mechanical and biological properties of the polyurethanes to identify the optimal ones for applications such as wound dressings or tissue engineering. Polyurethanes were characterized by stress-strain, contact angle by sessile drop method, thermogravimetric analysis, differential scanning calorimetry, water uptake and in vitro degradation by enzymatic processes. In vitro biological properties were evaluated by a 24 h cytotoxicity test using the colorimetric assay MTT and the LIVE/DEAD kit with cell line L-929 (mouse embryonic fibroblasts). In vitro evaluation of the possible inflammatory effect of polyurethane-based materials was evaluated by means of the expression of anti-inflammatory and proinflammatory cytokines expressed in a cellular model such as THP-1 cells by means of the MILLIPLEX® MAP kit. The modification of polyols derived from castor oil increases the mechanical properties of interest for a wide range of applications. The polyurethanes evaluated did not generate a cytotoxic effect on the evaluated cell line. The assessed polyurethanes are suggested as possible candidate biomaterials for wound dressings due to their improved mechanical properties and biocompatibility.