Chitosan-alginate Microparticles Research Articles

Enhancing antioxidant properties of lime juice powder through polyelectrolyte microparticles of chitosan-alginate: Formulation, characterization and stability study

Lime (Citrus aurantifolia) juice was reported to contain ascorbic acid (AA) and flavonoids, which has bioactivity as antioxidants. To develop an antioxidant product, improving its stability is necessary due to the perishable characteristics of compounds in lime. Therefore, the formulation of polyelectrolyte microparticles using chitosan and alginate was conducted to overcome the weaknesses. This study aims to evaluate the effect of various chitosan, alginate, and lime juice powder (LJP) concentrations on the physical characteristics and antioxidant activity of LJP encapsulated in chitosan-alginate microparticles (CALM). Microparticles with various concentrations of chitosan and alginate were prepared by ionic gelation method using CaCl2 as a crosslinker. The microparticles were evaluated for its physical properties and its antioxidant activity using 2-2-diphenyl-1-picrylhydrazyl reagent. A one-way ANOVA test and Tukey's honest significant difference post hoc were used to determine the effect of LJP amount on the antioxidant activity. The highest AA content in CALM was 0.14 mg/100 mg, with a % encapsulation efficiency of 18.38% ± 0.02%. Antioxidant activity tests revealed that LJP possessed the strong antioxidant activity with an IC50 value of 32.59 μg/mL, whereas IC50 values of the microparticles ranged from 24.79 ± 0.03 μg/mL to 39.96 ± 0.07 μg/mL. During storage, the IC50 of LJP decreased from 32.59 ± 0.13 μg/mL to 65.53 ± 0.03 μg/mL, whereas the IC50 of microparticles remained stable. This study concluded that the chitosan-alginate polyelectrolyte microparticle formulation can improve and protect LJP's antioxidant activity.

Synergistic effect of chitosan-alginate composite hydrogel enriched with ascorbic acid and alpha-tocopherol under hypoxic conditions on the behavior of mesenchymal stem cells for wound healing

BackgroundIn regenerative medicine, especially skin tissue engineering, the focus is on enhancing the quality of wound healing. Also, several constructs with different regeneration potentials have been used for skin tissue engineering. In this study, the regenerative properties of chitosan-alginate composite hydrogels in skin wound healing under normoxic and hypoxic conditions were investigated in vitro.MethodsThe ionic gelation method was used to prepare chitosan/alginate (CA) hydrogel containing CA microparticles and bioactive agents [ascorbic acid (AA) and α-tocopherol (TP)]. After preparing composite hydrogels loaded with AA and TP, the physicochemical properties such as porosity, pore size, swelling, weight loss, wettability, drug release, and functional groups were analyzed. Also, the hemo-biocompatibility of composite hydrogels was evaluated by a hemolysis test. Then, the rat bone marrow mesenchymal stem cells (rMSCs) were seeded onto the hydrogels after characterization by flow cytometry. The survival rate was analyzed using MTT assay test. The hydrogels were also investigated by DAPI and H&E staining to monitor cell proliferation and viability. To induce hypoxia, the cells were exposed to CoCl2. To evaluate the regenerative potential of rMSCs cultured on CA/AA/TP hydrogels under hypoxic conditions, the expression of the main genes involved in the healing of skin wounds, including HIF-1α, VEGF-A, and TGF-β1, was investigated by real-time PCR.ResultsThe results demonstrated that the prepared composite hydrogels were highly porous, with interconnected pores that ranged in sizes from 20 to 188 μm. The evaluation of weight loss showed that the prepared hydrogels have the ability to biodegrade according to the goals of wound healing. The reduction percentage of CA/AA/TP mass in 21 days was reported as 21.09 ± 0.52%. Also, based on wettability and hemolysis tests of the CA/AA/TP, hydrophilicity (θ = 55.6° and 53.7°) and hemocompatibility with a hemolysis ratio of 1.36 ± 0.19 were evident for them. Besides, MTT assay, DAPI, and H&E staining also showed that the prepared hydrogels provide a suitable substrate for cell growth and proliferation. Finally, based on real-time PCR, increased expression levels of VEGF and TGF-β1 were observed in rMSCs in hypoxic conditions cultured on the prepared hydrogels.ConclusionsIn conclusion, this study provides evidence that 3D CA/AA/TP composite hydrogels seeded by rMSCs in hypoxic conditions have great potential to improve wound healing.Graphical abstract

Tablet Formulation Containing Chitosan-Alginate Microparticles: Characterization and Release Profile of Xanthones

Tablet Formulation Containing Chitosan-Alginate Microparticles: Characterization and Release Profile of Xanthones

Chitosan-coated alginate micro-particles delivery of active principles through conventional pelleted food - A study in Tilapia (Oreochromis niloticus)

