Internal Gelation Technique Research Articles

Encapsulation of resveratrol in alginate microcapsules using internal gelation technique: Fabrication, characterization and release kinetics

Resveratrol (RES) is a proven anticancer, antioxidant, anti-inflammatory, and cardioprotective compound. However, low bioavailability, poor water solubility, and sensitivity to UV light and heat limit RES's use in food applications. In this study, we aim to protect RES by encapsulating it in sodium alginate (NaAlg) matrix using internal gelation, followed by drying the moist microencapsulates using spray and freeze-drying techniques. The spray-dried microencapsulates exhibited a smaller mean diameter (5.57 ± 2.40 μm), higher encapsulation efficiency (91.32 ± 1.98%), and higher ζ-potential (−61.9 ± 2.33 mV) compared to freeze-dried microencapsulates. SEM images revealed the smooth and spherical surface of the spray-dried microencapsulates, while the freeze-dried samples exhibited irregular shapes and porous textures. FTIR results showed polyelectrolyte interactions between NaAlg, RES, and CaCO3. XRD and DSC results confirmed the incorporation of RES in the NaAlg matrix. Spray-dried microencapsulates demonstrate the highest RES retention of 80.89 ± 0.70% and 78.59 ± 0.27% after 4 h of UV light and thermal treatments, respectively. In vitro release studies showed that spray-dried microencapsulates demonstrate a delayed gastric release compared to freeze-dried microencapsulates. The release mechanism of RES from the microencapsulates was effectively described by the Shalin-Peppas model.

Dairy wastewater treatment employing microencapsulated Pseudomonas aeruginosa on low acyl gellan gum

This study assessed the ability of Pseudomonas aeruginosa, microencapsulated in gellan gum, to decontaminate dairy wastewater and explored the potential reuse of microcapsules. P. aeruginosa was microencapsulated using the internal ionic gelation technique, employing low-acyl gellan gum as the wall material. The free and microencapsulated P. aeruginosa were inoculated into 150 mL of sterile wastewater and incubated in a shaking flask (150 rpm) at 30°C. Subsequently, the Baranyi Model was employed to calculate the growth parameters of P. aeruginosa. Concurrently, Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) were determined. The obtained results indicated that the microencapsulation process reduced the growth rate of the encapsulated microorganism. However, the microencapsulated bacteria achieved COD and BOD reduction percentages of 61.54% and 64.05%, respectively. Similarly, when reusing the microcapsules, removal percentages exceeding 57.00% were achieved. These findings could have significant implications for the industry in terms of reducing effluent contamination caused by substantial amounts of pollutants. Keywords: dairy wastewater, gellan gum, microencapsulation, Pseudomonas aeruginosa.

Development of Dispersible Vaginal Tablets of Tenofovir Loaded Mucoadhesive Chitosan Microparticles for Anti-HIV Pre-Exposure Prophylaxis.

Tenofovir disoproxil fumarate (TDF)-loaded bioadhesive chitosan microparticles (CM) were developed by an emulsification internal gelation technique. Among different batches produced, ECH-4 was found to display a high % entrapment efficiency (68.93 ± 1.76%) and sustained drug release of 88.05 ± 0.38% at 24 h. Solid state characterization of ECH-4 employing DSC and PXRD indicated that the TDF existed in an amorphous state as a solid-solid solution in chitosan. Scanning electron microscopy revealed CM of ECH-4 was spherical in shape with a rough surface topography. Laser scattering analysis using Malvern Master sizer indicated that particle size of ECH-4 was in the range of 0.52 ± 0.10 μm to 284.79 ± 21.42 μm with a surface-mean diameter of 12.41 ± 0.06 μm. Ex vivo mucoadhesion studies using rabbit mucosa as a substrate indicated that 10.34 ± 2.08% of CM of ECH-4 was retained at the end of 24 h. The microparticles of ECH-4 were incorporated into dispersible tablets (DT-TCM) intended for intravaginal administration, in view to arrest the pre-exposure transmission of HIV during sexual intercourse. In vitro release from the dispersible tablet (F3) into simulated vaginal fluid (pH 4.5) displayed a sustained release profile of TDF as 89.98 ± 1.61% of TDF was released at 24 h. The in vitro dissolution profile of the DT-TCM was found to be similar to that of TDF loaded CM with the values of f1 (difference factor) and f2 (similarity factor) being 1.52 and 78.02, respectively. Therefore, DT-TCM would be a promising novel drug delivery platform for pre-exposure prophylaxis against HIV.

