Search results for "Note"
showing 10 items of 10709 documents
Efficient Shielding of Polyplexes Using Heterotelechelic Polysarcosines
2018
Shielding agents are commonly used to shield polyelectrolyte complexes, e.g. polyplexes, from agglomeration, precipitation in complex media, like blood, and thus enhance their circulation times in vivo. Since up to now primarily poly(ethylene glycol) (PEG) has been investigated to shield non-viral carriers for systemic delivery, we report on the use of polysarcosine (pSar) as a potential alternative for steric stabilization. A redox-sensitive, cationizable lipo-oligomer structure (containing two cholanic acids attached via a bioreducible disulfide linker to an oligoaminoamide backbone in T-shape configuration) was equipped with azide-functionality by solid phase supported synthesis. After m…
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…
Unraveling the In Vivo Protein Corona
2021
Understanding the behavior of nanoparticles upon contact with a physiological environment is of urgent need in order to improve their properties for a successful therapeutic application. Most commonly, the interaction of nanoparticles with plasma proteins are studied under in vitro conditions. However, this has been shown to not reflect the complex situation after in vivo administration. Therefore, here we focused on the investigation of magnetic nanoparticles with blood proteins under in vivo conditions. Importantly, we observed a radically different proteome in vivo in comparison to the in vitro situation underlining the significance of in vivo protein corona studies. Next to this, we fou…
Continuously manufactured magnetic polymersomes--a versatile tool (not only) for targeted cancer therapy.
2013
Micromixer technology was used to prepare polymeric vesicles (Pluronic® L-121) dual loaded with the anti-cancer drug camptothecin and magnetic nanoparticles. Successful incorporation of the magnetic nanoparticles was confirmed by transmission electron microscopy. Dynamic light scattering measurements showed a relatively narrow size distribution of the hybrid polymersomes. Camptothecin polymersomes reduced the cell viability of prostate cancer cells (PC-3) measured after 72 h significantly, while drug-free polymersomes showed no cytotoxic effects. Covalent attachment of a cancer targeting peptide (bombesin) as well as a fluorescent label (Alexa Fluor® 647) to the hybrid polymersomes was perf…
Biocompatibility and biodistribution of functionalized carbon nano-onions (f-CNOs) in a vertebrate model
2016
AbstractFunctionalized carbon nano-onions (f-CNOs) are of great interest as platforms for imaging, diagnostic and therapeutic applications due to their high cellular uptake and low cytotoxicity. To date, the toxicological effects of f-CNOs on vertebrates have not been reported. In this study, the possible biological impact of f-CNOs on zebrafish during development is investigated, evaluating different toxicity end-points such as the survival rate, hatching rate, and heart beat rate. Furthermore, a bio-distribution study of boron dipyrromethene (BODIPY) functionalized CNOs in zebrafish larvae is performed by utilizing inverted selective plane illumination microscopy (iSPIM), due to its intri…
Effect of endothelial cell heterogeneity on nanoparticle uptake.
2020
Endothelial cells exhibit distinct properties in morphology and functions in different organs that can be exploited for nanomedicine targeting. In this work, endothelial cells from different organs, i.e. brain, lung, liver, and kidney, were exposed to plain, carboxylated, and amino-modified silica. As expected, different protein coronas were formed on the different nanoparticle types and these changed when foetal bovine serum (FBS) or human serum were used. Uptake efficiencies differed strongly in the different endothelia, confirming that the cells retained some of their organ-specific differences. However, all endothelia showed higher uptake for the amino-modified silica in FBS, but, inter…
Granulocyte Colony-Stimulating Factor Nanocarriers for Stimulation of the Immune System (Part I): Synthesis and Biodistribution Studies
2018
In the field of cancer immunotherapy, an original approach consists of using granulocyte colony-stimulating factor (G-CSF) to target and activate neutrophils, cells of the innate immune system. G-CSF is a leukocyte stimulating molecule which is commonly used in cancer patients to prevent or reduce neutropenia. We focused herein on developing a G-CSF nanocarrier which could increase the in vivo circulation time of this cytokine, keeping it active for targeting the spleen, an important reservoir of neutrophils. G-CSF-functionalized silica and gold nanoparticles were developed. Silica nanoparticles of 50 nm diameter were functionalized by a solid phase synthesis approach. The technology enable…
Minor changes in the macrocyclic ligands but major consequences on the efficiency of gold nanoparticles designed for radiosensitization
2016
International audience; Many studies have been devoted to adapting the design of gold nanoparticles to efficiently exploit their promising capability to enhance the effects of radiotherapy. In particular, the addition of magnetic resonance imaging modality constitutes an attractive strategy for enhancing the selectivity of radiotherapy since it allows the determination of the most suited delay between the injection of nanoparticles and irradiation. This requires the functionalization of the gold core by an organic shell composed of thiolated gadolinium chelates. The risk of nephrogenic systemic fibrosis induced by the release of gadolinium ions should encourage the use of macrocyclic chelat…
Chemical composition of essential oil from Italian populations of Artemisia alba Turra (Asteraceae).
2012
The use of essential oils as chemotaxonomic markers could be useful for the classification of Artemisia species and to caracterize biodiversity in the different populations. An analysis of the chemical composition of four essential oils from Italian populations of Artemisia alba Turra (collected in Sicily, Marche and Abruzzo) was investigated. In this paper an in depth study of the significant differences observed in the composition of these oils is reported.
Materials for molecular electronics and magnetism
2021
Functional molecular materials exhibiting, in particular, electrical, magnetic or optical properties have been an active focus of research over the last 50 years. These materials have been a source of inspiration in two interrelated areas of research, namely, molecular electronics and molecular magnetism, with important implications in biomedical areas. This themed issue highlights recent progress and perspectives in these important areas of materials science. The issue covers topics from the chemical design and manipulation of novel molecular materials with unprecedented control over their properties, even at the single-molecule level, to exciting applications of these special molecular sy…