Chitosan Coated Calcium Alginate Research Articles

Antiproliferative and Apoptotic Effects of Olive Leaf Extract Microcapsules on MCF-7 and A549 Cancer Cells.

Alginate microcapsules are a talented means for the delivery of broad curative biomacromolecules. In this study, we immobilized olive leaf extract (OLE) by calcium alginate (CA) and chitosan-coated CA (CCA) and characterized the OLE-loaded CA and CCA. The cytotoxic effect, the cell cycle arrest, and the apoptotic effect of OLE and its microcapsules were investigated against breast adenocarcinoma (MCF-7) and lung carcinoma (A549). As a result, the loading capacity of OLE-CA and OLE-CCA was found to be 80 and 99%, respectively, in optimal conditions. Also, OLE-CA and OLE-CCA were characterized by unique FTIR peaks and morphological display relative to the empty CCA microcapsules. The cytotoxicity analysis showed that the IC50 values of OLE-CA and OLE-CCA were determined to be 312 and 0.94 μg mL-1 against A549, respectively, whereas these were found to be 865.4 and 425.5 μg mL-1 for MCF-7 cells. On the other hand, the OLE microcapsules did not possess in any concentration of cytotoxic influence on the BEAS 2B healthy cell line. Also, the exposure of OLE-CCA to MCF-7 and A549 resulted in the arrest of more MCF-7 and A549 cells at the G0/G1 phase compared to the OLE. A549 and MCF-7 cells were predominantly found in the late apoptosis phase and necrosis phase, respectively. Optical microscopy images confirmed that OLE microcapsules were more effective against MCF-7 and A549 than free OLE. The present work suggested that the OLE microcapsules might be administered as nutrition supplements for cancer therapy.

Use of Poly(vinyl alcohol)-Malic Acid (CLHPMA) Hydrogels and Chitosan Coated Calcium Alginate (CCCA) Microparticles as Potential Sorbent Phases for the Extraction and Quantitative Determination of Pesticides from Aqueous Solutions.

Pesticides are used worldwide to increase crop yields in agriculture. However, their toxicity and accumulation capacity can make them toxic to the environment, animals and humans. In the case of workers chronically exposed to these substances, they must be sampled continuously, so urine is an excellent option. In this sense, this study proposes to use poly(vinyl alcohol)-malic acid hydrogels, and chitosan-coated calcium alginate as new sorbent phases to be used in pesticide determination processes in urine. To better understand the behavior of these materials in the capture and desorption process, molecular dynamics simulations (MDS) were used, and desorption experiments were performed, using mechanical agitation, ultrasound, and pH variation in the desorption process, in order to optimize the parameters to obtain better recoveries. Under the optimal experimental conditions, the maximum recoveries were of the order of 11% (CFN), 3% (KCF), 53% (DMT), 18% (MTD) and 35% (MTL). Although the recoveries were not exhaustive, they are a first approximation for the use of these new sorbent phases in the determination of this type of compound in aqueous solutions and urine.

Encapsulation of Synthesized Plant Growth Regulator Based on Copper(II) Complex in Chitosan/Alginate Microcapsules.

A new copper complex, trans-diaqua-trans-bis [1-hydroxy-1,2-di (methoxycarbonyl) ethenato] copper (abbreviation Cu(II) complex), was synthesized and its plant growth regulation properties were investigated. The results show a sharp dependence of growth regulation activity of the Cu(II) complex on the type of culture and its concentration. New plant growth regulator accelerated the development of the corn root system (the increase in both length and weight) but showed a smaller effect on the development of the wheat and barley root systems. Stimulation of corn growth decreased with increasing Cu(II) complex concentration from 0.0001% to 0.01% (inhibition at high concentrations—0.01%). The development of corn stems was also accelerated but to a lesser extent. Chitosan-coated calcium alginate microcapsules suitable for delivery of Cu(II) complex to plants were prepared and characterized. Analysis of the FTIR spectrum showed that complex molecular interactions between functional groups of microcapsule constituents include mainly electrostatic interactions and hydrogen bonds. Microcapsules surface exhibits a soft granular surface structure with substructures consisting of abundant smaller particles with reduced surface roughness. Release profile analysis showed Fickian diffusion is the rate-controlling mechanism of Cu(II) complex releasing. The obtained results give new insights into the complexity of the interaction between the Cu(II) complex and microcapsule formulation constituents, which can be of great help in accelerating product development for the application in agriculture

Microencapsulation of Lactiplantibacillus plantarum with inulin and evaluation of survival in simulated gastrointestinal conditions and roselle juice

