Binding and uptake of biodegradable poly-dl-lactide micro- and nanoparticles in intestinal epithelia (original) (raw)

Nanoparticles as carriers for oral peptide absorption: Studies on particle uptake and fate

Journal of Controlled Release, 1995

Previous work from our laboratories has provided quantitative proof of the importance of the gut associated lymphoid tissue (GALT) in the processes involved in the uptake of polystyrene nanoparticles delivered orally, and has confirmed the role of the Peyer's patches in the uptake of particles through the small intestine. In more recent work discussed here the role of lymphoid tissue in the large intestine has been demonstrated, a significant amount of the total uptake occurring in this region of the gut. Adsorption of poloxamers 188 and 407 onto 50 nm polystyrene nanopartictes inhibited uptake in the small intestine and reduced uptake from the large intestine, suggesting reduction in adhesion to GALT and other epithelial tissues in the presence of the poloxamer coating but also indirectly suggesting differences in the surface characteristics of lymphoid tissue at different sites in the gut. The covalent attachment of tomato (Lycopersicon esculentum) lectin molecules to the surface of 500 nm polystyrene particles had a significant effect not only on total uptake (well over a 10-fold increase in absorption over 'plain' particles after 5 days daily dosing) but on the locus of uptake, which is shifted from lymphoid to normal non-lymphoid intestinal tissue. We have demonstrated, therefore, both an increase and a decrease in absorption of nanoparticles from the gastro-intestinal tract and some, albeit serendipitous, control of the site of uptake and absorption, which should provide pointers for the future development of systems with optimal uptake characteristics.

Poly (lactide-co-glycolide) particles of different physicochemical properties and their uptake by peyer's patches in mice

European Journal of Pharmaceutics and Biopharmaceutics, 2005

Nano-and microparticles of poly(lactide-co-glycolide) (PLGA) were formulated using poly(vinyl alcohol) (PVA) or hydrophobically modified hydroxyethylcellulose (HMHEC) or polyethyleneimine (PEI) as stabilizers. The uptake by murine Peyer's patches (PPs) and the binding to Peyer's patches-free tissue (PPFT) of these particles was investigated using fluorescence microscopy providing qualitative information about the tissue distribution of particles. Observations of intestinal cryo-sections showed significant discrimination in the uptake by PP of nano-and microparticles. The uptake by PPs of PLGA-PVA and PLGA-HMHEC nano-and microparticles, of negative and neutral zeta potential, respectively, was comparable, whereas a smaller number was observed in the case of nano-and microparticles of PLGA-PEI, positively charged. Moreover, particle uptake by PPs appeared to be strongly size-dependent. The number of particles of mean diameter around 0.3 and 1 mm observed in PPs was much greater than that of particles of diameter average close to 3 mm. However, in all cases, particles were found in the PPFT for at least 48 h. In conclusion, regarding the tissue samples we have observed, it appeared that the uptake of particles by PPs and binding to PPFT could be influenced by the physicochemical properties of the particles but this may not have been true at all sites of the intestine and may differ between animals.

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

Interaction of biodegradable nanoparticles with intestinal cells: The effect of surface hydrophilicity

International Journal of Pharmaceutics, 2010

The aim of the present work was to study the influence of surface hydrophilicity of biodegradable polymeric nanoparticles on cellular uptake by Caco-2 cells. Poly(d,l-lactide-co-glycolide acid) particles loaded with a fluorescent dye, 3,3′-dioctadecyloxacarbo-cyanine perchlorate (DiO), were prepared by the emulsion–evaporation process. Three batches of particles with narrow size distribution (100, 300 and 1000 nm) were produced using selective centrifugation. One set of particles was coated by adsorption of chitosan to increase the hydrophilicity of the particles. The interaction of particles with Caco-2 cells was determined by fluorescence spectroscopy and the number of particles associated with one single cell was then calculated. Interaction with cells was clearly dependant on particle size and surface hydrophilicity. Particles in the range of 100 nm presented higher interaction when compared to larger particles. Approximately 6000 uncoated particles and more than 30,000 chitosan-coated particles were quantified per cell. Confocal microscopy confirmed the spectroscopic measurements and revealed the location of the particles in the cell monolayer. Only small particles were observed intracellularly, whereas particles larger than 300 nm were associated with the apical membranes. The location of particles <300 nm appeared to be intracellular and some particles colocalized with the nucleus.

Interactions between Nanoparticles and Intestine

International Journal of Molecular Sciences

The use of nanoparticles (NPs) has surely grown in recent years due to their versatility, with a spectrum of applications that range from nanomedicine to the food industry. Recent research focuses on the development of NPs for the oral administration route rather than the intravenous one, placing the interactions between NPs and the intestine at the centre of the attention. This allows the NPs functionalization to exploit the different characteristics of the digestive tract, such as the different pH, the intestinal mucus layer, or the intestinal absorption capacity. On the other hand, these same characteristics can represent a problem for their complexity, also considering the potential interactions with the food matrix or the microbiota. This review intends to give a comprehensive look into three main branches of NPs delivery through the oral route: the functionalization of NPs drug carriers for systemic targets, with the case of insulin carriers as an example; NPs for the delivery...

