Sodium alginate(SA)/chitosan(CH)polyelectrolyte scaffold is a suitable substrate for tissue-engineering application.The present study deals with further improvement in the tensile strength and biological properties of...Sodium alginate(SA)/chitosan(CH)polyelectrolyte scaffold is a suitable substrate for tissue-engineering application.The present study deals with further improvement in the tensile strength and biological properties of this type of scaffold to make it a potential template for bone-tissue regeneration.We experimented with adding 0%–15%(volume fraction)gelatin(GE),a protein-based biopolymer known to promote cell adhesion,proliferation,and differentiation.The resulting tri-polymer complex was used as bioink to fabricate SA/CH/GEmatrices by three-dimensional(3D)printing.Morphological studies using scanning electron microscopy revealed the microfibrous porous architecture of all the structures,which had a pore size range of 383–419μm.X-ray diffraction and Fourier-transform infrared spectroscopy analyses revealed the amorphous nature of the scaffold and the strong electrostatic interactions among the functional groups of the polymers,thereby forming polyelectrolyte complexes which were found to improve mechanical properties and structural stability.The scaffolds exhibited a desirable degradation rate,controlled swelling,and hydrophilic characteristics which are favorable for bone-tissue engineering.The tensile strength improved from(386±15)to(693±15)kPa due to the increased stiffness of SA/CH scaffolds upon addition of gelatin.The enhanced protein adsorption and in vitro bioactivity(forming an apatite layer)confirmed the ability of the SA/CH/GE scaffold to offer higher cellular adhesion and a bone-like environment to cells during the process of tissue regeneration.In vitro biological evaluation including the MTT assay,confocal microscopy analysis,and alizarin red S assay showed a significant increase in cell attachment,cell viability,and cell proliferation,which further improved biomineralization over the scaffold surface.In addition,SA/CH containing 15%gelatin designated as SA/CH/GE15 showed superior performance to the other fabricated 3D structures,demonstrating its potential for use in bone-tissue engineering.展开更多
The abuse of plastic food packaging has brought about severe white pollution issues around the world.Developing green and sustainable biomass packaging is an effective way to solve this problem.Hence,a chitosan/sodium...The abuse of plastic food packaging has brought about severe white pollution issues around the world.Developing green and sustainable biomass packaging is an effective way to solve this problem.Hence,a chitosan/sodium alginate-based multilayer film is fabricated via a layer-by-layer(LBL)self-assembly method.With the help of superior interaction between the layers,the multilayer film possesses excellent mechanical properties(with a tensile strength of 50 MPa).Besides,the film displays outstanding water retention property(blocking moisture of 97.56%)and ultraviolet blocking property.Anthocyanin is introduced into the film to detect the food quality since it is one natural plant polyphenol that is sensitive to the pH changes ranging from 1 to 13 in food when spoilage occurs.It is noted that the film is also bacteriostatic which is desired for food packaging.This study describes a simple technique for the development of advanced multifunctional and fully biodegradable food packaging film and it is a sustainable alternative to plastic packaging.展开更多
Immobilization biocatalysis is a potential technology to improve the activity and stability of biocatalysts in nonaqueous systems for efficient industrial production.Alginate-chitosan(AC)microcapsules were prepared as...Immobilization biocatalysis is a potential technology to improve the activity and stability of biocatalysts in nonaqueous systems for efficient industrial production.Alginate-chitosan(AC)microcapsules were prepared as immobilization carriers by emulsifi cation-internal gelation and complexation reaction,and their contribution on facilitating the growth and metabolism of yeast cells were testifi ed successfully in culture medium-solvent biphasic systems.The cell growth in AC microcapsules is superior to that in alginate beads,and the cells in both immobilization carriers maintain much higher activity than free cells,which demonstrates AC microcapsules can confer yeast cells the ability to resist the adverse effect of solvent.Moreover,the performance of AC microcapsules in biphasic systems could be improved by adjusting the formation of outer polyelectrolyte complex(PEC)membrane to promote the cell growth and metabolic ability under the balance of resisting solvent toxicity and permitting substrate diffusion.Therefore,these findings are quite valuable for applying AC microcapsules as novel immobilization carriers to realize the biotransformation of value-added products in aqueous-solvent biphasic systems.展开更多
Silver nanoparticles(Ag NPs)are an effective antibacterial agent,but their application in food packaging is limited due to their easy agglomeration and oxidation.In this study,antibacterial microcapsules were fabricat...Silver nanoparticles(Ag NPs)are an effective antibacterial agent,but their application in food packaging is limited due to their easy agglomeration and oxidation.In this study,antibacterial microcapsules were fabricated using Ginkgo biloba essential oil(GBEO)as core material and chitosan and type B gelatin biopolymer as capsule mate-rials.These antibacterial microcapsules were then modified with green-synthesized Ag NPs,blended into the bio-polymer polylactic acid(PLA),and finally formed as films.Physicochemical properties and antibacterial activity against Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)were evaluated.Results showed that the prepared antibacterial PLA films exhibited excellent antibacterial activity against foodborne pathogens.Its TVC exceeded the limit value of 7 log CFU/g at 7 days compared with the 5 days of pure PLA films.Therefore,these films can extend the shelf life of grass carp fillets by 2–3 days under refrigeration.展开更多
