ABSTRACT
Objective: To prepare and characterize poly lactic-co-glycolic acid (PLGA) nanoparticles loaded with soluble leishmanial antigen or autoclaved leishmanial antigen and explore in vitro and in vivo immunogenicity of antigen encapsulated nanoparticles. Methods: Water/oil/water double emulsion technique was employed to synthesize PLGA nanoparticles, and scanning electron microscopy, Fourier transform infrared spectroscopy and Zeta-potential measurements were used to identify the characteristics of nanoparticles. Cytotoxicity of synthetized nanoparticles on J774 macrophage were investigated by MTT assays. To determine the in vitro immunostimulatory efficacies of nanoparticles, griess reaction and ELISA was used to measure the amounts of NO and cytokines. During the in vivo analysis, Balb/c mice were immunized with vaccine formulations, and protective properties of nanoparticles were measured by Leishman Donovan unit in the liver following the infection. Cytokine levels in spleens of mice were determined by ELISA. Results: MTT assay showed that neither soluble leishmanial antigen nor autoclaved leishmanial antigen encapsulated nanoparticles showed cytotoxicity against J774 macrophage cells. Contrary to free antigens, both autoclaved leishmanial antigen-nanoparticle and soluble leishmanial antigen-nanoparticle formulations led to a 10 and 16-fold increase in NO amounts by macrophages, respectively. Leishman Donovan unit calculations revealed that soluble leishmanial antigen-nanoparticles and autoclaved leishmanial antigen-nanoparticles yielded 52% and 64% protection against visceral leishmaniasis in mouse models. Besides, in vitro and in vivo tests demonstrated that by increasing IFN-γ and IL-12 levels and inhibiting IL-4 and IL-10 secretions, autoclaved leishmanial antigen-nanoparticles and soluble leishmanial antigennanoparticles triggered Th1 immune response. Conclusions: Both autoclaved leishmanial antigen-nanoparticles and soluble leishmanial antigen-nanoparticles formulations provide exceptional in vitro and in vivo immunostimulatory activities. Hence, PLGA-based antigen delivery systems are recommended as potential vaccine candidates against visceral leishmaniasis.
ABSTRACT
Objective: To prepare and characterize poly lactic-co-glycolic acid (PLGA) nanoparticles loaded with soluble leishmanial antigen or autoclaved leishmanial antigen and explore in vitro and in vivo immunogenicity of antigen encapsulated nanoparticles. Methods: Water/oil/water double emulsion technique was employed to synthesize PLGA nanoparticles, and scanning electron microscopy, Fourier transform infrared spectroscopy and Zeta-potential measurements were used to identify the characteristics of nanoparticles. Cytotoxicity of synthetized nanoparticles on J774 macrophage were investigated by MTT assays. To determine the in vitro immunostimulatory efficacies of nanoparticles, griess reaction and ELISA was used to measure the amounts of NO and cytokines. During the in vivo analysis, Balb/c mice were immunized with vaccine formulations, and protective properties of nanoparticles were measured by Leishman Donovan unit in the liver following the infection. Cytokine levels in spleens of mice were determined by ELISA. Results: MTT assay showed that neither soluble leishmanial antigen nor autoclaved leishmanial antigen encapsulated nanoparticles showed cytotoxicity against J774 macrophage cells. Contrary to free antigens, both autoclaved leishmanial antigen-nanoparticle and soluble leishmanial antigen-nanoparticle formulations led to a 10 and 16-fold increase in NO amounts by macrophages, respectively. Leishman Donovan unit calculations revealed that soluble leishmanial antigen-nanoparticles and autoclaved leishmanial antigen-nanoparticles yielded 52% and 64% protection against visceral leishmaniasis in mouse models. Besides, in vitro and in vivo tests demonstrated that by increasing IFN-γ and IL-12 levels and inhibiting IL-4 and IL-10 secretions, autoclaved leishmanial antigen-nanoparticles and soluble leishmanial antigennanoparticles triggered Th1 immune response. Conclusions: Both autoclaved leishmanial antigen-nanoparticles and soluble leishmanial antigen-nanoparticles formulations provide exceptional in vitro and in vivo immunostimulatory activities. Hence, PLGA-based antigen delivery systems are recommended as potential vaccine candidates against visceral leishmaniasis.
