The Characteristics and Mechanisms of Uptake of PLGA Nanoparticles in Rabbit Conjunctival Epithelial Cell Layers (original) (raw)
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Molecular vision, 2003
The internalization of poly (dl-lactide-co-glycolide, PLGA) nanoparticles in rabbit conjunctival epithelial cells (RCEC) was previously shown to occur by an endocytic process, as evidenced its energy-dependence, inhibition by the vesicle formation blocker cytochalasin D, and by the characteristic display of punctate distribution under confocal microscopy. In addition, clathrin protein was implicated in the endocytosis of these nanoparticles in vascular smooth muscle cells. We sought to examine the expression of clathrin and caveolin-1 in RCECs and to determine whether they play a role in PLGA nanoparticle endocytosis. PLGA (50:50) nanoparticles (100 nm in diameter) containing 6-coumarin (fluorescent marker, 0.05% w/v) were used in this study. The effect of pharmacological treatments aimed at disrupting formation of clathrin-coated vesicles (hypertonic challenge and intracellular K+ depletion) and caveolae (nystatin and filipin) on apical uptake of nanoparticles in primary cultured R...
Poly (D,L-lactide-co-glycolide) nanoparticles:Uptake by epithelial cells and cytotoxicity
Nanoparticles as drug delivery systems offer benefits such as protection of the encapsulated drug against degradation, site-specific targeting and prolonged blood circulation times. The aim of this study was to investigate nanoparticle uptake into Caco-2 cell monolayers, their co-localization within the lysosomal compartment and their cytotoxicity in different cell lines. Rhodamine-6G labelled poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles were prepared by a double emulsion solvent evaporation freeze-drying method. Uptake and co-localisation of PLGA nanoparticles in lysosomes were visualized by confocal laser scanning microscopy. The cytotoxicity of the nanoparticles was evaluated on different mammalian cells lines by means of Trypan blue exclusion and the MTS assay. The PLGA nanoparticles accumulated in the intercellular spaces of Caco-2 cell monolayers, but were also taken up transcellularly into the Caco-2 cells and partially co-localized within the lysosomal compartment indicating involvement of endocytosis during uptake. PLGA nanoparticles did not show cytotoxic effects in all three cell lines. Intact PLGA nanoparticles are therefore capable of moving across epithelial cell membranes partly by means of endocytosis without causing cytotoxic effects. Keywords: biocompatible polymers, Caco-2 cells, cellular uptake, cytotoxicity, PLGA nanoparticles
ABSTRACTIn this study, it was aimed to investigate characteristics and intracellular delivery of two different-sizedPLGA nanoparticles in ouzo region by considering number of nanoparticles. To determine the effect offormulation parameters on average particle size, Dil labeled nanoparticles were prepared using a three-factor, two-level full factorial statistical experimental design. PLGA230(230.8 ± 4.32 nm) and PLGA160(157.9± 6.16 nm) nanoparticles were obtained by altering polymer amount based on experimentaldesign results and characterized. Same number of PLGA230and PLGA160nanoparticles per cell wereapplied onto HEK293 cells; then, cytotoxicity, uptake kinetics and mechanism were evaluated by flowcytometry and fluorescent microscopy. Also same weight of PLGA230and PLGA160nanoparticles wereapplied and cellular uptake of these nanoparticles was evaluated. It was found that PLGA230nanopar-ticles had higher encapsulation efficiency and slower dye release compared to PLGA160nanoparticles.When they were applied at same counts per cell, PLGA230nanoparticles displayed faster and higherintracellular dye transfer than PLGA160nanoparticles. On the other hand, PLGA160appeared to be amore effective vehicle than PLGA230when applied at the same weight concentration. It was also shownthat for both nanoparticles, HEK293 cells employed macropinocytic, caveolae- and clathrin-mediatedendocytic pathways
Journal of Microencapsulation, 2012
To improve poor water solubility of cyclosporine A (CsA), hydroxypropyl-beta-cyclodextrin (HPCD) was incorporated into the nanoparticle formulation. Solid complexes of CsA with HPCD in different ratios were prepared by the kneading method. CsA containing alone or in combination with HPCD in poly-lactide-coglycolide (P-CsA or P-CsA-HPCD) nanoparticles were prepared by the emulsification solvent evaporation method. The mean size of CsA-loaded NPs was found to be approximately 220 nm. The solubility of CsA was significantly improved and the phase solubility diagram of CsA-HPCD systems showed an A L type phase. Nanoparticles showed high CsA encapsulation efficiency (88%) and production yield (89%). Release rate was increased by the presence of HPCD and total cumulative release ranged from 75% to 96% in 24 h. In vitro cytotoxicity study assay resulted in a low toxicity for all types of nanoparticles. After 6 h incubation period, the cellular uptake was found at 33% and 32% for P-CsA and P-HPCD-CsA nanoparticles, respectively.
Permeation of PLGA nanoparticles across different in vitro models
Current Drug Delivery, 2012
and multidrug resistance. Some of the problems associated with currently available drug treatment for TB are poor permeation and low bioavailability. Many drug delivery systems have indicated improvement in targeteddelivery of various drug molecules and among these, biodegradable and biocompatible polymers such as poly(D,L-lactide-co-glycolide) (PLGA) have been shown to enhance intracellular uptake of drug candidates when formulated as nanoparticles. PLGA nanoparticles were prepared by means of a double emulsion solvent evaporation technique and evaluated in terms of size, encapsulation efficiency, surface charge, isoniazid release and in vitro transport. The nanoparticles have an average size of 237 nm, and were previously shown to be distributed in several tissues after oral administration without triggering an immune response. This study focussed on the in vitro permeation of the PLGA nanoparticles across different membranes and showed that although the nanoparticles are efficiently delivered across the intestinal epithelium, they release encapsulated isoniazid very slowly after being transported. This may improve the treatment efficiency due to continuous release of the isoniazid after effective delivery of the nanoparticulate system across the intestinal epithelium, however, this should be confirmed by future in vivo studies.
