Preparation and In vitro Evaluation of Intelligent Blood Glucose Regulating Nanonetwork Based on PLGA and Chitosan Nanoparticles

Introduction: Intelligent systems which release insulin in response to glucose level have been investigated thoroughly and many researches work in this area. In this work we present preparation and characterization of a novel Nano system composed of chitosan and PLGA nanoparticles, incorporating insulin, glucose oxidase and catalase. Methods and Results: Chitosan nanoparticles were prepared through ionic gelation method. First chitosan solution (2 mg/ml) in acetic acid 1% (v/v) was prepared. 2 mg insulin was dissolved in 5 ml of this solution. TPP solution was added dropwise. Stirring the solution was continued for 1 hour. Chitosan nanoparticles were separated by ultracentrifugation. Size of these nanoparticles was found to be 180-200 nm. Preparation of PLGA nanoparticles containing glucose oxidase (GOx) and catalase (CAT) was done by double emulsification technique.  PLGA was dissolved in ethyl acetate then aqueous solution of GOx and CAT were added to this organic phase. Sonication was performed to prepare w1/o emulsion. Deionized water was added and by second sonication w1/o/w2 emulsion was formed. Theorganic phase was removed by vacuum rotary evaporator and nanoparticles were separated through filtration, in size range of 130-150 nm. Chitosan NPs were added to PLGA NPs and the Nano system was formed through an electrostatic attraction between two oppositely charged particles. In vitro insulin release from this Nano system was investigated through radiolabeling method at two different glucose concentrations of 70 and 400 mg/dl. Conclusions: At high glucose concentration after glucose entrance into PLGA NPs it was converted to gluconic acid. Lowering of the Nano system microenvironment pH caused protonation and swelling of chitosan NPs and hence insulin release

Mucosal and systemic immunization against tuberculosis by ISCOMATRIX nano adjuvant co-administered with alginate coated chitosan nanoparticles

Objective(s): BCG vaccine has no longer been appreciated to immunize against tuberculosis, worldwide, so novel appropriate adjuvants have been dedicated to improve immune responses. This study aimed to evaluate the immunomodulatory effects of ISCOMATRIX as an adjuvant to stimulate potent humoral and cellular immune responses of the PPE17 loaded alginate coated nanoparticles through subcutaneous and intranasal vaccination. Materials and Methods: Size, polydispersity index, and morphology of the resulting colloidal particles were explored by dynamic light scattering (DLS). The cellular and/or humoral immune stimulation properties of ISCOMATRIX adjuvant were measured by measuring the level of IFNγ, IL-4, IL-17, and TGFβ in spleen cell cultures and IgG1 and IgG2a in serum and sIgA in nasal lavage of immunized mice, respectively. Results: The spherical cage-like particles of ISCOMATRIX adjuvant have optimal size of 59±6 nm appropriate for an immune adjuvant vaccine. ISCOMATRIX induced robust Th1 (IFN-γ) and IL-17 cytokine response also significant IgG2a and IgG1antibodies in both subcutaneous and intranasal routes and elicited mucosal sIgA response when administered intranasally. As a booster for BCG, ISCOMATRIX induced immune responses only in subcutaneous route. Conclusion: These findings indicate that ISCOMATRIX is a promising adjuvant with the potential for increasing cellular and humoral immunity both after subcutaneous and intranasal administration

Preparation and characterization of PLGA nanospheres loaded with inactivated influenza virus, CpG-ODN and Quillaja saponin

