Alginate Nanoparticles Research Articles

PH-sensitive magnetic alginate/γ-Fe2O3 nanoparticles for adsorption/desorption of a cationic dye from water

In this study, magnetic alginate nanoparticles (AlgMNP) were synthesized using a simple and green two-step method, which can be easily developed on an industrial scale. First, coprecipitation of both ferric and ferrous ions in alkaline medium followed by oxidation of magnetite into maghemite leads to a stable colloidal dispersion called ferrofluid. A sodium alginate solution was then added to the ferrofluid in order to obtain the magnetic nanocomposite. This approach combines the advantages of a biopolymer with magnetic properties of the maghemite nanoparticles. The morphology, structure, size and composition of the magnetic nanoparticles were characterized by means of atomic absorption spectrometry, transmission electron microscopy, X-ray diffraction, Fourier-transform-infrared spectroscopy and thermogravimetric analysis. Adsorption is one of the most efficient treatments for the removal of pollutants from wastewater. But the development of efficient and environmental friendly adsorbent still remains challenging. Using AlgMNP as a magnetic adsorbent could be a suitable response to this challenge. Its adsorption efficiency was investigated by using methylene blue as pollutant. The effects of pH, contact time, and initial concentration of the dye on adsorption were investigated. The high adsorption capacity with respect to the dye in a wide pH range (273 mg/g) was explained by the way magnetic nanoparticles bind to the alginate chains. We assumed an organization with alginate strands decorated by the magnetic nanoparticles leaving the adsorption sites of the particles more accessible rather than a configuration with a complete coating of magnetic nanoparticles by alginate. The reusability was successfully demonstrated through 10 adsorption/desorption cycles.

Control of sludge microbial biofilm by novel quorum quenching bacteria Pseudomonas nitroreducens JYQ3 and Pseudomonas JYQ4 encapsulated sodium alginate - Magnetic iron nanocomposites

Biofouling control via quorum quenching (QQ) approach is becoming popular among other fouling mitigation strategies. In the present study, the mitigation of membrane biofouling problem via disruption of cell-to-cell communication was studied by immobilizing QQ bacteria in sodium alginate magnetic nanocomposite beads. Two QQ bacteria viz. Pseudomonas nitroreducens JYQ3 and Pseudomonas JYQ4 isolated from dairy waste activated sludge was immobilized individually into the beads. Scanning electron microscopy (SEM) analysis revealed the successful immobilization of QQ bacteria into the alginate nanoparticle beads. The Confocal laser scanning microscopy (CLSM) results provided evidence of biofouling controlled activities of Pseudomonas nitroreducens JYQ3 and Pseudomonas JYQ4 immobilized nanocomposite (IMN) beads. Further, the membranes incubated with Pseudomonas nitroreducens JYQ3 and Pseudomonas JYQ4 IMN beads showed better flux (19% and 22% higher, respectively) than the control. Hence, the results revealed that the QQ bacteria IMN beads would be an efficient approach for controlling the biofilm developed on the cellulose acetate membrane surface.

Mucoadhesive assessment of different antifungal nanoformulations

Oral candidiasis is an important opportunistic fungal infection and polyenes and azoles are still the most used antifungal agents. However, the oral absorption resulting from most available treatments is generally poor and, consequently, a very high frequency of administrations of antifungal agents is strongly required. Therefore, the major challenge is to improve the retention of the antifungal agents in buccal mucosa, and the encapsulation into mucoadhesive systems may be considered as a possible strategy to achieve this objective. Three types of mucoadhesive polymeric nanoparticles (polylactic acid (PLA), polylactic-co-glycolic acid (PLGA) and alginate) were prepared using nystatin as model drug. The drug-loaded nanoparticles were then included in toothpaste, oral gel and oral films, respectively. The results demonstrated that the loaded nanoparticles were successfully produced, presenting a mean size between 300–900 nm and with a negative surface charge. Also, the determination of the encapsulation efficiency of all nanoparticles showed values above 70%. In terms of the in vitro mucoadhesion, the best formulation was the oral film loaded with the PLGA nanoparticles followed by the oral gel with PLA nanoparticles and thirdly the toothpaste with alginate nanoparticles. This was confirmed in an in vitro rinsing model with mucus producing HT29-MTX cells, where the percentage of nystatin retained to the cells after 40 min of simulated saliva flow was between 10–27% when formulations were used and only 4% for free nystatin. Further studies will include in vivo testing using animal models.

