Chitosan-coated Alginate Beads Research Articles

Degradation of Chlorothalonil by Catalytic Biomaterials

Chlorothalonil (2,4,5,6-tetrachloro-1,3-benzenedicarbonitrile, TPN, CAS: 1897-45-6) is a halogenated fungicide currently widely applied to a large variety of crops. Its carcinogenicity, embryo lethality, and high chronic oral toxicity in mammals, among other effects on a variety of organisms, has made its biodegradation of great interest. Chlorothalonil dehalogenase (Chd) from the bacterium Pseudomonas sp. CTN-3 offers a potential solution by catalyzing the first step in the degradation of chlorothalonil. Reported herein are active biomaterials of Chd when encapsulated in tetramethylorthosilicate (TMOS) gels using the sol–gel method (Chd/sol), alginate beads (Chd/alginate), and chitosan-coated alginate beads (Chd/chitosan). Both Chd/sol and Chd/chitosan increased protection from the endopeptidase trypsin as well as imparted stability over a pH range from 5 to 9. Chd/sol outperformed Chd/alginate and Chd/chitosan in long-term storage and reuse experiments, retaining similar activity to soluble Chd stored under similar conditions. All three materials showed a level of increased thermostability, with Chd/sol retaining >60% activity up to 70 °C. All materials showed activity in 40% methanol, suggesting the possibility for organic solvents to improve TPN solubility. Overall, Chd/sol offers the best potential for bioremediation of TPN using Chd.

An evaluation of the growth and immunity of New Zealand black-footed abalone (Haliotis iris) treated with encapsulated feed and probiotics

Encapsulation technology has been applied in aquaculture for developing more efficient delivery systems of nutrients and probiotics to various species. This study aims to investigate the effect of an encapsulated probiotics feed on the growth and health of New Zealand black-footed abalone (Haliotis iris). Juvenile abalone were fed with four different dietary treatments, including commercial pellets, commercial feed sprayed with probiotics, combination of commercial feed and chitosan-coated alginate (CCALG) beads containing probiotics and CCALG beads containing both probiotics and nutrients. A multi-technique approach was used to evaluate the growth performance and health parameters of the experimental animals after 57 days in feeding trial. The results showed a significantly higher growth rate (p < 0.05) in shell length (50.06 ± 5.91 µm/day) and weight (25.55 ± 2.55 mg/day) of abalone fed with CCALG beads containing both probiotics and nutrients (optimal diet) compared to the other groups. The feed conversion rate (FCR) for abalone fed with the optimal diet (1.04 ± 0.06) was significantly (p < 0.05) lower than the other experimental diets. Furthermore, a low level of haemocytes with reactive oxygen species (ROS) was found associated with the optimal diet (13.24 ± 4.2%). A total of 31 differently regulated metabolites across the four treatments were revealed with a characteristic enhancement of free amino acids in the samples obtained from abalone fed with the optimal diet. The combined results from the growth parameters, flowcytometry and metabolomics indicate that CCALG beads encapsulating probiotics and nutrients can efficiently improve the growth and immunity of juvenile abalone.

Development and Validation of UV Spectrophotometric Method for Determination of Paracetamol in Chitosan Coated Alginate Beads and Dissolution Studies

Development and Validation of UV Spectrophotometric Method for Determination of Paracetamol in Chitosan Coated Alginate Beads and Dissolution Studies

Chitosan coated alginate beads as probiotic delivery system for New Zealand black footed abalone (Haliotis iris)

AbstractThe potential benefits of probiotics for growth of black‐footed abalone (Haliotis iris) have been highlighted in previous studies. However, traditional methods of probiotic administration in aquaculture are inefficient due to environmental contamination and loss of bacterial viability. This study investigates a new delivery system for delivery of probiotics to H. iris. An extrusion technique coupled with ionotropic gelation was utilized to produce chitosan coated alginate beads (CCALG). Concentration of alginate, chitosan, and coating time were optimized to obtain beads with a desired morphology, stability, sinking time, and release profile. The results showed that increasing alginate concentration up to 1.5% w/w can improve the morphological characteristics of the beads while reducing the sinking time in seawater. Chitosan coating improved the stability of beads and reduced the release of the encapsulated probiotics in seawater. A higher probiotic load was found in the digestive tract of animals fed with CCALG beads ( compared to the control group (. High palatability and stability of CCALG beads in seawater combined with controlled release of viable probiotics show that encapsulation of probiotics in CCALG beads is an efficient method for delivery of probiotics in aquaculture.

