Mucoadhesive properties of tamarind-seed polysaccharide/hyaluronic acid mixtures: A nuclear magnetic resonance spectroscopy investigation

A review on revolutionizing ophthalmic therapy: Unveiling the potential of chitosan, hyaluronic acid, cellulose, cyclodextrin, and poloxamer in eye disease treatments

Ocular disorders, encompassing both common ailments like dry eye syndrome and more severe situations for instance age-related macular degeneration, present significant challenges to effective treatment due to the intricate architecture and physiological barriers of the eye. Polysaccharides are emerging as potential solutions for drug delivery to the eyes due to their compatibility with living organisms, natural biodegradability, and adhesive properties. In this review, we explore not only the recent advancements in polysaccharide-based technologies and their transformative potential in treating ocular illnesses, offering renewed optimism for both patients and professionals but also anatomy of the eye and the significant obstacles hindering drug transportation, followed by an investigation into various drug administration methods and their ability to overcome ocular-specific challenges. Our focus lies on biological adhesive polymers, including chitosan, hyaluronic acid, cellulose, cyclodextrin, and poloxamer, known for their adhesive characteristics enhancing drug retention on ocular surfaces and increasing bioavailability. A detailed analysis of material designs used in ophthalmic formulations, such as gels, lenses, eye drops, nanofibers, microneedles, microspheres, and nanoparticles, their advantages and limitations, the potential of formulations in improving therapeutic outcomes for various eye conditions. Moreover, we underscore the discovery of novel polysaccharides and their potential uses in ocular drug delivery.

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.

Comparative hydrodynamic and nanoscale imaging study on the interactions of teicoplanin-A2 and bovine submaxillary mucin as a model ocular mucin

Glycopeptide antibiotics are regularly used in ophthalmology to treat infections of Gram-positive bacteria. Aggregative interactions of antibiotics with mucins however can lead to long exposure and increases the risk of resistant species. This study focuses on the evaluation of potential interactions of the last line of defence glycopeptide antibiotic teicoplanin with an ocular mucin model using precision matrix free hydrodynamic and microscopic techniques: sedimentation velocity in the analytical ultracentrifuge (SV-AUC), dynamic light scattering (DLS) and atomic force microscopy (AFM). For the mixtures of teicoplanin at higher doses (1.25 mg/mL and 12.5 mg/mL), it was shown to interact and aggregate with bovine submaxillary mucin (BSM) in the distributions of both sedimentation coefficients by SV-AUC and hydrodynamic radii by DLS. The presence of aggregates was confirmed by AFM for higher concentrations. We suggest that teicoplanin eye drop formulations should be delivered at concentrations of < 1.25 mg/mL to avoid potentially harmful aggregations.

Hyaluronic Acid in Biomedical Fields: New Trends from Chemistry to Biomaterial Applications

The aim of this review is to give an updated perspective about the methods for chemical modifications of hyaluronic acid (HA) toward the development of new applications in medical devices and material engineering. After a brief introduction on chemical, structural and biological features of this important natural polysaccharide, the most important methods for chemical and physical modifications are disclosed, discussing both on the formation of new covalent bonds and the interaction with other natural polysaccharides. These strategies are of paramount importance in the production of new medical devices and materials with improved properties. In particular, the use of HA in the development of new materials by means of additive manufacturing techniques as electro fluid dynamics, i.e., electrospinning for micro to nanofibres, and three-dimensional bioprinting is also discussed.

Hyaluronic Acid and Galacto-Xyloglucan Eyedrop Efficacy in Young-Adult Oral Contraceptive Users of Childbearing Age

To assess the efficacy of 0.4% hyaluronic acid and 0.2% galacto-xyloglucan for the subjective symptoms of dry eye disease and tear film invasive and noninvasive signs in 34 young-adult oral contraceptive users of childbearing age, a prospective, longitudinal, single-blind, clinical study was performed in a population of childbearing-age oral-contraceptive consumers. Subjective dry eye disease questionnaires, and invasive and noninvasive tear film assessments were reported before and after six weeks of hyaluronic acid with galacto-xyloglucan (HA-GX) treatment versus hyaluronic acid alone (HA). HA-GX treatment resulted in a greater decrease in the ocular surface disease index (17.01 ± 11.36 score points, p < 0.01) than the HA variation (11.61 ± 11.18 score points, p < 0.01). The standard patient evaluation of eye dryness also decreased more in the HA-GX group (4.06 ± 5.50 score points, p < 0.01) than in the HA alone group (0.70 ± 3.16, p = 0.21). Regarding noninvasive break-up time (NIBUT), the HA-GX group’s first NIBUT achieved an increase of 1.75 ± 1.16 s, p < 0.01, while the HA-alone group increased by only 0.54 ± 1.01 s, p < 0.01. The HA-GX group’s mean NIBUT reported an increase of 3.72 ± 5.69 s, p < 0.01; however, the HA-alone group achieved 2.19 ± 5.26 s, p = 0.05. Hyaluronic acid in combination with galacto-xyloglucan significantly decreased subjective dry eye disease symptoms and increased first and mean NIBUT compared to hyaluronic acid alone. Galacto-xyloglucan added efficacy in young-adult childbearing-age oral contraceptive users.

