Preparation, characterization and biological properties of Gellan gum films with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide cross-linker

Exploring polysaccharide-based bio-adhesive topical film as a potential platform for wound dressing application: A review

Wound dressings act as a physical barrier between the wound site and the external environment, preventing additional harm; choosing suitable wound dressings is essential for the healing process. Polysaccharide biopolymers have demonstrated encouraging findings and therapeutic prospects in recent decades about wound therapy. Additionally, polysaccharides have bioactive qualities like anti-inflammatory, antibacterial, and antioxidant capabilities that can help the process of healing. Due to their excellent tissue adhesion, swelling, water absorption, bactericidal, and immune-regulating properties, polysaccharide-based bio-adhesive films have recently been investigated as intriguing alternatives in wound management. These films also mimic the structure of the skin and stimulate the regeneration of the skin. This review presented several design standards and functions of suitable bio-adhesive films for the healing of wounds. Additionally, the most recent developments in the use of bio-adhesive films as wound dressings based on polysaccharides, including hyaluronic acid, chondroitin sulfate, dextran, alginate, chitosan, cellulose, konjac glucomannan, gellan gum, xanthan gum, pectin, guar gum, heparin, arabinogalactans, carrageen, and tragacanth gum, are thoroughly discussed. Lastly, to create a road map for the function of polysaccharide-based bio-adhesive films in advanced wound care, their clinical performances and future challenges in making bio-adhesive films by three-dimensional bioprinting are summarized.

Gellan Gum in Wound Dressing Scaffolds

Several factors, such as bacterial infections, underlying conditions, malnutrition, obesity, ageing, and smoking are the most common issues that cause a delayed process of wound healing. Developing wound dressings that promote an accelerated wound healing process and skin regeneration is crucial. The properties of wound dressings that make them suitable for the acceleration of the wound healing process include good antibacterial efficacy, excellent biocompatibility, and non-toxicity, the ability to provide a moist environment, stimulating cell migration and adhesion, and providing gaseous permeation. Biopolymers have demonstrated features appropriate for the development of effective wound dressing scaffolds. Gellan gum is one of the biopolymers that has attracted great attention in biomedical applications. The wound dressing materials fabricated from gellan gum possess outstanding properties when compared to traditional dressings, such as good biocompatibility, biodegradability, non-toxicity, renewability, and stable nature. This biopolymer has been broadly employed for the development of wound dressing scaffolds in different forms. This review discusses the physicochemical and biological properties of gellan gum-based scaffolds in the management of wounds.

Advances in fermentative production, purification, characterization and applications of gellan gum

Multiple microbial exopolysaccharides have been reported in recent decade with their structural and functional features. Gellan gum (GG) is among these emerging biopolymers with versatile properties. Low production yield, high downstream cost, and abundant market demand have made GG a high cost material. Hence, an understanding on the various possibilities to develop cost-effective gellan gum bioprocess is desirable. This review focuses on details of upstream and downstream process of GG from an industrial perspective. It emphasizes on GG producing Sphingomonas spp., updates on biosynthesis, strain and media engineering, kinetic modeling, bioreactor design and scale-up considerations. Details of the downstream operations with possible modifications to make it cost-effective and environmentally sustainable have been discussed. The updated regulatory criteria for GG as a food ingredient and analytical tools required to validate the same have been briefly discussed. Derivatives of GG and their applications in various industrial segments have also been highlighted.

Preparation and characterization of bifunctional edible gellan-polylysine fiber

A gellan-polylysine (GPL) fiber was prepared by wet spinning molding with gellan solution containing glucose, soybean peptide, fish collagen peptide as spinning liquid, and ε-poly-l-lysine as fixative liquid. Results showed that the material addition order affects the spinning and an acceptable material addition order was as follows: soybean peptides →glucose → fish collagen peptides. The mechanical strength of the GPL fiber decreased with the collagen peptide titer and the fiber strength can reach 0.99 cN/dtex. In addition, the GPL fiber showed comparable water absorption capacity. The GPL fiber demonstrated good antibacterial properties against Escherichia coli and Staphylococcus aureus. The GPL fiber also had no cytotoxicity on mouse embryo fibroblast L-929 cells and could effectively promote wound healing for rats. As a result, the bifunctional edible GPL fiber is potentially used as a military and rescue emergency equipment.

Gellan gum modified hyaluronic acid hydrogel as viscosupplement with lubrication maintenance and enzymatic resistance

Osteoarthritis (OA) is a common disease caused by damage to articular cartilage and underlying bone tissues. Early OA can be treated by intra-articular injection of viscosupplements to restore the lost...