Abstract This study aimed to evaluate the survivability of Lactiplantibacillus plantarum 299v encapsulated in chitosan-coated calcium alginate beads with inulin as prebiotic in simulated gastrointestinal conditions and roselle juice. The concentration of calcium chloride and inulin for L. plantarum 299v microencapsulation was optimised and the survivability of free and microencapsulated L. plantarum was assessed under simulated gastrointestinal conditions. Storage stability of the optimised encapsulated L. plantarum 299v-inulin was determined throughout four (4) weeks of storage in roselle juice at 4 °C and 25 °C. The optimized formula for L. plantarum 299v was 2.0% (w/v) of calcium chloride and 3.0% (w/v) of inulin. Optimized calcium alginate-chitosan L. plantarum 299v microbeads with inulin did not affect (p > 0.05) the bead diameter, with a mean diameter of 685.27 μm, and microencapsulation efficiency of 95%. Encapsulated L. plantarum 299v with inulin showed higher survivability (>107 CFU/mL) than free cells and encapsulated L. plantarum 299v without inulin under simulated gastrointestinal conditions and after four (4) weeks of storage in roselle juice at 4 °C. The results indicate that co-extrusion encapsulation and addition of inulin had improved the viability of L. plantarum 299v in roselle juice by protecting probiotic against unfavourable gastrointestinal conditions and prolonged storage.

Chitosan coated calcium alginate beads for covalent immobilization of acrylamidase: Process parameters and removal of acrylamide from coffee

This study reports on removal of acrylamide from roasted coffee by acrylamidase from Cupriavidus oxalaticus ICTDB921. Chitosan coated calcium alginate beads were functionalized with citric acid as nontoxic cross linker and activated by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) (1.66:1 w/w) for covalent immobilization of acrylamidase. The optimum beads were obtained using 5% sodium alginate, 1.5% chitosan, and 0.6 mol/L citric acid. The beads prepared at each step were characterized by FTIR and SEM. Coating of chitosan matrix on calcium alginate beads enhanced the mechanical stability over that of calcium alginate and/or chitosan. The immobilized acrylamidase showed optimum pH/temperature of 8.5/65 °C, improved pH/thermal/shelf stability, and retained 80% activity after four cycles. Haldane model could describe the degradation kinetics of acrylamide in batch study. In packed bed column, a bed height, feed flow rate and inlet acrylamide concentration of 20 cm, 1 mL/min, and 100 mg/L gave best results.

Enhancing the stability of a carboxylesterase by entrapment in chitosan coated alginate beads.

A carboxylesterase isolated from Aeromonas caviae MTCC 7725 was immobilized by entrapping it in chitosan coated calcium alginate beads. This was characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FTIR). The activity of the native and immobilized enzyme was measured at various temperatures, pH levels, and organic solvents. The optimum temperature for activity of the native enzyme was found to be 40 °C and this increased to 50 °C on immobilization. The immobilized enzyme showed enhanced stability and high residual activity in various organic solvents as compared to the free enzyme. An environmentally benign approach was used for the synthesis of ethyl salicylate using the immobilized enzyme. The product obtained was confirmed by GC-MS. The kinetic parameters, such as K m and Vmax, were also determined for the native and immobilized enzyme. The immobilized enzyme retained 50% of its activity after vfie cycles. The immobilized enzyme retained 80% and 40% of its activity at 4 °C and at 37 °C, respectively, at the end of 40 days. The results obtained from our study show that the immobilized enzyme can serve as a robust catalyst for industrial applications.

Regeneration of Calcium Alginate and Chitosan Coated Calcium Alginate Sorbents to be Reused for Lead (II) Removal from Aqueous Solutions

The application of biopolymer-based sorbents in solving some environmental problems such as the removal and recovery of heavy metals from natural polluted water and wastewater has received lately a lot of attention due to their unique characteristics. The fundamental properties that recommend the usage of biopolymers-based sorbents for environmental remediation are: high selectivity and sorption capacity, renewability, safe manipulation, sorption capacity increase through simple physical and chemical methods, easy separation from treated water, and easy regeneration and reuse for repetitive sorption-desorption cycles. Accordingly, this research study has as purpose to present the results related to the usage of two types of alginate sorbents (calcium alginate and chitosan coated calcium alginate) in four repetitive lead(II) ions sorption-desorption cycles and to examine the influence of desorption agents on structural sorbent�s characteristics. The results obtained showed that both calcium alginate and chitosan coated calcium alginate are good stable sorbents to be used in lead(II) ions sorption-desorption cycles.

