A review on chitosan and alginate-based microcapsules: Mechanism and applications in drug delivery systems

Formulation Development of Natural Polymeric Nanoparticles, In Vitro Antiaging Evaluation, and Metabolite Profiling of Toona sinensis Leaf Extracts

Background/Objectives: Natural polymer nanoparticles have potential as delivery systems, can enhance pharmacological activity, and can improve stability in the cosmetic field. In this research, we implemented a development approach for chitosan-alginate and chitosan-pectin nanoparticles. This study aimed to investigate effect of formulation, process variables, in vitro antiaging evaluation, and metabolite profiling of Toona sinensis leaf extracts. Methods: Polymeric nanoparticles have been prepared using the ionic gelation method (Temperature = 40 °C, time = 1 h and speed = 1000 rpm), in vitro antiaging evaluation using the Neutrophil Elastase Inhibitor Screening Kit method, and analysis of metabolite profiling with UHPLC-HRMS. Results: Research results found that the SLE and EAFSL nanoparticles that have good and stable characteristics before and after storage in a climatic chamber after 3 months are FIIA-NPSLE (0.75% chitosan and 1.25% Alginate), FIP-NPSLE (1% chitosan and 0.5% Pectin), FIIA-NPEAFSL (0.75% chitosan and 1.25% Alginate), and FIIIP-NPEAFSL (0.125% chitosan and 0.375% Alginate). Chitosan-alginate polymers, such as FIIA-NPEAFSL, have higher inhibition of the elastase enzyme than FIIA-NPSLE, with a % inhibition (IC50) of FIIA-NPEAFSL being 87.30%, while the IC50 of FIIA-NPSLE is 39.40%. Meanwhile, using chitosan-pectin polymers, such as FIP-NPSLE, results in lower inhibition of the elastase enzyme compared to the chitosan-alginate polymer, with an IC50 of 27.28% while IC50 FIIIP-NPEAFSL is 39.53%. SLE and EAFSL nanoparticles with chitosan-alginate and chitosan-pectin polymers resulted in a significant PDI during storage from 1.3 to 1.9, and zeta potential values were very low, ranging from -11 mV to -27 mV. Metabolite profiling using UHPLC-HRMS on T. sinensis leaf extracts revealed that the main compounds contained were glycitein, quercetin, quercetin-3β-D-glucoside, kaempferol, and ellagic acid, which has potential as an antiaging agent. Conclusions: It can be concluded that using chitosan, alginate, and pectin in the process of encapsulating extracts into nanoparticles with the same process variables affect evaluation of antiaging activity in elastase enzymes. Further research will develop these nanoparticles into nanohydrogels with antiaging activity.

Alginate-polylysine-alginate (APA) microencapsulated transgenic human amniotic epithelial cells ameliorate fibrosis in hypertrophic scars

BACKGROUND

Hypertrophic scar (HS) is a severe skin fibrosis. Transplanting stem cells carrying anti-fibrotic cytokine genes, like interferon-gamma (IFN-γ), is a novel therapeutic strategy. Human amniotic epithelial cells (hAECs) are ideal seed cells and gene vectors. Microencapsulation creates a favorable environment for transplanted cells. This study investigates the effect of alginate-polylysine-alginate (APA)-microencapsulated hAECs modified with IFN-γ on HS fibrosis.

MATERIALS AND METHODS

hAECs were isolated from human placentas and characterized. The full-length IFN-γ gene was cloned into the pcDNA3.1 vector to create the recombinant plasmid IFN-γ-pcDNA3.1. This plasmid was then transfected into hAECs, resulting in the generation of IFN-γ-modified hAECs (IFN-γ-hAECs). Subsequently, these IFN-γ-hAECs were microencapsulated with APA to produce APA-IFN-γ-hAECs. In vitro, the release of IFN-γ, as well as the cellular and metabolic activities, growth, proliferation, migration, apoptosis, and trans-differentiation were assessed using HS-derived fibroblasts. In vivo, the weight loss of HS xenografts, collagen fiber arrangement, tissue oxidative stress, and inflammatory response were evaluated using a nude mouse model that had been transplanted with human HS tissues.