Polymethylmethacrylate (PMMA) coated microcapsules of diclofenac sodium (DFS) were prepared by a modified wa-ter-in-oil-in-water (W1/O/W2) emulsion solvent evaporation method using sodium alginate (SAL) as a matrix ma...Polymethylmethacrylate (PMMA) coated microcapsules of diclofenac sodium (DFS) were prepared by a modified wa-ter-in-oil-in-water (W1/O/W2) emulsion solvent evaporation method using sodium alginate (SAL) as a matrix material in the internal aqueous phase (W1).Their performance with respect to controlled release of the drug in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) were evaluated, and compared with non-matrix microcapsules prepared by the conventional W1/O/W2 emulsion solvent evaporation method. Scanning electron micrographs (SEM) revealed that all the microcapsules were discrete and spherical in shape;however, the surface porosity of the matrix microcap-sules appeared to be less than that of the non-matrix microcapsules. In case of non-matrix microcapsules, an increase in the volume of water in W1 phase resulted in decrease in the drug entrapment efficiency (DEE) along with increase in release of the drug in both SGF and SIF. While in case of matrix microcapsules increase in the amount of SAL in W1 phase and concentration of the coating polymer in organic phase led to increase in DEE of the matrix microcapsules and considerable decrease in the drug release in both SGF and SIF. No interaction between the drug and any of the polymers used to prepare microcapsules was evident from Fourier transform infra-red (FTIR) analysis. The matrix microcapsules prepared using higher concentration of SAL and PMMA released the drug following zero order or Case-II transport model. The matrix microcapsules appeared to be suitable for releasing lesser amounts of DFS in SGF and providing extended release in SIF.展开更多
This research aimed to optimize the formation of microcapsules from alginate and chitosan for Leydig cells encapsulation. Alginate was used as the first coating agent while chitosan was the second layer. Various conce...This research aimed to optimize the formation of microcapsules from alginate and chitosan for Leydig cells encapsulation. Alginate was used as the first coating agent while chitosan was the second layer. Various concentrations of alginate and CaCl2 were applied utilizing the extrusion method and the best concentration was determined based on their formation time, shape and diameter of microcapsules. Alginate microcapsule was applied with chitosan in various con- centrations. The best chitosan concentration was selected based on its mechanical stability. The results showed that the minimum concentration of alginate was 1.5% (w/v) with viscosity of 33.8 cPs, resulted to spherical microcapsules with diameters of 230 - 270 μm. The optimum concentration of chitosan as the second coating agent was 0.5% (w/v), resulted to spherical microcapsules with mechanical stability of 4 hours. Leydig cells were trapped inside the microcapsule with a density that is proportional to the concentration of cells used in the encapsulation.展开更多
The extractant tri-n-octylamine （TOA） was encapsulated in calcium alginate （CaALG） xerogel polymer matrices and the selective separation of Au（III） ions in HCI solution was investigated. The features of the TOA ...The extractant tri-n-octylamine （TOA） was encapsulated in calcium alginate （CaALG） xerogel polymer matrices and the selective separation of Au（III） ions in HCI solution was investigated. The features of the TOA microcapsules （TOA-MCs） were examined using DM, SEM/EDS and EPMA. The adsorption and elution properties of Au（III） were studied by the column method using spherical and highly porous TOA-MCs. The uptake properties of precious metals （Au（IIl）, Pt（IV）, and Pd（II）） were examined by the batch method using TOA-MCs in different concentrations of hydrochloric acid （HCI） solution. The order of uptake （%） of the precious metals was Au（III） 〉 Pt（IV） 〉 Pd（II）. TOA-MCs have strong affinity towards Au（III） in HCI solution. The uptake （%） of Au（III） by TOA-MCs was estimated to be -100% and equilibrium was attained within 1 hour. The breakthrough and elution behaviors of Au（III） were examined by varying the Au（III） concentration in the feed, flow rate, reaction temperature, and eluent concentration. The Au（IlI） in 1 M HCI solution was effectively extracted with TOA-MCs in the column operation. The breakthrough curve showed the S-shaped profile and no dislodgement of TOA from the matrices of CaALG. The breakthrough curve rose steeply and the uptake of Au（IIl） was fairly fast, which indicated a relatively high uptake rate of Au（III） in TOA-MCs. The break point （5% breakthrough） and breakthrough capacity （B. T. Capacity） were estimated to be 82 cm3 and 0.60 mmol/g, respectively. The total capacity （T. capacity） was estimated to be 1.30 mmol/g, which was considerably larger than those of conventional resins. The elution properties of Au（Ill） were studied by varying the concentration of thiourea （0.025 M-1 M） in 1 M HC1 solution. The retention volume （VR, cm3） tended to decrease with the increase in thiourea （TU） concentration. The loaded Au（III） ions were successfully eluted （- 100%, total elution percentage） by the eluent of TU （0.5 M） in HC1 （1 M） solution. The alginate gel microcapsules enclosing TOA extractant were thus effective for the selective separation and recovery of Au（IIl） ions in HCI solution.展开更多
Introduction: Improved drug delivery mechanisms for the treatment of residual peritoneal cancer cells following cytoreduction surgery are needed. Alginate microcapsules are a potentially useful mechanism for delivery ...Introduction: Improved drug delivery mechanisms for the treatment of residual peritoneal cancer cells following cytoreduction surgery are needed. Alginate microcapsules are a potentially useful mechanism for delivery of bioengineered cells, but when injected into the peritoneum, their distribution and properties are not well described. Methods: Aliquots of 300, 600 or 1200 microcapsules were injected into the peritoneum of 81 mice. Mice were sacrificed at 6, 12, 18, and 48 days and laparotomy was performed to quantify the distribution of microspheres. Results: The injections were well tolerated for up to 48 days. No peritoneal adherence or inflammatory reaction was noted to the microcapsules. Injection of 1200 microcapsules resulted in a better overall persistence and widespread peritoneal distribution at up to 48 days. The volume of fluid used for injection of the microcapsules did not affect their distribution or persistence. Conclusion: The intraperitoneal injection of alginate microspheres allows wide and persistent distribution throughout the abdominal cavity. The next step is to test the distribution of microcapsules when delivered following surgery in a rodent model.展开更多