Pb2 + removal from aqueous synthetic solutions by calcium alginate and chitosan coated calcium alginate

This research study deals with lead(II)/Pb2+ removal from aqueous solutions by calcium alginate (CA) and chitosan coated calcium alginate (CCCA) as adsorbents, in batch experiments. A simple synthesis method was used to prepare both adsorbent materials. CA and CCCA were characterized using infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and thermogravimetric analysis (TG).The main parameters determining the quantity of lead(II) ions adsorbed are: the initial pH solution, the lead(II)ions initial concentration and the temperature. The experiments revealed that the adsorption capacity, thus, the removal efficiency are higher for CCCA compared to CA.The adsorption of lead(II) ions onto both CA and CCCA materials is an endothermic spontaneous process, as resulted from the thermodynamic experiments. Consequently, a moderate increase of temperature improves the adsorption capacity.The thermodynamic equilibrium sorption experimental data are well fitted by Freundlich adsorption isotherm for both tested adsorbents, better than Langmuir's. Accordingly, lead(II) ions adsorption onto CA and CCCA develops obeying a multilayer mechanism.The kinetic experimental data were fitted by both pseudo-first, and pseudo-second order models. The former approaches better the experimental results for both adsorbents.The mechanism involved in lead removal is a combination between ion-exchange and coordination/chelation based on experimental results.

The preparation and properties of three types of microcapsules of sweet orange oil using alginate and chitosan as wall material

ABSTRACTA microcapsule of sweet orange oil was prepared by the gelation of sodium alginate with Ca2+. Orthogonal experiments were designed to investigate the encapsulation efficiency (EE) to be adopted as the target index. The optimum conditions were obtained as follows: sodium alginate concentration 2% (w/v), CaCl2 concentration 1.5% (w/v), ratio of core material to wall material 1.5:1, and emulsifying agents 0.1% (w/v) Tween80 and 0.1% (w/v) glyceryl monostearate. Under these conditions, the highest EE was 76.1%. Chitosan was added to prepare chitosan‐coated calcium alginate (CCCA) and chitosan–calcium alginate complex (CCAC) gel beads. The influence of the addition of chitosan on microcapsule's morphology, EE and release characteristic was the focus of study. For these three types of microcapsules, the results showed that both surface smoothness and EE in descending order were CCAC, CCCA and calcium alginate (CA) gel beads, while the order of release rate was CA, CCCA and CCAC gel beads. These three types of microcapsules could be used in chewing gum, puffed food and other food products to control release and prevent volatilization of flavour because of their different characteristics or properties. Copyright © 2014 John Wiley & Sons, Ltd.

Development and characterization of chitosan coated biopolymer sorbent for the removal of fluoride ion from aqueous solutions

A novel biosorbent, chitosan coated calcium alginate (CCCA), was developed by coating chitosan, a naturally and abundantly available cationic biopolymer, onto an anionic biopolymer calcium alginate for the removal of fluoride ion from aqueous solutions. The results were compared with calcium alginate (CA) beads obtained from natural biopolymer sodium alginate. Further the biosorbents were characterized by FTIR, SEM and TGA techniques and surface area analysis. Defluoridation of water was studied by using the biosorbent under batch equilibrium and column flow experimental conditions. The effect of various process parameters such as pH, contact time, concentration of fluoride and amount of biosorbent was investigated in order to optimize the process. The equilibrium data were used to study the kinetics of defluoridation process such as pseudo first order, pseudo-second order and Weber–Morris intraparticle diffusion models. The data were fitted to Langmuir and Freundlich adsorption isotherms. The column flow...

Studies in the Development of Nateglinide Loaded Calcium Alginate and Chitosan Coated Calcium Alginate Beads

Nateglinide loaded alginate-chitosan beads were prepared by ionic gelation method for controlling the drug release by using various combinations of chitosan and Ca2+ as cation and alginate as anion. IR spectrometry, scanning electron microscopy, differential scanning calorimetry and X-ray powder diffractometry were used to investigate the physicochemical characteristics of the drug in the bead formulations. The calcium content in beads was determined by atomic absorption spectroscopy. The swelling ability of the beads in different media (pH 1.2, 4.5, 6.8) has been found to be dependent on the presence of polyelectrolyte complex of the beads and the pH of the media. The ability to release the Nateglinide was examined as a function of chitosan and calcium chloride content in the gelation medium. It is evident that the rate of drug release and its kinetics could be controlled by changing the chitosan and the calcium chloride concentrations. Calcium alginate beads released more than 95% of drug with in 8 h; whereas coated beads sustained the drug release and released only 75-80% of drug. The drug release mechanism analyzed indicates that the release follows either "anomalous transport" or "case-II transport".