DEVELOPMENT AND CHARACTERIZATION OF GASTRO RETENTIVE MUCOADHESIVE MICROBEADS CONTAINING SIMVASTATIN WITH DIFFERENT CROSS LINKING AGENTS

Objective: The aim of the present work was to prepare and examine drug release of the oral controlled release microbeads using different curing agents by emulsification internal ionic gelation technique.
 Methods: Cross-linked alginate microbeads were prepared with different cross linking agents by using mucoadhesive properties. The formation and compatibility of microbeads were confirmed by compatibility studies. Prepared microbeads evaluated for encapsulated efficiency, micromeritic properties, drug loading, in vitro wash off studies, in vitro dissolution studies, drug release kinetics and stability studies
 Results: The in vitro drug release was influenced by both type of curing agents and type of polymers and no significant changes in characterization parameters was observed after 3 mo stability studies. The sustained release profile of optimized batch was found to be 99.66±0.18% in comparison to pure drug profile of 28.64±0.02% at 12 h release study. Results of both wash-off and in vitro studies suggests that batch (SF2) prepared with aluminium chloride has shown better mucoadhesive property. Drug release of optimized batch follows zero order with non fickian mechanism according to Korsmeyer-Peppas equation.
 Conclusion: The data suggest the use of simvastatin mucoadhesive cross linked microbeads to offer the potential for oral controlled drug delivery with improved gastric retention and capable to provide sustained drug release by using cross linking agents.

Controlled release alginate-chitosan microspheres of tolmetin sodium prepared by internal gelation technique and characterized by response surface modeling

Tolmetin sodium (TS) is a powerful non-steroidal mitigating drug for the treatment of rheumatoid joint inflammation, osteoarthritis, and adolescent rheumatoid joint pain. In addition to its gastrointestinal (GIT) problems, TS has a short biological half-life (1 hr). In a trial to overcome these side effects and control the rate of (TS) release, chitosan coated alginate microspheres are recommended. A Box-Behnken experimental design was employed to produce controlled release microspheres of TS in the sodium alginate and chitosan copolymers (Alg-Ch) by emulsification internal gelation methodology. The effect of critical formulation variables namely, drug to polymer ratio (D:P ratio), speed of rotation and span 80% on drug encapsulation efficiency (% EE), drug release at the end of 2 hours (Rel2) and drug release at the end of 8 hours (Rel8) were analyzed using response surface modeling. The parameters were assessed using the F test and mathematical models containing only the significant terms were generated for each parameter using multiple linear regression analysis. The produced microspheres were spherical in shape with extensive pores at D:P ratio 1:1 and small pores at a drug to polymer ratio (D:P ratio) 1:3. Differential scanning calorimetry (DSC) affirmed the steady character of TS in microspheres and revealed their crystalline form. All formulation variables examined exerted a significant influence on the drug release, whereas the speed emerged as a lone factor significantly influencing % EE. Increasing the D: P ratio decreases the release of the drug after two and 8 hours. The increase in speed results in an increase in drug release after two and eight hours. The drug release from the microspheres followed zero order kinetics. TS Alg-Ch microspheres exhibited a significant anti-inflammatory effect on incited rat paw edema after eight hours. These results revealed that the internal gelation technique is a promising method to control TS release and eradicate GIT side effects using Alg-Ch copolymers.

FABRICATION AND EVALUATION OF ORAL CONTROLLED RELEASE OF MUCOADHESIVE ALGINATE MICROBEADS CONTAINING FLUVASTATIN SODIUM

Objective: The aim of this study is to prepare oral controlled release (CR) of mucoadhesive alginate microbeads encapsulating fluvastatin by gastroretention technology.
 Methods: The mucoadhesive microbeads containing fluvastatin were produced using emulsification internal gelation technique. The effect of different variables such as sodium alginate concentration and its combination with other hydrophilic polymers, and the effect of various curing agents on particle size, entrapment efficiency, and in vitro studies were evaluated.
 Results: There was no marked change in drug entrapment efficiency, and dissolution studies occur during the stability studies of fluvastatin. The in vitro results give data that improvement in the CR of the drug from microbeads compared with marketed tablet. Hence, in this regard, to minimize the frequency of drug administration to reduce side effects. The optimum condition for the preparation of stable alginate beads and produce CR manner was occurred at a higher concentration of combined polymer mixture in equal ratios, i.e., 3% w/v. Infrared spectroscopic study (Fourier transform infrared) confirmed the no incompatibility between drug and other excipients. X-ray diffraction study and differential scanning calorimetry were provided evidence that successful entrapment of drug into the alginates microbeads and drug converted into amorphous nature. The efficiency of mucoadhesion strength of microbeads was determined by wash-off study.
 Conclusion: The kinetic modeling of the release data indicates drug release from the microbeads follow anomalous transport mechanism and super Case-II transport mechanism. Drug release is a function of pH dependent and controlled drug release depends on type and concentration of polymer blend and curing agents. The release kinetics of drug from the alginate beads followed zero order.