Oral isotretinoin for acne vulgaris side effects on the ocular surface: Hyaluronic acid and galacto-xyloglucan as treatment for dry eye disease signs and symptoms

The purpose was to assess the efficacy of 0.4% hyaluronic acid and 0.2% galacto-xyloglucan on the subjective symptoms of dry eye disease and invasive and non-invasive tear film signs in oral isotretinoin for acne vulgaris treatment. A prospective, longitudinal, single-blind, clinical study was performed in oral isotretinoin for the acne vulgaris consumer population. Subjective dry eye disease questionnaires and invasive and non-invasive tear film assessments were reported prior to and after 6 weeks of hyaluronic acid with galacto-xyloglucan (HA-GX) treatment vs. hyaluronic acid alone (HA). Participants in the HA-GX group reported a higher decrease in the ocular surface disease index (17.01 ± 11.36 score points) compared to the variation in participants in the HA group (11.61 ± 11.18 score points). Standard patient evaluation of eye dryness also decreased more in participants in the HA-GX group (4.06 ± 5.50 score points) than in participants who received HA alone (0.70 ± 3.16). Regarding non-invasive break-up time (NIBUT), participants in the HA-GX group first NIBUT achieved an increase of 1.75 ± 1.16 s while participants in the HA-alone group demonstrated an increase of only 0.54 ± 1.01 s. The HA-GX group mean NIBUT increased by of 3.72 ± 5.69 s; however, the value for the HA-alone group was 2.19 ± 5.26 s. Hyaluronic acid in combination with galacto-xyloglucan significantly decreased limbal and bulbar conjunctival redness classification and SPEED test outcomes. The inclusion of galacto-xyloglucan also increased BUT and mean NIBUT values compared to those obtained with hyaluronic acid alone.

Synergistic Properties of Arabinogalactan (AG) and Hyaluronic Acid (HA) Sodium Salt Mixtures

The properties of mixtures of two polysaccharides, arabinogalactan (AG) and hyaluronic acid (HA), were investigated in solution by the measurement of diffusion coefficients D of water protons by DOSY (Diffusion Ordered SpectroscopY), by the determination of viscosity and by the investigation of the affinity of a small molecule molecular probe versus AG/HA mixtures in the presence of bovine submaxillary mucin (BSM) by 1HNMR spectroscopy. Enhanced mucoadhesive properties, decreased mobility of water and decreased viscosity were observed at the increase of AG/HA ratio and of total concentration of AG. This unusual combination of properties can lead to more effective and long-lasting hydration of certain tissues (inflamed skin, dry eye corneal surface, etc.) and can be useful in the preparation of new formulations of cosmetics and of drug release systems, with the advantage of reducing the viscosity of the solutions.

Screening of polysaccharides from fruit pulp of Ziziphus mauritiana L. and Artocarpus heterophyllus L. as natural mucoadhesives

Background

Mucoadhesive polymers are applicable for improving the delivery of drug by prolonging the residence time and time of contact of the dosage form with the mucous membrane. Mucoadhesion may be defined as a process where the polymer substance gets adhered either to the biological substrate or synthetic or to a natural macromolecule, or to the mucus membrane. The natural polymers can be studied to determine whether they possess some mucoadhesive properties as several excipients derived from plants have proved their potential in the field of conventional or novel dosage form. The present work aims at determination of physical properties of polysaccharides from fruit pulp of Ziziphus mauritiana L. (ZM gum) and Artocarpus heterophyllus L. (AH gum), such as mucoadhesive strength (shear stress determination), swelling index, pH, viscosity, angle of repose, Carr’s index, density, and its comparative study with synthetic polymers Carbopol 934 and HPMC and also to study its FTIR and 1H-NMR spectra analysis.

Result

The most important properties such as mucoadhesive strength of ZM gum (3% w/v) and AH gum (3%) was found to be comparable with HPMC (3% w/v) and Carbopol 934 (3% w/v); also, the swelling index of the isolated gums were also found comparable with both HPMC and Carbopol 934. Falling sphere method is conducted in which the time taken by the sphere to move 50 divisions to the bottom for 3% w/v ZM gum solution was 10.14 s and for AH gum was 10.13 s which is comparable to HPMC and Carbopol 934. The FTIR & 1H NMR spectra showed typical characteristic signals of polysaccharides and presence of typical sugar residues.