QbD enabled Process Variable Study to Develop Sustained Release Chitosan-Alginate Embedded Delivery System for Improved Patient Compliance

The current investigation entail systematic Quality by Design (QbD)-enabled approach for the development of Sustained released embedded drug delivery systems of L-Arginine employing ionic gelation technique to attain improved patient compliance. Hence, in this QbD enabled systematic approach; quality target product profile (QTTP) was defined and critical quality attributes (CQAs) were identified. Further the risk assessment studies were undertaken through Ishikawa fish bone diagram to locate the critical material attributes (CMAs) and/or critical process parameters (CPPs) for the formulation of beads that may affect CQAs of drug product. A face centered central composite design (CCD) for two factors at three levels each with α =1 was employed for the optimization process to checkout the impact of concentration of sodium alginate and concentration of chitosan as CMAs which wereprior identified from risk assessment study and further evaluated for CQAs viz. bead size, swelling index and percent drug entrapment. The optimum formulation was embarked upon by using mathematical model being developed yielding desired CQAs. Thereby chitosan coated calcium-alginate delivery system was successfully developed by strategically employing QbD approach.In a nutshell, the presentinvestigation reports the successful development of optimized chitosan coated alginate beads employing QbD approach which can serve as a platform for other drugs too.

Effects of various polysaccharides (alginate, carrageenan, gums, chitosan) and their combination with prebiotic saccharides (resistant starch, lactosucrose, lactulose) on the encapsulation of probiotic bacteria Lactobacillus casei 01 strain

The probiotics are extremely sensitive to various environmental factors, which imposes limitation on their health and functional effectiveness. Thus, development of delivery system for protection of viable cells while passing through different stages of the human digestion system is key factor in application of probiotic products. In our study, the effects of several polysaccharides such as alginate, κ-carrageenan, locust bean gum, gellan gum, xanthan gum and their combination with various prebiotic components (resistant starch, lactulose, lactosucrose) on encapsulation of probiotic Lactobacillus casei 01 strain were studied. Both regular and unregular beads with size distributions from 2 mm up to 5 mm were obtained. The encapsulation efficiencies varied from 64.4% up to 79%. Based on the texture's profiles, the capsules can be grouped into 5 clusters with squared Euclidean distance 3.5. Meanwhile, the starch-alginate and the lactosucrose LS55L – alginate beads were found to be the most stable and to have massive textural properties, whereas the gellan gum – xanthan gum and the chitosan coated alginate beads emerged as the softest. Encapsulation significantly improved the degree of gastric tolerance of probiotic cells even in the presence of pepsin. The INFOGEST in vitro digestion protocol was adapted to investigate the protection effects of different capsules. The highest survival (with loss rate of lower than 1 log CFU/g) was observed in the case of the cells encapsulated in starch-alginate beads. Moreover, the alginate microcapsules combined with lactosucrose LS55L also provided very promising shield for probiotics from the low pH of gastric conditions. Our findings suggest that incorporation of prebiotics into alginate-base encapsulation would be good idea in development of micro delivery systems that helps the survival of probiotics and their delivery to the target sites of action in human body.

Application of chitosan-based particles for deinking of printed paper and its bioethanol fermentation

The deinking ability of chitosan-based particles in the pretreatment of recycling paper was studied. All these polymers were able to adsorb carbon black as ink pigment. Amount of adsorbents, contact time, solution pH and temperature were optimized to estimate maximum sorption capacity of polymers. The optimum condition of carbon black adsorption was achieved using chitosan-coated Ca-alginate beads at 30 min, 35 °C, pH 6.5 and 220 rpm of agitation speed. The adsorption capacity was more than 80%. Packed-bed reactor filled with chitosan-coated alginate beads was conducted and operated under the optimal conditions. More than 95% of ink was adsorbed onto carriers after 20 h. Saccharification with industrial enzyme preparation of deinked paper pulp was carried out and sugars released were converted into ethanol. The results of alcoholic fermentation confirmed the success of the deinking process. Our results are very promising in the development of pretreatment technology to enhance the efficiency of the utilization of recycling paper.