RESULTS

In vitro, APA-IFN-γ-hAECs exhibited significantly sustained and enhanced IFN-γ release, increased cellular vitality, and inhibited fibroblast growth, proliferation, migration, and trans-differentiation into myofibroblasts. APA-IFN-γ-hAECs also remarkably downregulated extracellular matrix (ECM) components and promoted apoptosis. In vivo, they significantly accelerated the weight reduction of HS xenografts, improved collagen fiber arrangement, and mitigated oxidative stress and inflammation.

CONCLUSIONS

This study suggests that APA-microencapsulated IFN-γ-hAECs may have potential in alleviating HS fibrosis, offering a new direction for exploring effective clinical HS management strategies.

An Overview on Bioactive Glasses for Bone Regeneration and Repair: Preparation, Reinforcement, and Applications

Synthetic bone transplantation has emerged in recent years as a highly promising strategy to address the major clinical challenge of bone tissue defects. In this field, bioactive glasses (BGs) have been widely recognized as a viable alternative to traditional bone substitutes due to their unique advantages, including favorable biocompatibility, pronounced bioactivity, excellent biodegradability, and superior osseointegration properties. This article begins with a comprehensive overview of the development and success of BGs in bone tissue engineering, and then focuses on their composite reinforcement systems with biodegradable metals, calcium-phosphorus (Ca-P)-based bioceramics, and biodegradable medical polymers, respectively. Moreover, the article outlines some frequently used manufacturing methods for three-dimensional BG-based bone bioscaffolds and highlights the remarkable achievements of these scaffolds in the field of bone defect repair in recent years. Lastly, based on the many potential challenges encountered in the preparation and application of BGs, a brief outlook on their future directions is presented. This review may help to provide new ideas for researchers to develop ideal BG-based bone substitutes for bone reconstruction and functional recovery.

A Comprehensive Review of Challenges in Oral Drug Delivery Systems and Recent Advancements in Innovative Design Strategies

The oral route of drug administration is often preferred by patients and healthcare providers due to its convenience, ease of use, non-invasiveness, and patient acceptance. However, traditional oral dosage forms have several limitations, including low bioavailability, limited drug loading capacity, and stability and storage issues, particularly with solutions and suspensions. Over the years, researchers have dedicated considerable effort to developing novel oral drug delivery systems to overcome these limitations. This review discusses various challenges associated with oral drug delivery systems, including biological, pharmaceutical, and physicochemical barriers. It also explores common delivery approaches, such as gastroretentive drug delivery, small intestine drug delivery, and colon-targeting drug delivery systems. Additionally, numerous strategies aimed at improving oral drug delivery efficiency are reviewed, including solid dispersion, absorption enhancers, lipidbased formulations, nanoparticles, polymer-based nanocarriers, liposomal formulations, microencapsulation, and micellar formulations. Furthermore, innovative approaches like orally disintegrating tablets (ODT), orally disintegrating films (ODF), layered tablets, micro particulates, self-nano emulsifying formulations (SNEF), and controlled release dosage forms are explored for their potential in enhancing oral drug delivery efficiency and promoting patients' compliance. Overall, this review highlights significant progress in addressing challenges in the pharmaceutical industry and clinical settings, offering novel approaches for the development of effective oral drug delivery systems.

Active herbal ingredients and drug delivery design for tumor therapy: a review

Active herbal ingredients are gaining recognition for their potent anti-tumor efficacy, attributable to various mechanisms including tumor cell inhibition, immune system activation, and tumor angiogenesis inhibition. Recent studies have revealed that numerous anti-tumor herbal ingredients, such as ginsenosides, ursolic acid, oleanolic acid, and Angelica sinensis polysaccharides, can be utilized to develop smart drug carriers like liposomes, micelles, and nanoparticles. These carriers can deliver active herbal ingredients and co-deliver anti-tumor drugs to enhance drug accumulation at tumor sites, thereby improving anti-tumor efficacy. This study provides a comprehensive analysis of the mechanisms by which these active herbal ingredients-derived carriers enhance therapeutic outcomes. Additionally, it highlights the structural properties of these active herbal ingredients, demonstrating how their unique features can be strategically employed to design smart drug carriers with improved anti-tumor efficacy. The insights presented aim to serve as a reference and guide future innovations in the design and application of smart drug carriers for cancer therapy that leverage active herbal ingredients.

