Search results for "PSU"
showing 10 items of 678 documents
<p>Silica Nanocapsules with Different Sizes and Physicochemical Properties as Suitable Nanocarriers for Uptake in T-Cells</p>
2020
Introduction Adoptive T-cell immunotherapy emerged as a powerful and promising cancer therapy, as the problem regarding the immuno-reaction between different donors and recipients can be avoided. However, this approach is challenging. After long cultivation and expansion under laboratory media conditions, T-cells are losing their viability and function due to immune checkpoint proteins, leading to decreased efficiency in killing cancer cells. Therefore, a new strategy to improve T-cell survival and function is needed. With the advantages of nanotechnology and the biocompatibility of silica-based material, silica nanocapsules (SiNCs) provide an ideal delivery system to transport therapeutic …
Characterization and biodistribution of Au nanoparticles loaded in PLGA nanocarriers using an original encapsulation process
2021
Due to their imaging and radiosensitizing properties, ultrasmall gadolinium chelate-coated gold nanoparticles (AuNP) represent a promising approach in the diagnosis and the treatment of tumors. However, their poor pharmacokinetic profile, especially their rapid renal clearance prevents from an efficient exploitation of their potential for medical applications. The present study focuses on a strategy which resides in the encapsulation of AuNP in large polymeric NP to avoid the glomerular filtration and then to prolong the vascular residence time. An original encapsulation procedure using the polyethyleneimine (PEI) was set up to electrostatically entrap AuNP in biodegradable poly(lactic-co-g…
Influence of Surface Charge and Polymer Coating on Internalization and Biodistribution of Polyethylene Glycol-Modified Iron Oxide Nanoparticles
2015
International audience; The aim of this study was to investigate the influence of the surface charge and coating of Superparamagnetic Iron Oxide Nanoparticles (SPIONs) on their in vitro and in vivo behaviors. Neutral and negatively-charged PEG-based SPIONs were synthesized and compared to Resovist (R), a carboxydextran-based SPION currently used in clinics. Their cytotoxicity, cell internalization, and potential as contrast agents for magnetic resonance imaging were assessed. Neutral pegylated SPIONs were internalized less readily by the reticuloendothelial system and showed a lower uptake by the liver, compared to negatively-charged SPIONs (with carboxydextran and PEG). These results sugge…
Highly Loaded Semipermeable Nanocapsules for Magnetic Resonance Imaging.
2017
Magnetic resonance imaging has become an essential tool in medicine for the investigation of physiological processes. The key issues related to contrast agents, i.e., substances that are injected in the body for imaging, are the efficient enhancement of contrast, their low toxicity, and their defined biodistribution. Polyurea nanocapsules containing the gadolinium complex Gadobutrol as a contrast agent in high local concentration and high relaxivity up to 40 s-1 mmol-1 L are described. A high concentration of the contrast agent inside the nanocapsules can be ensured by increasing the crystallinity in the shell of the nanocapsules. Nanocapsules from aliphatic polyurea are found to display hi…
Encapsulation of polyprodrugs enables an efficient and controlled release of dexamethasone
2021
Water-soluble low molecular weight drugs, such as the synthetic glucocorticoid dexamethasone (DXM), can easily leak out of nanocarriers after encapsulation due to their hydrophilic nature and small size. This can lead to a reduced therapeutic efficacy and therefore to unwanted adverse effects on healthy tissue. Targeting DXM to inflammatory cells of the liver like Kupffer cells or macrophages is a promising approach to minimize typical side effects. Therefore, a controlled transport to the cells of interest and selective on-site release is crucial. Aim of this study was the development of a DXM-phosphate-based polyprodrug and the encapsulation in silica nanocontainers (SiO2 NCs) for the red…
NOVEL COMPOSED GALACTOSYLATED NANODEVICES CONTAINING A RIBAVIRIN PRODRUG AS HEPATIC CELL-TARGETED CARRIERS FOR HCV TREATMENT
2013
In this paper, we describe the preparation of liver-targeted nanoparticles potentially able to carry to hepatocytes a ribavirin (RBV) prodrug, exploiting the presence of carbohydrate receptors in the liver (i.e., ASGPR in hepatocytes). These particles were obtained starting from a galactosylated phospholipid-polyaminoacid conjugate. This latter was obtained by chemical reaction of ALPHA, BETA -poly(N-2-hydroxyethyl) (2-aminoethylcarbamate)-DL-aspartamide (PHEA-EDA) with 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-(succinyl) sodium salt (DPPE), and subsequent reaction with lactose, obtaining PHEA-EDA-DPPE-GAL copolymer. To enhance the entrapment into obtained nanostructures, a hydroph…
Compartmentalization of gypsum and halite associated with cyanobacteria in saline soil crusts
2016
The interface between biological and geochemical components in surface crust of a saline soil was investigated using X-Ray Diffraction (XRD), and variable pressure scanning electron microscopy (SEM) in combination with Energy Dispersive X-ray Spectrometry (EDS). Mineral compounds such as halite and gypsum were identified crystallized around filaments of cyanobacteria. A total of 92 genera were identified from the bacterial community based on 16S gene pyrosequencing analysis. The occurrence of the gypsum crystals, their shapes and compartmentalization suggested that they separated NaCl from the immediate microenvironment of the cyanobacteria, and that some cyanobacteria and communities of su…
Protection of Saccharomyces cerevisiae by a layer-by-layer system : effect on yeast metabolic activity in response to environmental conditions
2016
In order to protect the Saccharomyces cerevisiae yeast during dehydration, two strategies were used to improve cell survival. Strengthening cell resistance (internal protection) was performed by improving the concentration of intracellular glutathione in yeast. Encapsulation was performed by layer-by-layer method using two biopolymers β-lactoglobulin and alginate for the external protection of the yeast. The adequate medium culture and favorable growing conditions for glutathione enhancement were determined. The composition of the culture medium is rich in nutrients and glutathione precursors consisting in 30 g/L glucose, 30 g/L yeast extract, 0.6 g/L KH2PO4 and 0.6 g/L cysteine. The succes…
Physical Inactivity from Youth to Adulthood and Risk of Impaired Glucose Metabolism
2018
Introduction: Physical activity (PA) is important in the prevention and treatment of impaired glucose metabolism. However, association of physical inactivity during the transition between childhood and adulthood with glucose metabolism is unknown. Therefore, we studied the association of persistent physical inactivity since childhood with glucose metabolism in adulthood. Methods: Data were drawn from the ongoing, Cardiovascular Risk in Young Finns Study with repeated follow-ups between 1980 and 2011 (baseline age, 3-18 yr; n = 3596). Impaired glucose metabolism was defined as having impaired fasting glucose (6.1-6.9 mmol·L-1) or type 2 diabetes in adulthood. Leisure-time PA habits were repe…
Immunohistochemical and morphological characteristics of tissues response to polylactic acid membranes with silver nanoparticles
2019
Background The aim of this research was to study anti-microbial and anti-inflammatory characteristics of silver nanoparticles helping bone structures to recover during late stage of parodontitis, which afterwards will increase the effect of bone regeneration operations. Material and Methods We assessed colloid solution-derived silver nanoparticles coating of polylactic acid membrane regarding tissue foreign body response. Thirty eight polylactic acid membranes were implanted intracranially in rabbits – ten unmodified (control group) and twenty eight with silver nanoparticles coating (experimental group). In controls, penicillin was used for infection prophylaxis. Tissue response was assesse…