Alginate-Based Encapsulation Fabrication Technique for Drug Delivery: An Updated Review of Particle Type, Formulation Technique, Pharmaceutical Ingredient, and Targeted Delivery System

Gellan gum-based microbeads for Colon-targeted drug delivery: A promising polysaccharide for controlled and site-specific release

Targeting drug delivery to the colon presents significant challenges due to unfavorable pH conditions and enzymatic activity in the upper gastrointestinal tract. This obstacle can be overcome with colon-targeted microbeads, which have led to significant advancements in treating colonic diseases such as inflammatory bowel disease and colorectal cancer, as well as in achieving sustained delivery of macromolecules like peptides and proteins. Polysaccharide-based microbeads (MBs) formulated with gellan gum (GLG) offer a robust platform for controlled and site-specific drug release. GLG, a natural anionic polysaccharide, is renowned for its gelation properties in the presence of divalent cations, biocompatibility, and enzymatic degradability, making it ideal for colon-specific applications. In this review, we explored the potential of GLG-MBs for colon-targeted drug delivery and their physicochemical properties, drug release mechanisms, formulation strategies, therapeutic applications, methods for analytical characterizations, highlighting their advantages over conventional drug delivery, and target specificity towards the colonic disease. Furthermore, we discussed the significant limitations of GLG-MBs, such as burst release, processing, scaling up production, regulatory challenges, and clinical uniformity towards colonic environments. We explored the strategies to overcome key limitations in clinical translation, such as uniformity and regulatory hurdles. The review concludes by outlining the direction of advancing GLG-MBs, emphasizing their potential in achieving efficient and targeted drug delivery towards the colon.

Alginate gels: Chemistry, gelation mechanisms, and therapeutic applications with a focus on GERD treatment

Alginate, a natural polysaccharide derived primarily from marine algae, has become popular in biomedical research due to its versatile gelation properties and biocompatibility. This review explores the chemistry, gelation mechanisms, and therapeutic applications of alginate gels, with a particular focus on their role in gastroesophageal reflux disease (GERD) management. Alginate's structure, comprised of guluronic and mannuronic acid blocks, allows for gel formation by ionic cross-linking with divalent cations like calcium ions, generating a stable "egg-box" structure. The effects of pH, temperature, and ion concentration on gelation are explored, as well as other gel forms such as in situ and heat-sensitive gels. Alginate is widely used in the medical and pharmaceutical areas to promote tissue engineering through cell encapsulation and scaffolding, as well as in drug delivery systems for controlled and targeted release. In GERD therapy, alginate produces a gel raft that inhibits acid reflux, providing an effective alternative to proton pump inhibitors. Alginate-based products have demonstrated clinical success, strengthening alginate's medicinal promise. The review also discusses alginate-related issues, such as source variability and stability, as well as innovative modifications to improve treatment effects. These improvements establish alginate as a potential material for customized medication and tailored delivery systems.

Development of Luteolin-Loaded Calcium Alginate and Gum Tragacanth Blend Microbeads for Oral Delivery: In Vitro Characterization, Antioxidant, Antimicrobial, and Anticancer Activity Against Colon Cancer Cell Line (HT-29)

The utilization of herbal bioactive compounds for health maintenance is now increasing the interest of consumers because it has therapeutic benefits. Luteolin (LLN) is a natural bioactive compound and is found in various plant sources. It has many pharmacological activities, i.e., anticancer, antidiabetic, antioxidant, anti-inflammatory, and antimicrobial. It has poor water solubility, leading to low dissolution, low bioavailability, and low therapeutic efficacy. The present research work was to develop the LLN-loaded gel microbeads using a combination of sodium alginate (SA) and gum tragacanth polymers to strengthen microbeads (BD) and enhance the therapeutic efficacy. The microbeads were prepared by using the ionotropic gelation method and evaluated by various physicochemical parameters, i.e., particle size, encapsulation efficiency, swelling index, FITR, and X-ray diffraction study. The optimized microbeads (LLNBD3) showed a 97.63 ± 3.12% yield, 845 ± 6.21 μm in size, and 78.54 ± 3.65% drug entrapment efficiency. The microbeads exhibited excellent swelling in intestinal pH (6.8) compared with an acidic medium (pH 1.2). The LLNBD3 exhibited a sustained release profile (89.23 ± 2.51% in 12 h) with first-order release kinetics (R2 = 0.9752) with the Fickian diffusion mechanism of drug release. The Fourier transform infrared spectra and X-ray diffractograms did not show any distinct peaks of LLN, revealing that the LLN was encapsulated into a microbeads matrix. The LLNBD3 showed significant antioxidant activity compared with pure LLN, confirmed by the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) method. In addition, it also showed remarkable in vitro anticancer activity against the colorectal cell line (HT-29) and antimicrobial activity against Staphylococcus aureus and Escherichia coli. The stability study demonstrated no significant change in swelling and release behavior. The finding concluded that tragacanth gum and SA microbeads could be promising drug carriers to improve the dissolution and oral delivery of herbal bioactive compounds and synthetic drugs.

