Functional network copolymeric hydrogels derived from moringa gum: Physiochemical, drug delivery and biomedical properties

The article explores the synthesis of network hydrogels derived from moringa gum (MG) through a grafting reaction with poly (vinylsulfonic acid) and carbopol. These hydrogels are designed for use in drug delivery (DD) and wound hydrogels dressing (HYDR) applications. The copolymers were characterized by FESEM, EDX, AFM, FTIR, 13C NMR, XRD and DSC. Tetracycline release from hydrogel occurred gradually with a non-Fickian diffusion and was best described by the Hixson-Crowell kinetic model in artificial wound fluid. The HYDR demonstrated compatibility with blood, exhibited antioxidant properties and possessed tensile strength, in addition to their mucoadhesive characteristics. The copolymer dressings absorbed approximately 7 g of simulated fluid. The copolymers exhibited significant antioxidant activity, measuring at 84 % free radicals scavenging, during DPPH assay. These dressings demonstrated permeability to H2O and O2,. The hydrogel alone did not reveal antibacterial activities; however, when combined with antibiotic drug tetracycline, the dressings revealed notable antibacterial activities against Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. The observed biomedical properties suggested that these hydrogels could serve as promising materials for drug delivery HYDR applications.

Towards scalable and degradable bioplastic films from Moringa oleifera gum/poly(vinyl alcohol) as packaging material

The use of plant gum-based biodegradable bioplastic films as a packaging material is limited due to their poor physicochemical properties. However, combining plant gum with synthetic degradable polymer and some additives can improve these properties. Keeping in view, the present study aimed to synthesize a series of bioplastic films using Moringa oleifera gum, polyvinyl alcohol, glycerol, and citric acid via thermal treatment followed by a solution casting method. The films were characterized using analytical techniques such as FTIR, XRD, SEM, AFM, TGA, and DSC. The study examined properties such as water sensitivity, gas barrier attributes, tensile strength, the shelf life of food, and biodegradability. The films containing higher citric acid amounts showed appreciable %elongation without compromising tensile strength, good oxygen barrier properties, and biodegradation rates (>95%). Varying the amounts of glycerol and citric acid in the films broadened their physicochemical properties ranging from hydrophilicity to hydrophobicity and rigidity to flexibility. As all the films were synthesized using economical and environmentally safe materials, and showed better physicochemical and barrier properties, this study suggests that these bioplastic films can prove to be a potential alternative for various packaging applications.

Coagulative removal of microplastics from aqueous matrices: Recent progresses and future perspectives

Coagulation-flocculation-sedimentation (CFS) system has been identified as one of the favored treatment technique in water/wastewater treatment systems and hence, it is crucial to comprehend the efficacy of different coagulants used in removing microplastics (MPs) from aqueous matrices. Henceforth, this study critically reviews the recent progress and efficacy of different coagulants used to date for MPs removal. This includes laboratory and field-scale studies on inorganic and organic coagulants, as well as laboratory-scale studies on natural coagulants. Inorganic and organic coagulants have varying MPs removal efficiencies such as: Fe/Al-salts (30 %-95 %), alum (99 %), and poly aluminum chloride (13 %-97 %), magnesium hydroxide (84 %), polyamine (99 %), organosilanes (>95 %), and polyacrylamide (85 %-98 %). Moreover, studies have highlighted the use of natural coagulants, such as chitosan, protein amyloid fibrils, and starch has shown promising results in MPs removal with sevral advantages over traditional coagulants. These natural coagulants have demonstrated high MPs removal efficiencies with chitosan-tannic acid (95 %), protein amyloid fibrils (98 %), and starch (>90 %). Moreover, the MPs removal efficiencies of natural coagulants are compared and their predominant removal mechanisms are determined. Plant-based natural coagulants can potentially remove MPs through mechanisms such as polymer bridging and charge neutralization. Further, a systematic analysis on the effect of operational parameters highlights that the pH affects particle surface charge and coagulation efficiency, while mixing speed affects particle aggregation and sedimentation. Also, the optimal mixing speed for effective MPs removal depends on coagulant type and concentration, water composition, and MPs characteristics. Moreover, this work highlights the advantages and limitations of using different coagulants for MPs removal and discusses the challenges and future prospects in scaling up these laboratory studies for real-time applications.