Spinal cord injury results in the loss of motor and sensory pathways and spontaneous regeneration of adult mammalian spinal cord neurons is limited. Chitosan and sodium alginate have good biocompatibility, biodegradab...Spinal cord injury results in the loss of motor and sensory pathways and spontaneous regeneration of adult mammalian spinal cord neurons is limited. Chitosan and sodium alginate have good biocompatibility, biodegradability, and are suitable to assist the recovery of damaged tissues, such as skin, bone and nerve. Chitosan scaffolds, sodium alginate scaffolds and chitosan-sodium alginate scaffolds were separately transplanted into rats with spinal cord hemisection. Basso-Beattie-Bresnahan locomotor rating scale scores and electrophysiological results showed that chitosan scaffolds promoted recovery of locomotor capacity and nerve transduction of the experimental rats.Sixty days after surgery, chitosan scaffolds retained the original shape of the spinal cord. Compared with sodium alginate scaffolds- and chitosan-sodium alginate scaffolds-transplanted rats, more neurofilament-H-immunoreactive cells （regenerating nerve fibers） and less glial fibrillary acidic protein-immunoreactive cells （astrocytic scar tissue） were observed at the injury site of experimental rats in chitosan scaffold-transplanted rats. Due to the fast degradation rate of sodium alginate, sodium alginate scaffolds and composite material scaffolds did not have a supporting and bridging effect on the damaged tissue. Above all, compared with sodium alginate and composite material scaffolds, chitosan had better biocompatibility, could promote the regeneration of nerve fibers and prevent the formation of scar tissue,and as such, is more suitable to help the repair of spinal cord injury.展开更多
For efficient mucosal vaccine delivery, nanoparticulate antigens are better taken by microfold cells in the nasal associated lymphoid tissue and also dendritic cells. Nanoparticles based on polymers such as chitosan(C...For efficient mucosal vaccine delivery, nanoparticulate antigens are better taken by microfold cells in the nasal associated lymphoid tissue and also dendritic cells. Nanoparticles based on polymers such as chitosan(CHT) and its water soluble derivative, trimethylchitosan(TMC), could be successfully used as carrier/adjuvant for this purpose. Sodium alginate, a negatively charged biopolymer, could modify the immunostimulatory properties of CHT and TMC NPs and increase their stability. Sodium alginate(ALG)-coated chitosan(CHT)and trimethylchitosan(TMC) nanoparticles(NPs) loaded with inactivated PR8 influenza virus were successfully prepared by direct coating of the virus with CHT or TMC polymers to evaluate their immunoadjuvant potential after nasal immunization. After nasal immunizations in BALB/c mice, PR8-CHT formulation elicited higher IgG2 a and Ig G1 antibody titers compared with PR8-TMC. ALG coating of this formulation(PR8-CHT-ALG) significantly decreased the antibody titers and a less immune response was induced than PR8-TMC-ALG formulation. PR8-TMC-ALG formulation showed significantly higher Ig G2 a/Ig G1 ratio, as criteria for Th1-type immune response, compared with PR8-CHT-ALG and PR8 virus alone. Altogether, the PR8-TMC-ALG formulation could be considered as an efficient intranasal antigen delivery system for nasal vaccines.展开更多
A novel poly-/-arginine microcapsule was prepared due to its nutritional function and pharmacological efficacy. A high-voltage electrostatic droplet generator was used to make uniform microcapsules. The results show t...A novel poly-/-arginine microcapsule was prepared due to its nutritional function and pharmacological efficacy. A high-voltage electrostatic droplet generator was used to make uniform microcapsules. The results show that the membrane strength and permeating property are both remarkably affected with the changes of sodium alginate concentration. With the sodium alginate concentration increasing, gel beads sizes increase from 233μm to 350μm, release ratio is also higher at the same time, but the membrane strength decreases.展开更多
The resaerch examined the effect of the two oceanic materials as coating materials on the soybean growth.The results showed chitosan and sodium alginate seed coating can enhance the growth of seedling root,increase th...The resaerch examined the effect of the two oceanic materials as coating materials on the soybean growth.The results showed chitosan and sodium alginate seed coating can enhance the growth of seedling root,increase the nodule mumber,root activity and the growth of underground.The suggested coating ratios were 0.5～1.0g/kgseed,the same as chitosan.The two materials could increase the contents of CAT and NR in soybean leaves,decrease the contents of POD in soybean leaves.展开更多
