Ionically cross-linked alginate-chitosan core-shell hydrogel beads for oral delivery of insulin

Alginate-Chitosan Biodegradable and Biocompatible Based Hydrogel for Breast Cancer Immunotherapy and Diagnosis: A Comprehensive Review

Breast cancer is the most common type of cancer and the second leading cause of cancer-related mortality in females. There are many side effects due to chemotherapy and traditional surgery, like fatigue, loss of appetite, skin irritation, and drug resistance to cancer cells. Immunotherapy has become a hopeful approach toward cancer treatment, generating long-lasting immune responses in malignant tumor patients. Recently, hydrogel has received more attention toward cancer therapy due to its specific characteristics, such as decreased toxicity, fewer side effects, and better biocompatibility drug delivery to the particular tumor location. Researchers globally reported various investigations on hydrogel research for tumor diagnosis. The hydrogel-based multilayer platform with controlled nanostructure has received more attention for its antitumor effect. Chitosan and alginate play a leading role in the formation of the cross-link in a hydrogel. Also, they help in the stability of the hydrogel. This review discusses the properties, preparation, biocompatibility, and bioavailability of various research and clinical approaches of the multipolymer hydrogel made of alginate and chitosan for breast cancer treatment. With a focus on cases of breast cancer and the recovery rate, there is a need to find out the role of hydrogel in drug delivery for breast cancer treatment.

Orally ingestible medication utilizing layered double hydroxide nanoparticles strengthened alginate and hyaluronic acid-based hydrogel bead for bowel disease management

In the treatment of bowel diseases such as ulcerative colitis through oral administration, an effective drug delivery system targeting the colon is crucial for enhancing efficacy and minimizing side effects of therapeutic agents. This study focuses on the development of a novel nanocomposite hydrogel bead comprising a synergistic blend of biological macromolecules, namely sodium alginate (ALG) and hyaluronic acid (HA), reinforced with layered double hydroxide nanoparticles (LDHs) for the oral delivery of dual therapeutics. The synthesized hydrogel bead exhibits significantly enhanced gel strength and controllable release of methylprednisolone (MP) and curcumin (CUR), serving as an anti-inflammatory drug and a mucosal healing agent, compared to native ALG or ALG/HA hydrogel beads without LDHs. The physicochemical properties of the synthesized LDHs and hydrogel beads were characterized using various techniques, including scanning electron microscopy, zeta potential measurement, transmission electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. In vitro release studies of MP and CUR under simulated gastrointestinal tract (GIT) conditions demonstrate the superior controlled release property of the nanocomposite hydrogel bead, particularly in minimizing premature drug release in the upper GIT environment while sustaining release of over 82 % of drugs in the colonic environment. Thus, the modularly engineered carrier designed for oral colon targeting holds promise as a potential candidate for the treatment of ulcerative colitis.

Synthesis and active manipulation of magnetic liquid beads

We report the fabrication and characterisation of magnetic liquid beads with a solid magnetic shell and liquid core using microfluidic techniques. The liquid beads consist of a fluorinated oil core and a polymer shell with magnetite particles. The beads are generated in a flow-focusing polydimethylsiloxane (PDMS) device and cured by photo polymerisation. We investigated the response of the liquid beads to an external magnetic field by characterising their motion towards a permanent magnet. Magnetic sorting of liquid beads in a channel was achieved with 90% efficiency. The results show that the liquid beads can be controlled magnetically and have potential applications in digital microfluidics including nucleic acid amplification, drug delivery, cell culture, sensing, and tissue engineering. The present paper also discusses the magnetophoretic behaviour of the liquid bead by varying its mass and magnetite concentration in the shell. We also demonstrated the two-dimensional self-assembly of magnetic liquid beads for potential use in digital polymerase chain reaction and digital loop mediated isothermal amplification.

Formulation and Evaluation of Insulin-Loaded Sodium-Alginate Microparticles for Oral Administration

The development of oral insulin drug delivery systems is still an ongoing challenge for pharmaceutical technology researchers, as the formulation process has to overcome a number of obstacles due to the adverse characteristics of peptides. The aim of this study was to formulate different sodium-alginate microparticles as a possible method for oral insulin administration. In our previous studies, the method has been successfully optimized using a small model peptide. The incorporation of insulin into alginate carriers containing nonionic surfactants has not been described yet. In order to enhance the absorption of insulin through biological barriers, Labrasol ALF and Labrafil M 2125 CS were selected as permeation-enhancing excipients. They were applied at a concentration of 0.10% (v/v%), along with various combinations of the two, to increase oral bioavailability. Encapsulation efficiency showed sufficient drug incorporation, as it resulted in over 80% in each composition. In vitro dissolution and enzymatic stability test results proved that, as a pH-responsive polymer, alginate bead swelling and drug release occur at higher pH, thus protecting insulin against the harsh environment of the gastrointestinal tract. The remaining insulin content was 66% due to SIF degradation after 120 min. Permeability experiments revealed the impact of permeation enhancers and natural polymers on drug absorption, as they enhanced drug transport significantly through Caco-2 cells in the case of alginate microparticle formulations, as opposed to the control insulin solution. These results suggest that these formulations are able to improve the oral bioavailability of insulin.