Moringa oleifera gum capped MgO nanoparticles: Synthesis, characterization, cyto- and ecotoxicity assessment

Nano-based drug delivery research is increasing due to the therapeutic applications for human health care. However, traditional chemical capping-based synthesis methods lead to unwanted toxicity effects. Hence, there is an urgent need for green synthesis-based and biocompatible synthesis methods. The current work describes for the first time the green synthesis of Moringa gum-capped MgO nanoparticles (Mgm-MgO NPs). Their antioxidant activity, hemolysis potential, cytotoxicity, phytotoxicity, toxicity by chorioallantoic membrane (CAM) chick embryo assay and in vivo toxicity in zebrafish embryos were described. The Mgm-MgO NPs exhibited significant antioxidant activity. The Mgm-MgO NPs at 500 μg/ml produced significant hemolysis (72.54 %), while lower concentrations did not. Besides, the cytotoxicity assessment of the Mgm-MgO NPs was conducted in PA-1 cells from human ovarian teratocarcinoma by MTT assay. The Mgm-MgO NPs (0.1-500 μg/ml) considerably reduced the viability of PA-1 cells. Furthermore, Mgm-MgO NPs had no significant effect on seed germination but had a significant effect on root and shoot length of mungbean (Vigna radiata). Additionally, the CAM assay was used to analyze the antiangiogenic potential of Mgm-MgO NPs, exhibiting no significant alterations after 72 h. Finally, the zebrafish embryotoxicity assay revealed that the Mgm-MgO NPs (0.1-500 μg/ml) did not affect morphology, mortality or survival rate.

Recent developments in Moringa oleifera Lam. polysaccharides: A review of the relationship between extraction methods, structural characteristics and functional activities

Moringa oleifera Lam. (M. oleifera Lam) is a perennial tropical deciduous tree that belongs to the Moringaceae family. Polysaccharides are one of the major bioactive compounds in M. oleifera Lam and show immunomodulatory, anticancer, antioxidant, intestinal health protection and antidiabetic activities. At present, the structure and functional activities of M. oleifera Lam polysaccharides (MOPs) have been widespread, but the research data are relatively scattered. Moreover, the relationship between the structure and biological activities of MOPs has not been summarized. In this review, the current research on the extraction, purification, structural characteristics and biological activities of polysaccharides from different sources of M. oleifera Lam were summarized, and the structural characteristics of purified polysaccharides were focused on this review. Meanwhile, the biological activities of MOPs were introduced, and some molecular mechanisms were listed. In addition, the relationship between the structure and biological activities of MOPs was discussed. Furthermore, new perspectives and some future research of M. oleifera Lam polysaccharides were proposed in this review.

Moringa (Moringa oleifera Lam.) polysaccharides: Extraction, characterization, bioactivities, and industrial application

Owing to numerous biological activities of different parts of Moringa oleifera Lam., various studies have been carried out to isolate and explore the activities of its various bioactive compounds including polysaccharides. Polysaccharides of M. oleifera have been reported to possess a variety of biofunctionalities including antihyperlipidemic, anti-diabetic, immunomodulatory, antihypertensive and gastrointestinal protection. In addition to bioactive polysaccharides, the gum exudated by stem of this plant is of commercial importance with wide range of applications in pharmaceutical industries. Various extraction and purification methods as well as combination of methods have been used to isolate and purify moringa polysaccharides. Studies suggest that extraction methods influence the structure of polysaccharides and thus their biological activity. This review summarizes all the available literature to provide updated information related to extraction, purification, modification, structural characterization, bioactivities and potential applications of moringa polysaccharides. This review will provide novel insights for future research and applications of moringa polysaccharides.

Purification, structural characterization and antioxidant activity of a new arabinogalactan from Dorema ammoniacum gum

Gum ammoniacum is a polymer obtained from Dorema ammoniacum and its medicinal use was already known to the ancient times. In this study, a new D. ammoniacum carbohydrate (DAC-1) with a molecular weight of 27.1 kDa was extracted by hot water and then purified on DEAE-52-cellulose and Sephadex G-100 columns. The structural features of DAC-1 were investigated by partial acid hydrolysis, fourier-transform infrared spectroscopy (FT-IR), methylation, gas chromatography-mass spectrometry (GC-MS), gas chromatography-flame ionization detection (GC-FID), and 1D and 2D nuclear magnetic resonance spectroscopy (1D & 2D NMR). The results indicated that DAC-1 was an arabinogalactan including galactose, arabinose, rhamnose, glucuronic acid and 4-O-methyl-β-d-glucopyranosyl uronic acid (meGlcpA) with a relative percentage of 44.63%, 23.30%, 13.46%. 12.47%, and 6.14%. The structure units of DAC-1 were elucidated as 3,1)-β-_D-Galp-(6 → 1)-β-_D-Galp-(3,6 → containing four branch chains of →1,6)-β-_D-Galp-(3 → 1)-α-_L-Araf-(5 → 1)-β-_D-GlcpA-(4 → 1)-α-_L-Rhap-T (two times), →1,6)-β-_D-Galp-(3→1)-β-_D-Galp-(3 → 1)-β-_D-Galp-(3 → 1)-β-_D-Galp-(3  →  1)-α-_L-Araf-T and →1,6)-β-_D-Galp-(3 → 1)-α-_L-Araf-(5 → 1)-β-_D-meGlcpA-T. X-ray diffraction (XRD) pattern indicated a semi-crystalline structure. Thermal behavior of the polysaccharide was evaluated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) and revealed temperatures higher than 200 °C as dominant region of weight loss. DAC-1 showed acceptable antioxidant activity when analyzed by DPPH, ABTS, FRAP, and OH radical removal methods.