  Objective(s): The purpose of this study was preparation and evaluation of PLGA nanospheres containing the influenza virus and different adjuvants, Quillaja saponin (QS) and CpG-ODN.   Materials and Methods: Nanospheres were prepared using the double emulsion-solvent evaporation method. The morphological and physicochemical properties were studied by scanning electron microscopy (SEM), determination of zeta potential, encapsulation efficiency and release profile. Results: The particle size of formulations was less than 1000 nm, except for formulations containing antigen. The results were confirmed with SEM images. Encapsulation efficiency of antigen, QS and CpG ODN were 80%, 62% and 31%, respectively. The zeta potential of nanospheres was about -30 mV. The burst release was observed for all encapsulates and reached to about 48%, 44% and 35% within 90 min for antigen, CpG-ODN and Qs content, respectively. Conclusion: The formulations showed proper physicochemical properties. These nanospheres have good potential to be used as delivery systems/adjuvants for immunization against influenza

In vivo evaluation of mucoadhesive properties of nanoliposomal formulations upon coating with trimethylchitosan polymer

  Objective(s): Drug delivery via mucosal routes has been confirmed to be effective in inducing strong immune responses. Liposomes could enhance immune responses and mucoadhesive potentials, make them useful mucosal drug delivery systems. Coating of liposomes by mucoadhesive polymers succeeded in enhancing immune responses. Our studies aim at preparation and characterization of trimethylchitosan-coated nanoliposomes for nasal delivery of a model antigen, tetanus toxoid (TT).   Materials and Methods: Anionic liposomes were prepared by dehydration-rehydration method with an average size of 100 nm and were coated with 0.01% (w/v) solution of trimethyulchitosan (TMC) with 50±10% of quaternization. Surface properties and zeta potential were evaluated by DLS. Antigen stability and integrity were studied by SDS-PAGE electrophoresis. Nasal clearance rate and mucoadhesive properties of liposomes were studied by gamma scintigraphy method using 99mTc-labelled liposomes. Results: The zeta potential of non-coated and TMC-coated liposomes was -40 and +38.8, respectively. Encapsulation rate of tetanus toxoid was 77 ± 5.5%. SDS-PAGE revealed that the antigens remained intact during formulation procedure. Gamma scintigraphy confirmed that both types of liposomes could remain in nasal cavity up to ten folds over the normal residence time for conventional nasal formulations. Conclusion: TMC-coated nanoliposomes have several positive potentials including good mucoadhesive properties, preserved integrity of loaded antigen and presence of TMC as a mucoadhesive polymer with innate immunoadjuvant potential which make them suitable for efficient adjuvant/delivery system

Alginate Microsphere as a Delivery System and Adjuvant forAutoclaved Leishmania majorand Quillaja Saponin: Preparationand Characterization: Microspheres for antigen delivery

The goal of this study was to prepare and characterize alginate microspheres asan antigen delivery system and adjuvant for immunization against leishmaniasis.Microspheres encapsulated with autoclaved Leishmania major(ALM) and Quillajasaponin (QS) were prepared by an emulsification technique and characterized forsize, encapsulation efficiency and release profile of encapsulates. Selection ofappropriate parameters (viscosity of alginate, emulsifier and sonication times)enabled the preparation of alginate microspheres with a mean diameter of 1.92±1.0μm, as determined by scanning electron microscopy and particle size analyzer. Theencapsulation efficiency was about 34.2±6.7% for ALM and 31.0±4.4% for QS, asdetermined by spectrophotometric assays.In vitro release profile showed a slowrelease rate for encapsulated ALM and QS, 35.7±8.7% of ALM and 36.9±4.7% ofQS were released during 1 week. The molecular weight was evaluated by SDS-PAGEand showed that the process of encapsulation did not affect the molecular weightof the entrapped antigen. With regard to the optimum diameter (less than 5 m), slowrelease rate and preservation of antigen molecules, formulated alginate microspherescould be considered as a promising antigen delivery system and adjuvant for ALMand QS

Combined effects of PEGylation and particle size on uptake of PLGA particles by macrophage cells