The search for alternatives to antibiotics in aquaculture has focused on the use of vaccines for immune-prophylaxis. The purpose of this study was to examine the feasibility and characteristics of chitosan-alginate microparticles for the oral delivery of immune-prophylactics to finfish. The microparticles, which incorporate fluorescent-labelled lysozyme, were produced by spray-drying method; their structural properties and uptake from the gastrointestinal tract of Tilapia (Oreochromis niloticus) were assessed by microscopy. The main findings show that the microparticles are able to retain their content in an acidic environment and to release it later in slightly alkaline conditions such as those found in the intestines. Moreover, both the microencapsulation procedure and the biopolymers used have no deleterious impact on the lysozyme lytic activity, which is maintained after the protein has been released from the microparticles. Administered in vivo in Tilapia by medicated food, the microparticles transit unaffected through the stomach, and reach the anterior intestines, in particular the villum sectum and the basal lamina of epithelial cells, 2 and 4 h after feeding.Overall, the evidence obtained here supports the potential of these chitosan-alginate microparticles as agents for oral immune-prophylaxis in the management of fish diseases.

Optimization of Chitosan-Alginate Microparticles for Delivery of Mangostins to the Colon Area Using Box-Behnken Experimental Design.

Chitosan-alginate microparticles loaded with hydrophobic mangostins present in the mangosteen rind extract have been formulated and optimized for colon-targeted bioactive drug delivery systems. The chitosan–mangostin microparticles were prepared using the ionotropic gelation method with sodium tripolyphosphate as the cross-linking agent of chitosan. The chitosan–mangostin microparticles were then encapsulated in alginate with calcium chloride as the linking agent. The mangostin release profile was optimized using the Box–Behnken design for response surface methodology with three independent variables: (A) chitosan–mangostin microparticle size, (B) alginate:chitosan mass ratio, and (C) concentration of calcium chloride. The following representative equation was obtained: percent cumulative release of mangostins (10 h) = 59.51 − 5.16A + 20.00B − 1.27C − 1.70AB − 5.43AC − 5.04BC + 0.0579A2 + 10.25B2 + 1.10C2. Cumulative release of 97% was obtained under the following optimum condition for microparticle preparation: chitosan–mangosteen particle size < 100 µm, alginate:chitosan mass ratio of 0.5, and calcium chloride concentration of 4% w/v. The alginate to chitosan mass ratio is the statistically significant variable in the optimization of sequential release profile of mangostins in simulated gastrointestinal fluids. Furthermore, a sufficient amount of alginate is necessary to modify the chitosan microparticles and to achieve a complete release of mangostins. The results of this work indicate that the complete release of mangostins to the colon area can be achieved using the chitosan–alginate microparticles as the bioactive delivery system.

Effect of biopolymers composition on release profile of iron(II) fumarate from chitosan-alginate microparticles

Microencapsulation using biopolymers is considered as a proper method for protecting the iron from oxidation reaction, inhibitors (fitat, tannin) and competitors (divalent metal). Chitosan and alginate are carbohydrate biopolymers commonly used in food and drug application. In order to have a carrier that can send iron to the small intestine which has a high pH, but previously had to survive through the stomach which has gastric acid, the composition of chitosan-alginate as a carrier must be investigated. The objectives in this work were to investigate the effect of both chitosan and alginate concentrations on release profile of iron(II) fumarate in simulated gastric acid and intestinal fluids and its physicochemical property. The microparticles were prepared by dropping chitosan-iron solution into sodium tripolyphosphate solution as crosslinking agent. The electrostatic complexation was formed when the chitosan microparticles were mixed with alginate solution and followed with calcium chloride solution for ionotropic gelation to form chitosan-alginate-iron microparticles. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were employed to describe polyelectrolyte properties of microparticles. The results showed that suitable compositions of chitosan-alginate have successfully improved the pH-sensitivity of the microparticles, thus the iron release was sustained in simulated gastric fluid (pH 1.2), while the release in simulated intestinal fluid (pH 7.4) extended. The release profile of iron from the chitosan-alginate microparticle indicated the effect of alginate on the release of iron. The existence of the polyelectrolyte complex of chitosan-alginate was proven by the appearance of certain functional groups at FTIR spectrum and surface images of iron loaded microparticles from SEM.