Vibration-assisted Microbead Production: A New Frontier for Biocompatible Surfaces

The encapsulation of active pharmaceutical ingredients (APIs) in microbeads is an essential step in drug delivery; however, it is also inherently associated with the need to control particle size and drug release profiles. Nevertheless, most conventional methods of microencapsulation fail to provide consistent results. A new method called vibration-assisted microbead coating is a novel unified technique utilizing mechanical vibrations to enable the controlled, uniform coating of microbeads on APIs. This chapter discusses the technology of vibration-assisted encapsulation performed by the authors through microbead formation and the physical activity of coating APIs. This chapter focuses on achieving uniform control of the final coated surface of the API, microbead shape, size, and loading through vibration parameters. Additionally, this chapter discusses the biocompatibility and stability of the final coated surface. This new means of encapsulation has high potential for drug delivery. This method reduces most of the traditional challenges of encapsulation, if not eliminates them, and is more reliable. Based on the abovementioned findings, the authors propose the following main areas for their further work: optimisation of vibration parameters for various APIs, research into the long-term stability of the loading–release profile, and possible use of the technique in targeted drug delivery.

Regulation of mechanical properties of microcapsules and their applications

Microcapsules encapsulating payloads are one of the most promising delivery methods. The mechanical properties of microcapsules often determine their application scenarios. For example, microcapsules with low mechanical strength are more widely used in biomedical applications due to their superior biocompatibility, softness, and deformability. In contrast, microcapsules with high mechanical strength are often mixed into the matrix to enhance the material. Therefore, characterizing and regulating the mechanical properties of microcapsules is essential for their design optimization. This paper first outlines four methods for the mechanical characterization of microcapsules: nanoindentation technology, parallel plate compression technology, microcapillary technology, and deformation in flow. Subsequently, the mechanisms of regulating the mechanical properties of microcapsules and the progress of applying microcapsules with different degrees of softness and hardness in food, textile, and pharmaceutical formulations are discussed. These regulation mechanisms primarily include altering size and morphology, introducing sacrificial bonds, and construction of hybrid shells. Finally, we envision the future applications and research directions for microcapsules with tunable mechanical properties.

Bioengineered carbohydrate polymers for colon-specific drug release: Current trends and future prospects

The worldwide health burden of colorectal cancer is still substantial, and traditional chemotherapeutic drugs sometimes have poor selectivity, which can result in systemic toxicity and unfavorable side effects. For colon-specific medication delivery, bioengineered carbohydrate polymers have shown promise as carriers. They may enhance treatment effectiveness while minimizing systemic exposure and associated side effects. The unique properties of these manufactured or naturally occurring biopolymers, such as hyaluronic acid, chitosan, alginate, and pectin, enable targeted medicine release. These qualities can be changed to meet the physiological needs of the colon. In the context of colorectal cancer therapy, this article provides a comprehensive overview of current developments and prospective future directions in the field of bioengineered carbohydrate polymer synthesis for colon-specific drug delivery. We discuss numerous techniques for achieving colon-targeted drug release, including enzyme-sensitive polymers, pH-responsive devices, and microbiota-activated processes. To increase tumor selectivity and cellular uptake, we also examine the inclusion of active targeting approaches, such as conjugating specific ligands. Furthermore, we discuss the potential of combination treatment strategies, which use the coadministration of numerous therapeutic medications to target multiple pathways implicated in cancer growth and address drug resistance mechanisms. We address recent biomimetic advances that potentially improve the biocompatibility, cellular uptake, and tumor penetration of carbohydrate polymer-based nanocarriers. These methods involve protein corona engineering and cell membrane coating. Furthermore, we look at the possibility of intelligent and sensitive systems that may adjust their behaviors in response to certain inputs or feedback loops, allowing for precise and regulated drug distribution.