The use of deoxycholic acid to enhance the oral bioavailability of biodegradable nanoparticles

Biomaterials, 2008

Oral delivery of nanoparticles encapsulating drugs and proteins remains a challenging route for administration due to the many barriers in the gastrointestinal tract that limit bioavailability. We hypothesized that bile salts could be used to improve the bioavailability of poly(lactide-co-glycolide) (PLGA) nanoparticles by protecting them during their transport through the gastrointestinal tract and enhancing their absorption by the intestinal epithelia. A deoxycholic acid emulsion is shown to protect PLGA nanoparticles from degradation in acidic conditions and enhance their permeability across a Caco-2 cell monolayer, an in vitro model of human epithelium. Oral administration of loaded PLGA nanoparticles to mice, using a deoxycholic acid emulsion, produced sustained levels of the encapsulant in the blood over 24-48 h with a relative bioavailability of 1.81. Encapsulant concentration was highest in the liver, demonstrating a novel means for targeted delivery to the liver by the oral route. r

Mammalian gastrointestinal tract parameters modulating the integrity, surface properties, and absorption of food-relevant nanomaterials

Wiley interdisciplinary reviews. Nanomedicine and nanobiotechnology, 2015

Many natural chemicals in food are in the nanometer size range, and the selective uptake of nutrients with nanoscale dimensions by the gastrointestinal (GI) tract is a normal physiological process. Novel engineered nanomaterials (NMs) can bring various benefits to food, e.g., enhancing nutrition. Assessing potential risks requires an understanding of the stability of these entities in the GI lumen, and an understanding of whether or not they can be absorbed and thus become systemically available. Data are emerging on the mammalian in vivo absorption of engineered NMs composed of chemicals with a range of properties, including metal, mineral, biochemical macromolecules, and lipid-based entities. In vitro and in silico fluid incubation data has also provided some evidence of changes in particle stability, aggregation, and surface properties following interaction with luminal factors present in the GI tract. The variables include physical forces, osmotic concentration, pH, digestive en...

Can lipid nanoparticles improve intestinal absorption?

International Journal of Pharmaceutics, 2016

Lipid nanoparticles and their multiple designs have been considered appealing nanocarrier systems. Bringing the benefits of these nanosystems together with conventional coating technology clearly results in product differentiation. This work aimed at developing an innovative solid dosage form for oral administration based on tableting nanostructured lipid carriers (NLC), coated with conventional polymer agents. NLC dispersions co-encapsulating olanzapine and simvastatin (Combo-NLC) were produced by high pressure homogenization, and evaluated in terms of scalability, drying procedure, tableting and performance from in vitro release, cytotoxicity and intestinal permeability stand points. Factorial design indicated that the scaling-up of the NLC production is clearly feasible. Spray-drying was the method selected to obtain dry particles, not only because it consists of a single step procedure, but also because it facilitates the coating process of NLC with different polymers. Modified NLC formulations with the polymers allowed obtaining distinct release mechanisms, comprising immediate, delayed and prolonged release. Sureteric:Combo-NLC provided a low cytotoxicity profile, along with a ca. 12-fold OL/3-fold SV higher intestinal permeability, compared to those obtained with commercial tablets. Such findings can be ascribed to drug protection and control over release promoted by NLC, supporting them as a versatile platform able to be modified according to the intended needs. 2016 Elsevier B.V. All rights reserved.

A novel In Vitro Model for Studying Nanoparticle Interactions with the Small Intestine

EURO-NanoTox-Letters, 2016

Manufactured nanomaterials provide promising features for new technologies in cosmetic, food, and pharmaceutical applications. On the other hand, orally ingested nanomaterials/nanoparticles may interact with or enter intestinal cells via different mechanisms, resulting in possible injuries of the biological system. For that reason, the current study aims to provide useful information concerning physicochemical properties of nanoparticles with regard to cytotoxic effects and uptake mechanisms in the small intestine. Differently charged polystyrene nanoparticles were used and cytotoxicity and uptake were studied with an intestinal in vitro co-culture model, mimicking the villus epithelium and a triple-culture model recapitulating the follicle-associated epithelium. Mechanisms of cellular transport were investigated at 37°C and 4°C to verify that internalization mainly occurs energy-dependently. Chemical inhibitors (i.e., chlorpromazine, genistein, dynasore) were used to block dynamin-dependent endocytic pathways without affecting cell viability and membrane integrity. Qualification and quantification were performed via confocal microscopy and flow cytometry. Furthermore, co-localization studies with commonly used markers (i.e., transferrin, lactosylceramide) were carried out and co-localization was assessed via calculation of Pearson´s correlation coefficient and Mander´s overlap coefficient. The results show that size and surface chemistry play a crucial role in cytotoxic interactions and cellular uptake of nanoparticles (NPs). Independent of the surface charge, NPs strongly interact with intestinal mucus and are immobilized. Uptake predominantly occurs via M cells and is surface-charge dependent. Whereas negatively charged particles fail to enter cells, positive and neutral particles penetrate M cells energy-dependently. More precisely, both clathrin-and caveolae-mediated endocytosis are involved. It can be concluded that the presented system serves as a valuable tool to assess safety aspects of manufactured nanomaterials and hence, substantially contributes to nanosafety efforts.