Taste masking of paracetamol encapsulated in chitosan-coated alginate beads

Taste masking is required for bitter drugs to enhance patient compliance, especially among the paediatric population. Paracetamol, the first line for paediatricians to treat pain and fever, is known for its bitter taste. This study aimed to mask the bitter taste of paracetamol and explore the potential of alginate microencapsulation in palatability improvement. Chitosan-coated paracetamol alginate beads were optimised using electrospray to obtain spherical beads with size below 1.5 mm. The encapsulation efficiency (EE) of the uncoated beads decreased with increased gelation time to reach 5 ± 1.32% at 60 min. Chitosan coating enhanced EE to 50–76% depending on chitosan type and concentration. EE significantly improved to 99.0 ± 1.1% by saturating the gelation bath with paracetamol. In vitro taste masking test and in vivo palatability evaluation using 12 human volunteers demonstrated that dry chitosan-coated paracetamol alginate beads were superior to the wet ones for taste masking, which was similar to the marketed paracetamol suspension and even better in aftertaste evaluation. This indicates that the microencapsulation in alginate with further chitosan coating can compensate for the usage of sweetening and flavouring agents. This helps to formulate paediatric dosage forms with minimal undesired excipients.

Microencapsulation of Lactobacillus plantarum 299v incorporated with oligofructose in chitosan coated-alginate beads and its storage stability in ambarella juice

Microencapsulation of Lactobacillus plantarum 299v incorporated with oligofructose in chitosan coated-alginate beads and its storage stability in ambarella juice

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.

Improving survivability of Lactobacillus plantarum in alginate-chitosan beads reinforced by Na-tripolyphosphate dual cross-linking

In the present study, Lactobacillus plantarum PTCC 1058 was microencapsulated in Alginate-chitosan blended beads based on ionically dual cross-linking by Na-tripolyphosphate (Na-TPP). The homogenous solution of bacteria and alginate was dripped into the gelling bath of calcium chloride. After 30 min hardening, filtrate beads were transferred into the solution of chitosan. Dual cross-linked gel beads were prepared by employing Na-TPP solution to the chitosan coated beads. Morphology, particle size, alginate-chitosan interaction, characterizing the structure of single and dual cross-linked beads were determined by using scanning electron microscopy SEM, FTIR and XRD analysis. FTIR analysis demonstrated fabrication of the Na-tripolyphosphate dual cross-linked microcapsules. X-ray diffractograms revealed less amorphous nature of Ag/Cs/TPP microcapsules compared to Ag/Cs ones. Survivability of probiotics and swelling behavior of microcapsules were also evaluated under simulated gastrointestinal conditions. Based on the results, the highest viability corresponds to the dual cross-linked beads (by only 1.58 ± 0.03 log reduction) compared to single cross-linked alginate (2.26 ± 0.09 log) and chitosan-coated alginate beads (1.78 ± 0.1 log). Thus, the reinforced microcapsules could be suitable for improving the capsule stability in site-specific delivery applications.

Controlled Release of 5-Fluorouracil from Alginate Beads Encapsulated in 3D Printed pH-Responsive Solid Dosage Forms.

Three-dimensional printing is being steadily deployed as manufacturing technology for the development of personalized pharmaceutical dosage forms. In the present study, we developed a hollow pH-responsive 3D printed tablet encapsulating drug loaded non-coated and chitosan-coated alginate beads for the targeted colonic delivery of 5-fluorouracil (5-FU). A mixture of Eudragit® L100-55 and Eudragit® S100 was fabricated by means of hot-melt extrusion (HME) and the produced filaments were printed utilizing a fused deposition modeling (FDM) 3D printer to form the pH-responsive layer of the tablet with the rest comprising of a water-insoluble poly-lactic acid (PLA) layer. The filaments and alginate particles were characterized for their physicochemical properties (thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction), their surface topography was visualized by scanning electron microscopy and the filaments' mechanical properties were assessed by instrumented indentation testing and tensile testing. The optimized filament formulation was 3D printed and the structural integrity of the hollow tablet in increasing pH media (pH 1.2 to pH 7.4) was assessed by means of time-lapsed microfocus computed tomography (μCT). In vitro release studies demonstrated controlled release of 5-FU from the alginate beads encapsulated within the hollow pH-sensitive tablet matrix at pH values corresponding to the colonic environment (pH 7.4). The present study highlights the potential of additive manufacturing in fabricating controlled-release dosage forms rendering them pertinent formulations for further in vivo evaluation.