Optimization of alginate/carboxymethyl chitosan microbeads for the sustained release of celecoxib and attenuation of intestinal inflammation in vitro

Multiple anti-inflammatory medications have helped treat inflammatory bowel disease (IBD). However, oral administration has minimal absorption and systemic side effects. This study aims to investigate the potential of encapsulating anti-inflammatory drug celecoxib (Cele) within microbeads for the treatment of IBD. Microbeads were formed by cross-linking carboxymethyl chitosan (CMCs) with sodium alginate (Alg) through the ionic gelation method and optimized through response surface methodology. Additionally, the study revealed a mucoadhesivity value of 59.32 ± 0.74 % for the optimized microbead system. The drug release study demonstrated the sustained release of Cele CMCs/Alg microbeads upto 24 h compared to quick release of the free drug. The results of the cell viability assay indicated that the Cele-Alg/CMCs microbeads exhibited a non-toxic nature within the concentration range of 100-250 μM. A significant decrease in nitric oxide (NO) generation (61.14 ± 3.67 %) was seen in HCT-116 cells stimulated with lipopolysaccharide (LPS) upon treatment with Cele-250μM/CMCs/Alg microbeads. The results of the reactive oxygen species and wound healing assay suggest that Cele-250μM/CMCs/Alg microbeads had improved anti-inflammatory characteristics comparable to those of free drug treatment. The western blot analysis demonstrated that the microbeads composed of CMCs/Alg-Cele possess the capacity to inhibit the expression of COX-2 in vitro supressing inflammation.

O-carboxymethyl chitosan in biomedicine: A review

O-carboxymethyl chitosan (O-CMC) is a chitosan derivative produced through the substitution of hydroxyl (-OH) functional groups in glucosamine units with carboxymethyl (-CH2COOH) substituents, effectively addressing the inherent solubility issues of chitosan in aqueous solutions. O-CMC has garnered significant interest due to its enhanced solubility, elevated viscosity, minimal toxicity, and advantageous biocompatibility properties. Furthermore, O-CMC demonstrates antibacterial, antifungal, and antioxidant characteristics, rendering it a promising candidate for various biomedical uses such as wound healing, tissue engineering, anti-tumor therapies, biosensors, and bioimaging. Additionally, O-CMC is well-suited for the fabrication of nanoparticles, hydrogels, films, microcapsules, and tablets, offering opportunities for effective drug delivery systems. This review outlines the distinctive features of O-CMC, offers analyses of advancements and future potential based on current research, examines significant obstacles for clinical implementation, and foresees its ongoing significant impacts in the realm of biomedicine.

Advances in chitosan-based blends as potential drug delivery systems: A review

During the last decades, the ever-increasing incidence of diseases has led to high rates of mortality throughout the world. On the other hand, the inability and deficiencies of conventional approaches (such as chemotherapy) in the suppression of diseases remain challenging issues. As a result, there is a fundamental requirement to develop novel, biocompatible, bioavailable, and practical nanomaterials to prevent the incidence and mortality of diseases. Chitosan (CS) derivatives and their blends are outstandingly employed as promising drug delivery systems for disease therapy. These biopolymers are indicated more efficient performance against diseases compared with conventional modalities. The CS blends possess improved physicochemical properties, ease of preparation, high affordability, etc. characteristics compared with other biopolymers and even pure CS which result in efficient thermal, mechanical, biochemical, and biomedical features. Also, these blends can be administrated through different routes without a long-term treatment period. Due to the mentioned properties, numerous formulations of CS blends are developed for pharmaceutical sciences to treat diseases. This review article highlights the progressions in the development of CS-based blends as potential drug delivery systems against diseases.

A review on the immobilization of bromelain

This review shows the endeavors performed to prepare immobilized formulations of bromelain extract, usually from pineapple, and their use in diverse applications. This extract has a potent proteolytic component that is based on thiol proteases, which differ depending on the location on the fruit. Stem and fruit are the areas where higher activity is found. The edible origin of this enzyme is one of the features that determines the applications of the immobilized bromelain to a more significant degree. The enzyme has been immobilized on a wide diversity of supports via different strategies (covalent bonds, ion exchange), and also forming ex novo solids (nanoflowers, CLEAs, trapping in alginate beads, etc.). The use of preexisting nanoparticles as immobilization supports is relevant, as this facilitates one of the main applications of the immobilized enzyme, in therapeutic applications (as wound dressing and healing components, antibacterial or anticancer, mucus mobility control, etc.). A curiosity is the immobilization of this enzyme on spores of probiotic microorganisms via adsorption, in order to have a perfect in vivo compatibility. Other outstanding applications of the immobilized enzyme are in the stabilization of wine versus haze during storage, mainly when immobilized on chitosan. Curiously, the immobilized bromelain has been scarcely applied in the production of bioactive peptides.