Modified chitosan and calcium alginate biopolymer sorbents for removal of nickel (II) through adsorption

Removal of nickel (II) from aqueous solutions through adsorption on to biopolymer sorbents, such as calcium alginate (CA), chitosan coated calcium alginate (CCCA) and chitosan coated silica (CCS), was studied using equilibrium batch and column flow techniques. The biosorbents were characterized by FTIR, SEM, TGA and surface area analysis. The extent of adsorption was found to be a function of the pH of the solution, contact time, sorbate concentration and adsorbent dose. The optimum pH was found to be 5.0. The adsorption of Ni (II) ions on CA was comparatively higher than CCCA and CCS. Adsorption of Ni (II) on to the biopolymers followed pseudo-second order kinetics. The equilibrium adsorption data for Ni (II) on CA, CCCA and CCS were fitted to Freundlich, and Langmuir Isotherms. The maximum monolayer adsorption capacity of the biosorbents (CA, CCCA and CCS), as obtained from Langmuir adsorption isotherm, was found to be 310.4, 222.2 and 254.3 mg/g, respectively. Breakthrough curves were obtained for adsorption of Ni (II) on all the three adsorbents through column flow technique. The Ni (II) loaded biosorbents were regenerated using 0.1 M EDTA solution.

Characterization of calcium alginate and chitosan-treated calcium alginate gel beads entrapping allyl isothiocyanate

Calcium alginate (CA), chitosan-coated calcium alginate (CCA-I), and chitosan–calcium alginate complex (CCA-II) gel beads, in which an oil-in-water emulsion containing allyl isothiocyanate (AITC) was entrapped, were prepared and characterized for efficient oral delivery of AITC. The AITC entrapment efficiency was 81% for CA gel beads, whereas about 30% lower values were determined for the chitosan-treated gel beads. Swelling studies showed that all the gel beads suddenly shrunk in simulated gastric fluid (pH 1.2). In simulated intestinal fluid (pH 7.4), CA and CCA-I gel beads rapidly disintegrated, whereas CCA-II gel beads highly swelled without degradation probably due to the strong chitosan–alginate complexation. Release studies revealed that most entrapped AITC was released during the shrinkage, degradation, or swelling of the gel beads, and the chitosan treatments, especially the chitosan–alginate complexation, were effective in suppressing the release. CCA-II gel beads showed the highest bead stability and AITC retention under simulated gastrointestinal pH conditions.

A Novel Approach for Testing the Hixon‐Crowel Model For In Vitro Release of Vitamin B2 From Chitosan Coated Calcium Alginate Beads

The dynamic release of a model drug (vitamin B2) from chitosan coated calcium alginate beads has been studied in the media of varying pH and the Hixon‐Crowel model has been applied to the experimental data, using a novel ‘curve area measurement’ (CAM) approach. The two release profiles, namely experimental and ideal, were found to be in close agreement except for the initial phase of the release process.

Sustained release of vascular endothelial growth factor from calcium-induced alginate hydrogels reinforced by heparin and chitosan

A possible alternative for immunosuppression is a microencapsulation technique using hydrogels, which have been utilized for cell immobilization and drug delivery systems. Angiogenesis is crucial for delivery of the metabolic products to the host tissues as well as to supply oxygen and nutrients to cells. The local delivery of angiogenic growth factors, such as VEGF and basic FGF, has been recently studied to enhance angiogenesis on peripheral tissue of graft. In this study, we evaluated sustained VEGF release with a model using hydrogels coated with chitosan and heparin in vitro. We fabricated calcium alginate gels and chitosan-coated calcium alginate gels. Heparinized chitosan-coated calcium-induced alginate hydrogel beads were prepared by soaking chitosan-coated calcium alginate gels in heparin solution. We compared the stability and VEGF release manner between three kinds of hydrogels. To compare the stability, 5 mL of each hydrogel was incubated with 20 mL PBS under the rotational culture. Compression forces were measured using a rheometer. The amount of VEGF released from the gels was measured by ELISA. The heparin-coated chitosan alginate hydrogels showed the highest surface stability among the three hydrogels. VEGF from the heparinized gel was released in sustained manner up to 10 days in vitro. Chitosan-coated alginate gels released 90% of loaded VEGF within 5 days. These results suggest that local delivery of VEGF using a heparinized hydrogel may provide a long-term supply of angiogenic growth factor that might induce new vessel formation in vivo.