Objective:To formulate and evaluate Albendazole microcapsules using chitosan,a natural polymer for colon-specific delivery for better treatment of helminthiasis,filariasis,colorectal cancer,avoiding the side effects.M...Objective:To formulate and evaluate Albendazole microcapsules using chitosan,a natural polymer for colon-specific delivery for better treatment of helminthiasis,filariasis,colorectal cancer,avoiding the side effects.Methods:The Albendazole microcapsules were prepared by the use of different concentrations of sodium alginate,chitosan and hydroxypropyl methylcellulose(HPMC).The polysaccharides chitosan reacted with sodium alginate in the presence of calcium chloride to form microcapsules with a polyelectrolyte complex membrane by electrostatic interactions between the two oppositely charged polymers.The microcapsules were then studied for entrapment efficiency,drug-polymer compatibility and surface morphology. In vitro drug release study in presence and absence of cecal content were also studied.Further, kinetic modellings were employed to find out release mechanisms.Results:Albendazole loaded microspheres showd high entrapment efficiency(72.8%) and the microcapsules were free flowing,non aggregated and spherical,between 600 and 1 000μm in diameter.The surface of microcapsules were found to be porous and wavy.The FT-IR spectrum showed that there is no interaction between the polymer and the drug.The in vitro drug release study found to be affected by change in chitosan,sodium alginate and HPMC concentration.The microcapsules with 2.5% sodium alginate and 0.4% chitosan shown minimum release in gastrointestinal simulated condition but shows maximum drug release at the end of 24th hour in presence of cecal content.The rate of drug release follows Korsmeyer-peppas model that was the drug release is by diffusion and erosion.Conclusions:The study reveals that Albendazole loaded chitosanalginate based microsphere can be used effectively for the colon targeting.展开更多
The objective of this study is to investigate the feasibility of using chitosanesodium alginate(CSeSA)based matrix tablets for extended-release of highly water-soluble drugs by changing formulation variables.Using tri...The objective of this study is to investigate the feasibility of using chitosanesodium alginate(CSeSA)based matrix tablets for extended-release of highly water-soluble drugs by changing formulation variables.Using trimetazidine hydrochloride(TH)as a water-soluble model drug,influence of dissolution medium,the amount of CSeSA,the CS:SA ratio,the type of SA,the type and amount of diluents,on in vitro drug release from CSeSA based matrix tablets were studied.Drug release kinetics and release mechanisms were elucidated.In vitro release experiments were conducted in simulated gastric fluid(SGF)followed by simulated intestinal fluid(SIF).Drug release rate decreased with the increase of CSeSA amount.CS:SA ratio had only slight effect on drug release and no influence of SA type on drug release was found.On the other hand,a large amount of water-soluble diluents could modify drug release profiles.It was found that drug release kinetics showed the best fit to Higuchi equation with Fickian diffusion as the main release mechanism.In conclusion,this study demonstrated that it is possible to design extended-release tablets of watersoluble drugs using CSeSA as the matrix by optimizing formulation components,and provide better understanding about drug release from CSeSA matrix tablets.展开更多
Seed coating can make soybean seedling grow more strongly and reinforce the resistance of soybean plant.Sodium alginate and chitosan are highˉmolecular compound of two different kind,have the characteristic of promot...Seed coating can make soybean seedling grow more strongly and reinforce the resistance of soybean plant.Sodium alginate and chitosan are highˉmolecular compound of two different kind,have the characteristic of promoting the crop growth.Using Sodium alginate and chitosan as coating materials under different concentration can improve the growth and photosynthesis obviously and can decrease pollution because of their characteristics.The analysis show that the effects of Sodium Alginate on soybean plant are better than chitosan and the best concentration is 0.50 g·kg -1 .展开更多
The aim of this study was to evaluate the effect of coating of alginate-chitosan (AL:CS) beads on the colonic drug delivery. The AL:CS systems containing triamcinolone (TC) were coated with the HPMCP and Eudragit? L10...The aim of this study was to evaluate the effect of coating of alginate-chitosan (AL:CS) beads on the colonic drug delivery. The AL:CS systems containing triamcinolone (TC) were coated with the HPMCP and Eudragit? L100 by immersion and by spraying methods. The drug release profile in simulated colonic medium was determined using 5% human fecal content suspension in 0.01 N buffer solution, pH 6.8. The systems coated with HPMCP showed a lower rate of drug delivery in simulated enteric medium. The delivery profile in simulated colonic medium followed zero-order kinetic. The coated systems provided a promising drug-delivery profile for application in colonic drug delivery.展开更多
Yerba mate (Ilex paraguariensis) contains a high amount of polyphenols associated with antiradical activity and possible benefits for preventing degenerative diseases. Natural extracts from this South American herb we...Yerba mate (Ilex paraguariensis) contains a high amount of polyphenols associated with antiradical activity and possible benefits for preventing degenerative diseases. Natural extracts from this South American herb were encapsulated in calcium alginate and calcium alginate-chitosan beads to be incorporated as an additive in food products. The interactions between the active compound and the polymers were evaluated by Scanning Electron Microscopy (SEM), thermal analysis (Thermo Gravimetric Assays, TGA, and Differential Scanning Calorimetry, DSC) and Fourier Transform Infrared Spectrometry (FT-IR) studies. Also, the effect of these interactions on extract release in a gastrointestinal model system was evaluated. Results showed the interactions between the calcium alginate matrix and the chitosan external layer. Also, interactions between the natural extract and each polymer were observed. In both encapsulation systems the highest polyphenol content was released in simulated gastric fluid. However, capsules coated with chitosan allowed releasing a higher amount of polyphenols into the simulated intestinal fluid. This fact was attributed to both the protection of the chitosan barrier and the strong interaction between yerba mate extract and chitosan.展开更多
基金The authors are thankful to Ministry of Human Resource Development(presently Ministry of Education),Government of India,New Delhi,for providing research facility by sanctioning Center of Excellence(F.No.5-6/2013-TS VII)in Tissue Engineering and Center of Excellence in Orthopedic Tissue Engineering and Rehabilitation funded by World Bank under TEQIP-II.
