Fabrication Methods and Form Factors of Gellan Gum-Based Materials for Drug Delivery and Anti-Cancer Applications

Diffusion-Patterned Multi-Component Supramolecular Gels Loaded with Gold Nanoparticles Direct Mesenchymal Stem Cell Growth and Differentiation

This article describes a new fabrication method using simple paper stamps to pattern gold nanoparticles (AuNPs) in a hybrid hydrogel, creating multi-domain gels in which different domains have different cell compatibilities. Soaking a paper stamp in AuCl3 solution, and placing it on top of the gel, allows diffusion of Au(III) from the paper into the gel to create a patterned domain within the gel in which AuNPs are formed, with spatial resolution on the millimeter length-scale. The gels combine a low-molecular-weight gelator that chemically enables the in situ AuNP patterning and offers mesenchymal stem cell (MSC) compatibility with a rheologically stiff polymer gelator. Only the AuNP-loaded domains support MSC proliferation on the multi-domain system, inducing cell spreading and promoting osteogenesis with a reproducible pattern. This simple approach therefore programs a soft supramolecular material, enabling it to achieve spatially-resolved biological outcomes, and may have applications in tissue engineering.

Ionotropic Gelation and Chemical Crosslinking as Tools to Obtain Gellan Gum-Based Beads with Mesalazine

Introduction: Many orally administered drugs are either unstable in the acidic environment of the stomach or cause moderate to severe side effects in the upper gastrointestinal tract (GIT). These limitations can reduce therapeutic efficacy, discourage patient compliance, worsen the disease, and even contribute to the risk of cancer development. To overcome these issues, drug release often needs to be modified and targeted to the distal parts of the GIT. This is typically achieved through the use of pH-sensitive polymer coatings or incorporation into polymeric delivery systems. With this in mind, the aim of this project was to design, develop, and characterize gellan gum-based beads for colon-specific prolonged release of mesalazine, with potential application in the chemoprevention and treatment of bowel diseases. Materials and Methods: The dehydrated capsules were characterized using Raman spectroscopy and scanning electron microscopy. The crosslinked gellan gum was additionally evaluated for cytotoxicity. Key parameters such as pH-dependent swelling behavior, drug content, encapsulation efficiency, and drug release in simulated gastrointestinal fluids were also assessed. Furthermore, the behavior of the capsules in the gastrointestinal tract was studied in a rat model to evaluate their in vivo performance. Results: Significant differences in drug release profiles were observed between formulations crosslinked solely with calcium ions and those additionally crosslinked with glutaraldehyde (GA). The incorporation of GA effectively prolonged the release of mesalazine. These findings were further supported by in vivo studies conducted on Wistar rats, where the GA-crosslinked formulation demonstrated a markedly extended release compared to the formulation prepared using only ionotropic gelation. Conclusions: The combination of ionotropic gelation and glutaraldehyde crosslinking in gellan gum-based beads appears to be a promising strategy for achieving colon-specific prolonged release of mesalazine, facilitating targeted delivery to the distal regions of the gastrointestinal tract.

Formulation and characterization of ionically crosslinked gellan gum hydrogels using trilysine at low temperatures for antibody delivery

