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Biomedical subjects

Jesus M de la Fuente

Publications and source records attributed to Jesus M de la Fuente.

6 recordsLinked to original sources
PubMed2006

Fluorescent aromatic platforms for cell patterning.

This paper describes a simple experimental method of patterning fluorescent organic dyes, fluorescein, and rhodamine on gold substrates by microcontact printing techniques. The development of this step-by-step protocol has allowed us to prepare striped and squared micropatterns with poly(ethylene glycol) (PEG) linkers terminated by these fluorophores using a fast, easy, and inexpensive technique. Although the rest of the surface was covered with aliphatic molecules (methyl terminated), human fibroblasts demonstrated an unexpected response, aligning themselves according to the aromatic patterns, despite the presence of PEG, which is a cell resistant molecule, in the fluorescent regions.

Cell Adhesion↗
PubMed2006

Nanoparticle targeting at cells.

Gold nanoparticles have been used for analytical and biomedical purposes for many years. In fact, the labeling of targeting molecules with nanoparticles has revolutionized the visualization of cellular or tissue components by electron microscopy. We report in this study the derivatization of tiopronin-protected nanoparticles with ethylenediamine and poly(ethylene glycol) bis(3-aminopropyl) terminated and their functionalization with the GRGDSP peptide sequence by a straightforward and economical methodology. The particles were subsequently tested in vitro with a human fibroblast cell line to determine the biocompatibility, and the cell-particle interactions, using fluorescence and scanning electron microscopies. The results indicate that tiopronin gold nanoparticles aggregate due to culture medium proteins, whereas the tiopronin gold nanoparticles derivatized with ethylenediamine induce endocytosis, and the same nanoparticles derivatized with poly(ethylene glycol) derivative promote particle-cell adhesion.

Cell Adhesion↗
PubMed2005

Do inhaled carbon nanoparticles translocate directly into the circulation in humans?

RATIONALE: Increased exposure to particulate air pollution (PM(10)) is a risk factor for death and hospitalization with cardiovascular disease. It has been suggested that the nanoparticulate component of PM(10) is capable of translocating into the circulation with the potential for direct effects on the vasculature. OBJECTIVE: The study's aim was to determine the extent to which inhaled technetium-99m ((99m)Tc)-labeled carbon nanoparticles (Technegas) were able to access the systemic circulation. METHODS AND MAIN RESULTS: Ten healthy volunteers inhaled Technegas and blood samples were taken sequentially over the following 6 h. Technegas particles were 4-20 nm in diameter and aggregated to a median particle diameter of approximately 100 nm. Radioactivity was immediately detected in blood, with levels increasing over 60 min. Thin-layer chromatography of whole blood identified a species that moved with the solvent front, corresponding to unbound (99m)Tc-pertechnetate, which was excreted in urine. There was no evidence of particle-bound (99m)Tc at the origin. gamma Camera images demonstrated high levels of Technegas retention (95.6 +/- 1.7% at 6 h) in the lungs, with no accumulation of radioactivity detected over the liver or spleen. CONCLUSIONS: The majority of (99m)Tc-labeled carbon nanoparticles remain within the lung up to 6 h after inhalation. In contrast to previous published studies, thin-layer chromatography did not support the hypothesis that inhaled Technegas carbon nanoparticles pass directly from the lungs into the systemic circulation.

Adult↗
PubMed2004

Understanding carbohydrate-carbohydrate interactions by means of glyconanotechnology.

Carbohydrate-carbohydrate interaction is a reliable and versatile mechanism for cell adhesion and recognition. Glycosphingolipid (GSL) clusters at the cell membrane are mainly involved in this interaction. To investigate carbohydrate-carbohydrate interaction an integrated strategy (Glyconanotechnology) was developed. This strategy includes polyvalent tools (gold glyconanoparticles) mimicking GSL clustering at the cell membrane as well as analytical techniques such as AFM, TEM, and SPR to evaluate the interactions. The results obtained by means of this strategy and current status are presented.

Biosensing Techniques↗
PubMedDate not supplied

Tat peptide as an efficient molecule to translocate gold nanoparticles into the cell nucleus.

The labeling of targeting molecules with nanoparticles has revolutionized the visualization of cellular or tissue components by electron microscopy. A particularly desirable target is the nucleus, because the genetic information is there. To date, utilizing nanoparticles for nuclear targeting has not proved very successful due to the impermeable nature of the plasma and nuclear membranes; thus nanoparticle design and synthesis is a critical factor. We report in this article the synthesis of water-soluble gold nanoparticles functionalized with a Tat protein-derived peptide sequence by a straightforward and economical methodology. The particles were subsequently tested in vitro with a human fibroblast cell line by optical and transmission electron microscopy to determine the biocompatibility of these nanoparticles and whether the functionalization with the translocation peptide allowed particles to transfer across the cell membrane and locate in the nucleus.

Biological Transport↗