Alginate Beads with Encapsulated Date Palm Pollen Extract: Development, Characterization and Their Potential Role in Hepato-Protection and Fertility-Stimulating Hormones Improvement in Bisphenol A-Treated Rats

The goal of this study was to design polymeric beads with a core of date palm pollen (DPP, Phoenix dactylifera L.) extract using the ionic gelation method and then assess the effects of the extract in combination with alginate polymer (alginate/DPP beads) on the profile of phenolic compounds, their in vitro controlled release, as well as their antioxidant characteristics, and potential role in hepato-protection and fertility-stimulating hormones improvement in bisphenol A (BPA)-treated rats. The encapsulation efficiency (EE) was 94.27 ± 1.47%. The study found that phenolic release was highest (89.81%) at pH 7.4 (simulated intestinal fluid) and lowest (59.43%) at pH 2 (simulated stomach fluid) after 3 h. This particular type of bead also exhibited significant antioxidant activity, phenolic component content, and flavonoid content. The estimated phenolic content was 66.48 mg GAE/g, with methyl gallate, gallic acid, and naringenin as the main components. In vivo evaluation findings revealed that both doses of alginate/DPP beads (delivering 250 and 350 mg/kg of extract per day) significantly protected the liver (as demonstrated by downregulated liver function parameters), improved levels of male fertility-stimulating hormones, reduced oxidative stress parameters and inflammatory cytokines, and protected both liver and testicular tissues from BPA-induced changes. Thus, the actions of alginate/DPP beads make them a promising choice for antioxidant, liver-protecting, and male hormone-enhancing hydrogels.

Development of novel multi-responsive 4D printed smart nanocomposites with polypyrrole coated iron oxides for remote and adaptive transformation

Four-dimensional (4D) printing, a state-of-the-art additive manufacturing technology, enables the creation of objects capable of changing shape, properties, or functionality over time in response to external stimuli. However, the lack of effective remote control and reliance on a single actuation method pose significant challenges, limiting its applications in various fields. This study aims to address these limitations by developing a novel multi-responsive nanocomposite. By coating near-infrared light (NIR)-responsive polypyrrole (PPy) onto the surface of magnetic iron oxide (Fe2O3) nanoparticles (NPs), multi-responsive PPy@Fe2O3 NPs were synthesized. Doping PPy@Fe2O3 into a thermo-responsive shape memory polymer (SMP) matrix created a nanocomposite with excellent NIR and magnetic responsiveness, enabling dynamic, remote-controlled shape transformation of printed objects with precise timing and positioning using NIR and a magnetic field. Using the nanocomposite, a proof-of-concept semi-tubular construct was fabricated to evaluate its controllable transformation capability and assess the potential for modulating neural stem cell (NSC) behaviors. Furthermore, three proof-of-concept smart robots with distinct features were designed and fabricated for cargo delivery in diverse scenarios and different purposes. Importantly, all complex operations of these robots were remotely controlled using NIR illumination and an external magnetic field. This novel approach demonstrates significant progress in addressing the key challenges of remote control and actuation in 4D printing, highlighting its potential for enhanced versatility and functionality across various applications.