Coumarin-Modified Starch Fluorescent Nanoparticles as Sensor of Fe3+ and Zn2+ ions Utilizing Dynamic Quenching and Chelation Mechanisms

Zinc and iron are two essential trace minerals that play a pivotal role in maintaining optimal health and well-being in the human body. Despite being required in relatively small quantities, their significance can be understated as they participate in a wide array of critical physiological processes such as oxygen transport, DNA synthesis, controlling nutrient availability, etc. Understanding the distribution and behavior of these ions in natural water bodies is essential for assessing water quality, studying ecological processes, and managing environmental impacts. In this study, we have developed a dual fluorescence probe using starch which was functionalized with coumarin derivatives, for efficient detection of Fe3+ and Zn2+ ions. This structure led a self-assembled starch/coumarin (SC) fluorescent nanoparticles with strong fluorescence intensity under ultraviolet light (365 nm). The quenching effect of Fe3+ on the SC fluorescent probe enabled efficient specific detection of Fe3+. Furthermore, Zn2+ ions increased fluorescence intensity of coumarin compounds (λemission = 459). This phenomenon occurs when the coumarin compound forms a complex or interacts with the zinc ion, resulting in enhanced fluorescence emission. In summary, the developed fluorescent probe offered a promising approach for sensitive and specific detection of iron and zinc ions in aqueous solutions.

Preparation and characterization of astaxanthin-loaded microcapsules stabilized by lecithin-chitosan-alginate interfaces with layer-by-layer assembly method

Astaxanthin is a kind of keto-carotenes with various health benefits. However, its solubility and chemical stability are poor, which leads to low bio-availability. Microcapsules have been reported to improve the solubility, chemical stability, and bio-availability of lipophilic bioactives. Freeze-dried astaxanthin-loaded microcapsules were prepared by layer-by-layer assembly of tertiary emulsions with maltodextrin as the filling matrix. Tertiary emulsions were fabricated by performing chitosan and sodium alginate electrostatic deposition onto soybean lecithin stabilized emulsions. 0.9 wt% of chitosan solution, 0.3 wt% of sodium alginate solution and 20 wt% of maltodextrin were optimized as the suitable concentrations. The prepared microcapsules were powders with irregular blocky structures. The astaxanthin loading was 0.56 ± 0.05 % and the encapsulation efficiency was >90 %. A slow release of astaxanthin could be observed in microcapsules promoted by the modulating of chitosan, alginate and maltodextrin. In vitro simulated digestion displayed that the microcapsules increased the bio-accessibility of astaxanthin to 69 ± 1 %. Chitosan, alginate and maltodextrin can control the digestion of microcapsules. The coating of chitosan and sodium alginate, and the filling of maltodextrin in microcapsules improved the chemical stability of astaxanthin. The constructed microcapsules were valuable to enrich scientific knowledge about improving the application of functional ingredients.

Astaxanthin-loaded alginate-chitosan gel beads activate Nrf2 and pro-apoptotic signalling pathways against oxidative stress

Oxidative stress (OS) plays a crucial role in disease development. Astaxanthin (ATX), a valuable natural compound, may reduce OS and serve as a treatment for diseases like neurodegenerative disorders and cancer. Nuclear factor-erythroid 2-related factor 2 (Nrf2) regulates antioxidant enzymes and OS management. We evaluated ATX's antioxidant activity via Alg-CS/ATX gel beads in vitro. ATX-encapsulated alginate-chitosan (Alg-CS/ATX) gel beads were synthesized and structurally/morphologically characterized by SEM, FT-IR, and XRD. Their biological effects were examined in human umbilical vein endothelial cells (HUVECs) treated with H2O2 through MTT assay, Annexin V/PI, cell cycle studies, and western blotting. Alg-CS effectively carried ATX, with high capacity and reduced pore size. Alg-CS/ATX displayed an 84% encapsulation efficiency, maintaining stability for 30 days. In vitro studies showed a 1.4-fold faster release at pH 5.4 than at neutral pH, improving ATX's therapeutic potential. HUVECs treated with Alg-CS/ATX showed enhanced viability via increased Nrf2 expression. Alg-CS gel beads exhibit significant potential as a biocompatible vehicle for delivering ATX to combat OS with considerable opportunity for clinical applications.

