Alginate-coated Chitosan Nanoparticles Research Articles

Alginate-coated chitosan nanoparticles for pH-dependent release of tamoxifen citrate

Chitosan-based nano-sized particles increase the penetration of the drug through the narrow junction into the bloodstream and target the specific site. The objective of this study was to prepare chitosan nanoparticles to entrap a hydrophobic drug (tamoxifen citrate), followed by the alginate coating of the developed nanoparticles to decrease their degradation in the acidic pH. Drug-loaded chitosan nanoparticles were prepared by the ionic gelation method. Alginate coating was done by dissolving sodium alginate to buffer solution and drug-loaded chitosan nanoparticles drop-wise under mild agitation. The size of alginate coated chitosan nanoparticles, zeta potential, surface morphology, in-vitro drug release, and entrapment efficiency was measured. The optimised formulation of both uncoated (SH3) and coated (SH7) formulation showed the particle size, PDI, and zeta potential with values 221 & 338 nm, 0.161 & 0.230 and 36.5 & −20.7 mV, respectively. The resulted nanoparticle surface was non-porous. The percentage yield of the optimised formulation SH3 was 28% and SH6 was 33%. The entrapment efficiency of the optimised formulation SH3 (uncoated formulation) and SH6 (coated formulation) is 69.5 and 58.51%, respectively. Chitosan nanoparticles were successfully prepared to entrap tamoxifen citrate. The coating of chitosan nanoparticles decreased their degradation in the acidic pH.

Formulation and Characterization of Alginate Coated Chitosan Nanoparticles as Therapeutic Protein for Oral Delivery System

Nanoparticles have been promptly studied and developed for oral protein delivery. Selection of excipients and formulation method depends on the physicochemical characteristics of the protein carried. Therefore, this study aims to design a formulation and characterize the alginate coated chitosan nanoparticles which carried different protein. Alginate coated chitosan nanoparticles were formed using an ionic gelation method. Optimization was done by varying the parameter such as crosslinker concentration, agitation method, rate, and time. The results show that chitosan nanoparticles formed by sonication using sodium tripolyphosphate (STPP): chitosan (1:0.8) was the best method to form nanoparticles. The particle size and polydispersity index (PDI) of bovine serum albumin (BSA) and lysozyme nanoparticles were 812.2 nm and 0.412 for BSA while 793.3 nm and 0.438 for lysozyme. Encapsulation efficiency (EE) of BSA is 52 % and lysozyme is 68 %. In vitro tests on acidic/gastric conditions showed that lysozyme (±32 %) was released faster than BSA (±10 %) during the 24 h incubation. Under neutral/terminal intestine conditions, percentage of BSA (±17 %) release is slightly higher than lysozyme (±13 %) for 8 h incubation period. It was concluded that the formulation of alginate coated chitosan nanoparticles in this study appears to be more effective for BSA delivery than lysozyme.
 HIGHLIGHTS
 
 Nanoparticle vesicular system is an effective approach for protein drug delivery system
 Factors affecting the formation of chitosan nanoparticle are crosslinker concentration, agitation method, rate, and time
 Alginate coated chitosan nanoparticle was more effective for oral delivery of BSA compared to lysozyme
 
 GRAPHICAL ABSTRACT

Alginate-coated chitosan nanoparticles protect protein drugs from acid degradation in gastric media

Alginate-coated chitosan nanoparticles protect protein drugs from acid degradation in gastric media

T helper type 1 biased immune responses by PPE17 loaded core-shell alginate-chitosan nanoparticles after subcutaneous and intranasal administration