Seaweed-derived laminarin and alginate as potential chemotherapeutical agents: An updated comprehensive review considering cancer treatment

Seaweed-derived bioactive substances such as polysaccharides have proven to be effective chemotherapeutic and chemopreventive agents. Laminarin and alginate antioxidant properties aid in the prevention of cancer through dynamic modulation of critical intracellular signaling pathways via apoptosis which produce low cytotoxicity and potential chemotherapeutic effects. Understanding the effects of laminarin and alginate on human cancer cells and their molecular roles in cell death pathways can help to develop a novel chemoprevention strategy. This review emphasizes the importance of apoptosis-modulating laminarin and alginate in a range of malignancies as well as their extraction, molecular structure, and weight. In addition, future nano-formulation enhancements for greater clinical efficacy are discussed. Laminarin and alginate are perfect ingredients because of their distinct physicochemical and biological characteristics and their use-based delivery systems in cancer. The effectiveness of laminarin and alginate against cancer and more preclinical and clinical trials will open up as new chemotherapeutic natural drugs which lead to established as potential cancer drugs.

Polymer- and Lipid-Based Nanostructures Serving Wound Healing Applications: A Review

Management of hard-to-heal wounds often requires specialized care that surpasses the capabilities of conventional treatments. Even the most advanced commercial products lack the functionality to meet the needs of hard-to-heal wounds, especially those complicated by active infection, extreme bleeding, and chronic inflammation. The review explores how supramolecular nanovesicles and nanoparticles-such as dendrimers, micelles, polymersomes, and lipid-based nanocarriers-can be key to introducing advanced wound healing and monitoring properties to address the complex needs of hard-to-heal wounds. Their potential to enable advanced functions essential for next-generation wound healing products-such as hemostatic functions, transdermal penetration, macrophage polarization, targeted delivery, and controlled release of active pharmaceutical ingredients (antibiotics, gaseous products, anti-inflammatory drugs, growth factors)-is discussed via an extensive overview of the recent reports. These studies highlight that the integration of supramolecular systems in wound care is crucial for advancing toward a new generation of wound healing products and addressing significant gaps in current wound management practices. Current strategies and potential improvements regarding personalized therapies, transdermal delivery, and the promising critically evaluated but underexplored polymer-based nanovesicles, including polymersomes and proteinosomes, for wound healing.

Applications of Natural Polymers in the Grapevine Industry: Plant Protection and Value-Added Utilization of Waste

The grapevine industry is confronted with challenges such as plant stress from environmental factors and microbial infections, alongside the need for sustainable waste management practices. Natural polymers offer promising solutions to these issues due to their biocompatibility, biodegradability, and functional versatility. This review explores the dual role of natural polymers in enhancing the grapevine industry: as protective agents against various stressors and as carriers for the delivery of valuable compounds recovered from grapevine wastes. We examine the use of natural polymers such as chitosan, alginate, and cellulose in formulating bio-based protective coatings and treatments that bolster plant resistance to abiotic stress, pathogens, and pests. Additionally, the review delves into the innovative utilization of grapevine residues, including skins, seeds, and stems, as sources of polyphenols and other bioactive compounds. These compounds can be efficiently encapsulated in natural polymer matrices for applications in agriculture, food, and pharmaceuticals. Key topics include the mechanisms of action, benefits, and limitations of natural polymer-based interventions, as well as case studies demonstrating their practical implementation in vineyards. The review also addresses future research directions, emphasizing the need for integrated approaches that enhance sustainability and economic viability in the grapevine industry.

Advanced drug delivery strategies for diabetic retinopathy: current therapeutic advancement, and delivery methods overcoming barriers, and experimental modalities

INTRODUCTION

Diabetic retinopathy, a significant trigger for blindness among working age individuals with diabetes, poses a substantial global health challenge. Understanding its underlying mechanisms is pivotal for developing effective treatments. Current treatment options, such as anti-VEGF agents, corticosteroids, laser photocoagulation, and vitreous surgery, have their limitations, prompting the exploration of innovative approaches like nanocapsules based drug-delivery systems. Nanoparticles provide promising solutions to improve drug delivery in ocular medicine, overcoming the complexities of ocular anatomy and existing treatment constraints.

AREAS COVERED

This review explored advanced therapeutic strategies for diabetic retinopathy, focusing on current medications with their limitations, drug delivery methods, device innovations, and overcoming associated barriers. Through comprehensive review, it aimed to contribute to the discovery of more efficient management strategies for diabetic retinopathy in the future.