Antimicrobial and cytocompatible chitosan, N,N,N-trimethyl chitosan, and tanfloc-based polyelectrolyte multilayers on gellan gum films

In this work free-standing gels formed from gellan gum (GG) by solvent evaporation are coated with polysaccharide-based polyelectrolyte multilayers, using the layer-by-layer approach. We show that PEMs composed of iota-carrageenan (CAR) and three different natural polycationic polymers have composition-dependent antimicrobial properties, and support mammalian cell growth. Cationic polymers (chitosan (CHT), N,N,N-trimethyl chitosan (TMC), and an amino-functionalized tannin derivative (TN)) are individually assembled with the anionic iota-carrageenan (CAR) at pH 5.0. PEMs (15-layers) are alternately deposited on the GG film. The GG film and coated GG films with PEMs are characterized by infrared spectroscopy with attenuated total reflectance (FTIR-ATR), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and water contact angle (WCA) measurements. The TN/CAR coating provides a hydrophobic (WCA = 127°) and rough surface (R_q = 243 ± 48 nm), and the TMC/CAR coating provides a hydrophilic surface (WCA = 78°) with the lowest roughness (R_q = 97 ± 12 nm). Polymer coatings promote stability and durability of the GG film, and introduce antimicrobial properties against Gram-negative (Salmonella enteritidis) and Gram-positive (Staphylococcus aureus) bacteria. The films are also cytocompatible. Therefore, they have properties that can be further developed as wound dressings and food packaging.

Gellan gum hydrogels cross-linked with carbodiimide stimulates vacuolation of human tooth-derived stem cells in vitro

The natural polysaccharides are promising compounds for applications in regenerative medicine. Gellan gum (GG) is the bacteria-derived polysaccharide widely used in food industry. Simple modifications of its chemical properties make GG superior for the development of biocompatible hydrogels. Beside reversible cationic integration of GG chains, more efficient binding is accomplished with 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide (EDC). However, the side-products of polymer cross-linking might affect viability and differentiation of stem cells introduced into the hydrogels. We found that O-acylisourea (EDU) stimulates autophagy-based vacuolation in both periodontal ligament and dental pulp stem cells. 24-h treatment of cells with GG extracts cross-linked with 15 mM EDC developed large cytoplasmic vacuoles. Freshly prepared EDU (2-6 mM) but not 15 mM EDC solutions initiated vacuole development with concomitant reduction of cell viability/metabolism. Most of the vacuoles stained with acridine orange displayed highly acidic environment further confirmed by flow cytometric analysis. Western blot of the LC3 autophagy marker followed by a transmission electron microscopy indicated the process is autophagy-dependent. We propose that the high reactivity of EDU with intracellular components initiates autophagy, although the targets of EDU remain unknown. Nevertheless, a burst release of EDU from GG hydrogels might modulate negatively cellular processes and final effectiveness of tissue regeneration.

Recent Advances in Natural Gum-Based Biomaterials for Tissue Engineering and Regenerative Medicine: A Review

The engineering of tissues under a three-dimensional (3D) microenvironment is a great challenge and needs a suitable supporting biomaterial-based scaffold that may facilitate cell attachment, spreading, proliferation, migration, and differentiation for proper tissue regeneration or organ reconstruction. Polysaccharides as natural polymers promise great potential in the preparation of a three-dimensional artificial extracellular matrix (ECM) (i.e., hydrogel) via various processing methods and conditions. Natural polymers, especially gums, based upon hydrogel systems, provide similarities largely with the native ECM and excellent biological response. Here, we review the origin and physico-chemical characteristics of potentially used natural gums. In addition, various forms of scaffolds (e.g., nanofibrous, 3D printed-constructs) based on gums and their efficacy in 3D cell culture and various tissue regenerations such as bone, osteoarthritis and cartilage, skin/wound, retinal, neural, and other tissues are discussed. Finally, the advantages and limitations of natural gums are precisely described for future perspectives in tissue engineering and regenerative medicine in the concluding remarks.

Application of Gellan Gum-Based Scaffold for Regenerative Medicine

Gellan gum (GG) is a linear microbial exopolysaccharide which is derived naturally by the fermentation process of Pseudomonas elodea. Application of GG in tissue engineering and regeneration medicine (TERM) is already over 10 years and has shown great potential. Although this biomaterial has many advantages such as biocompatibility, biodegradability, nontoxic in nature, and physical stability in the presence of cations, a variety of modification methods have been suggested due to some disadvantages such as mechanical properties, high gelation temperature, and lack of attachment sites. In this review, the application of GG-based scaffold for tissue engineering and approaches to improve GG properties are discussed. Furthermore, a recent trend and future perspective of GG-based scaffold are highlighted.