PurposeTuberculosis, a cost and life threatening disease, was being subjected for improving vaccine strategies beyond BCG. Thus, a novel particulate delivery system using alginate-coated chitosan nanoparticles including PPE17 protein and CpG were administered through intranasal (IN) and subcutaneous (SC) routes. MethodsThe encapsulated nanoparticles were first characterized for size, surface charge, encapsulation efficiency and in vitro release of PPE17 antigen. The nanoparticles were then administered intranasal and subcutaneously to evaluate the induction of systemic and/or mucosal immune responses in mice. ResultsAccording to our result, the mean size of nanoparticles was measured about 427 nm, and exhibited a negative zeta potential of −37 mV. Following subcutaneous and intranasal administration, the results from cytokines assay showed that an increasing in the level of IFN-γ, and adversely a decrease in the level of IL-4 (presumptive Th1 biased immune response) was happened and also a notable elicitation in IL-17 cytokine was observed. ConclusionIn conclusion, our study demonstrated that alginate-coated chitosan nanoparticles showed to be an effective way to improve BCG efficiency as booster strategy for subcutaneous vaccine, and also can induce strong immune responses as prime strategy through intranasal vaccination.

Lipopolysaccharide derived alginate coated Hepatitis B antigen loaded chitosan nanoparticles for oral mucosal immunization

Mucosal administration of vaccine can produce a strong immune response. Antigens adhere to “M-cells”, present at the intestinal mucosa and the M-cells produce immunity after actively transporting luminal antigens to the underlying immune cells. The objective of the present study was to prepare and characterize alginate coated chitosan nanoparticles (ACNPs) loaded with HBsAg as an antigen to produce immunity; additionally anchored with lipopolysaccharide (LPS) as an adjuvant. Ionic gelation method was used to prepare chitosan nanoparticles (CNPs) which were loaded with HBsAg and stabilized by alginate coating to protect from gastric environment. Results showed that the prepared LPS-HB-ACNPs were small and spherical with mean particle size 605.23 nm, polydispersity index 0.234 and Zeta potential −26.2 mV and could effectively protect antigen at GIT in acidic medium. HB-ANCPs were stable during storage at 4 ± 1 and 27 ± 2 °C. Anchoring with LPS showed increased immunity as compared to other formulations. Additionally, NPs elicited significant sIgA at mucosal secretions and IgG antibodies in systemic circulation. Thus, the prepared LPS anchored alginate coated chitosan NPs may be a promising approach as a vaccine delivery system for oral mucosal immunization.

Alginate-coated chitosan nanoparticles act as effective adjuvant for hepatitis A vaccine in mice

The numerous recent hepatitis A outbreaks emphasize the need for vaccination; despite the effectiveness of the current ones, developments are needed to overcome its high cost plus some immune response limitations. Our study aims to evaluate the use of chitosan and alginate-coated chitosan nanoparticles as an adjuvant/carrier for the hepatitis A vaccine (HAV) against the traditional adjuvant alum. Immune responses towards (HAV-Al) with alum, (HAV-Ch) with chitosan, and (HAV-aCNP) with alginate-coated chitosan nanoparticles, were assessed in mice. HAV-aCNP significantly improved the immunogenicity by increasing the seroconversion rate (100%), the hepatitis A antibodies level, and the splenocytes proliferation. Thus, the HAV-aCNP adjuvant was superior to other classes in IFN-γ and IL-10 development. Meanwhile, the solution formula of HAV with chitosan showed comparable humoral and cellular immune responses to alum-adjuvanted suspension with a balanced Th1/Th2 immune pathway. The current study showed the potential of alginate-coated chitosan nanoparticles as an effective carrier for HAV. Consequently, this would impact the cost of HAV production positively.

Hyaluronic Acid Coated Chitosan Nanoparticles Reduced the Immunogenicity of the Formed Protein Corona