EXPERT OPINION

In the next five to ten years, we expect a revolutionary shift in how diabetic retinopathy is treated. As we deepen our understanding of oxidative stress and metabolic dysfunction, antioxidants with specialised delivery matrices are poised to take center stage in prevention and treatment strategies. Our vision is to create a more integrated approach to diabetic retinopathy management that not only improves patient outcomes but also reduces the risks associated to traditional therapies.

Advances of naturally derived biomedical polymers in tissue engineering

The extensive utilization of natural polymers in tissue engineering is attributed to their excellent biocompatibility, degradability, and resemblance to the natural extracellular matrix. These polymers have a wide range of applications such as delivering therapeutic medicine, detecting diseases, sensing biological substances, promoting tissue regeneration, and treating diseases. This is a brief review of current developments in the properties and uses of widely used biomedical polymers derived from nature. Additionally, it explores the correlation between the characteristics and functions of these materials in different biomedical applications and highlights the prospective direction for the advancement of natural polymer materials in tissue engineering.

Development of Nanocomposite Microspheres for Nasal Administration of Deferiprone in Neurodegenerative Disorders

Elevated brain iron levels are characteristic of many neurodegenerative diseases. As an iron chelator with short biological half-life, deferiprone leads to agranulocytosis and neutropenia with a prolonged therapeutic course. Its inclusion in sustained-release dosage forms may reduce the frequency of administration. On the other hand, when administered by an alternative route of administration, such as the nasal route, systemic exposure to deferiprone will be reduced, thereby reducing the occurrence of adverse effects. Direct nose-to-brain delivery has been raised as a non-invasive strategy to deliver drugs to the brain, bypassing the blood-brain barrier. The aim of the study was to develop and characterize nanocomposite microspheres suitable for intranasal administration by combining nano- and microparticle-based approaches. Nanoparticles with an average particle size of 213 ± 56 nm based on the biodegradable polymer poly-ε-caprolactone were developed using the solvent evaporation method. To ensure the deposition of the particles in the nasal cavity and avoid exhalation or deposition into the small airways, the nanoparticles were incorporated into composite structures of sodium alginate obtained by spray drying. Deferiprone demonstrated sustained release from the nanocomposite microspheres and high iron-chelating activity.

Development of cashew-alginate microbeads and powdered dose forms: prospects for oral vaccine delivery in chickens

Conventional oral vaccine delivery in poultry is challenging due to vaccine degradation in the gastrointestinal (GI) environment and the need for cold-chain storage. Microencapsulation offers a solution by protecting vaccines from GI degradation and improving stability. Natural polymers like alginate and cashew gum have mucoadhesive properties, making them promising candidates for oral vaccine delivery. This study developed cashew-alginate microbeads and a powdered dose form for oral vaccine delivery in chickens. The microbeads were created using ionotropic gelation, while the powdered form was obtained via freeze-drying. These formulations were characterized for size, shape, and stability using scanning electron microscopy (SEM), light microscopy, X-ray diffraction (XRD), and Energy Dispersive X-ray (EDX). Peak adhesion time (PAT) was determined using chicken intestinal and esophageal tissues, and antigenicity was assessed with in-vitro hemagglutination (HA) and hemagglutination inhibition (HI) assays. The microbeads exhibited a spherical shape with a porous structure, suggesting enhanced antigen accommodation. Hemagglutination Inhibition tests indicated that the experimental vaccine remained effective without cold-chain storage for three months. These findings suggest that cashew-alginate microbeads are promising for oral vaccine delivery in poultry.

Alginate-based hydrogels mediated biomedical applications: A review

With the development in the field of biomaterials, research on alternative biocompatible materials has been initiated, and alginate in polysaccharides has become one of the research hotspots due to its advantages of biocompatibility, biodegradability and low cost. In recent years, with the further understanding of microscopic molecular structure and properties of alginate, various physicochemical methods of cross-linking strategies, as well as organic and inorganic materials, have led to the development of different properties of alginate hydrogels for greatly expanded applications. In view of the potential application prospects of alginate-based hydrogels, this paper reviews the properties and preparation of alginate-based hydrogels and their major achievements in delivery carrier, dressings, tissue engineering and other applications are also summarized. In addition, the combination of alginate-based hydrogel and new technology such as 3D printing are also involved, which will contribute to further research and exploration.