Objective: At the present study, relationship between phagocytosis of PLGA particles and combined effects of particle size and surface PEGylation was investigated. Materials and Methods: Microspheres and nanospheres (3500 nm and 700 nm) were prepared from three types of PLGA polymers (non-PEGylated and PEGylation percents of 9% and 15%). These particles were prepared by solvent evaporation method. All particles were labeled with FITC-Albumin. Interaction of particles with J744.A.1 mouse macrophage cells, was evaluated in the absence or presence of 7% of the serum by flowcytometry method. Results: The study revealed more phagocytosis of nanospheres. In the presence of the serum, PEGylated particles were phagocytosed less than non-PEGylated particles. For nanospheres, this difference was significant (

Potential of polymeric particles as future vaccine delivery systems/adjuvants for parenteral and non-parenteral immunization against tuberculosis: A systematic review

Objective(s): Production of effective tuberculosis (TB) vaccine is necessity. However, the development of new subunit vaccines is faced with concerns about their weak immunogenicity. To overcome such problems, polymers-based vaccine delivery systems have been proposed to be used via various routes. The purpose of this study was to determine the potential of polymeric particles as future vaccine delivery systems/adjuvants for parenteral and non-parenteral immunization against TB. Materials and Methods: PubMed, Scopus, Science-Direct, and the ISI web of knowledge databases were searched for related keywords. A total of 420 articles, written up to June 25, 2016, were collected on the potential of polymeric particles as TB vaccine delivery systems after parenteral and non-parenteral immunization. Thirty-one relevant articles were selected by applying inclusion and exclusion criteria. Results: It was shown that the immunogenicity of TB vaccines had been improved by using biodegradable and non-biodegradable synthetic polymers as well as natural polymers and they are better able to enhance the humoral and cellular immune responses, compared to TB vaccines alone. The present study revealed that various polymeric particles, after M. tuberculosis challenge in animal models, provide long-lasting protection against TB. PLGA (poly (lactide-co-glycolide)) and chitosan polymers were widely used as TB vaccine delivery systems/adjuvants. Conclusion: It seems that PLGA and chitosan polymers are well-suited particles for the parenteral and non-parenteral administration of TB vaccines, respectively. Non-biodegradable synthetic polymers in comparison with biodegradable synthetic and natural polymers have been used less frequently. Therefore, further study on this category of polymers is required

Comparison of Intralesional Two Percent Zinc Sulfate and Glucantime Injection in Treatment of Acute Cutaneous Leishmaniasis

Introduction: Cutaneous leishmaniasis is an endemic disease in developing countries caused by different species of leishmania parasite, and if left untreated, it will result in a deformed scar after a relatively long period. Although various systemic and topical treatments have been proposed for leishmaniasis, pentavalent Antimony compounds remain the first-line treatment for it. Considering the cases with treatment failure, potential side effects and reluctance of patients to receive the drug, there are continuing efforts to find better treatment alternatives. Aim: Comparison of the effect of intralesional 2% zinc sulfate injection with Glucantime in treatment of acute cutaneous leishmaniasis. Materials and Methods: In this clinical trial, 45 patients with clinical diagnosis of cutaneous leishmaniasis and positive direct smear for leishman body were treated by intralesional injection of either 2% zinc sulfate or Glucantime. After simple randomization, in one group the patients were treated with 2 bouts of intralesional 2% zinc sulfate with a 2-week interval, and in the other group they were treated with 6 weekly bouts of intralesional Glucantime. The patients were monitored in two week intervals for 8 weeks. Healing of the lesions was evaluated clinically and by direct smear, and the data were analyzed using SPSS (11.5) software, t-Student, Mann-Whitney and Analysis of covariance (ANCOVA) statistical tests. Findings: In the end of study, 34 patients completed the study, 10 of whom received intralesional Glucantime and 24 of whom received intralesional 2% zinc sulfate. The healing rate after 8 weeks was 80% in the group receiving intralesional Glucantime and 33.3% in the one receiving 2% zinc sulfate (P=0.009). Conclusion: Based on the results of this study, intralesional injection of 2% zinc sulfate was less effective in treatment of cutaneous leishmaniasis than intralesional Glucantime