6 research outputs found
pH-mediated molecular differentiation for fluorimetric quantification of chemotherapeutic drugs in human plasma
At present, drug dosage is based on standardised approaches that disregard pharmakokinetic differences between patients and lead to non-optimal efficacy and unnecessary side effects. In this work, we demonstrate the potential of pH-mediated fluorescence spectroscopy for therapeutic drug monitoring in complex media. We apply this principle to the simultaneous quantification of the chemotherapeutic prodrug Irinotecan and its active metabolite SN-38 from human plasma across the clinically relevant concentration range, i.e. from micromolar to nanomolar at molar ratios of up to 30:1
Therapeutic Benefits from Nanoparticles: The Potential Significance of Nanoscience in Diseases with Compromise to the Blood Brain Barrier
Therapeutic Benefits from Nanoparticles: The Potential
Significance of Nanoscience in Diseases with Compromise to the Blood
Brain Barrie
Data_Sheet_1_Selective Targeting of Proteins by Hybrid Polyoxometalates: Interaction Between a Bis-Biotinylated Hybrid Conjugate and Avidin.docx
<p>The Keggin-type polyoxometalate [Îł-SiW<sub>10</sub>O<sub>36</sub>]<sup>8â</sup> was covalently modified to obtain a bis-biotinylated conjugate able to bind avidin. Spectroscopic studies such as UV-vis, fluorimetry, circular dichroism, coupled to surface plasmon resonance technique were used to highlight the unique interplay of supramolecular interactions between the homotetrameric protein and the bis-functionalized polyanion. In particular, the dual recognition mechanism of the avidin encompasses (i) a complementary electrostatic association between the anionic surface of the polyoxotungstate and each positively charged avidin subunit and (ii) specific host-guest interactions between each biotinylated arm and a corresponding pocket on the tetramer subunits. The assembly exhibits peroxidase-like reactivity and it was used in aqueous solution for L-methionine methyl ester oxidation by H<sub>2</sub>O<sub>2</sub>. The recognition phenomenon was then exploited for the preparation of layer-by-layer films, whose structural evolution was monitored in situ by ATR-FTIR spectroscopy. Finally, cell tracking studies were performed by exploiting the specific interactions with a labeled streptavidin.</p
Evolution of Nanoparticle Protein Corona across the BloodâBrain Barrier
Engineered
nanoparticles offer the chance to improve drug transport
and delivery through biological barriers, exploiting the possibility
to leave the blood circulation and traverse the endothelial vascular
bed, bloodâbrain barrier (BBB) included, to reach their target.
It is known that nanoparticles gather molecules on their surface upon
contact with biological fluids, forming the âprotein coronaâ,
which can affect their fate and therapeutic/diagnostic performance,
yet no information on the coronaâs evolution across the barrier
has been gathered so far. Using a cellular model of the BBB and gold
nanoparticles, we show that the composition of the corona undergoes
dramatic quantitative and qualitative molecular modifications during
passage from the âbloodâ to the âbrainâ
side, while it is stable once beyond the BBB. Thus, we demonstrate
that the nanoparticle corona dynamically and drastically evolves upon
crossing the BBB and that its initial composition is not predictive
of nanoparticle fate and performance once beyond the barrier at the
target organ
Evolution of Nanoparticle Protein Corona across the BloodâBrain Barrier
Engineered
nanoparticles offer the chance to improve drug transport
and delivery through biological barriers, exploiting the possibility
to leave the blood circulation and traverse the endothelial vascular
bed, bloodâbrain barrier (BBB) included, to reach their target.
It is known that nanoparticles gather molecules on their surface upon
contact with biological fluids, forming the âprotein coronaâ,
which can affect their fate and therapeutic/diagnostic performance,
yet no information on the coronaâs evolution across the barrier
has been gathered so far. Using a cellular model of the BBB and gold
nanoparticles, we show that the composition of the corona undergoes
dramatic quantitative and qualitative molecular modifications during
passage from the âbloodâ to the âbrainâ
side, while it is stable once beyond the BBB. Thus, we demonstrate
that the nanoparticle corona dynamically and drastically evolves upon
crossing the BBB and that its initial composition is not predictive
of nanoparticle fate and performance once beyond the barrier at the
target organ
Superparamagnetic Nanoparticles as High Efficiency Magnetic Resonance Imaging T<sub>2</sub> Contrast Agent
Nanoparticle-based
magnetic resonance imaging <i>T</i><sub>2</sub> negative
agents are of great interest, and much effort
is devoted to increasing cell-loading capability while maintaining
low cytotoxicity. Herein, two classes of mixed-ligand protected magnetic-responsive,
bimetallic gold/iron nanoparticles (Au/Fe NPs) synthesized by a two-step
method are presented. Their structure, surface composition, and magnetic
properties are characterized. The two classes of sulfonated Au/Fe
NPs, with an average diameter of 4 nm, have an average atomic ratio
of Au to Fe equal to 7 or 8, which enables the Au/Fe NPs to be superparamagnetic
with a blocking temperature of 56 K and 96 K. Furthermore, preliminary
cellular studies reveal that both Au/Fe NPs show very limited toxicity.
MRI phantom experiments show that <i>r</i><sub>2</sub>/<i>r</i><sub>1</sub> ratio of Au/Fe NPs is as high as 670, leading
to a 66% reduction in <i>T</i><sub>2</sub> relaxation time.
These nanoparticles provide great versatility and potential for nanoparticle-based
diagnostics and therapeutic applications and as imaging contrast agents