Nanoengineered injectable hydrogels derived from layered double hydroxides and alginate for sustained release of protein therapeutics in tissue engineering applications

Chronic Kidney Disease (CKD) which involves gradual loss of kidney function is characterized by low levels of a glycoprotein called Erythropoietin (EPO) that leads to red blood cell  deficiency and anemia. Recombinant human EPO (rhEPO) injections that are administered intravenously or subcutaneously is the current gold standard for treating CKD. The rhEPO injections have very short half-lives and thus demands frequent administration with a risk of high endogenous EPO levels leading to severe side effects that could prove fatal. To this effect, this work provides a novel approach of using lamellar inorganic solids with a brucite-like structure for controlling the release of protein therapeutics such as rhEPO in injectable hydrogels. The nanoengineered injectable system was formulated by incorporating two-dimensional layered double hydroxide (LDH) clay materials with a high surface area into alginate hydrogels for sustained delivery. The inclusion of LDH in the hydrogel network not only improved the mechanical properties of the hydrogels (5-30 times that of alginate hydrogel) but also exhibited a high binding affinity to proteins without altering their bioactivity and conformation. Furthermore, the nanoengineered injectable hydrogels (INHs) demonstrated quick gelation, injectability, and excellent adhesion properties on human skin. The in vitro release test of EPO from conventional alginate hydrogels (Alg-Gel) showed 86% EPO release within 108 h while INHs showed greater control over the initial burst and released only 24% of EPO in the same incubation time. INH-based ink was successfully used for 3D printing, resulting in scaffolds with good shape fidelity and stability in cell culture media. Controlled release of EPO from INHs facilitated superior angiogenic potential in ovo (chick chorioallantoic membrane) compared to Alg-Gel. When subcutaneously implanted in albino mice, the INHs formed a stable gel in vivo without inducing any adverse effects. The results suggest that the proposed INHs in this study can be utilized as a minimally invasive injectable platform or as 3D printed patches for the delivery of protein therapeutics to facilitate tissue regeneration.

Development and characterization of crosslinked k-carrageenan/sericin blend with covalent agents or thermal crosslink for indomethacin extended release

Modified release of multiparticulate pharmaceutical forms is a key therapeutic strategy to reduce side effects and toxicity caused by high and repeated doses of immediate-release oral drugs. This research focused on the encapsulation of indomethacin (IND) in the crosslinked k-Car/Ser polymeric matrix by covalent and thermal methods to evaluate drug delivery modulation and properties of the crosslinked blend. Therefore, the entrapment efficiency (EE %), drug loading (DL %) and physicochemical properties of the particles were investigated. The particles presented a spherical shape and a rough surface with a mean diameter of 1.38-2.15 mm (CCA) and 1.56-1.86 mm (thermal crosslink). FTIR investigation indicated the presence of IDM in the particles and X-ray pattern showed the maintenance of crystallinity of IDM. The in vitro release in acidic medium (pH 1.2) and phosphate buffer saline solution (pH 6.8) was 1.23-6.81 % and 81-100 %, respectively. Considering the results, the formulations remained stable after 6 months. The Weibull equation was adequately fitted for all formulations and a diffusion mechanism, swelling and relaxation of chain were observed. IDM-loaded k-carrageenan/sericin/CMC increases cell viability (> 75 % for neutral red and > 81 % for MTT). Finally, all formulations present gastro-resistance, pH response and altered release and have the potential to be used as drug delivery careers.

Chitosan-Based Composites: Development and Perspective in Food Preservation and Biomedical Applications

Chitin, which may be the second-most common polymer after cellulose, is the raw material of chitosan. Chitosan has been infused with various plant extracts and subsidiary polymers to improve its biological and physiological properties. Chitosan's physicochemical properties are enhanced by blending, making them potential candidates that can be utilized in multifunctional areas, including food processing, nutraceuticals, food quality monitoring, food packaging, and storage. Chitosan-based biomaterials are biocompatible, biodegradable, low toxic, mucoadhesive, and regulate chemical release. Therefore, they are used in the biomedical field. The present manuscript highlights the application of chitosan-based composites in the food and biomedical industries.