Research of the nontraditional polysaccharide gellan gum (GG) is a growing space for the development of novel drug delivery systems due to its tunable physic-mechanical properties, biocompatibility, and stability in a wide range of environments. Unfortunately, high temperature crosslinking is often required, representing a limiting factor for the incorporation of thermosensitive therapeutic agents. Here, we demonstrated that GG can be crosslinked at a low temperature (38 °C) using a simple fabrication process that utilizes trilysine as an alternative to traditional mono- or divalent ion crosslinkers. While elevated temperature mixing is still required to form a clear GG solution, crosslinking of 0.5 - 1 % GG (w/v) in the presence of trilysine (0.03 % - 0.05 % w/v) was achieved at 38 °C resulting in hydrogels with suitable working formulations to facilitate syringe loading. Low injection forces (< 20 N), and biocompatibility was evaluated with normal human dermal fibroblast (cell viability > 90 %). Frequency sweep showed a transition from purely liquid-like behavior to gel-like behavior with increased trilysine concentration. A temperature dependent behavior was lost with higher trilysine concentrations, indicating stable hydrogel formation. NMR results suggest that trilysine participates in gelation via both ionic interactions between the primary amines of trilysine and the carboxylate residues of glucuronic acid and hydrogen bonding. Released studies showed that GG hydrogels can entrap and provide sustained release of IgG in relation to the crosslinker, and antibody concentration used, with a burst release within the first 24 h (∼80 % cumulative released) followed by a sustained released for up to 5 days. Overall, findings demonstrate a promising nontoxic injectable hydrogel that requires lower crosslinking temperatures, is simple to manufacture and serves as a carrier of thermosensitive therapeutic agents.

Dimethyl Fumarate-Loaded Gellan Gum Hydrogels Can Reduce In Vitro Chemokine Expression in Oral Cells

Dimethyl fumarate (DMF), originally proposed to treat multiple sclerosis, is considered to have a spectrum of anti-inflammatory effects that effectively control periodontitis, mainly when applied with a hydrogel delivery system. Chemokine expression by gingival fibroblasts is a significant driver of periodontitis; thus, hydrogel-based strategies to deliver DMF, which in turn dampen chemokine expression, are of potential clinical relevance. To test this approach, we have established a bioassay where chemokine expression is induced by exposing gingival fibroblast to IL1β and TNFα, or with saliva. We show herein that DMF effectively reduced the expression of CXCL8, CXCL1, CXCL2, and CCL2-and lowered the phosphorylation of ERK and JNK-without affecting cell viability. This observation was confirmed by immunoassays with CXCL8. Consistently, the forced chemokine expression in HSC2 oral squamous epithelial cells was greatly diminished by DMF. To implement our hydrogel-based delivery system, gingival fibroblasts were cocultured with gellan gum hydrogels enriched for DMF. In support of our strategy, DMF-enriched gellan gum hydrogels significantly reduced the forced chemokine expression in gingival fibroblasts. Our data suggest that DMF exerts its anti-inflammatory activity in periodontal cells when released from gellan gum hydrogels, suggesting a potential clinical relevance to control overshooting chemokine expression under chronic inflammatory conditions.

Biopolymeric nanocarriers in cancer therapy: unleashing the potency of bioactive anticancer compounds for enhancing drug delivery

Effective cancer treatment is becoming a global concern, and recent developments in nanomedicine are essential for its treatment. Cancer is a severe metabolic syndrome that affects the human population and is a significant contributing factor to deaths globally. In science, nanotechnology offers rapidly developing delivery methods for natural bioactive compounds that are becoming increasingly prominent and can be used to treat diseases in a site-specific way. Chemotherapy and radiotherapy are conventional approaches for preventing cancer progression and have adverse effects on the human body. Many chemically synthesized drugs are used as anticancer agents, but they have several side effects; hence, they are less preferred. Medicinal plants and marine microorganisms represent a vast, mostly untapped reservoir of bioactive compounds for cancer treatment. However, they have several limitations, including nonspecific targeting, weak water solubility and limited therapeutic potential. An alternative option is the use of biopolymeric nanocarriers, which can generate effective targeted treatment therapies when conjugated with natural anticancer compounds. The present review focuses on biopolymeric nanocarriers utilizing natural sources as anticancer drugs with improved tumor-targeting efficiency. This review also covers various natural anticancer compounds, the advantages and disadvantages of natural and synthetic anticancer compounds, the problems associated with natural anticancer drugs and the advantages of biopolymeric nanocarriers over synthetic nanocarriers as drug delivery agents. This review also discusses various biopolymeric nanocarriers for enhancing the controlled delivery of anticancer compounds and the future development of nanomedicines for treating cancer.