文摘Sodium alginate(SA)/chitosan(CH)polyelectrolyte scaffold is a suitable substrate for tissue-engineering application.The present study deals with further improvement in the tensile strength and biological properties of this type of scaffold to make it a potential template for bone-tissue regeneration.We experimented with adding 0%–15%(volume fraction)gelatin(GE),a protein-based biopolymer known to promote cell adhesion,proliferation,and differentiation.The resulting tri-polymer complex was used as bioink to fabricate SA/CH/GEmatrices by three-dimensional(3D)printing.Morphological studies using scanning electron microscopy revealed the microfibrous porous architecture of all the structures,which had a pore size range of 383–419μm.X-ray diffraction and Fourier-transform infrared spectroscopy analyses revealed the amorphous nature of the scaffold and the strong electrostatic interactions among the functional groups of the polymers,thereby forming polyelectrolyte complexes which were found to improve mechanical properties and structural stability.The scaffolds exhibited a desirable degradation rate,controlled swelling,and hydrophilic characteristics which are favorable for bone-tissue engineering.The tensile strength improved from(386±15)to(693±15)kPa due to the increased stiffness of SA/CH scaffolds upon addition of gelatin.The enhanced protein adsorption and in vitro bioactivity(forming an apatite layer)confirmed the ability of the SA/CH/GE scaffold to offer higher cellular adhesion and a bone-like environment to cells during the process of tissue regeneration.In vitro biological evaluation including the MTT assay,confocal microscopy analysis,and alizarin red S assay showed a significant increase in cell attachment,cell viability,and cell proliferation,which further improved biomineralization over the scaffold surface.In addition,SA/CH containing 15%gelatin designated as SA/CH/GE15 showed superior performance to the other fabricated 3D structures,demonstrating its potential for use in bone-tissue engineering.
基金National Undergraduate Training Program for Innovation and Entrepreneurship of China (Grant No.202210288027).
文摘The abuse of plastic food packaging has brought about severe white pollution issues around the world.Developing green and sustainable biomass packaging is an effective way to solve this problem.Hence,a chitosan/sodium alginate-based multilayer film is fabricated via a layer-by-layer(LBL)self-assembly method.With the help of superior interaction between the layers,the multilayer film possesses excellent mechanical properties(with a tensile strength of 50 MPa).Besides,the film displays outstanding water retention property(blocking moisture of 97.56%)and ultraviolet blocking property.Anthocyanin is introduced into the film to detect the food quality since it is one natural plant polyphenol that is sensitive to the pH changes ranging from 1 to 13 in food when spoilage occurs.It is noted that the film is also bacteriostatic which is desired for food packaging.This study describes a simple technique for the development of advanced multifunctional and fully biodegradable food packaging film and it is a sustainable alternative to plastic packaging.
基金Supported by the National Natural Science Foundation of China(No.21276033)the Open Foundation of the State Key Laboratory of Bioactive Seaweed Substances(Nos.SKL-BASS1707,SKL-BASS1711)the Liaoning Provincial BaiQianWan Talents Program(No.2017-6)
文摘Immobilization biocatalysis is a potential technology to improve the activity and stability of biocatalysts in nonaqueous systems for efficient industrial production.Alginate-chitosan(AC)microcapsules were prepared as immobilization carriers by emulsifi cation-internal gelation and complexation reaction,and their contribution on facilitating the growth and metabolism of yeast cells were testifi ed successfully in culture medium-solvent biphasic systems.The cell growth in AC microcapsules is superior to that in alginate beads,and the cells in both immobilization carriers maintain much higher activity than free cells,which demonstrates AC microcapsules can confer yeast cells the ability to resist the adverse effect of solvent.Moreover,the performance of AC microcapsules in biphasic systems could be improved by adjusting the formation of outer polyelectrolyte complex(PEC)membrane to promote the cell growth and metabolic ability under the balance of resisting solvent toxicity and permitting substrate diffusion.Therefore,these findings are quite valuable for applying AC microcapsules as novel immobilization carriers to realize the biotransformation of value-added products in aqueous-solvent biphasic systems.