Influence of prebiotic and coating materials on morphology and survival of a probiotic strain of Lactobacillus casei exposed to simulated gastrointestinal conditions

Inulin type fructans are among the most studied prebiotics that contribute to enhance gastrointestinal system conditions. To improve the survival and stability of probiotic Lactobacillus casei, native inulin, long-chain and short-chain inulin, were separately incorporated into alginate and chitosan coated alginate beads during the microencapsulation of bacteria. Morphology, particle size and viability of different beads were measured before and after exposure to simulated gastro-intestinal condition. Application of inulin, with different chain lengths, did not alter the shape and size of alginate/inulin beads (2.25–2.28 mm) but slightly increased the size of chitosan-coated beads (about 2.9 mm), while the diameter of micro particles containing alginate alone was 2.2 mm. When alginate beads were exposed to the simulated gastric solution, their size was significantly decreased (by about 0.2 mm), while the size of chitosan-coated beads was not affected. Using inulin and chitosan-coating, the survival of co-encapsulated cells in simulated gastro-intestinal condition was improved with only 2.7–2.9 logs reduction for L. casei and long-chain inulin showed the highest survival rate (2.7 log reduction).

Effect of immobilisation materials on viability and fermentation activity of dairy starter culture in whey-based substrate.

The main objectives of the paper were to study influence of immobilisation of dairy starter culture 'Lactoferm ABY 6' on fermentation and probiotic potential of fermented whey-based substrate. Fermentation with free cells takes 1.5 h less than fermentation with encapsulated cells, but samples with encapsulated cells have better characteristics after 28 days of storage. Chitosan coating provides additional protection of cells in bile salt solution (95.86% of viable cells compared to the initial number) and simulated gastric juice (37.8% for pH 2.5) compared to the alginate beads (94.54% in bile salt solution and 36.18% in simulated gastric juice for pH 2.5). Free cells had a drastic reduction in the number of viable cells (83.0% in bile salt solution and no viable cells in simulated gastric juice for pH 2.5). Samples with alginate beads and chitosan-coated alginate beads have significantly (P < 0.05) higher viable cell count than samples with free cells, during 4 h monitoring survival at pH 2.5, pH 3.0 and 0.3% bovine bile solution. These beads can be used to improve survival of probiotic cells in fermented whey-based beverage during storage and consummation, which improves the quality of the product.

Improving the controlled delivery formulations of caffeine in alginate hydrogel beads combined with pectin, carrageenan, chitosan and psyllium

Alginate-based blends consisting of carrageenan, pectin, chitosan or psyllium husk powder were prepared for assessment of the best formulation aimed at encapsulation of caffeine. Alginate-pectin blend exhibited the lowest viscosity and provided the smallest beads. Alginate-psyllium husk blend was characterised with higher viscosity, yielding the largest bead size and the highest caffeine encapsulation efficiency (83.6%). The release kinetics of caffeine indicated that the porosity of alginate hydrogel was not reduced sufficiently to retard the diffusion of caffeine from the beads. Chitosan coated alginate beads provided the most retarded release of caffeine in water. Morphological characteristics of beads encapsulating caffeine were adversely affected by freeze drying. Bitterness intensity of caffeine-containing beads in water was the lowest for alginate-psyllium beads and chitosan coated alginate beads. Higher sodium alginate concentration (3%) for production of hydrogel beads in combination with psyllium or chitosan coating would present the most favourable carrier systems for immobilization of caffeine.

Chitosan reinforced alginate controlled release beads of losartan potassium: design, formulation and in vitro evaluation

The work investigates the development and optimization of chitosan-alginate beads containing Losartan potassium (LP) through ionotropic/external gelation technique using 32 factorial design. The effect of polymer-blend concentrations i.e. chitosan and sodium alginate on the drug encapsulation efficiency (DEE%), and cumulative drug release after 20 h (R20h %) was optimized. The DEE% of all these beads was within the range of 67.12 ± 1.97–89.81 ± 1.52 % with sustained in vitro drug release of 80.98–97.13 % over 20 h. The in vitro drug release from these beads was followed first order kinetic model. The beads were also characterized by FE-SEM, FTIR and XRD analysis. The swelling of chitosan–alginate beads containing LP were influenced by the pH of the test medium. Chitosan coated alginate beads were developed as oral sustained delivery carriers for LP in order to improve patient compliance, to reduce side effects associated with it and also to reduce the dose/dosing frequency in the management of hypertension.