Revisiting microbial exopolysaccharides: a biocompatible and sustainable polymeric material for multifaceted biomedical applications

Microbial exopolysaccharides (EPS) have gained significant attention as versatile biomolecules with multifarious applications across various sectors. This review explores the valorisation of EPS and its potential impact on diverse sectors, including food, pharmaceuticals, cosmetics, and biotechnology. EPS, secreted by microorganisms, possess unique physicochemical properties, such as high molecular weight, water solubility, and biocompatibility, making them attractive for numerous functional roles. Additionally, EPS exhibit significant bioactivity, contributing to their potential use in pharmaceuticals for drug delivery and tissue engineering applications. Moreover, the eco-friendly and sustainable nature of microbial EPS production aligns with the growing demand for environmentally conscious processes. However, challenges still exist in large-scale production, purification, and regulatory approval for commercial use. Advances in bioprocessing and microbial engineering offer promising solutions to overcome these hurdles. Stringent investigations have concluded EPS as novel sources for sustainable applications that are likely to emerge and develop, further reinforcing the significance of these biopolymers in addressing contemporary societal needs and driving innovation in various industrial sectors. Overall, the microbial EPS represents a thriving field with immense potential for meeting diverse industrial demands and advancing sustainable technologies.

Improved Solubility and Activity of Natural Product in Nanohydrogel

With the development of technology, natural material components are widely used in various fields of science. Natural product components in phytochemical compounds are secondary metabolites produced by plants; they have been shown to have many pharmacological activities. Phytochemical compounds obtained from plants have an important role in herbal medicine. Herbal medicine is safer and cheaper than synthetic medicine. However, herbal medicines have weaknesses, such as low solubility, less stability, low bioavailability, and experiencing physical and chemical degradation, reducing their pharmacological activity. Recent herbal nano-delivery developments are mostly plant-based. A nanotechnology-based system was developed to deliver herbal therapies with better bioavailability, namely the nanohydrogel system. Nanohydrogel is a delivery system that can overcome the disadvantages of using herbal compounds because it can increase solubility, increase pharmacological activity and bioavailability, reduce toxicity, slow delivery, increase stability, improve biodistribution, and prevent physical or chemical degradation. This review article aimed to provide an overview of recent advances in developing nanohydrogel formulations derived from natural ingredients to increase solubility and pharmacological activity, as well as a summary of the challenges faced by delivery systems based on nanohydrogel derived from natural materials. A total of 25 phytochemicals derived from natural products that have been developed into nanohydrogel were proven to increase the activity and solubility of these chemical compounds.

How Magnetic Composites are Effective Anticancer Therapeutics? A Comprehensive Review of the Literature

Chemotherapy is the most prominent route in cancer therapy for prolonging the lifespan of cancer patients. However, its non-target specificity and the resulting off-target cytotoxicities have been reported. Recent in vitro and in vivo studies using magnetic nanocomposites (MNCs) for magnetothermal chemotherapy may potentially improve the therapeutic outcome by increasing the target selectivity. In this review, magnetic hyperthermia therapy and magnetic targeting using drug-loaded MNCs are revisited, focusing on magnetism, the fabrication and structures of magnetic nanoparticles, surface modifications, biocompatible coating, shape, size, and other important physicochemical properties of MNCs, along with the parameters of the hyperthermia therapy and external magnetic field. Due to the limited drug-loading capacity and low biocompatibility, the use of magnetic nanoparticles (MNPs) as drug delivery system has lost traction. In contrast, MNCs show higher biocompatibility, multifunctional physicochemical properties, high drug encapsulation, and multi-stages of controlled release for localized synergistic chemo-thermotherapy. Further, combining various forms of magnetic cores and pH-sensitive coating agents can generate a more robust pH, magneto, and thermo-responsive drug delivery system. Thus, MNCs are ideal candidate as smart and remotely guided drug delivery system due to a) their magneto effects and guide-ability by the external magnetic fields, b) on-demand drug release performance, and c) thermo-chemosensitization under an applied alternating magnetic field where the tumor is selectively incinerated without harming surrounding non-tumor tissues. Given the important effects of synthesis methods, surface modifications, and coating of MNCs on their anticancer properties, we reviewed the most recent studies on magnetic hyperthermia, targeted drug delivery systems in cancer therapy, and magnetothermal chemotherapy to provide insights on the current development of MNC-based anticancer nanocarrier.