基金supported by the National Key R&D Program of China(Grant No.2020YFD0900905).
文摘Silver nanoparticles(Ag NPs)are an effective antibacterial agent,but their application in food packaging is limited due to their easy agglomeration and oxidation.In this study,antibacterial microcapsules were fabricated using Ginkgo biloba essential oil(GBEO)as core material and chitosan and type B gelatin biopolymer as capsule mate-rials.These antibacterial microcapsules were then modified with green-synthesized Ag NPs,blended into the bio-polymer polylactic acid(PLA),and finally formed as films.Physicochemical properties and antibacterial activity against Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)were evaluated.Results showed that the prepared antibacterial PLA films exhibited excellent antibacterial activity against foodborne pathogens.Its TVC exceeded the limit value of 7 log CFU/g at 7 days compared with the 5 days of pure PLA films.Therefore,these films can extend the shelf life of grass carp fillets by 2–3 days under refrigeration.
文摘Polymethylmethacrylate (PMMA) coated microcapsules of diclofenac sodium (DFS) were prepared by a modified wa-ter-in-oil-in-water (W1/O/W2) emulsion solvent evaporation method using sodium alginate (SAL) as a matrix material in the internal aqueous phase (W1).Their performance with respect to controlled release of the drug in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) were evaluated, and compared with non-matrix microcapsules prepared by the conventional W1/O/W2 emulsion solvent evaporation method. Scanning electron micrographs (SEM) revealed that all the microcapsules were discrete and spherical in shape;however, the surface porosity of the matrix microcap-sules appeared to be less than that of the non-matrix microcapsules. In case of non-matrix microcapsules, an increase in the volume of water in W1 phase resulted in decrease in the drug entrapment efficiency (DEE) along with increase in release of the drug in both SGF and SIF. While in case of matrix microcapsules increase in the amount of SAL in W1 phase and concentration of the coating polymer in organic phase led to increase in DEE of the matrix microcapsules and considerable decrease in the drug release in both SGF and SIF. No interaction between the drug and any of the polymers used to prepare microcapsules was evident from Fourier transform infra-red (FTIR) analysis. The matrix microcapsules prepared using higher concentration of SAL and PMMA released the drug following zero order or Case-II transport model. The matrix microcapsules appeared to be suitable for releasing lesser amounts of DFS in SGF and providing extended release in SIF.
文摘This research aimed to optimize the formation of microcapsules from alginate and chitosan for Leydig cells encapsulation. Alginate was used as the first coating agent while chitosan was the second layer. Various concentrations of alginate and CaCl2 were applied utilizing the extrusion method and the best concentration was determined based on their formation time, shape and diameter of microcapsules. Alginate microcapsule was applied with chitosan in various con- centrations. The best chitosan concentration was selected based on its mechanical stability. The results showed that the minimum concentration of alginate was 1.5% (w/v) with viscosity of 33.8 cPs, resulted to spherical microcapsules with diameters of 230 - 270 μm. The optimum concentration of chitosan as the second coating agent was 0.5% (w/v), resulted to spherical microcapsules with mechanical stability of 4 hours. Leydig cells were trapped inside the microcapsule with a density that is proportional to the concentration of cells used in the encapsulation.
文摘The extractant tri-n-octylamine （TOA） was encapsulated in calcium alginate （CaALG） xerogel polymer matrices and the selective separation of Au（III） ions in HCI solution was investigated. The features of the TOA microcapsules （TOA-MCs） were examined using DM, SEM/EDS and EPMA. The adsorption and elution properties of Au（III） were studied by the column method using spherical and highly porous TOA-MCs. The uptake properties of precious metals （Au（IIl）, Pt（IV）, and Pd（II）） were examined by the batch method using TOA-MCs in different concentrations of hydrochloric acid （HCI） solution. The order of uptake （%） of the precious metals was Au（III） 〉 Pt（IV） 〉 Pd（II）. TOA-MCs have strong affinity towards Au（III） in HCI solution. The uptake （%） of Au（III） by TOA-MCs was estimated to be -100% and equilibrium was attained within 1 hour. The breakthrough and elution behaviors of Au（III） were examined by varying the Au（III） concentration in the feed, flow rate, reaction temperature, and eluent concentration. The Au（IlI） in 1 M HCI solution was effectively extracted with TOA-MCs in the column operation. The breakthrough curve showed the S-shaped profile and no dislodgement of TOA from the matrices of CaALG. The breakthrough curve rose steeply and the uptake of Au（IIl） was fairly fast, which indicated a relatively high uptake rate of Au（III） in TOA-MCs. The break point （5% breakthrough） and breakthrough capacity （B. T. Capacity） were estimated to be 82 cm3 and 0.60 mmol/g, respectively. The total capacity （T. capacity） was estimated to be 1.30 mmol/g, which was considerably larger than those of conventional resins. The elution properties of Au（Ill） were studied by varying the concentration of thiourea （0.025 M-1 M） in 1 M HC1 solution. The retention volume （VR, cm3） tended to decrease with the increase in thiourea （TU） concentration. The loaded Au（III） ions were successfully eluted （- 100%, total elution percentage） by the eluent of TU （0.5 M） in HC1 （1 M） solution. The alginate gel microcapsules enclosing TOA extractant were thus effective for the selective separation and recovery of Au（IIl） ions in HCI solution.