Preparation of self-assembled nanoparticles of ε-polylysine-sodium alginate: A sustained-release carrier for antigen delivery.

Low immunogenicity prohibits the widespread use of subunit vaccine against infectious diseases and cancers. Hence, a new generation of adjuvants and delivery systems is indispensable for more potent antigen-specific immune responses. Predominantly, nanoparticles formulated from biodegradable polymers are being widely explored as carriers of novel vaccines owing to their outstanding natural properties. We fabricated a model antigen - bovine serum albumin (BSA) encapsulated ε-polylysine (ε-PL) - sodium alginate (SA) nanoparticles (PSNPs), which were self-assembled by ionotropic complexation method, a very simple and mild process, as a result of the electrostatic interaction between oppositely charged polyelectrolyte complexes (PEC). After the preparation, various in vitro parameters were characterized. Scanning electron microscope and dynamic light scattering were employed to study the morphology, size, zeta potential and optimize formulation. Forming mechanism of PSNPS was analyzed and verified by infrared absorption spectra and thermal analysis. Delivery behavior of PSNPs was assessed via release study, cytotoxicity measurement and cellular uptake. BSA-PSNPs with a mean particle diameter 133.2 ± 0.5 nm, narrow size distribution and negatively charged surface had been synthesized successfully by this method. The results of in vitro studies demonstrated that the nanosuspension was able to prevent burst release of loaded BSA and presented sustained-release behavior. It was no cytotoxicity by the bio-assessment using macrophage cells, and was observed significantly higher uptake compared with BSA free solution. Herein, ε-polylysine - sodium alginate nanoparticles had been found to be a potential candidate for vaccine delivery.

Alginate-C18 Conjugate Nanoparticles Loaded in Tripolyphosphate-Cross-Linked Chitosan-Oleic Acid Conjugate-Coated Calcium Alginate Beads as Oral Insulin Carrier.

Simple alginate, alginate-stearic acid, and alginate-C18 conjugate nanoparticles and tripolyphosphate-cross-linked chitosan-oleic acid conjugate-coated calcium alginate beads as the vehicle of nanoparticles were designed. Their size, ζ potential, morphology, drug load, drug release, matrix molecular characteristics, mucus penetration, HT-29 cell line cytotoxicity and intracellular trafficking, in vivo blood glucose lowering, and insulin delivery profiles were characterized. Alginate-C18 conjugate nanoparticles were nontoxic. Among all nanoparticle variants, they had reduced size and ζ potential thus enhancing particulate mucus penetration and intracellular trafficking. Their insulin reabsorption tendency was minimized as alginate active COOH/COO- sites were preoccupied with C18. Their loading into coated beads was translated to reduced drug release in simulated gastric phase with nanoparticles being released in the intestinal phase. The combination dosage form increased the blood glucose lowering extent of insulin and blood insulin level compared with nanoparticles or beads alone. Nanoparticles in beads represented a viable approach for oral insulin delivery.

Synthesis and Characterization of Alginate Nanoparticles Encapsulating Selenium and their Antimicrobial Evaluation

Synthesis and Characterization of Alginate Nanoparticles Encapsulating Selenium and their Antimicrobial Evaluation

Vaccine approach against scorpion envenoming: Comparative study between the efficiency of MF59 adjuvant and alginate nanoparticles associated to irradiated venom

Vaccine approach against scorpion envenoming: Comparative study between the efficiency of MF59 adjuvant and alginate nanoparticles associated to irradiated venom

Development and characterization of polymeric-based nanoparticles for sustained release of amoxicillin – an antimicrobial drug