Insulin-Loaded Soybean Trypsin Inhibitor-Chitosan Nanoparticles: Preparation, Characterization, and Protective Effect Evaluation

The aim of this work was to prepare insulin-loaded nanoparticles using soybean trypsin inhibitor (STI) and chitosan (CS) as a potential coating. The nanoparticles were prepared by complex coacervation, and characterized for their particle size, polydispersity index (PDI), and encapsulation efficiency. In addition, the insulin release and enzymatic degradation of nanoparticles in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) were evaluated. The results showed that the optimal conditions for preparing insulin-loaded soybean trypsin inhibitor-chitosan (INs-STI-CS) nanoparticles were as follows: CS concentration of 2.0 mg/mL, STI concentration of 1.0 mg/mL, and pH 6.0. The INs-STI-CS nanoparticles prepared at this condition had a high insulin encapsulation efficiency of 85.07%, the particle diameter size was 350 ± 5 nm, and the PDI value was 0.13. The results of the in vitro evaluation of simulated gastrointestinal digestion showed that the prepared nanoparticles could improve the stability of insulin in the gastrointestinal tract. Compared with free insulin, the insulin loaded in INs-STI-CS nanoparticles was retained at 27.71% after 10 h of digestion in the intestinal tract, while free insulin was completely digested. These findings will provide a theoretical basis for improving the stability of oral insulin in the gastrointestinal tract.

Self-assembled chitosan-insulin oral nanoparticles - A critical perspective review

Chitosan is an abundant natural cationic polysaccharide with excellent biodegradability, bioadhesion, and biocompatibility. Chitosan is extensively researched for various particulate oral insulin drug delivery systems. Oral insulin is economically efficient and more convenient than injections, with greater patient compliance. Electrostatic ionic interaction between cationic chitosan and anionic polymer or insulin leads to the formation of spontaneously self-assembled nanoparticles. This simple technique attracted many researchers as it can be carried out quickly in mild conditions without harmful solvents, such as surfactants or chemical cross-linkers that might degrade the insulin structure. The formulated chitosan nanoparticles help to protect the core insulin from enzymatic degradation in the digestive system and improve paracellular intestinal uptake from the enterocytes due to mucoadhesion and reversible tight junction opening. Moreover, functionalized chitosan nanoparticles create newer avenues for targeted and prolonged delivery. This review focuses on modified chitosan-insulin nanoparticles and their implications on oral insulin delivery. Dependent variables and their optimal concentration ranges used in self-assembly techniques for chitosan-insulin nanoparticular synthesis are summarized. This review provides a comprehensive guide to fine-tune the essential factors to formulate stable insulin-chitosan nanoparticles using mild ionic interactions.

Natural and Synthetic Clay Minerals in the Pharmaceutical and Biomedical Fields

Clay minerals are historically among the most used materials with a wide variety of applications. In pharmaceutical and biomedical fields, their healing properties have always been known and used in pelotherapy and therefore attractive for their potential. In recent decades, the research has therefore focused on the systematic investigation of these properties. This review aims to describe the most relevant and recent uses of clays in the pharmaceutical and biomedical field, especially for drug delivery and tissue engineering purposes. Clay minerals, which are biocompatible and non-toxic materials, can act as carriers for active ingredients while controlling their release and increasing their bioavailability. Moreover, the combination of clays and polymers is useful as it can improve the mechanical and thermal properties of polymers, as well as induce cell adhesion and proliferation. Different types of clays, both of natural (such as montmorillonite and halloysite) and synthetic origin (layered double hydroxides and zeolites), were considered in order to compare them and to assess their advantages and different uses.

Multifunctional Layered Double Hydroxides for Drug Delivery and Imaging

Two-dimensional nanomaterials, particularly layered double hydroxides (LDHs), have been widely applied in the biomedical field owing to their biocompatibility, biodegradability, controllable drug release/loading ability, and enhanced cellular permeability. Since the first study analyzing intercalative LDHs in 1999, numerous studies have investigated their biomedical applications, including drug delivery and imaging; recent research has focused on the design and development of multifunctional LDHs. This review summarizes the synthetic strategies and in-vivo and in-vitro therapeutic actions and targeting properties of single-function LDH-based nanohybrids and recently reported (from 2019 to 2023) multifunctional systems developed for drug delivery and/or bio-imaging.