Conclusion

From the study, it can be concluded that ZM and AH gum has potential to be better than Carbopol 934 and HPMC in respect of mucoadhesive strength and also it has the potential to replace some synthetic mucoadhesive polymers and polysaccharides.

Polysaccharide-Based Nanomaterials for Ocular Drug Delivery: A Perspective

Ocular drug delivery is one of the most challenging issues in ophthalmology because of the complex physiological structure of the eye. Polysaccharide-based nanomaterials have been extensively investigated in recent years as ideal carriers for enhancing the bioavailability of drugs in the ocular system because of their biocompatibility and drug solubilization. From this perspective, we discuss the structural instability of polysaccharides and its impact on the synthesis process; examine the potential for developing bioactive polysaccharide-based ocular drug nanocarriers; propose four strategies for designing novel drug delivery nanomaterials; and suggest reviewing the behavior of nanomaterials in ocular tissues.

Hydrodynamic Compatibility of Hyaluronic Acid and Tamarind Seed Polysaccharide as Ocular Mucin Supplements

Hyaluronic acid (HA) has been commonly used in eyedrop formulations due to its viscous lubricating properties even at low concentration, acting as a supplement for ocular mucin (principally MUC5AC) which diminishes with aging in a condition known as Keratoconjunctivitis sicca or “dry eye”. A difficulty has been its short residence time on ocular surfaces due to ocular clearance mechanisms which remove the polysaccharide almost immediately. To prolong its retention time, tamarind seed gum polysaccharide (TSP) is mixed as a helper biopolymer with HA. Here we look at the hydrodynamic characteristics of HA and TSP (weight average molar mass M_w and viscosity η) and then explore the compatibility of these polymers, including the possibility of potentially harmful aggregation effects. The research is based on a novel combination of three methods: sedimentation velocity in the analytical ultracentrifuge (SV-AUC), size-exclusion chromatography coupled to multiangle light scattering (SEC-MALS) and capillary viscometry. HA and TSP were found to have Mw=(680±30) kg/mol and (830±30) kg/mol respectively, and η=1475±30 ml/g and 675±20 ml/g, respectively. The structure of HA ranges from a rodlike molecule at lower molar masses changing to a random coil for M_w > 800 kg/mol, based on the Mark–Houwink–Kuhn–Sakurada (MHKS) coefficient. TSP, by contrast, is a random coil across the range of molar masses. For the mixed HA-TSP systems, SEC-MALS indicates a weak interaction. However, sedimentation coefficient (s) distributions obtained from SV-AUC measurements together with intrinsic viscosity demonstrated no evidence of any significant aggregation phenomenon, reassuring in terms of eye-drop formulation technology involving these substances.

Crosslinked hyaluronic acid with liposomes and crocin for management symptoms of dry eye disease caused by moderate meibomian gland dysfunction

AIM

To study the effect of uncrosslinked and crosslinked hyaluronic acid combined with other artificial tear components in patients with dry eye caused by moderate meibomian gland dysfunction.

METHODS

Prospective, single-blind, contralateral eye study. Fifty eyes (25 patients) were analyzed. Eye selection for each tear type was random, and the eye drop formulations, 0.4% uncrosslinked hyaluronic acid and 0.2% galactoxyloglucan (tear A) and 0.15% crosslinked hyaluronic acid, crocin, and liposomes (tear B) were used. The determined dosing schedule was three times a day for six weeks, and the study participants underwent a clinical examination before and 45d after lubricant treatment. The Schirmer test, tear breakup time (TBUT) test, and Ocular Surface Disease Index (OSDI) questionnaire were applied before and after instillation period with both types of artificial tears.

RESULTS

On the Schirmer test, a significant improvement was obtained with both tear A (P<0.01) and tear B (P<0.01). On the TBUT test, a significant improvement was obtained with tear A (P<0.01) and tear B (P<0.01). The OSDI score significantly decreased after instillation period with both artificial tear types (P<0.01).

CONCLUSION

Uncrosslinked hyaluronic acid combined with other components, such as tamarind seed polysaccharide, and crosslinked hyaluronic acid combined with liposomes and crocin are effective for management symptoms of dry eye disease.

Binding and mucoadhesion of sulfurated derivatives of quaternary ammonium-chitosans and their nanoaggregates: An NMR investigation

The effect of insertion of SH and S-protected groups on the binding and mucoadhesion properties of quaternary ammonium-chitosans and their nanoparticulate forms has been investigated by NMR spectroscopy. Diclofenac sodium salt has been assumed as low molecular weight probe to detect the different binding behaviour of polymeric materials; mucin from bovine submaxillary glands was selected as the model protein for differentiating their mucoadhesion. NMR proton selective relaxation rates of the probe molecule were remarkably sensitive to the presence of very low amounts of sulfurated moieties. Impact of supramolecular aggregation in nanostructured species was demonstrated as well as the relevance of S-protection.