Macroporous alginate foams crosslinked with strontium for bone tissue engineering

Nowadays, the need of novel strategies to repair and regenerate bone defects in the field of biomedical applications has increased. Novel approaches include the design of natural bioactive scaffolds mimicking bone tissue. These bioactive scaffolds have to possess biophysical properties suitable to address biological response towards newly bone tissue formation. In particular, scaffold porosity and pore size play a pivotal role in cell migration, adhesion and proliferation, thus increasing cell-material surface interaction and osteogenic signals transmission. Here we propose the development of macroporous alginate foams (MAFs) with porous and well interconnected structure, useful to enhance growth and osteogenic differentiation of human Mesenchymal Stem Cells (hMSCs). Moreover, in this study we report a new method for MAFs fabrication based on the combination of internal gelation technique with gas foaming. Strontium was employed in combination with calcium as cross-linking agent for the alginate chains and as enhancer of the osteogenic differentiation. The influence of strontium ions on the gelation kinetics, physical properties and degradation in physiological medium of MAFs was investigated. Our results suggest that the combination of internal gelation technique with gas foaming followed by freeze-drying is an easy and straightforward procedure to prepare alginate foams with high porosity and interconnectivity, able to support cell infiltration. Finally, biological assays showed how scaffolds with high strontium content are able to support cell growth and differentiation in long times by promoting osteogenic marker expression.

Use of boiled hexamethylenetetramine and urea to increase the porosity of cerium dioxide microspheres formed in the internal gelation process

Cerium dioxide (CeO2) is a commonly used simulant for plutonium dioxide and for plutonium (Pu) in uranium (U) and Pu oxide [(U, Pu)O2] mixtures used in nuclear fuel development. This effort developed CeO2 microspheres with a various porosities and diameters. The internal gelation technique has only been used to produce CeO2 microspheres with limited initial porosity. Previous studies have shown that the crystallite size and porosity of mixed U and thorium oxide microspheres and the (U, Pu)O2 microspheres from the internal gelation process increased when an equal molar solution of hexamethylenetetramine (HMTA) and urea is gently boiled for 1 h prior to its use in the gelation process. In this study with cerium, the combination of ammonium cerium nitrate and 1-h boiled HMTA-urea failed to produce a stable feed broth. However, when the 1-h heated HMTA-urea was combined with unheated HMTA-urea in 1–3 vol ratio or the boiling time of the HMTA-urea was reduced to 15–20 min, a stable solution of HMTA, urea, and Ce was formed at 273 K. This new Ce solution produced very porous CeO2 microspheres, which are suitable simulants for uranium microspheres.

Development of a nutraceutical nano-delivery system through emulsification/internal gelation of alginate.

Alginate nano/microspheres are produced by emulsification/internal gelation of sodium alginate dispersed within vegetable oils containing surfactant, followed by CaCl2 addition resulting in hardened particles. In this work, the impact was evaluated of alginate, CaCl2, oil and surfactant content on the size and encapsulation efficiency of nanocarriers containing peppermint phenolic extract and prepared by a low energy internal gelation technique. The results revealed that size of nanoparticles decreased at higher oil and surfactant contents, higher molarity of CaCl2 and lower alginate concentrations. Also, it was found that the encapsulation efficiency was inversely proportional to the size of nanoparticles, and the impact of alginate concentration and surfactant content was markedly higher than the other two factors. The composition of 0.5% alginate, 400ml oil, 0.05M CaCl2 and 100ml surfactant was recognized as the optimized treatment with a reasonable encapsulation efficiency of 5.6% and a nanoparticle size of 785nm.