An introduction to antibacterial materials in composite restorations

The longevity of direct esthetic restorations is severely compromised because of, among other things, a loss of function that comes from their susceptibility to biofilm-mediated secondary caries, with Streptococcus mutans being the most prevalent associated pathogen. Strategies to combat biofilms range from dental compounds that can disrupt multispecies biofilms in the oral cavity to approaches that specifically target caries-causing bacteria such as S mutans. One strategy is to include those antibacterial compounds directly in the material so they can be available long-term in the oral cavity and localized at the margin of the restorations, in which many of the failures initiate. Many antibacterial compounds have already been proposed for use in dental materials, including but not limited to phenolic compounds, antimicrobial peptides, quaternary ammonium compounds, and nanoparticles. In general, the goal of incorporating them directly into the material is to increase their availability in the oral cavity past the fleeting effect they would otherwise have in mouth rinses. This review focuses specifically on natural compounds, of which polyphenols are the most abundant category. The authors examined attempts at using these either as pretreatment or incorporated directly into restorative material as a step toward fulfilling a long-recognized need for restorations that can combat or prevent secondary caries formation. Repeatedly restoring failed restorations comes with the loss of more tooth structure along with increasingly complex and costly dental procedures, which is detrimental to not only oral health but also systemic health.

Nanospheres as the delivery vehicle: novel application of Toxoplasma gondii ribosomal protein S2 in PLGA and chitosan nanospheres against acute toxoplasmosis

Toxoplasma gondii (T. gondii) is a zoonotic disease that poses great harm to humans and animals. So far, no effective T. gondii vaccine has been developed to provide fully protection against such parasites. Recently, numerous researches have focused on the use of poly-lactic-co-glycolic acid (PLGA) and chitosan (CS) for the vaccines against T. gondii infections. In this study, we employed PLGA and CS as the vehicles for T. gondii ribosome protein (TgRPS2) delivery. TgRPS2-PLGA and TgRPS2-CS nanospheres were synthesized by double emulsion solvent evaporation and ionic gelation technique as the nano vaccines. Before immunization in animals, the release efficacy and toxicity of the synthesized nanospheres were evaluated in vitro. Then, ICR mice were immunized intramuscularly, and immune protections of the synthesized nanospheres were assessed. The results showed that TgRPS2-PLGA and TgRPS2-CS nanospheres could induce higher levels of IgG and cytokines, activate dendritic cells, and promote the expression of histocompatibility complexes. The splenic lymphocyte proliferation and the enhancement in the proportion of CD4+ and CD8+ T lymphocytes were also observed in immunized animals. In addition, two types of nanospheres could significantly inhabit the replications of T. gondii in cardiac muscles and spleen tissues. All these obtained results in this study demonstrated that the TgRPS2 protein delivered by PLGA or CS nanospheres provided satisfactory immunoprotective effects in resisting T. gondii, and such formulations illustrated potential as prospective preventive agents for toxoplasmosis.

A multi-epitope protein vaccine encapsulated in alginate nanoparticles as a candidate vaccine against Shigella sonnei

Shigellosis, caused by the Gram-negative bacterium Shigella, is a major global health challenge. Despite extensive research over the past two decades, no commercial vaccine is available to prevent Shigella infection. Developing multi-epitope vaccines offers a promising and innovative approach to tackling infectious diseases. In this study, we produced a multi-epitope vaccine candidate using E. coli BL21 (DE3) plysS bacteria and purified the vaccine protein with Ni-NTA affinity chromatography. We then prepared alginate nanoparticles containing the vaccine protein, with a particle size of 122 ± 6 nm, PDI 0.17, SPAN 0.83, and zeta potential of -27 ± 2 mV. Successful protein loading was confirmed through nanodrop and ATR-FTIR analyses. To evaluate the immunogenicity of the encapsulated vaccine, mice were orally vaccinated, and their serum was analyzed for IgG, IL-4, and IFN-γ levels cytokines. The results showed a significant increase in IgG level in the vaccinated group compared to controls. Additionally, the vaccinated group exhibited a notable increase in IL-4 and IFN-γ cytokines, indicating a robust Th-cell-mediated immune response essential for combating Shigella. Our nano-vaccine demonstrated high efficacy in activating both humoral and cellular immunity, effectively protecting against the bacteria. The alginate-based oral vaccine candidate thus emerges as a promising strategy for developing a multi-epitope vaccine candidate against Shigella.