The heparin-mimicking arabinogalactan sulfates from Anogeissus latifolia gum: Production, structures, and anti-herpes simplex virus activity

Herpes simplex virus type 1(HSV-1) attaches to cell surface heparan sulfate aiming to enter into susceptible cells. In this work, we utilized a sulfur trioxide-pyridine in N,N-dimethylformamide (SO₃·Pyr/DMF) based amalgamated extraction-sulfation procedure for producing arabinogalactan sulfates from Anogeissus latifolia gum. Chemical, chromatographic, spectroscopic and chemical data revealed that the derived polymers contained varying molecular masses (31-69 kDa) and degrees of sulfation (0.1-0.5), but similar saccharide compositions. The highly active polymer (HSV-1: IC₅₀ and SI, respectively, of 127 μg/mL and 15.7) was a 69 kDa arabinogalactan holding sulfates at O-5 of arabinofuranosyl residues and showed no cytotoxicity as far as 2 mg/mL concentration. This chemically sulfated macromolecule acted by obstructing viral attachment and entry. Thus, SO₃·Pyr/DMF is suitable for producing new molecules with varied structures and altered pharmacological activities from plant sources.

Bioactive components and anti-diabetic properties of Moringa oleifera Lam

Moringa oleifera Lam. is a perennial tropical deciduous tree with high economic and pharmaceutical value. As an edible plant, M. oleifera Lam. is rich in nutrients, such as proteins, amino acids, mineral elements and vitamins. Besides, it also contains an important number of bioactive phytochemicals, such as polysaccharides, flavonoids, alkaloids, glucosinolates and isothiocyanates. M. oleifera for long has been used as a natural anti-diabetic herb in India and other Asian countries. Thus, the anti-diabetic properties of Moringa plant have evolved highly attention to the researchers. In the last twenty years, a huge number of new chemical structures and their pharmacological activities have been reported in particularly the anti-diabetic properties. The current review highlighted the bioactive phytochemicals from M. Oleifera. Moreover, evidence regarding the therapeutic potential of M. oleifera for diabetes including experimental and clinical data was presented and the underlying mechanisms were revealed in order to provide insights for the development of novel drugs.

Exploiting the Amazing Diversity of Natural Source-Derived Polysaccharides: Modern Procedures of Isolation, Engineering, and Optimization of Antiviral Activities

Naturally occurring polysaccharide sulfates are highly diverse, owning variations in the backbone structure, linkage pattern and stereochemistry, branching diversity, sulfate content and positions of sulfate group(s). These structural characteristics bring about diverse sulfated polymers with dissimilar negative charge densities and structure-activity relationships. Herein, we start with a short discussion of techniques needed for extraction, purification, chemical sulfation, and structural characterization of polysaccharides. Processes of isolation and sulfation of plant-derived polysaccharides are challenging and usually involve two steps. In this context, we describe an integrated extraction-sulfation procedure that produces polysaccharide sulfates from natural products in one step, thereby generating additional pharmacological activities. Finally, we provide examples of the spectrum of natural source-derived polysaccharides possessing specific features of bioactivity, in particular focusing on current aspects of antiviral drug development and drug-target interaction. Thus, the review presents a detailed view on chemically engineered polysaccharides, especially sulfated derivatives, and underlines their promising biomedical perspectives.

Moringa gum and its modified form as a potential green polymer used in biomedical field

Over the past few decades, natural gums are extensively investigated by the researchers due to their beneficial physicochemical properties. Among them, the polysaccharide exudates obtained from the stem of the plant Moringa oleifera, known as moringa gum, is investigated widely in the food, pharmaceutical, and other areas. The moringa gum is used in the form of dried powder as a pharmaceutical excipient in various formulations. It is also derivatized either by grafting or by other chemical modifications for enhancing its properties. The research on moringa gum and modified moringa gum has diversified in numerous biomedical fields. However, summarization of these progress are not available in the literature. This article gives an overview of the collection, purification, structural elucidation, and modification of moringa gum. Moreover, the present review furnishes complete information on the various aspects of moringa gum and its applications in various industrial and biomedical fields.