International journal of pharmaceutics, 2016
Pranoprofen (PF) is a NSAID considered as a safe anti-inflammatory treatment for strabismus and/or cataract surgery. The drug has been formulated in poly (lactic/glycolic) acid (PLGA) nanoparticles (PF-F1NPs with cPF 1.5mg/mL, PF-F2NPs with cPF 1mg/mL) produced by solvent displacement technique and tested the in vitro cytotoxicity, ex vivo corneal permeation, in vivo ocular tolerance and in vivo anti-inflammatory efficacy of PF-F1NPs, PF-F2NPs, in comparison to eye drops conventional dosage form (Oftalar(®), PF 1mg/mL) and free drug solution (PF dissolved in PBS, 1.5mg/mL). The mean particle size of both formulations was around 350nm, with polydispersity index below 0.1, and a net negative charge of -7.41mV and -8.5mV for PF-F1NPs and PF-F2NPs, respectively. Y-79 human retinoblastoma cell line was used to evaluate the cytotoxicity of PF-F1NPs and PF-F2NPs, which were compared to blank NPs and free drug solution (PF dissolved in PBS, 1.5mg/mL). Concentrations up to 75μg/mL exhibited ...
In vivo evaluation of the biodistribution and safety of PLGA nanoparticles as drug delivery systems
Nanomedicine-nanotechnology Biology and Medicine, 2010
The remarkable physicochemical properties of particles in the nanometer range have been proven to address many challenges in the field of science. However, the possible toxic effects of these particles have raised some concerns. The aim of this article is to evaluate the effects of poly(lactide-co-glycolide) (PLGA) nanoparticles in vitro and in vivo compared to industrial nanoparticles of a similar size range such as zinc oxide, ferrous oxide, and fumed silica. An in vitro cytotoxicity study was conducted to assess the cell viability following exposure to PLGA nanoparticles. Viability was determined by means of a WST assay, wherein cell viability of greater than 75% was observed for both PLGA and amorphous fumed silica particles and ferrous oxide, but was significantly reduced for zinc oxide particles. In vivo toxicity assays were performed via histopathological evaluation, and no specific anatomical pathological changes or tissue damage was observed in the tissues of Balb/C mice. The extent of tissue distribution and retention following oral administration of PLGA particles was analyzed for 7 days. After 7 days, the particles remained detectable in the brain, heart, kidney, liver, lungs, and spleen. The results show that a mean percentage (40.04%) of the particles were localized in the liver, 25.97% in the kidney, and 12.86% in the brain. The lowest percentage was observed in the spleen. Thus, based on these assays, it can be concluded that the toxic effects observed with various industrial nanoparticles will not be observed with particles made of synthetic polymers such as PLGA when applied in the field of nanomedicine. Furthermore, the biodistribution of the particles warrants surface modification of the particles to avoid higher particle localization in the liver.
Nanomedicine
Aim: Development of fluorometholone-loaded PEG-PLGA nanoparticles (NPs) functionalized with cell-penetrating peptides (CPPs) for the treatment of ocular inflammatory disorders. Materials & methods: Synthesized polymers and peptides were used for elaboration of functionalized NPs, which were characterized physicochemically. Cytotoxicity and ability to modulate the expression of proinflammatory cytokines were evaluated in vitro using human corneal epithelial cells (HCE-2). NPs uptake was assayed in both in vitro and in vivo models. Results: NPs showed physicochemical characteristics suitable for ocular administration without evidence of cytotoxicity. TAT-NPs and G2-NPs were internalized and displayed anti-inflammatory activity in both HCE-2 cells and mouse eye. Conclusion: TAT-NPs and G2-NPs could be considered a novel strategy for the treatment of ocular inflammatory diseases of the anterior and posterior segment.
Colloids and Surfaces B: …, 2010
The interaction of PLGA-chitosan Nanoplexes with ocular mucosa was investigated ex vivo and in vivo to assess their potential as ocular delivery system. Fluorescent Rhodamine Nanoplexes (Rd-Nanoplexes) were prepared by ionotropic gelation method. The size and morphology of Nanoplexes was investigated by TEM, SEM and PCS. The corneal retention, uptake and penetration of Nanoplexes were analyzed by spectrofluorimetry and confocal microscopy. Corneas from Rd-Nanoplexes-treated rabbits were evaluated for the in vivo uptake and ocular tolerance. The Nanoplexes prepared were round with a mean diameter of 115.6 ± 17 nm and the encapsulation efficiency of Rd was 59.4 ± 2.5%. Data from ex vivo and in vivo studies showed that the amounts of Rd in the cornea were significantly higher for Nanoplexes than for a control Rd solution, these amounts being fairly constant for up to 24 h. Confocal microscopy of the corneas revealed paracellular and transcellular uptake of the Nanoplexes. The uptake mechanism postulated was adsorptive-mediated endocytosis and opening of the tight junctions between epithelial cells. No alteration was microscopically observed after ocular surface exposure to Nanoplexes. Taken together, these data demonstrate that Nanoplexes are potentially useful as ocular drug carriers.