The Effect of Tri Poly Phosphate Concentration towards Chitosan-Alginate Micro-particle Characterization and Dissolution Process in Acidic Medium

Chitosan-Alginate micro-particles can serve as coating to the drug through the encapsulation process for controlled release. The addition of Tri Poly Phosphate would change the characterization of Chitosan-Alginate micro-particles because of the process of cross linking. This study aims to determine the characterization of micro-particles of Chitosan-Alginate based on particle size distribution, particle surface morphology and dissolution process in acid medium. The method used to make micro-particles of Chitosan-Alginate is using spray drying, thus the micro-particles can be made by mixing Chitosan-Alginate with a weight ratio of 1: 1, 1: 2, 2: 1 then mixed the crosslinking compound Tri Poly Phosphate (TPP) with a concentration of 0.1%, 0.3%, 0.5%, and added emulsifier Tween 80 3% v / v, stirred at a speed of 20,000 rpm for 10 minutes then inserted into the spray dryer to form micro-particles. The powder of micro-particles then analysed by Scanning Electron Microscopy (SEM) and performed in vitro of stomach acid solution using acidic medium for the test of dissolution. Based on the research that has been done, 0.1% TPP concentration of Chitosan-Alginate ratio of 2: 1 can produce the most uniform size distribution with a ratio of 40.54%. The biggest dissolution of micro-particles obtained from the samples with Chitosan-Alginate ratio of 2: 1 with a concentration of 0.1% TPP was 80.8%.

Characterization of nisin containing chitosan-alginate microparticles

Nisin is a naturally occurring bacteriocin that has GRAS status for use in foods granted by the FDA. Encapsulation of nisin within microparticles can protect it from interactions with other food components, thereby increasing its stability and functionality. The effects of formulation parameters on the physico-chemical characteristics of nisin-loaded chitosan-alginate microparticles were studied. Chitosan-alginate microparticles were prepared using the ionotropic pre-gelation method, which involves inducing coiling of the alginate polymer by forming a calcium-alginate pre-gel state, and followed by chitosan complexation. Calcium-alginate pre-gel states were investigated using various calcium concentrations (0–5 mM) through viscosity measurements, and calcium concentrations below 2 mM were found to promote the formation of a coiled alginate nucleus. Calcium concentration had a significant effect (p < 0.05) on the size and zeta potential of microparticles. Nisin containing microparticles prepared using 2 mM calcium concentration had a particle size diameter of 7.86 ± 0.34 μm, and zeta potential value of −10.6 ± 1.22. The average polydispersity index (PDI) of particles was found to be 0.25 ± 0.01, indicating a wide variation in particle sizes. SEM images revealed that the microparticles showed a tendency to aggregate, perhaps due to their low surface charge. Chitosan-alginate complex formation was confirmed using FTIR analysis, and the nisin peptide was found to be intact upon encapsulation, with no change in its secondary structure.

BCG-loaded chitosan microparticles: interaction with macrophages and preliminary in vivo studies

The aim of this study was to develop a novel BCG-loaded chitosan vaccine with high association efficiency which can afford efficient interaction with APC and elicit local and Th1-type-specific immune response after intranasal administration. Chitosan-suspended BCG and BCG-loaded chitosan-alginate microparticles were prepared by ionotropic gelation. Interaction with APC was evaluated by fluorescence microscopy using rBCG-GFP. Specific immune responses were evaluated following intranasal immunisation of mice. Cellular uptake was approximately two-fold higher for chitosan-suspended BCG. A single dose of BCG-loaded microparticles or chitosan-suspended BCG by intranasal route improved Th1-type response compared with subcutaneous BCG. Chitosan-suspended BCG originated the highest mucosal response in the lungs by intranasal route. These positive results indicate that the proposed approach of whole live BCG microencapsulation in chitosan-alginate for intranasal immunisation was successful in allowing efficient interaction with APC, while improving the cellular immune response, which is of interest for local immunisation against tuberculosis.

Chitosan-Alginate Microparticles as a Protein Carrier

The oral administration of peptidic drugs requires their protection from degradation in the gastric environment and the improvement of their absorption in the intestinal tract. For these requirements, a microsystem based on cross-linked alginate as the carrier of bovine serum albumin (BSA), used as a model protein, was proposed. A spray-drying technique was applied to BSA/sodium alginate solutions to obtain spherical particles having a mean diameter less than 10 μm. The microparticles were hardened using first a solution of calcium chloride and then a solution of chitosan (CS) to obtain stable microsystems. The cross-linking process was carried out at different CS concentrations and pH values of the cross-linking medium. The CS concentration affected the BSA loading in the microparticles prepared at a pH value less than the protein isoelectric point (pI). Moreover, the BSA loading at a pH value less than the pI was higher than that at a pH similar to the pI regardless of the CS concentration. This finding could be attributable to the formation of a BSA/alginate complex. The evaluation of the interaction between BSA and alginate at different pH values by means rheological measurements confirmed this hypothesis. This approach may represent a promising way to devise a microcarrier system with appropriate size for targeting the Peyer's patches, with appropriate immobilization capacity, and suitable for the oral administration of peptidic drugs.