Enriched Gellan Gum hydrogel as visco-supplement

Viscosupplementation, i.e. intra-articular injection of hyaluronic acid derivatives, is considered as the most effective treatment for patients with mild to moderate osteoarthritis. Even if hyaluronic acid is still considered as the gold standard, research is now focusing on the development of new products with enhanced injectability and yet reasonable viscoelastic behavior for OA treatment. A Gellan Gum (GG) hydrogel was synthesized and coated with crosslinked polyvinyl alcohol (PVA) to protect the polysaccharide from degradation during sterilization and improve its performance for the foreseen application. Thermal analyses indicated that mixed hydrogel showed a higher degree of structuring than the bare polysaccharide core without losing its swelling properties, thanks to the hydrophylicity of both coating and cross-linking agent. The PVA coating increased elastic and viscous moduli of the polysaccharide core conferring it a higher resistance to shear and compression and better thixotropic properties. Despite the double crosslinking, hydrogel was injectable. Cytocompatibility towards chondrocytes was verified.

Sericin-chitosan doped maleate gellan gum nanocomposites for effective cell damage in Mycobacterium tuberculosis

Polysaccharides are increasingly used as biodegradable nanocarrier to selectively deliver therapeutic agents to specific cells. In this study, maleate gellan gum (MA-GG) formed by addition of free radical polymerizable groups, which can be polymerized presence of acetone to design biodegradable three-dimensional networks, were synthesized by esterification. Natural silk sericin was grafted over the maleate gellan gum surface. Maleate Gellan Gum- Silk Sericin-Chitosan (MA-GG-SS-CS) nanocomposites loaded with rifampicin (RF) and pyrazinamide (PZA) to overcome the problems associated with Tuberculosis (TB) therapy. The pH responsive behavior of gellan gum nanocomposites was reposed by silk sericin and exhibited sustained release of 79% RF and 82% PZA for 120 h at pH 4.0. The designed formulations shows higher antimycobacterial activity and rapid delivery of drugs at TB infected macrophage. Nanomaterial effectively aggregated and internalized into the bacterial cells and MH-S cells. Dual drug release inside the cells makes damage in the cell membrane. Green nanocomposites studies pave the way for important use of macromolecules in pulmonary delivery TB drugs.

Manufacture and Characterization of Mucoadhesive Buccal Films Based on Pectin and Gellan Gum Containing Triamcinolone Acetonide

The treatment of canker sores can be quite compromised by the short period of the drug in the place of action. In this context, there is a need to develop drug dosage forms that allow more contact with the oral mucosa providing prolonged drug release. Therefore, the aim of this work was to obtain and characterize buccal films based on pectin and gellan gum in order to evaluate the potential use of these natural polymers in the production of pharmaceutical dosage forms for controlled release of TA in the oral mucosa. Using a 23 full factorial design, eight formulations were prepared by solvent casting method. The raw materials and films were characterized using techniques such as FTIR, DSC, and TG. In addition, thickness, mechanical properties, mucoadhesive strength, swelling, drug content, and dissolution profile of the films were evaluated. The results of FTIR, DSC, and TG showed that new chemical species are not formed in the production of films, and that these dosage forms have an adequate thermal behavior. All formulation showed a high degree of swelling, good mechanical resistance and elasticity, and a good mucoadhesive strength as well as able to act as a controlled release system.

Effect of glycerol on the physical and mechanical properties of thin gellan gum films for oral drug delivery

In this work, deacylated gellan gum and the plasticizer glycerol were used as primary components for the preparation of thin films intended for the oral delivery of therapeutic molecules. The samples were prepared by a solvent casting method and characterized for their thickness, tensile properties, swelling ability, mucoadhesion capacity and uniform drug distribution. The amount of glycerol was varied from 20% to 75% w/w in order to obtain films with tunable mechanical properties and high drug loading efficiency. The addition of glycerol was able to positively influence the mechanical characteristics of gellan gum thin film overcoming the brittleness caused by the rigid interconnection among the polymeric chains. Plasticized gellan gum films containing 50% w/w of glycerol showed optimal mechanical resistance and mucoadhesion capacity, which were adversely affected by the inclusion of higher concentrations of glycerol. On the contrary, only high amounts of the plasticizer (≥70% w/w) enabled a homogeneous distribution of the model drug fluconazole within the polymeric matrix. Overall, these results indicate that gellan gum-based thin films can be potentially used for buccal drug delivery upon precise selection of the appropriate concentration of glycerol used as a plasticizer.

Tissue engineering with gellan gum

Engineering complex tissues for research and clinical applications relies on high-performance biomaterials that are amenable to biofabrication, maintain mechanical integrity, support specific cell behaviours, and, ultimately, biodegrade. In most cases, complex tissues will need to be fabricated from not one, but many biomaterials, which collectively fulfill these demanding requirements. Gellan gum is an anionic polysaccharide with potential to fill several key roles in engineered tissues, particularly after modification and blending. This review focuses on the present state of research into gellan gum, from its origins, purification and modification, through processing and biofabrication options, to its performance as a cell scaffold for both soft tissue and load bearing applications. Overall, we find gellan gum to be a highly versatile backbone material for tissue engineering research, upon which a broad array of form and functionality can be built.