Surface Morphology and Physicochemical Characterization of Thermostable Moringa Gum: A Potential Pharmaceutical Excipient

An efficient protocol for physico-chemical characterization of gum exudates collected from the drumstick tree (Moringa oleifera Lam.) has been reported in the present study. Extraction of gum metabolites was done using a series of water, alcohol, acid, and alkali solvent systems. The gum was sparingly soluble in water at room temperature and formed a colloidal solution. Solubility of the gum gradually increased in the solvent gradient (80% ethanol, deionized water, 0.05 M HCl, and 0.05 M NaOH) at 90 °C. Further, electron microscopy revealed that the acetyl group is essential in maintaining the structural integrity, and deacetylation of gum resulted in formation of a mesh of scattered and fibrous particles. Treatment of gum with deionized water resulted in development of a hydrocolloidal matrix with a pore size of 0.5 μm, which upon deacetylation was reduced up to 0.2 μm. The polymer was amorphous in nature and showed maximum thermal stability in ethanol. Gas chromatography-mass spectrometry of the gum polymer revealed that carbohydrate derivatives constituted its major part (>75%). Maximum carbohydrate concentration was obtained in the ethanol soluble fraction, along with fatty acids (10%) and secondary metabolites (9%). The results provided very first confirmation of the hydrocolloidal properties and thermostability of the gum exudates obtained from the drumstick tree, which can further be used to develop an eco-friendly and nontoxic bioligand.

Morphological and Swelling Potential Evaluation of Moringa oleifera Gum/Poly(vinyl alcohol) Hydrogels as a Superabsorbent

Synergistic use of superabsorbent hydrogels has vital contribution to the daily life. This work gives an account of a facile approach to synthesize superabsorbent hydrogels based on Moringa oleifera gum and polyvinyl alcohol cross-linked with borax. Fourier transform infrared, X-ray diffraction, and scanning electron microscopy were employed to characterize the structure, crystallinity, and surface morphologies of the samples. The cross-link density, swelling ratio, reswelling, water retention properties, and salt sensitivity of hydrogels were investigated. Reaction parameters for the hydrogel synthesis were optimized on the basis of water absorbency, and the reaction condition of greater water absorbency after 12 h at room temperature was taken as an ideal condition. Optimum conditions were obtained as [poly(vinyl alcohol) PVA] = 10% (w/v) and [borax] = 1.05 × 10-3 mol/L. Under the optimized conditions, the maximum swelling ratio of MOG/PVA hydrogel reached 1163 g/g in deionized water and 290 g/g in 0.9 wt % NaCl solution. Furthermore, all hydrogels exhibited salt sensitivity and excellent water retention capacity under the high temperature state and displayed smart swelling behaviors in physiological saline solutions. The water absorbency, reusability, and salt sensitivity of the hydrogels give these smart polymer wide promising applications.

Effect of the in vitro gastrointestinal digestion on free-phenolic compounds and mono/oligosaccharides from Moringa oleifera leaves: Bioaccessibility, intestinal permeability and antioxidant capacity

Moringa oleifera is a plant recognized for its compounds such as dietary fiber (oligosaccharides, amongst others) and polyphenols, with biological activities. These properties depend on bioactive compounds (BC) interactions with food matrix/digestion conditions, which have not been evaluated. Thus, the aim of this study was to evaluate the bioaccessibility, intestinal permeability and antioxidant capacity of BC (free-phenolic compounds (PC); and mono/oligosaccharides (MOS)) from Moringa oleifera leaves (ML) powder during in vitro gastrointestinal digestion. The gallic/caffeic acids, morin, kaempferol, mannose and stachyose showed the highest bioaccessibilities (~6-210%). The PC correlated with the antioxidant capacity (R²: 0.59-0.98, p < .05), whereas gallic/caffeic acids were the highest. The apparent permeability coefficients of bioactive compounds (0.62-36.65 × 10^-4 cm/s) and water flux/glucose transport confirmed the model similarity to in vivo experiments. The results suggest that ML digestion dynamically modifies PC/MOS bioaccessibility/antioxidant capacity while most of them are not completely absorbed in the small intestine.

Hydrogel formation by radiation induced crosslinked copolymerization of acrylamide onto moringa gum for use in drug delivery applications

Keeping in view the importance of polysaccharides gum in designing drug delivery systems, the present work is the exploration of the potential of the moringa gum in hydrogel formation via radiation induced crosslinking method for drug delivery applications. These polymers were characterized by cryo-SEM, AFM, FTIR, ¹³C-NMR spectroscopy and swelling studies. Some properties of the polymers such as blood compatibility, antioxidant activity, mucoadhesion and gel strength were also determined along with the evaluation of drug release profile of an antibiotic drug levofloxacin. The slow release of drug was observed without burst effect from the drug loaded hydrogels. Release of drug occurred through non-Fickian diffusion mechanism and release profile best fitted in Korsmeyer-Peppas kinetic model. Cryo-SEM showed the porous nature of the hydrogels. The polymers were found to be mucoadhesive and antioxidant in nature. These results indicated that these pure and sterile polymers can be proposed as gastrointestinal drug delivery system.