In this study, amoxicillin (AMO)-loaded poly(vinyl alcohol)/sodium alginate (PVA/NaAlg) nanoparticles were prepared as a polymer-based controlled release system. The physicochemical properties of the obtained nanoparticles were investigated by XRD, DSC/TGA, particle size analyses and zeta potential measurements. The average particle sizes were in the range from 336.3 ± 25.66 to 558.3 ± 31.39 nm with negative zeta potential values from −41.86 ± 0.55 to −47.3 ± 2.76 mV. The influences of PVA/NaAlg ratio, span 80 concentration, exposure time to glutaraldehyde (GA) and the drug/polymer ratio on AMO release profiles were evaluated. In vitro drug release studies showed a controlled and pH dependent AMO release with an initial burst effect. XRD patterns and DSC thermograms of AMO-loaded nanoparticles revealed that the drug in the nanoparticles was in amorphous form, which was more stable than the crystalline form. The antibacterial activity of the optimal formulation was also investigated. The minimum inhibitory concentration (MIC) values of this formulation had the comparable antibacterial activity with that of pure AMO. These results indicate that the developed nanoparticles could be a promising candidate drug delivery system for AMO.

Chitosan-alginate nano-carrier for transdermal delivery of pirfenidone in idiopathic pulmonary fibrosis

Pirfenidone (PFD) is one of the pyridine family components with anti-inflammatory, antifibrotic effects and US FDA approved for the treatment of idiopathic pulmonary fibrosis (IPF). Presently, PFD is administered orally and this has setbacks. Hence, it is important to eliminate the pharmacotherapeutic limitations of PFD. This research was carried out to study the possibility of transdermal delivery of PFD using chitosan-sodium alginate nanogel carriers. In order to synthesize chitosan-sodium alginate nanoparticles loaded with PFD, the pre-gelation method was used. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), and Fourier-transform infrared spectroscopy (FTIR) analyses were used for the characterization. Drug encapsulation and release manner were studied using UV spectroscopy. Ex vivo permeation examinations were performed using Franz diffusion cell and fluorescence microscopy. The results showed that nanoparticles having spherical morphology and size in the range of 80 nm were obtained. In vitro drug release profile represents sustained release during 24 h, while 50% and 94% are the loading capacity and efficiency, respectively. Also, the skin penetration of PFD loaded in nanoparticles was significantly increased as compared to PFD solution. The obtained results showed that synthesized nanoparticles can be considered as promising carriers for PFD delivery.

Chitosan-sodium alginate nanoparticle as a delivery system for ε-polylysine: Preparation, characterization and antimicrobial activity

ε-Polylysine-loaded chitosan-sodium alginate nanoparticles (ε-PL NPs) were synthesized and characterized in terms of particle size distribution, surface morphology, thermal properties and structure, respectively. Their antibacterial activity on Escherichia coli, Bacillus subtilis, Staphylococcus aureus and Micrococcus luteus were studied. The ε-PL NPs were well dispersed as spherical particles within the range of 200–500 nm. In vitro release studies showed an initial burst release of ε-PL from the nanoparticles followed by a sustained release. The minimum inhibitory concentrations (MIC) of ε-PL NPs against four test bacteria were 7.81 μg/mL (E. coli), 31.25 μg/mL (B. subtilis), 15.63 μg/mL (S. aureus) and 38.67 μg/mL (M. luteus), respectively. The bacteriostatic activity of ε-PL NPs was three times higher (P < 0.05) than that of free ε-PL in terms of inhibition zone diameter, suggesting that ε-PL NPs has stronger antibacterial activity. These findings may provide some basis for the application of ε-PL NPs as a promising food preservative.

Bupivacaine in alginate and chitosan nanoparticles: an in vivo evaluation of efficacy, pharmacokinetics, and local toxicity.

ObjectiveThis study reports a preclinical evaluation of an alginate/chitosan nanoparticle formulation containing NovaBupi®, a racemic bupivacaine (BVC) containing 25% dextrobupivacaine and 75% levobupivacaine.MethodsNew Zealand White rabbits (n=6) received intraoral or intrathecal injections of BVC 0.5% or BVC 0.5%-loaded alginate–chitosan nanoparticles (BVCALG). BVC plasma levels and pharmacokinetic parameters were determined in blood samples of these rabbits. An infraorbital nerve blockade was performed in male Wistar rats (n=7) with the same formulations and the vehicle (NPALG). Histological evaluation of local toxicity after 6 hours and 24 hours of the treatments was performed in rats’ (n=6) oral tissues.ResultsNo statistically significant difference was observed between plasma concentrations and pharmacokinetic parameters (p>0.05) after intraoral injections. However, after intrathecal injection BVCALG changed approximately three times the values of volume of distribution and area under the curve (AUC0–t; p<0.05). The total analgesic effect of BVC after infraorbital nerve blockade was improved by 1.4-fold (p<0.001) with BVCALG. BVC and BVCALG did not induce significant local inflammatory reaction.ConclusionThe encapsulation of BVC prolongs the local anesthetic effect after infraorbital nerve blockade and altered the pharmacokinetics after intrathecal injection.