SUSTAINABILITY OF THE PROBIOTIC LACTOBACILLUS CASEI IN FORTIFIED INDIAN MILK CAKES UNDER DIFFERENT PRESERVATION CONDITIONS-EFFECTS OF CO-IMMOBILIZATION OF L. CASEI AND COMMERCIAL PREBIOTIC INULIN (CHICORY BASED) AND MILLET INULIN

<p><strong>Objective: </strong>The objective of the present article is to identify the most suitable Indian millet inulin for the growth of probiotic <em>Lactobacillus casei</em> and to evaluate the effects of the fortification vectors (probiotics and probiotic-prebiotic combination in immobilized conditions) and immobilization methods on the sustainability of <em>L. casei</em> in a fortified Indian sweet (milk cake) preserved under different conditions.</p><p><strong>Methods: </strong>Inulin was extracted from pearl, finger and great millets. The concentrations of <em>L. casei</em>, grown on three millet inulins, were compared in 24 h batch culture. The <em>L. casei</em> and probiotic-prebiotic combinations namely <em>L. casei</em>-commercial inulin and <em>L. casei</em>-pearl millet inulin were immobilized using entrapment, external and internal microencapsulation methods. The Indian milk cake samples were fortified with the immobilized probiotic cells, co-immobilized probiotic-prebiotic combinations. The fortified samples were preserved at different conditions (temperature: 4 °C and-20 °C; Time: 1-4 w). The sustainability of <em>L. casei</em> in the preserved samples was determined using spread plate method and the cell concentrations were compared among all fortified samples.</p><p><strong>Results: </strong>Pearl millet inulin is determined to be the most suitable millet inulin for the growth of <em>L. casei</em>. The synergistic combination of <em>L. casei</em>–pearl millet inulin, co-immobilized with internal gelation technique is the best fortification vector for the viability of <em>L. casei</em> in preserved food samples.</p><p><strong>Conclusion: </strong>The <em>L. casei</em>, co-immobilized with pearl millet inulin through internal gelation technique, can be utilized as an effective fortification vector for the sustainability of probiotic cells in preserved Indian milk cakes and similar food samples.</p>

Recovery and recycling of uranium from rejected coated particles for compact high temperature reactors

UO2 microspheres prepared by internal gelation technique were coated with pyrolytic carbon and silicon carbide using CVD technique. The particles which were not meeting the specifications were rejected. The rejected/failed UO2 based coated particles prepared by CVD technique was used for oxidation and recovery and recycling. The oxidation behaviour of sintered UO2 microspheres coated with different layers of carbon and SiC was studied by thermal techniques to develop a method for recycling and recovery of uranium from the failed/rejected coated particles. It was observed that the complete removal of outer carbon from the spheres is difficult. The crushing of microspheres enabled easier accessibility of oxygen and oxidation of carbon and uranium at 800–1000 °C. With the optimized process of multiple crushing using die & plunger and sieving the broken coated layers, we could recycle around fifty percent of the UO2 microspheres which could be directly recoated. The rest of the particles were recycled using a wet recycling method.

Calcium Alginate-Neusilin US2 Nanocomposite Microbeads for Oral Sustained Drug Delivery of Poor Water Soluble Drug Aceclofenac Sodium

The aim of the present study was to formulate and investigate the calcium alginate- (CA-) Neusilin US2 nanocomposite microbeads containing preconcentrate of aceclofenac sodium (ACF-Na) liquid microemulsion (L-ME) for enhancement of oral bioavailability. The preconcentrate L-ME is prepared by using Labrafac PG, Labrasol, and Span 80 as oil, surfactant, and cosurfactant, respectively. The solid CA nanocomposite microbeads of L-ME prepared by microemulsification internal gelation technique using sodium alginate (SA) gelling agent, Neusilin US2 as adsorbent, and calcium chloride as crosslinking agent. L-ME has good thermodynamic stability; globule size was found to be 32.4 nm with polydispersity index 0.219 and −6.32 mV zeta potential. No significant interactions of excipients, drug in the formulations observed by FT-IR, DSC and XPRD. The concentration of SA and Neusilin US2 influences the flow properties, mean particle size, mechanical strength, drug entrapment efficiency, and percentage of drug release. All the formulations show minimum drug release in simulated gastric fluid (SGF) pH 1.2 for initial 2 h, maximum drug release in pH 6.8 phosphate buffer solution (PBS) at 6 h, followed by sustaining in simulated intestinal fluid (SIF) of pH 7.4 up to 12 h. The interaction of SA with Neusilin US2 creates a thick thixotropic gel network structure which acts as barrier to control the release of drug in the alkaline pH environment. Neusilin US2 is a novel filler used to convert L-ME into solid nanocomposite microbeads to enhance dissolution rate of poor water soluble drugs sustaining the drug release for prolonged period of time.