文摘Introduction: Improved drug delivery mechanisms for the treatment of residual peritoneal cancer cells following cytoreduction surgery are needed. Alginate microcapsules are a potentially useful mechanism for delivery of bioengineered cells, but when injected into the peritoneum, their distribution and properties are not well described. Methods: Aliquots of 300, 600 or 1200 microcapsules were injected into the peritoneum of 81 mice. Mice were sacrificed at 6, 12, 18, and 48 days and laparotomy was performed to quantify the distribution of microspheres. Results: The injections were well tolerated for up to 48 days. No peritoneal adherence or inflammatory reaction was noted to the microcapsules. Injection of 1200 microcapsules resulted in a better overall persistence and widespread peritoneal distribution at up to 48 days. The volume of fluid used for injection of the microcapsules did not affect their distribution or persistence. Conclusion: The intraperitoneal injection of alginate microspheres allows wide and persistent distribution throughout the abdominal cavity. The next step is to test the distribution of microcapsules when delivered following surgery in a rodent model.
基金supported by the National Natural Science Foundation of China,No.81671243 and 81373429
文摘Spinal cord injury results in the loss of motor and sensory pathways and spontaneous regeneration of adult mammalian spinal cord neurons is limited. Chitosan and sodium alginate have good biocompatibility, biodegradability, and are suitable to assist the recovery of damaged tissues, such as skin, bone and nerve. Chitosan scaffolds, sodium alginate scaffolds and chitosan-sodium alginate scaffolds were separately transplanted into rats with spinal cord hemisection. Basso-Beattie-Bresnahan locomotor rating scale scores and electrophysiological results showed that chitosan scaffolds promoted recovery of locomotor capacity and nerve transduction of the experimental rats.Sixty days after surgery, chitosan scaffolds retained the original shape of the spinal cord. Compared with sodium alginate scaffolds- and chitosan-sodium alginate scaffolds-transplanted rats, more neurofilament-H-immunoreactive cells （regenerating nerve fibers） and less glial fibrillary acidic protein-immunoreactive cells （astrocytic scar tissue） were observed at the injury site of experimental rats in chitosan scaffold-transplanted rats. Due to the fast degradation rate of sodium alginate, sodium alginate scaffolds and composite material scaffolds did not have a supporting and bridging effect on the damaged tissue. Above all, compared with sodium alginate and composite material scaffolds, chitosan had better biocompatibility, could promote the regeneration of nerve fibers and prevent the formation of scar tissue,and as such, is more suitable to help the repair of spinal cord injury.
基金part of Amir-Hossein Sabbaghi Pharm.D.thesis(Grant number:911042)supported by Vice Chancellor for Research,Mashhad University of Medical Sciences
文摘For efficient mucosal vaccine delivery, nanoparticulate antigens are better taken by microfold cells in the nasal associated lymphoid tissue and also dendritic cells. Nanoparticles based on polymers such as chitosan(CHT) and its water soluble derivative, trimethylchitosan(TMC), could be successfully used as carrier/adjuvant for this purpose. Sodium alginate, a negatively charged biopolymer, could modify the immunostimulatory properties of CHT and TMC NPs and increase their stability. Sodium alginate(ALG)-coated chitosan(CHT)and trimethylchitosan(TMC) nanoparticles(NPs) loaded with inactivated PR8 influenza virus were successfully prepared by direct coating of the virus with CHT or TMC polymers to evaluate their immunoadjuvant potential after nasal immunization. After nasal immunizations in BALB/c mice, PR8-CHT formulation elicited higher IgG2 a and Ig G1 antibody titers compared with PR8-TMC. ALG coating of this formulation(PR8-CHT-ALG) significantly decreased the antibody titers and a less immune response was induced than PR8-TMC-ALG formulation. PR8-TMC-ALG formulation showed significantly higher Ig G2 a/Ig G1 ratio, as criteria for Th1-type immune response, compared with PR8-CHT-ALG and PR8 virus alone. Altogether, the PR8-TMC-ALG formulation could be considered as an efficient intranasal antigen delivery system for nasal vaccines.
文摘A novel poly-/-arginine microcapsule was prepared due to its nutritional function and pharmacological efficacy. A high-voltage electrostatic droplet generator was used to make uniform microcapsules. The results show that the membrane strength and permeating property are both remarkably affected with the changes of sodium alginate concentration. With the sodium alginate concentration increasing, gel beads sizes increase from 233μm to 350μm, release ratio is also higher at the same time, but the membrane strength decreases.