Magnetic hybrid TiO2/Alg/FeNPs triads for the efficient removal of methylene blue from water

A new adsorbent material with combined adsorption, photocatalytic, and magnetic properties has been successfully synthesized and tested for the efficient dye removal from methylene blue (MB) contaminated water. A facile non-thermal method was applied to synthesize a hybrid nanocomposite consisting of TiO2/calcium alginate (TiO/Alg) and magnetite (Fe3O4) nanoparticles (FeNPs). The potential of the adsorbent Alg as a barrier to prevent direct contact between the magnetic core and TiO2 was experimented by varying the synthesis conditions. The performance of four differently synthesized TiO2/Alg/FeNPs samples (TiO2/Alg/FeNPs-1, TiO2/Alg/FeNPs-2, TiO2/Alg/FeNPs-3, and TiO2/Alg/FeNPs-4) was found to be fairly comparable and stable based on their efficiency in removing MB from aqueous solution due to the physico-chemical characterization (surface morphology, functional groups and elemental analysis) which supports the performance of TiO2/Alg/FeNPs. For the optimization study using the response surface methodology (RSM) with three factorial Box-Behnken experimental designs, TiO2/Alg/FeNPs-2 was selected as it exhibited the highest MB removal of 97.6% after 120 min under ultra violet irradiation (254 nm wavelength). Among the three independent variables studied (i.e., pH, contact time and initial MB concentration), the initial concentration of MB had significant effect towards the MB removal performance. A recycling study was performed, thus confirming the stability of TiO2/Alg/FeNPs-2 up to three cycles, with only a slight drop in the removal efficiency from 93.1% to 88.5%. The fabricated TiO2/Alg/FeNPs nanocomposites could be a potential functional material for treating artificial dye laden wastewater such as in textile, cosmetic, and paper industries.

Entrapment of LTB protein in alginate nanoparticles protects against Enterotoxigenic Escherichia coli.

Vaccine delivery vehicles are just as important in vaccine efficiency. Through the progress in nanotechnology, various nanoparticles have been evaluated as carriers for these substances. Among them, alginate nanoparticles are a good choice because of their biodegradability, biocompatibility, ease of production, etc. In this study, feasibility of alginate nanoparticles (NPs) such as recombinant LTB from Enterotoxigenic Escherichia coli (ETEC) carrier was investigated. To do this, the eltb gene was cloned and expressed in E.coli BL21 (DE3) host cells, and a Ni-NTA column purified the protein. NPs were achieved through ion gelation method in the presence of LTB protein and CaCl2 as the cross-Linker and NPs were characterized physicochemically. Balb/C mice groups were immunized with LTB-entrapped NPs or LTB with adjuvant and immunogenicity was assessed by evaluating IgG titer. Finally, the neutralization of antibodies was evaluated by GM1 binding and loop assays. LTB protein was expressed and efficiently entrapped into the alginate NPs. The size of NPs was less than 50nm, and entrapment efficiency was 80%. Western blotting showed maintenance of the molecular weight and antigenicity of the released protein from NPs. Administration of LTB-entrapped NPs stimulated antibody responses in immunized mice. Immunization induced protection against LT toxin of ETEC in ileal loops and inhibits enterotoxin binding to GM1-gangliosides. Alginate NPs are also appropriate vehicle for antigen delivery purpose. Moreover because of their astonishing properties, they have the potential to serve as an adjuvant.

Alginate membranes loaded with hyaluronic acid and silver nanoparticles to foster tissue healing and to control bacterial contamination of non-healing wounds.

