Ion Mediated Monolayer Deposition of Gold Nanoparticles on Microorganisms: Discrimination by Age

Abstract

A general strategy to target cells by nanoparticles for drug delivery, imaging, or diagnostics involves immunospecific binding between the probes and target molecules on the particles and on the cell surface, respectively. Usually, the macromolecular nature of the molecules requires a specific conformation to achieve the desired immunospecificity, and the extent of deposition of particles is limited by the number of receptor molecules present on the cell. In this report, we successfully obtain targeted binding by decorating the nanoparticle with simple ions, such as Ca(2+), without affecting the cell's vitality. The yeast cells for study, Saccharomyces cerevisiae, have no specific electrostatic affinity toward positive charge as confirmed by lysine-coated Au nanoparticles. The specificity of nanoparticle binding is found to be directly related to the metabolic vitality of the yeast cell (i.e., a significantly larger deposition occurs on a younger generation with higher metabolism than on older cells). The ion-mediated targeted deposition seems to be a general phenomenon for biologically important ions, as demonstrated by the contrast between Mg(2+) and (toxic) Cd(2+). The high density of (percolating) nanoparticle deposition as a monolayer on the cells, as a result of the large number of ion receptors on the cell surface, is shown to be a potential method for building bioelectronic devices. The use of ions as an interface to target cells can have possible applications in diagnosing diseases and making biosensors using live cells.

Therapeutic Potential of Biomineralization‐Based Engineering

“…[58] Some organisms such as the fungus, Rhizopus oryzae, can use a biosynthesis mechanism to reduce AuCl 4and form gold shells on cell walls, indicating that mineral shells can be produced via a bioprocess inside the bacterial cells. [60] The ability of cell membranes to bind metal ions can promote the in situ nucleation of mineral clusters, resulting in the formation of continuous manganese dioxide (MnO 2 ) nanozyme shells onto the yeast cells. [60] The ability of cell membranes to bind metal ions can promote the in situ nucleation of mineral clusters, resulting in the formation of continuous manganese dioxide (MnO 2 ) nanozyme shells onto the yeast cells.…”

Gold nanoparticles delivery in mammalian live cells: a critical review

“…Sensor arrays have been developed to differentiate normal, cancerous, and metastatic cells using the fluorescence quenching properties of gold nanoparticles (30). The interactions and fate of a broad range of functionalized nanoparticles is currently under investigation in a wide diversity of biological models, ranging from whole organisms to tissues to cells in culture, and also to yeast (33) and prokaryote bacteria (34). The needs of intracellular delivery depend on the applications.…”

Identification of Gold Nanoparticle-Resistant Mutants of Saccharomyces cerevisiae Suggests a Role for Respiratory Metabolism in Mediating Toxicity

“…Although the multiplicity of both gold nanoparticle type and toxicity assay complicate direct comparisons, a number of reports indicate that the type of particle tested in the present study (ϳ1 nm, positively charged) can elicit toxicity (7)(8)(9)(10). While the yeast Saccharomyces cerevisiae has been a prominent and highly informative biological model (11), its use for evaluating the effects of nanomaterials appears to be limited based on few published reports (12)(13)(14)(15). Here, we asked whether use of the yeast model could be informative with respect to determining the toxicity of the same functionalized gold nanoparticle previously found to cause significant mortality in embryonic zebrafish (8).…”