Studying the interactions of nanoparticles (NPs) with serum proteins is necessary for the rational development of nanocarriers. Optimum surface chemistry is a key consideration to modulate the formation of the serum protein corona (PC) and the resultant immune response. We investigated the constituent of the PC formed by hyaluronic acid-coated chitosan NPs (HA-CS NPs). Non-decorated chitosan NPs (CS NPs) and alginate-coated chitosan NPs (Alg-CS NPs) were utilized as controls. Results show that HA surface modifications significantly reduced protein adsorption relative to controls. Gene Ontology analysis demonstrates that HA-CS NPs were the least immunogenic nanocarriers. Indeed, less inflammatory proteins were adsorbed onto HA-CS NPs as opposed to CS and Alg-CS NPs. Interestingly, HA-CS NPs differentially adsorbed two unique anti-inflammatory proteins (ITIH4 and AGP), which were absent from the PC of both controls. On the other hand, CS and Alg-CS NPs selectively adsorbed a proinflammatory protein (Clusterin) that was not found on the surfaces of HA-CS NPs. While further studies are needed to investigate abilities of the PCs of only ITIH4 and AGP to modulate the interaction of NPs with the host immune system, our results suggest that this proof-of-concept could potentially be utilized to reduce the immunogenicity of a wide range of nanomaterials.

Sodium Alginate Coated Chitosan Nanoparticles Enhance Antitumor Efficiency via Smartly Regulating Drug Release at Different pH

Sodium Alginate Coated Chitosan Nanoparticles Enhance Antitumor Efficiency via Smartly Regulating Drug Release at Different pH

Optimization of process parameters for removal of heavy metals by biomass of Cu and Co-doped alginate-coated chitosan nanoparticles

In this study, the efficiency of alginate-coated chitosan nanoparticles (Alg-CS-NPs) for removal of heavy metals from industrial effluents was investigated. To this end, the researchers constructed a reactor containing biomass, using response surface methodology (RSM) for process optimization. Reactor tests were carried out with both synthetic and industrial effluents containing nickel. The optimum conditions to achieve maximum removal efficiency (RE) rates for both synthetic and industrial effluents were specified for contact time (0–120min), pH level (1–9), biomass dose (0.1–0.9g), and initial metal ion concentration (10–90mg/L). It was determined that 94.48% of the nickel could be removed at pH=3, 70mg/L initial nickel concentration, a dose of 0.3g biomass, and 30min contact time. The kinetic data fit well to a pseudo second-order model and the equilibrium data of the metal ions could be described well with Freundlich isotherm models.

Fabrication of monodispersive nanoscale alginate–chitosan core–shell particulate systems for controlled release studies

Biopolymers such as chitosan and alginate are widely used for controlled drug delivery systems. The present work aimed to develop a new protocol for preparation of monodisperse alginate-coated chitosan nanoparticles at nanoscale. Modifications of preparation protocol contain changing the pH of polymer solutions and adding extra centrifugation steps into the procedure. While chitosan nanoparticles were synthesized by ionic gelation method, they were coated with alginate by electrostatic interaction. The size, morphology, charge, and structural characterization of prepared core–shell nanoparticulated system were performed by AFM, Zeta sizer, and FTIR. BSA and DOX were loaded as test biomolecules to core and shell part of the nanoparticle, respectively. Release profiles of BSA and DOX were determined by spectrophotometry. The sizes of both chitosan and alginate-coated chitosan nanoparticles which were prepared by modified protocol were measured to be 50 ± 10 and 60 ± 3 nm, respectively. After loading BSA and DOX, the average size of the particles increased to 80 ± 7 nm. Moreover, while the zeta potential of chitosan nanoparticles was positive value, the value was inverted to negative after alginate coating. Release profile measurements of BSA and DOX were determined during 57 and 2 days, respectively. Our results demonstrated that monodisperse alginate-coated nanoparticles were synthesized and loaded successfully using our modified protocol.

A New Strategy Based on Smrho Protein Loaded Chitosan Nanoparticles as a Candidate Oral Vaccine against Schistosomiasis