Chronic non-healing wounds are a clinically important problem in terms of number of patients and costs. Wound dressings such as hydrogels, hydrocolloids, polyurethane films and foams are commonly used to manage these wounds since they tend to maintain a moist environment which is shown to accelerate re-epithelialization. The use of antibacterial compounds is important in the management of wound infections. A novel wound-dressing material based on a blended matrix of the polysaccharides alginate, hyaluronic acid and Chitlac-silver nanoparticles is here proposed and its application for wound healing is examined. The manufacturing approach to obtain membranes is based on gelling, foaming and freeze-casting of alginate, hyaluronic acid and Chitlac-silver nanoparticles mixtures using calcium ions as the cross-linking agent. Comprehensive evaluations of the morphology, swelling kinetics, permeability, mechanical characteristics, cytotoxicity, capability to inhibit metalloproteinases and of antibacterial property were conducted. Biological in vitro studies demonstrated that hyaluronic acid released by the membrane is able to stimulate the wound healing meanwhile the metal silver exploits an efficient antibacterial activity against both planktonic bacteria and biofilms. Overall, the experimental data evidence that the studied material could be used as antibacterial wound dressing for wound healing promotion.

BIOSORPTION OF CHROMIUM IONS BY CALCIUM ALGINATE NANOPARTICLES

The objectives of the present work include synthesis of nanoparticles of calcium alginate by emulsion crosslinking method, their characterization by techniques such as FTIR, scanning electron microscopy (SEM), XRD, particle size and surface charge analysis, and study of removal of chromium ions from synthetic aqueous solutions. In order to study the effect of various factors like adsorbent dose, initial metal ion concentration, pH and temperature on the adsorption of chromium ions from water, a series of batch sorption experiments were conducted. The obtained results were analysed by Langmuir and Freundlich isotherm models and it was found that the adsorption of chromium more precisely follows Langmuir absorption isotherm. The metal ion removal capacity of the nanoparticles was found to depend on the chemical composition of the adsorbent, concentration of the metal ion solution, pH and temperature of the medium and speed of the suspension from wastewater before disposal.

Preparation, characterization and immunological evaluation of alginate nanoparticles loaded with whole inactivated influenza virus: Dry powder formulation for nasal immunization in rabbits

It has become important to explore more efficient and feasible influenza vaccines, since epidemics of influenza virus cause hundreds of thousands of deaths all around the world. Improving immunogenicity of parentral influenza vaccines has given rise to mucosal delivery routes. In this study, alginate nanoparticles (NPs) were efficiently synthetized by ionic gelation method and influenza virus and CpG ODN or Quillaja Saponin (QS) adjuvants were actively incorporated into alginate NPs. The prepared particles were evaluated for both humoral and cellular immune responses in rabbits‘ nostrils. The vaccination started with a prime dose and followed by three boosters (two intranasal (IN) on days 45 and 60 and the last dose, intramuscular (IM) on day 75). HAI titer had increased in all the samples; although, only in the group received WV + CPG suspension reached to the protective HAI titer. All the immunized rabbits elicited significantly high sIgA levels on day 75, compared to the negative and the IM groups. At the end of the study, IN administration of CpG ODN adjuvant with virus antigen induced higher IgG level than the groups vaccinated with alginate NPs with or without CpG ODN (P < 0.001). As for the cellular immunity, CpG ODN was capable of inducing significant levels of IL-4 and TNF-α, either through inoculation along with the virus suspension or as incorporated in alginate NPs. According to the obtained data, CpG ODN adjuvant showed higher immunogenic potential as part of a vaccine delivery system than QS. Moreover, applying alginate polymer as a nasal delivery system carrier was not deemed immunogenic against influenza whole virus.

Sodium alginate nanoparticles as a new transdermal vehicle of glucosamine sulfate for treatment of osteoarthritis

AbstractGlucosamine sulfate (GS) has been used orally for the treatment of osteoarthritis (OA). However, it may be susceptible to the liver first pass phenomenon, which greatly affects its bioavailability, in addition to its side effects on the gastrointestinal tract. Alginate nanoparticles (Alg NPs) were investigated as a new drug carrier for transdermal delivery of GS to improve its effectiveness and reduce side effects. GS-Alg NPs were characterized by encapsulation efficiency, NP yield, particle size and surface charge properties. The in vitro release studies of GS and the ex vivo permeability through rat skin were determined using a UV-Vis spectrophotometer. GS-Alg NPs are within the nanometer range of size. High negative surface charge values are obtained and indicate the high suspension stability of the prepared formulation. The in vitro release studies showed that GS is released from Alg NPs in a sustained and prolonged manner. The ex vivo permeability of GS through rat skin is enhanced significantly after encapsulation in the negatively charged Alg NPs. We successfully reported a highly stable nanoparticlulate system using Alg NPs that permits the encapsulation of GS for topical administration, overcoming the disadvantages of oral administration.