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Objective: To prepare Juglone-loaded poly lactic-co-glycolic acid nanoparticles (Jug-PLGA-NPs), and investigate their physicochemical properties, release characteristics in vitro and anti-tumor activities on A375 melanoma cells in vitro. Method: Jug-PLGA-NPs were prepared by emulsification-solvent evaporation method. Then the particle size, encapsulation efficiency, drug loading rate and in vitro release characteristics were investigated. Fluorescence microscopy was used to observe the uptake of PLGA-NPs in vitro. The distribution of PLGA-NPs in BALB/c nude mice after tail vein injection was observed by the small living animal imaging system. Their inhibition effect on proliferation of A375 cells was detected by thiazolyl blue tetrazolium bromide (MTT) assay. Apoptosis rate and cell cycle detection were performed by flow cytometry. Western blot was used to determine the protein kinase B (Akt), phosphorylated Akt (p-Akt) and cyclinD1. Result: The average particle size of the prepared Jug-PLGA-NPs was (149.6±21.5) nm, entrapment rate of (68.39±2.51)%, and drug-loading rate of (5.07±0.98)%, showing good sustained-release characteristics. PLGA-NPs showed good penetration and targeting properties in cellular uptake in vitro and in vivo imaging. Different concentrations of Jug-PLGA-NPs could significantly inhibit the proliferation and promote apoptosis of A375 cells in a time and concentration dependent manner (P1 expression (P0/G1 phase (PConclusion: The Jug-PLGA-NPs are easy to prepare and have good sustained-release characteristics, tumor targeting and anti-tumor ability, providing a new pharmaceutical dosage form for the future clinical application of Jug.
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OBJECTIVE To formulate atractylodin-loaded poly (lactic- co- glycolic acid) (PLGA) nanoparticles and characterize the prepared nanoparticle formulation.METHODS The nanoparticle formu-lation was developed using solvent displacement method. The encapsulation and loading efficiency were characterized and particle size, and zeta potential were determined by dynamic light scattering technique.Drug release was assessed in vitro.RESULTS The size(mean±SD of diameter)of the prepared atractylodin-loaded PLGA nanoparticles were (161.27 ± 1.87)nm with narrow size distribution (mean PDI: 0.068±0.015)and zeta potential(28.83±0.35)mV.The encapsulation and loading efficiency were (48.31±0.83)% and(2.15±0.04)%,respectively.Drug release from atractylodin-loaded PLGA nanoparticles was observed up to (87.70 ± 0.47)% in 72 h with biphasic manner. Moreover, the nanoparticles were found to be freely dispersible in water without aggregation. CONCLUSION Results suggest that PLGA nanoparticles may be used as an effective drug delivery system for atractylodin.The anti-cholangiocar-cinoma activity of this nanoparticle formulation is required.
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OBJECTIVE: To study the synthesis technique of poly(lactic-co-glycolic acid) (PLGA) via ring-opening polymerization. METHODS: Orthogonal experiments were carried out to optimize the synthesis conditions of PLGA under atmospheric condition. Three batches of repeated experiments were conducted to verify the technological conditions. RESULTS: The target product could be synthesized by using 0.03% stannous octoate and 0.02% lauryl alcohol reacted at 16°C for 10 h at a stir speed of 300 r·min-1. The ratio of glycolide and lactide was determined to be 45:55 to ensure the formation of PLGA5050. CONCLUSION: The screened out synthesis technique can obtain PLGA5050 with Mw of 52000 and coefficient of distribution between 1.5-1.7 at atmospheric pressure, and its quality is controllable.