BackgroundSchistosomiasis is one of the most important neglected tropical diseases and an effective control is unlikely in the absence of improved sanitation and vaccination. A new approach of oral vaccination with alginate coated chitosan nanoparticles appears interesting because their great stability and the ease of target accessibility, besides of chitosan and alginate immunostimulatory properties. Here we propose a candidate vaccine based on the combination of chitosan-based nanoparticles containing the antigen SmRho and coated with sodium alginate.Methods and FindingsOur results showed an efficient performance of protein loading of nanoparticles before and after coating with alginate. Characterization of the resulting nanoparticles reported a size around 430 nm and a negative zeta potential. In vitro release studies of protein showed great stability of coated nanoparticles in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF). Further in vivo studies was performed with different formulations of chitosan nanoparticles and it showed that oral immunization was not able to induce high levels of antibodies, otherwise intramuscular immunization induced high levels of both subtypes IgG1 and IgG2a SmRho specific antibodies. Mice immunized with nanoparticles associated to CpG showed significant modulation of granuloma reaction. Mice from all groups immunized orally with nanoparticles presented significant levels of protection against infection challenge with S. mansoni worms, suggesting an important role of chitosan in inducing a protective immune response. Finally, mice immunized with nanoparticles associated with the antigen SmRho plus CpG had 38% of the granuloma area reduced and also presented 48% of protection against of S. mansoni infection.ConclusionsTaken together, this results support this new strategy as an efficient delivery system and a potential vaccine against schistosomiasis.

Surface Engineered Nanoparticles for Oral Immunization

A rationally designed oral vaccine should be successfully delivered to the intestinal mucosal immune cells, and induce both humoral and cellular counterparts of immunity along with the mucosal immune response. The aim of this study is to mimic these natural infections and excel the utility of a specific ligand for beta1 integrin (RGD peptide) to target M cells which seems to be the only portal for any particulate matter in GIT. The in vivo studies have shown higher antibody titre for alginate coated chitosan nanoparticles compared to plain chitosan nanoparticles. RGD peptide conjugated alginate coated chitosan nanoparticles proved to be the suitable carrier system for antigen delivery to gut associated lymphoid tissue. Based upon the release kinetics and strong systemic as well as mucosal immune response we can conclude that this cost effective carrier construct can be utilized for oral vaccination.

Alginate coated chitosan nanoparticles are an effective subcutaneous adjuvant for hepatitis B surface antigen

We recently described a delivery system that is composed of a chitosan core to which the hepatitis B surface antigen (HBsAg) was adsorbed and subsequently coated with sodium alginate. In this present work, alginate coated chitosan nanoparticles were evaluated as a subcutaneous adjuvant for HBsAg.HBsAg loaded, alginate coated or uncoated chitosan nanoparticles, associated or not with CpGODN were subcutaneously administered to mice and several immunological parameters were evaluated.A high anti-HBsAg IgG titer (2271±120 mIU/ml), with the majority of antibodies being of Th2 type, was observed within group I, vaccinated with HBsAg loaded onto coated nanoparticles. However, regarding cellular immune response, no significant differences were observed for antigen-specific splenocyte proliferation or for the secretion of IFN-γ and IL-4, when compared to the control group. The co-delivery of antigen-loaded nanoparticles in the presence of the immunopotentiator, CpG ODN 1826, resulted in an increase of anti-HBsAg IgG titers that was not statistically different from the first group; however, an increase of the IgG2a/IgG1 ratio from 0.1 to 1.0 and an increase (p<0.01) of the IFN-γ production by the splenocytes stimulated with the HBV antigen was observed.The enhancement of the immune response observed with the antigen-loaded nanoparticles demonstrated that chitosan is a promising platform for parenteral HBsAg delivery and, when co-administered with the CpG ODN, resulted in a mixed Th1/Th2 type immune response.

Immune response by nasal delivery of hepatitis B surface antigen and codelivery of a CpG ODN in alginate coated chitosan nanoparticles