Influence of different classes of crosslinkers on alginate polyelectrolyte nanoparticle formation, thermodynamics and characteristics

Complexation of linear alginate polyanions with different classes of crosslinkers (divalent cations, polycations, positively charged surfactants) was investigated, to unravel their effects on nanoparticle formation. The goal was to define the crosslinker-to-alginate molar ratios at which nanoparticles are formed, and to reveal the underlying thermodynamics and molecular interactions using dynamic and electrophoretic light scattering, isothermal titration calorimetry, and infrared spectroscopy. Alginate nanoparticles were formed across a limited range of molar ratios that was specific for each crosslinker, and had different size and stability. Thermodynamic parameters of alginate complexation with crosslinkers showed that nanoparticle formation was in all cases entropy driven, together with a minor enthalpic contribution. The crosslinking mechanism was based on ionic interactions, with accompanying weaker interactions specific for each crosslinker, and involved characteristic macroscopic association constants (Ka1) for complexation of alginate (range, 104–109M−1). Additionally, the ionic strengths of the media influenced the characteristics and stabilities of the polyelectrolyte nanoparticles.

Removal of copper (II) from aqueous solutions by sodium alginate/hydroxy apatite hydrogel modified by Zeolite

The study presented in this article investigated the removal of copper ions from aqueous solutions by a synthetic hydrogel-forming adsorbent polymer based on sodium alginate (SA) and hydroxy apatite (HA) nanoparticles. The effect of adding Zeolite on the adsorption performance of this hydrogel was also investigated, and the optimum amount of Zeolite was determined by changing its quantity. The FTIR spectrum determined the structure of the synthesized adsorbent; non-continuous adsorption tests were performed to study the kinetics and thermodynamics of adsorption and also the recovery of the adsorbent. The degree of adsorption of the synthesized nanocomposite was compared with that of Zeolite, and the results showed that the maximum adsorption capacities of Zeolite and the nanocomposite for Cu ions were 29.7 and 75.8 mg/g, respectively. The kinetic studies indicated that the process of adsorption of Cu ions on both absorbents followed a pseudo second order kinetic equation. It took the Zeolite and the hydrogel 90 and 120 minutes, respectively, to reach equilibrium. The thermodynamic studies showed that Cu absorption by both adsorbents matched the Langmuir isotherm very well (R2=0.99). Since adsorbent recovery and its lifespan are of significant importance in absorption processes, recovery was carried out by hydrochloric acid (2% by weight). The repulsion coefficient of the recovered adsorbent and its efficiency in five recovery cycles were measured. The results of the tests indicated that the repulsion coefficient of Cu was 70-82.75 percent and the adsorption efficiency of Cu after 5 recovery cycles was 75 percent of the initial adsorbent.

Encapsulation of zidovudine in PF-68 coated alginate conjugate nanoparticles for anti-HIV drug delivery

Retroviral drug delivery faces many challenges due to its low bioavailability, short half life and hydrophobicity. In this study, the anti viral drug zidovudine (AZT) was encapsulated inside the amide functionalised alginate nanoparticles (AZT-GAAD NPs) using emulsion solvent evaporation method. The amide derivative of alginate was prepared by coupling reaction with d,l glutamic acid using carbodiimide activation chemistry. The stabilizer, PF-68 was integrated during the preparation of nanoparticles. The alginate nanoparticles were prepared via chemical cross linking. The novelty of this work imparts the absence of chemical cross-linking for the preparation of nanoparticles.The resulting nanoparticles had spherical shape with an average size of 432±11.9nm as confirmed by TEM images. The nanoparticles had a loading efficacy of 29.5±3.2% obtained by dialysis method. The release of AZT in PBS(pH-7.4) was studied and a slow and sustained release of AZT was observed. The nanoparticles were found to be biocompatible and in vitro cellular internalization studies indicated significantly higher internalization efficiency. All these results suggested that (AZT-GAAD NPs) can function as a promising delivery vectors for efficient antiviral drug delivery.