Nose-to-brain delivery of hyaluronate - FG loop peptide conjugate for non-invasive hypoxic-ischemic encephalopathy therapy

The intranasal drug administration has attracted great interest as a non-invasive route allowing targeted delivery of drugs directly to the brain. However, one of the main issues in nasal drug administration is mucociliary clearance. Hyaluronate (HA) has been widely used as a mucoadhesive excipient for ocular, rectal, and vaginal delivery. Here, FG loop peptide (FGL) was conjugated to HA for improving enzymatic stability and delivery efficiency from the nose to the brain. The successful conjugation of FGL to aldehyde modified HA was confirmed by gel permeation chromatography (GPC) and ¹H nuclear magnetic resonance (NMR). The outstanding enzymatic stability of HA-FGL conjugate was also corroborated by the GPC. The HA-FGL conjugate showed enhanced binding affinity onto nasal epithelial cells. In addition, in vivo nose-to-brain delivery of HA-FGL conjugate could be visualized by using an IVIS imaging system and fluorescence microscopy. Finally, in vivo therapeutic effect of HA-FGL conjugate was successfully confirmed by histological analysis, transferase-mediated uridine 5-triphosphate-biotin nick end-labeling (TUNEL) assay, immunofluorescent staining, transmission electron microscopy (TEM), and rotarod tests in hypoxic-ischemic encephalopathy model animals.

Extraction and Characterization of Tamarind (Tamarind indica L.) Seed Polysaccharides (TSP) from Three Difference Sources

Tamarind seed polysaccharide (TSP), a natural polysaccharide extracted from tamarind seeds is used in the pharmaceutical, textile and food industries as a mucoadhesive polymer. This work aimed to extract TSP from tamarind seeds from three sources with two methods and characterized its physical and chemical properties. Kernel powder of tamarind seeds was slurried into a clear solution, set aside overnight and then centrifuged at 6000 rpm for 20 min to separate all foreign matter. The supernatant was separated and poured into excess 95% ethanol with continuous stirring. The precipitate obtained was collected and dried in the oven and then the dried TSP polymer was stored in a desiccator. The dried TSP was analyzed by ¹H-NMR, FT-IR and XRD. The results showed TSP from tamarind seeds taken from paddy farmland (A), a waste from the export tamarind juice industry (B) and the export tamarind powder industry(C) gave yields of 31.55%, 26.95% and 17.30%, respectively, using method 1 and 11.15%, 53.65% and 54.65%, with method 2, respectively, but method 2 gave purer TSP than method 1. The FT-IR spectra displayed peaks at 3351.95 cm⁻¹, 2920.76 cm⁻¹, 1018.85 cm⁻¹ and 555.16 cm⁻¹. The ¹H-NMR showed polysaccharide peaks between δ 3.50–4.20 ppm and XRD diagrams indicated their amorphous nature. Future works will focus on the quantitative analysis, biological activity and possible use of TSP as a drug delivery system.

Micro/nanofabricated platforms for oral drug delivery

The oral route of drug administration is most preferred due to its ease of use, low cost, and high patient compliance. However, the oral uptake of many small molecule drugs and biotherapeutics is limited by various physiological barriers, and, as a result, drugs suffer from issues with low solubility, low permeability, and degradation following oral administration. The flexibility of micro- and nanofabrication techniques has been used to create drug delivery platforms designed to address these barriers to oral drug uptake. Specifically, micro/nanofabricated devices have been designed with planar, asymmetric geometries to promote device adhesion and unidirectional drug release toward epithelial tissue, thereby prolonging drug exposure and increasing drug permeation. Furthermore, surface functionalization, nanotopography, responsive drug release, motion-based responses, and permeation enhancers have been incorporated into such platforms to further enhance drug uptake. This review will outline the application of micro/nanotechnology to specifically address the physiological barriers to oral drug delivery and highlight technologies that may be incorporated into these oral drug delivery systems to further enhance drug uptake.

Mucoadhesivity and release properties of quaternary ammonium-chitosan conjugates and their nanoparticulate supramolecular aggregates: an NMR investigation

Selective relaxation rate measurements effectively proved the affinity of dexamethasone 21-phosphate disodium salt for quaternary ammonium-chitosan conjugates, their thiolated derivatives and the corresponding nanostructured aggregates. Affinity was also probed by dynamic dialysis. The release profile of dexamethasone loaded nanoparticles was defined by quantitative NMR and interrupted dialysis experiments, and mucoadhesivity of empty nanoparticles was effectively probed by selective relaxation rate measurements.