The effect of alginate and chitosan concentrations on some properties of chitosan-coated alginate beads and survivability of encapsulated Lactobacillus rhamnosus in simulated gastrointestinal conditions and during heat processing

In this study, chitosan-coated alginate beads were produced with different concentrations of chitosan and alginate to evaluate the survival of encapsulated Lactobacillus rhamnosus GG during exposure to adverse conditions in gastrointestinal simulated juice and heat processing. The encapsulation yield of different encapsulation treatments was between 25 and 53.2%. Although there was a drastic decrease in pH within 48 h of incubation in MRS medium inoculated with free and encapsulated bacteria, no significant changes (P > 0.05) in bacterial count were observed among different encapsulation treatments. Moreover, the survival rate after gastrointestinal juice exposure of all prepared beads was 10-87 times greater than that of free cells and was significantly enhanced by increasing chitosan and alginate concentrations. The encapsulated bacteria survived significantly (P < 0.05) better than the free cells during heat exposure at 55, 60 and 65 °C: free cells experienced about 5 log cycles reduction after heat treatment at 65 °C for 30 min, whereas 40 g L(-1) alginate/10 g L(-1) chitosan-encapsulated L. rhamnosus was reduced by only 2.55 log cycles. Encapsulation effectively protected L. rhamnosus against heat treatment and gastrointestinal conditions, and this effect is important in delivering sufficient numbers of viable probiotic bacteria to the gastrointestinal tract.

Selenium enriched green tea increase stability of Lactobacillus casei and Lactobacillus plantarum in chitosan coated alginate microcapsules during exposure to simulated gastrointestinal and refrigerated conditions

The effects of selenium enriched green tea (SGT; 85.8–96 mg/kg) in different concentrations of 1 g and 2 g/100 mL, on the in vitro exposure to simulated gastrointestinal juice and refrigerated storage of encapsulated Lactobacillus casei and Lactobacillus plantarum were investigated in chitosan coated alginate beads. The encapsulation yield of viable cells in chitosan coated alginate beads with and without SGT was not significantly different (P < 0.05). These results together with the study about the survival of probiotic bacteria in microspheres with SGT during storage at 4 °C, demonstrated significantly higher number (P < 0.05) of survival bacteria in microcapsules with SGT 2 g/100 mL. Microencapsulated L. casei and L. plantarum with SGT 1 g and 2 g/100 mL were resistant to simulated gastric conditions (pH 2.0, 2 h) and bile solution (3 g/100 mL, 2 h) resulting in significantly (P < 0.05) improved survival when compared with microencapsulation without SGT addition.

Efficiency of double layered microencapsulated probiotic to modulate proinflammatory molecular markers for the management of alcoholic liver disease.

Alcohol-related disorders are one of the challenging current health problems with medical, social, and economic consequences. Endotoxemia, oxidative stress, and release of a variety of inflammatory molecules are established mediators in alcoholic liver injury (ALD). Probiotics like L. plantarum though were reported to attenuate ALD, their in vivo health benefits are limited by their survival and sustenance in the adverse gut conditions. Therefore, to enhance their in vivo performance, chitosan coated alginate beads entrapping L. plantarum were prepared, characterized, and evaluated for their efficacy against ALD in rats. Following chronic alcohol exposure, rats developed endotoxemia, showed enhanced levels of liver enzyme markers, NF-κB levels, and increased cytokines such as TNF-α and IL12/p40 subunit, and reflected significant histological changes in the intestine and liver. However, cosupplementation with double layered microencapsulated probiotic significantly (P < 0.05) reduced the levels of endotoxemia, serum transaminases, NF-κB, and cytokines complemented with restoration of normal histoarchitecture of the intestine and liver. It is being documented here for the first time that the probiotics have the potential to inhibit IL-12/p40 subunit which is a recently explored potential marker for developing novel therapeutic agents. This study reveals that microencapsulation of probiotics may offer a biopharmacological basis for effective management of ALD.

Bioconversion of Glycerol to Dihydroxyacetone by Immobilized Gluconacetobacter Xylinus Cells

In this study, Gluconacetobacter xylinus cells were immobilized in calcium alginate and chitosan-coated alginate beads. The immobilized cells were used in the conversion of glycerol to dihydroxyacetone (DHA) in a stirred-tank reactor. Fermentations using free cells and 2% (w/v) initial glycerol yielded 6.3 gL -1 DHA after 60 h. This corresponded to a productivity of 0.11 gL -1 h -1 . Using 2% (w/v) initial glycerol and 0.3 vvm air flow, G.xylinus cells immobilized in alginate beads gave a DHA concentration of 12.7 gL -1 and a productivity of 0.09 gL -1 h -1 . The final DHA concentration and productivity of G.xylinus cells immobilized in chitosan-coated alginate beads were 11.9 gL -1 and 0.07 gL -1 h -1 , respectively, at 0.3 vvm air flow. Final DHA concentration and productivity further increased to 17.0 gL -1 and 0.11 gL -1 h -1 at 1.0 vvm airflow. Chitosan coating provided greater stability to the alginate beads with increased aeration rate.