Modeling sunset yellow removal from fruit juice samples by a novel chitosan-nickel ferrite nano sorbent

Analysis of food additives is highly significant in the food industry and directly related to human health. This investigation into the removal efficiency of sunset yellow as an azo dye in fruit juices using Chitosan-nickel ferrite nanoparticles (Cs@NiFe2O4 NPs). The nanoparticles were synthesized and characterized using various techniques. The effective parameters for removing sunset yellow were optimized using the response surface methodology (RSM) based on the central composite design (CCD). Under the optimum conditions, the highest removal efficiency (94.90%) was obtained for the initial dye concentration of 26.48 mg L-1 at a pH of 3.87, a reaction time of 67.62 min, and a nanoparticle dose of 0.038 g L-1. The pseudo-second-order kinetic model had a better fit for experimental data (R2 = 0.98) than the other kinetic models. The equilibrium adsorption process followed the Freundlich isotherm model with a maximum adsorption capacity of 212.766 mg g-1. The dye removal efficiency achieved for industrial and traditional fruit juice samples (91.75% and 93.24%), respectively, confirmed the method's performance, feasibility, and efficiency. The dye adsorption efficiency showed no significant decrease after five recycling, indicating that the sorbent has suitable stability in practical applications. variousThe synthesized nanoparticles can be suggested as an efficient sorbent to remove the sunset yellow dye from food products.

Application of Encapsulation Strategies for Probiotics: From Individual Loading to Co-Encapsulation

Consumers are increasingly showing a preference for foods whose nutritional and therapeutic value has been enhanced. Probiotics are live microorganisms, and their existence is associated with a number of positive effects in humans, as there are many and well-documented studies related to gut microbiota balance, the regulation of the immune system, and the maintenance of the intestinal mucosal barrier. Hence, probiotics are widely preferred by consumers, causing an increase in the corresponding food sector. As a consequence of this preference, food industries and those involved in food production are strongly interested in the occurrence of probiotics in food, as they have proven beneficial effects on human health when they exist in appropriate quantities. Encapsulation technology is a promising technique that aims to preserve probiotics by integrating them with other materials in order to ensure and improve their effectiveness. Encapsulated probiotics also show increased stability and survival in various stages related to their processing, storage, and gastrointestinal transit. This review focuses on the applications of encapsulation technology in probiotics in sustainable food production, including controlled release mechanisms and encapsulation techniques.

Template-Free Manufacturing of Defined Structure and Size Polymeric Microparticles

Complex-structured polymeric microparticles hold significant promise as an advance in next-generation medicine mostly due to demand from developing targeted drug delivery. However, the conventional methods for producing these microparticles of defined size, shape, and sophisticated composition often face challenges in scalability, reliance on specialized components such as micro-patterned templates, or limited control over particle size distribution and cargo (functional payload) release kinetics. In this study, we introduce a novel and reliably scalable approach for manufacturing microparticles of defined structures and sizes with variable parameters. The concept behind this method involves the deposition of a specific number of polymer layers on a substrate with low surface energy. Each layer can serve as either the carrier for cargo or a programmable shell-former with predefined permeability. Subsequently, this layered structure is precisely cut into desired-size blanks (particle precursors) using a laser. The manufacturing process is completed by applying heat to the substrate, which results in sealing the edges of the blanks. The combination of the high surface tension of the molten polymer and the low surface energy of the substrate enables the formation of discrete particles, each possessing semi-spherical or other designed geometries determined by their internal composition. Such anisotropic microparticles are envisaged to have versatile applications.