Low acyl gellan gum immobilized Lactobacillus bulgaricus T15 produce D-lactic acid from non-detoxified corn stover hydrolysate

Straw biorefinery offers economical and sustainable production of chemicals. The merits of cell immobilization technology have become the key technology to meet D-lactic acid production from non- detoxified corn stover. In this paper, Low acyl gellan gum (LA-GAGR) was employed first time for Lactobacillus bulgaricus T15 immobilization and applied in D-lactic acid (D-LA) production from non-detoxified corn stover hydrolysate. Compared with the conventional calcium alginate (E404), LA-GAGR has a hencky stress of 82.09 kPa and excellent tolerance to 5-hydroxymethylfurfural (5-HMF), ferulic acid (FA), and vanillin. These features make LA-GAGR immobilized T15 work for 50 days via cell-recycle fermentation with D-LA yield of 2.77 ± 0.27 g/L h, while E404 immobilized T15 can only work for 30 days. The production of D-LA from non-detoxified corn stover hydrolysate with LA-GAGR immobilized T15 was also higher than that of free T15 fermentation and E404 immobilized T15 fermentation. In conclusion, LA-GAGR is an excellent cell immobilization material with great potential for industrial application in straw biorefinery industry.

Molecular origin of the two-step mechanism of gellan aggregation

Among hydrocolloids, gellan is one of the most studied polysaccharides due to its ability to form mechanically stable gels. Despite its long-standing use, the gellan aggregation mechanism is still not understood because of the lack of atomistic information. Here, we fill this gap by developing a new gellan force field. Our simulations offer the first microscopic overview of gellan aggregation, detecting the coil to single-helix transition at dilute conditions and the formation of higher-order aggregates at high concentration through a two-step process: first, the formation of double helices and then their assembly into superstructures. For both steps, we also assess the role of monovalent and divalent cations, complementing simulations with rheology and atomic force microscopy experiments and highlighting the leading role of divalent cations. These results pave the way for future use of gellan-based systems in a variety of applications, from food science to art restoration.

Specific Six-Transmembrane Epithelial Antigen of the Prostate 1 Capture with Gellan Gum Microspheres: Design, Optimization and Integration

This work demonstrates the potential of calcium- and nickel-crosslinked Gellan Gum (GG) microspheres to capture the Six-Transmembrane Epithelial Antigen of the Prostate 1 (STEAP1) directly from complex Komagataella pastoris mini-bioreactor lysates in a batch method. Calcium-crosslinked microspheres were applied in an ionic exchange strategy, by manipulation of pH and ionic strength, whereas nickel-crosslinked microspheres were applied in an affinity strategy, mirroring a standard immobilized metal affinity chromatography. Both formulations presented small diameters, with appreciable crosslinker content, but calcium-crosslinked microspheres were far smoother. The most promising results were obtained for the ionic strategy, wherein calcium-crosslinked GG microspheres were able to completely bind 0.1% (v/v) DM solubilized STEAP1 in lysate samples (~7 mg/mL). The target protein was eluted in a complexed state at pH 11 with 500 mM NaCl in 10 mM Tris buffer, in a single step with minimal losses. Coupling the batch clarified sample with a co-immunoprecipitation polishing step yields a sample of monomeric STEAP1 with a high degree of purity. For the first time, we demonstrate the potential of a gellan batch method to function as a clarification and primary capture method towards STEAP1, a membrane protein, simplifying and reducing the costs of standard purification workflows.