文摘The resaerch examined the effect of the two oceanic materials as coating materials on the soybean growth.The results showed chitosan and sodium alginate seed coating can enhance the growth of seedling root,increase the nodule mumber,root activity and the growth of underground.The suggested coating ratios were 0.5～1.0g/kgseed,the same as chitosan.The two materials could increase the contents of CAT and NR in soybean leaves,decrease the contents of POD in soybean leaves.
文摘Objective:To formulate and evaluate Albendazole microcapsules using chitosan,a natural polymer for colon-specific delivery for better treatment of helminthiasis,filariasis,colorectal cancer,avoiding the side effects.Methods:The Albendazole microcapsules were prepared by the use of different concentrations of sodium alginate,chitosan and hydroxypropyl methylcellulose(HPMC).The polysaccharides chitosan reacted with sodium alginate in the presence of calcium chloride to form microcapsules with a polyelectrolyte complex membrane by electrostatic interactions between the two oppositely charged polymers.The microcapsules were then studied for entrapment efficiency,drug-polymer compatibility and surface morphology. In vitro drug release study in presence and absence of cecal content were also studied.Further, kinetic modellings were employed to find out release mechanisms.Results:Albendazole loaded microspheres showd high entrapment efficiency(72.8%) and the microcapsules were free flowing,non aggregated and spherical,between 600 and 1 000μm in diameter.The surface of microcapsules were found to be porous and wavy.The FT-IR spectrum showed that there is no interaction between the polymer and the drug.The in vitro drug release study found to be affected by change in chitosan,sodium alginate and HPMC concentration.The microcapsules with 2.5% sodium alginate and 0.4% chitosan shown minimum release in gastrointestinal simulated condition but shows maximum drug release at the end of 24th hour in presence of cecal content.The rate of drug release follows Korsmeyer-peppas model that was the drug release is by diffusion and erosion.Conclusions:The study reveals that Albendazole loaded chitosanalginate based microsphere can be used effectively for the colon targeting.
基金supported by Liaoning Institutions excellent talents support plan(No.LR2013047).
文摘The objective of this study is to investigate the feasibility of using chitosanesodium alginate(CSeSA)based matrix tablets for extended-release of highly water-soluble drugs by changing formulation variables.Using trimetazidine hydrochloride(TH)as a water-soluble model drug,influence of dissolution medium,the amount of CSeSA,the CS:SA ratio,the type of SA,the type and amount of diluents,on in vitro drug release from CSeSA based matrix tablets were studied.Drug release kinetics and release mechanisms were elucidated.In vitro release experiments were conducted in simulated gastric fluid(SGF)followed by simulated intestinal fluid(SIF).Drug release rate decreased with the increase of CSeSA amount.CS:SA ratio had only slight effect on drug release and no influence of SA type on drug release was found.On the other hand,a large amount of water-soluble diluents could modify drug release profiles.It was found that drug release kinetics showed the best fit to Higuchi equation with Fickian diffusion as the main release mechanism.In conclusion,this study demonstrated that it is possible to design extended-release tablets of watersoluble drugs using CSeSA as the matrix by optimizing formulation components,and provide better understanding about drug release from CSeSA matrix tablets.
文摘Seed coating can make soybean seedling grow more strongly and reinforce the resistance of soybean plant.Sodium alginate and chitosan are highˉmolecular compound of two different kind,have the characteristic of promoting the crop growth.Using Sodium alginate and chitosan as coating materials under different concentration can improve the growth and photosynthesis obviously and can decrease pollution because of their characteristics.The analysis show that the effects of Sodium Alginate on soybean plant are better than chitosan and the best concentration is 0.50 g·kg -1 .
文摘The aim of this study was to evaluate the effect of coating of alginate-chitosan (AL:CS) beads on the colonic drug delivery. The AL:CS systems containing triamcinolone (TC) were coated with the HPMCP and Eudragit? L100 by immersion and by spraying methods. The drug release profile in simulated colonic medium was determined using 5% human fecal content suspension in 0.01 N buffer solution, pH 6.8. The systems coated with HPMCP showed a lower rate of drug delivery in simulated enteric medium. The delivery profile in simulated colonic medium followed zero-order kinetic. The coated systems provided a promising drug-delivery profile for application in colonic drug delivery.
文摘Yerba mate (Ilex paraguariensis) contains a high amount of polyphenols associated with antiradical activity and possible benefits for preventing degenerative diseases. Natural extracts from this South American herb were encapsulated in calcium alginate and calcium alginate-chitosan beads to be incorporated as an additive in food products. The interactions between the active compound and the polymers were evaluated by Scanning Electron Microscopy (SEM), thermal analysis (Thermo Gravimetric Assays, TGA, and Differential Scanning Calorimetry, DSC) and Fourier Transform Infrared Spectrometry (FT-IR) studies. Also, the effect of these interactions on extract release in a gastrointestinal model system was evaluated. Results showed the interactions between the calcium alginate matrix and the chitosan external layer. Also, interactions between the natural extract and each polymer were observed. In both encapsulation systems the highest polyphenol content was released in simulated gastric fluid. However, capsules coated with chitosan allowed releasing a higher amount of polyphenols into the simulated intestinal fluid. This fact was attributed to both the protection of the chitosan barrier and the strong interaction between yerba mate extract and chitosan.