Psychrotrophic Streptomyces spp. cells immobilisation in alginate microspheres produced by emulsification–internal gelation

The objective of the investigations was the optimisation of the parameters for cold-adapted Streptomyces MIUG 4 Alga strain cells immobilisation using emulsification–internal gelation technique in calcium alginate microspheres and testing their ability to produce cold-active β-amylase. By Box–Behnken design and response surface methodology, the effects of independent variables were established, which included sodium alginate concentration (A), sodium alginate:living cell ratio (B) and the Span 80 concentration (C) upon microspheres formation and their functionality. Mean diameter of formed microspheres with immobilised biomass and cold-active β-amylase production were chosen as dependent variables in order to increase the yield of starch hydrolysis. Diameters of microspheres <25.5 μm provided large yield of cold-active β-amylase comparing with microspheres with bigger diameter. A 1.5-fold increase in the substrate hydrolysis yield was achieved using the immobilised biocatalyst compared with the crude enzyme extract, after 96 h of substrate bioconversion.

Microencapsulation of Lactobacillus helveticus and Lactobacillus delbrueckii using alginate and gellan gum

Sodium alginate (SA) at 2% (w/v) and low acylated gellan gum (LAG) at 0.2% (w/v) were used to microencapsulate Lactobacillus helveticus and Lactobacillus delbrueckii spp lactis by employing the internal ionic gelation technique through water–oil emulsions at three different stirring rates: 480, 800 and 1200rpm. The flow behavior of the biopolymer dispersions, the activation energy of the emulsion, the microencapsulation efficiency, the size distribution, the microcapsules morphology and the effect of the stirring rate on the culture viability were analyzed. All of the dispersions exhibited a non-Newtonian shear-thinning flow behavior because the apparent viscosity decreased in value when the shear rate was increased. The activation energy was calculated using the Arrhenius-like equation; the value obtained for the emulsion was 32.59kJ/mol. It was observed that at 400rpm, the microencapsulation efficiency was 92.83%, whereas at 800 and 1200rpm, the stirring rates reduced the efficiency to 15.83% and 4.56%, respectively, evidencing the sensitivity of the microorganisms to the shear rate (13.36 and 20.05s−1). Both optical and scanning electron microscopy (SEM) showed spherical microcapsules with irregular topography due to the presence of holes on its surface. The obtained size distribution range was modified when the stirring rate was increased. At 400rpm, bimodal behavior was observed in the range of 20–420μm; at 800 and 1200rpm, the behavior became unimodal and the range was from 20 to 200μm and 20 to 160μm, respectively.

Microencapsulation of Rutin in Chitosan-Coated Alginate Microspheres through Internal Gelation Technique

The present study is aimed to prepare the chitosan-coated alginate microspheres by an internal gelation technique with rutin as model drug. Recovery of microspheres and microspheres morphology were evaluated by determination of rutin encapsulation efficiency and microscope observation, respectively. The interaction between chitosan and alginate was assessed by differential scanning calorimetry (DSC). The microscope observation showed that the microspheres were homogeneous and the surface was spherical and smooth. The result of DSC indicated that the main force of complex formation was electrostatic interactions between ammonium of chitosan and carboxylate groups of alginate. In vitro release of the chitosan-coated alginate gel beads indicated that it had a satisfactory sustained releasing behavior for the drug within 20 h, and still maintain existed within 180 h. The microspheres which were biodegradable, biocompatible, metal ion adsorbable and persistable in environment may be applied to wastewater treatment.