Synthesis and evaluation of thermo-rheological behaviour and ionotropic crosslinking of new gellan gum-alkyl derivatives

This paper reports the synthesis and the physicochemical characterization of two series of gellan gum (GG) derivatives functionalized with alkyl chains with different number of carbon, from 8 to 18. In particular, low molecular weight gellan gum samples with 52.6 or 96.7 kDa, respectively, were functionalized with octylamine (C₈), dodecylamine (C₁₂) and octadecylamine (C₁₈) by using bis(4-nitrophenyl) carbonate (4-NPBC) as a coupling agent. Thermo-rheological and ionotropic crosslinking properties of these gellan gum-alkyl derivatives were evaluated and related to the degree of derivatization in alkyl chains. Results suggested as length and degree of derivatization differently influenced coil-to-helix gelation mechanism of GG derivatives, ionotropic crosslinking, and strength of crosslinked hydrogels obtained in CaCl₂ 0.102 M and NaCl 0.15 M. Statement of hypothesis: The insertion of alkyl chains on the gellan gum backbone interferes with coil-to-helix transition mechanism and allows the production of hydrophobically assembled hydrogels.

Recent trends on gellan gum blends with natural and synthetic polymers: A review

Gellan gum (GG), a linear negatively charged exopolysaccharide,is biodegradable and non-toxic in nature. It produces hard and translucent gel in the presence of metallic ions which is stable at low pH. However, GG has poor mechanical strength, poor stability in physiological conditions, high gelling temperature and small temperature window.Therefore,it is blended with different polymers such as agar, chitosan, cellulose, sodium alginate, starch, pectin, polyanaline, pullulan, polyvinyl chloride, and xanthan gum. In this article, a comprehensive overview of combination of GG with natural and synthetic polymers/compounds and their applications in biomedical field involving drug delivery system, insulin delivery, wound healing and gene therapy, is presented. It also describes the utilization of GG based materials in food and petroleum industry. All the technical scientific issues have been addressed; highlighting the recent advancement.

Recent progress in gellan gum hydrogels provided by functionalization strategies

Gellan gum and its functionalized derivatives present a wide range of applications that open up new possibilities in tissue engineering and regenerative medicine.

Crosslinking of collagen using a controlled molecular weight bio-crosslinker: β-cyclodextrin polyrotaxane multi-aldehydes

A novel bio-crosslinker which can improve the properties of collagen effectively.

Evaluation of Gellan Gum Film Containing Virgin Coconut Oil for Transparent Dressing Materials

We examined the potential of virgin coconut oil (VCO) incorporated in gellan gum (GG) films as a dressing material. Pure GG film is extremely brittle and inclusion of 0.3% (w/w) VCO in the GG film (GG-VCO3) improved the toughness (T≈0.67±0.33 J g−1) of the composite films. Swelling properties and water vapor transmission rates of GG-VCO composite films decreased, whereas thermal behavior values increased upon the addition of higher concentrations of VCO. Cell studies exhibit that the VCO is noncytotoxic to human skin fibroblast cells (CRL2522) with limited cell growth observed on GG-VCO3 films at 1,650 cells/well after incubation for 72 h which could be due to hydrophobic influence of the material surface. The qualitative and in vitro quantitative antibacterial results revealed that VCO does not possess strong bacterial resistance against all four tested bacteria, that is, two Gram-positive (Staphylococcus aureus and Staphylococcus epidermidis) and two Gram-negative bacteria (Pseudomonas aeruginosa and Proteus mirabilis).

Physical and biological effects of gellan gum on decreasing postoperative adhesion in a rat model

An antiadhesion membrane made from gellan gum was fabricated and characterized. A 12-µm-thick membrane of gellan gum was prepared and reacted with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide to obtain a cross-linked membrane (G/A70) with 87% gel content and a tensile strength of 46.5 MPa. In vivo, the G/A70 membrane had 90% less tissue adhesion. Inflammation-related and extracellular matrix protein gene expression in a rat model of abdominal surgery was found by real-time quantitative reverse transcription polymerase chain reaction analysis. On day 3, after surgery, the gene expression of ceruloplasmin and type V collagen in the G/A70-treated group was 1.9 and 0.3 times that of the control group, respectively. The G/A70 membrane elicited mild inflammation but suppressed type V collagen synthesis and reduced the occurrence of tissue adhesion. These findings provide insights into the properties of gellan gum antiadhesion membranes and help to overcome problems involving tissue adhesions in surgical procedures.