Alginate coated chitosan nanoparticles were previously developed with the aim of protecting the antigen, adsorbed on the surface of those chitosan nanoparticles, from enzymatic degradation at mucosal surfaces. In this work, this new delivery system was loaded with the recombinant hepatitis B surface antigen (HBsAg) and applied to mice by the intranasal route. Adjuvant effect of the delivery system was studied by measuring anti-HBsAg IgG in serum, anti-HBsAg sIgA in faeces extracts or nasal and vaginal secretions and interferon-γ production in supernatants of the spleen cells. The mice were primed with 10 μg of the vaccine associated or not with nanoparticles and associated or not with 10 μg CpG oligodeoxynucleotide (ODN) followed by two sequential boosts at three week intervals. The association of HBsAg with the alginate coated chitosan nanoparticles, administered intranasally to the mice, gave rise to the humoral mucosal immune response. Humoral systemic immune response was not induced by the HBsAg loaded nanoparticles alone. The generation of Th1-biased antigen-specific systemic antibodies, however, was observed when HBsAg loaded nanoparticles were applied together with a second adjuvant, the immunopotentiator, CpG ODN. Moreover, all intranasally vaccinated groups showed higher interferon-γ production when compared to naïve mice.

Evaluation of the immune response following a short oral vaccination schedule with hepatitis B antigen encapsulated into alginate-coated chitosan nanoparticles

The purpose of this work was to assess the ability of recombinant hepatitis B vaccine, encapsulated in alginate-coated chitosan nanoparticles, to induce local and systemic immune responses following oral vaccination. The antigen was administered either alone or in combination with the immunopotentiator, synthetic oligodeoxynucleotide containing immunostimulatory CpG motif (CpG ODN) as adjuvant, and associated or not with the alginate-coated chitosan nanoparticles. After two immunizations the group I (HBsAg associated with nanoparticles) and the group VI (HBsAg and CpG, both associated with nanoparticles) showed enhanced immune responses. Both groups showed significant higher values of the CD69 expression in CD4+ and CD8+ T-lymphocytes and lower values of this marker in B lymphocytes. Moreover, a strongest proliferative response of the splenocytes, ex vivo stimulated with concanavalin A, was observed in the same groups. Although with a presence of non-responder mice within the groups, only mice of the groups I and VI elicited the generation of anti-HBsAg antibodies detected in serum (IgG) and in the intestinal washings (sIgA). The results demonstrated that coated chitosan nanoparticles might have potential for being used as a deliver system for oral vaccination with the recombinant hepatitis B surface antigen.

Uptake studies in rat Peyer's patches, cytotoxicity and release studies of alginate coated chitosan nanoparticles for mucosal vaccination

The design of particulate vaccine delivery systems, particularly for mucosal surfaces, has been a focus of interest in recent years. In this context, we have previously described the development and the characterization of a new nanosized delivery system, consisting of a model antigen adsorbed to chitosan particles and coated with sodium alginate. In the present work the ovalbumin release profiles from these coated nanoparticles in different pH buffers were investigated and compared to those of the uncoated particles. Cytotoxicity of the polymers and nanoparticles was assessed using the MTT assay. Finally, particle uptake studies in rat Peyer's patches were performed. It was demonstrated that the coating of the nanoparticles with sodium alginate not only avoided a burst release observed with uncoated particles but also increased the stability of the particles at pH 6.8 and 7.4 at 37 °C. At neutral pH, the release was lower than 5% after 3.5 h incubation in a low ionic strength buffer. For both, chitosan and alginate polymers, and for the nanoparticles, comparable cell viability data close to 100%, were obtained. Additionally, based on confocal laser scanning microscopy observations, it was shown that alginate coated nanoparticles were able to be taken up by rat Peyer's patches, rendering them suitable carriers for intestinal mucosal vaccination.

Efficient gene transfection using chitosan ? alginate core-shell nanoparticles

Reverse microemulsion was used as a template to fabricate chitosan-alginate core-shell nanoparticles encapsulated with enhanced green fluorescent protein (EGFP)-encoded plasmids. The average size of DNA-entrapped nanoparticles measured by dynamic light scattering was increased proportionally, with the N/P ratios ranging from 5 to 20. These alginate-coated chitosan nanoparticles endocytosed by NIH 3T3 cells trigged swelling of transport vesicles which render gene escape before entering digestive endolysosomal compartment and concomitantly promote gene transfection rate. Results showed that DNA-encapsulated chitosan-alginate nanoparticles with average size of 64nm (N/P ratio of 5) could achieve the level of gene expression comparable with the one obtained by using polyethyleneimine-DNA complexes.