Selective Effect of Procaine, Tetracaine and Dibucaine on Gold Nanoparticles

Abstract

An aqueous colloid dispersion of gold nanoparticles (AuNPs) was prepared by reduction of gold(III) chloride and its interaction with three local anesthetics (procaine, dibucaine or tetracaine) was investigated. Optical spectra reveal the modifications in the absorption band of nanoparticles related to their self assembly mediated by anesthetic molecules and depending on the progress in time of the aggregation process. TEM images show the features of the self assemblies formed by the association of gold nanoparticles in presence of anesthetics, and reveal marked differences in the behavior of the AuNPs against the three anesthetics. The main effect of various anesthetics can be described in terms of electrostatic forces between the negatively charged metal nanoparticles and anesthetic molecules, existing in their cationic form at the working pH. Then, the anesthetics functionalized nanoparticles trigger specific interactions to form different self assemblies through a selective combination of hydrophobic and hydrogen bonding interactions between the coated nanoparticles and anesthetics molecular species.

Assessing the Potential for Drug–Nanoparticle Surface Interactions To Improve Drug Penetration into the Skin

“…However, this interaction did not induce size and zeta potential changes to the nanoparticles when subjected to 10 μM tetracaine (data not shown). This was unlike the results obtained by Mocanu et al, 39 who observed a decrease in zeta potential values when nanoparticles were mixed with tetracaine molecules. The difference in the results was probably due to the different concentrations investigated.…”

New procedure to synthesize silver nanoparticles and their interaction with local anesthetics

“…As discussed elsewhere, 35 the investigated anesthetic molecule tertiary amines (Figure 1) all have a tertiary nitrogen atom and another basic nitrogen atom: primary in procaine ( Figure 1A), secondary in tetracaine ( Figure 1C), and quinoline aromatic in dibucaine ( Figure 1B). The two pK a values, for the two steps of dissociation from the dicationic form BH 2 2+ to the monocationic BH + , respectively, from this to the neutral form (B) are between 8.8 and 9 for the tertiary nitrogen in procaine, and between 2.0 and 2.3 for its −NH 2 group.…”

“…However, there were some differences in the effect of the three anesthetics on the AgNPs, so one should assume that specific interactions between these organic molecules and the NPs must also play a role in the self-assembly of AgNPs mediated by these molecules. As in the case of citrate-capped gold NPs, 35 the formation of hydrogen bonds should be considered, …”

Silymarin Based Complexes – a mini review

“…Gold nanoparticles are also of particular interest for science, nanotechnology and medical applications [121]. This is due to its ability to bind to biomolecules such as amino acids [122][123][124][125][126][127][128], anesthetics [129], chemotherapeutic drugs [130,131], and proteins [132][133][134][135]. GNPs and silymarin was observed to improve liver function and reduced cholestasis.…”