Recent advances on chitosan/hyaluronic acid-based stimuli-responsive hydrogels and composites for cancer treatment: A comprehensive review

Cancer, as leading cause of death, has a high rate of mortality worldwide. Although there is a wide variety of conventional approaches for the treatment of cancer (such as surgery and chemotherapy), they have considerable drawbacks in terms of practicality, treatment efficiency, and cost-effectiveness. Therefore, there is a fundamental requirement for the development of safe and efficient treatment modalities based on breakthrough technologies to suppress cancer. Chitosan (CS) and hyaluronic acid (HA) polysaccharides, as FDA-approved biomaterials for some biomedical applications, are potential biopolymers for the efficient treatment of cancer. CS and HA have high biocompatibility, bioavailability, biodegradability, and immunomodulatory function which guarantee their safety and non-toxicity. CS-/HA-based hydrogels (HGs)/composites stand out for their potential anticancer function, versatile preparation and modification, ease of administration, controlled/sustained drug release, and active and passive drug internalization into target cells which is crucial for efficient treatment of cancer compared with conventional treatment approaches. These HGs/composites can respond to external (magnetic, ultrasound, light, and thermal) and internal (pH, enzyme, redox, and ROS) stimuli as well which further paves the way to their manipulation, targeted drug delivery, practicality, and efficient treatment. The above-mentioned properties of CS-/HA-based HGs/composites are unique and practical in cancer treatment which can ignore the deficiencies of conventional approaches. The present manuscript comprehensively highlights the advances in the practical application of stimuli-responsive HGs/composites based on CS/HA polysaccharides.

Half-Curcuminoids Encapsulated in Alginate-Glucosamine Hydrogel Matrices as Bioactive Delivery Systems

The therapeutic effects of curcumin and its derivatives, based on research in recent years, are limited by their low bioavailability. To improve bioavailability and develop the medical field of application, different delivery systems have been developed that are adapted to certain environments or the proposed target type. This study presents some half-curcuminoids prepared by the condensation of acetylacetone with 4-hydroxybenzaldehyde (C1), 4-hydroxy-3-methoxybenzaldehyde (C2), 4-acetamidobenzaldehyde (C3), or 4-diethylaminobenzaldehyde (C4), at microwaves as a simple, solvent-free, and eco-friendly method. The four compounds obtained were characterized in terms of morphostructural and photophysical properties. Following the predictions of theoretical studies on the biological activities related to the molecular structure, in vitro tests were performed for compounds C1-C3 to evaluate the antitumor properties and for C4's possible applications in the treatment of neurological diseases. The four compounds were encapsulated in two types of hydrogel matrices. First, the alginate-glucosamine network was generated and then the curcumin analogs were loaded (G1, G3, G5-G7, and G9). The second type of hydrogels was obtained by loading the active compound together with the generation of the hydrogel carrier matrices, by simply dissolving (G4 and G10) or by chemically binding half-curcuminoid derivatives to glucosamine (G2 and G8). Thus, two types of curcumin analog delivery systems were obtained, which could be applied in various types of medical treatments.

Glycan-based scaffolds and nanoparticles as drug delivery system in cancer therapy

Glycan-based scaffolds are unique in their high specificity, versatility, low immunogenicity, and ability to mimic natural carbohydrates, making them attractive candidates for use in cancer treatment. These scaffolds are made up of glycans, which are biopolymers with well biocompatibility in the human body that can be used for drug delivery. The versatility of glycan-based scaffolds allows for the modulation of drug activity and targeted delivery to specific cells or tissues, which increases the potency of drugs and reduces side effects. Despite their promise, there are still technical challenges in the design and production of glycan-based scaffolds, as well as limitations in their therapeutic efficacy and specificity.