Protein–Polyanion Interactions for the Controlled Release of Monoclonal Antibodies

The objective of the present study was to investigate ionic interactions between alginate and a monoclonal antibody (mAb1) and to utilize those interactions for the sustained release of mAb1. The existence of ionic interactions between alginate and mAb1 was strongly reflected by their rheological behavior. A 3-4 times increase in storage modulus (G') was observed by addition of 30 mg/mL mAb1 to a 20 mg/mL alginate solution. This increase was strongly dependent on pH and ionic strength. In vitro release studies revealed a marked pH-dependence of release rates and the reversibility of alginate-mAb1 complexation under physiological conditions. Two alginate-mAb1 sustained release formulations were developed by an internal gelation technique using CaCO(3) and CaHPO(4) as calcium sources for physical cross-linking. The CaCO(3) formulation provided a stable pH-environment, optimally suited for pH-sensitive proteins. CaHPO(4) led to a lower pH and stronger alginate-mAb1 interactions. The CaHPO(4) cross-linked alginate released mAb1 over a period of 10-15 days. The long release period and changes in viscoelastic properties of alginate, when being mixed with mAb1, indicate the incorporation of mAb1 molecules into a mixed network with alginate. The results of this study demonstrate that ionic interactions between polyanions and mAb1 are present and that they can be exploited for sustained release delivery of mAb1.

Preparation and characterization of Li2TiO3 pebbles by internal gelation sol–gel process

Lithium titanate, one of the promising candidates for tritium breeding in International Thermonuclear Experimental Reactor (ITER), was prepared in the form of pebbles by internal gelation technique of sol–gel process. High purity and nano-sized Li2TiO3 pebbles were obtained at 500°C. Phase analysis, morphology, microstructure and crushing load strength of the pebbles were determined. The pebbles showed excellent sinterability and could be sintered to 90% TD at 1100°C in 2h. The process developed is short and simple as it combines the conversion and consolidation into a single step. Other attributes of the process include its ability to yield pebbles with desired characteristics for size, shape, density and porosity.

Encapsulation of &lt;i&gt;Bifidobacterium bifidum&lt;/i&gt; in Improved Alginate Microcapsules to Prolonging Viability

Bifidobacterium bifidum were encapsulated as fresh cultures in water insoluble food grade microcapsules by emulsification–internal gelation technique, using gelatin, pectin, alginate and chitose as immobilization material. The optical photomicroscope photograph and laser scanning confocal microscope photograph shows that the microcapsules obtained by this method has narrow size distribution (10-20 μm). Survival of Bifidobacterium bifidum in microcapsules was 109cfu•g-1 , and the embedding ratio was 72.32%. The survival was remaining more than 108cfu•g-1 after exposure to gastric acid and bile acid, which implies that the microcapsules expressed superior acid resistance. These microcaosules were disaggregation subtotal after 15 min in simulated intestinal juices, and the release rate was 96%. The survival was 108 cfu•g-1 at room temperature after 1 year by classic accelerated test. The results indicate that encapsulation of Bifidobacterium bifidum in alginate microcapsules is a good approach to prolonging viability.

Preparation of alginate coated chitosan hydrogel beads by thermosensitive internal gelation technique

Chitosan hydrogel beads were successfully prepared by the method of thermosensitive internal gelation technique. The prepared beads were spherical, smooth-surfaced and non-aggregated with a diameter of 1.7–2.1 mm. The diameters of beads can be controlled and have a correlation with the initial drop size, the concentration of CaCl2, alginate and the time of solidification. The bead is comprised of three parts, which are chitosan/glycerophosphate (CS/GP) hydrogel core, chitosan-alginate (CS/SA) gel layer in the middle and calcium-alginate gelatin capsules in outer layer. Swelling studies indicate that the beads can be stable in simulated gastric fluid. But the beads shrink sharply when removed to simulated intestinal fluid. Drug release behavior showed that release of ornidazole in the beads is much slower than in the CS/GP hydrogel.

Immobilization of Laccase by Alginate–Chitosan Microcapsules and its Use in Dye Decolorization

Laccase is a ligninolytic enzyme that is widespread in white-rot fungi. Alginate–chitosan microcapsules prepared by an emulsification–internal gelation technique were used to immobilize laccase. Parameters of the immobilization process were optimized. Under the optimal immobilization conditions (2% sodium alginate, 2% CaCl2, 0.3% chitosan and 1:8 ratio by volume of enzyme to alginate), the loading efficiency and immobilized yield of immobilized laccase were 88.12% and 46.93%, respectively. Laccase stability was increased after immobilization. Both the free and immobilized laccase alone showed a very low decolorization efficiency when Alizarin Red was selected for dye decolorization test. When 0.1 mM 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) was added into the decolorization system, the decolorization efficiency increased significantly. Immobilized laccase retained 35.73% activity after three reaction cycles. The result demonstrated that immobilized laccase has potential application in dyestuff treatment.