Living Fungi Cells Encapsulated in Polyelectrolyte Shells Doped with Metal Nanoparticles

Abstract

We report the layer-by-layer coating of living fungi cells (Saccharomyces cerevisiae and Trichoderma asperellum) with polyelectrolytes poly(allylamine hydrochloride)/sodium poly(styrene sulfonate) and bovine serum albumin/DNA and citrate-stabilized gold and silver nanoparticles. It was found that the nanoparticles were effectively incorporated between oppositely charged polyelectrolyte layers, modifying the topography and the roughness of cell walls. The formation of large aggregates of nanoparticles on the cell walls of encapsulated cells was shown. It was found that the encapsulated cells preserved their viability and the shells were soft enough to allow the growth of mycelium. The surface-enhanced Raman scattering (SERS) was used to investigate the biochemical environments of the gold and silver nanoparticles immobilized on the surface of T. asperellum conidia. The SERS spectra from encapsulated conidia and polyelectrolytes indicate that both gold and silver nanoparticles interact with cell walls from different locations, and nanoparticle-polyelectrolyte interaction is limited. The approach described in this paper might have potential applications in modification of living cells.

Interfacing Living Yeast Cells with Graphene Oxide Nanosheaths

“…Organic polymers and inorganic nanoparticles can bring various new functionalities to the cell membranes, including fluorescent and magnetic property, catalytic moieties, and supporting templates. [11][12][13][14][15][16][17][18][19] For that, we have attempted to assemble multilayers on the yeast cells with a combination of GO nanosheets with two most common strong polyelectrolytes such as PDDA þ , and PSS -. According to the same protocol, the yeast cells were encapsulated based on the electrostatic interactions between oppositely charged GO nanosheets and organic polyelectrolytes in a format of yeast@(PDDA þ /GO-COO -) and yeast@(GO-NH þ 3 / PSS -), respectively.…”

“…The layer-by-layer (LbL) self-assembly of polymers also has been used for encapsulating individual living cells with organic macromolecules. [3][4][5][6][7][8][9] In addition, the surface of microbial cells was doped with various nanoparticles, such as silica, [10,11] gold, [12] silver, and iron, [13] and carbon nanotubes [14] by the LbL self-assembly. Very recently, individual yeast cells were encapsulated within silica, [15,16] calcium phosphate, [17] calcium carbonate, [18] and polydopamine, [19] inspired by biomineralization processes or an adhesive protein found in mussels.…”

Nanostructured Assemblies of Gold and Silver Nanoparticles for Plasmon Enhanced Spectroscopy Using Living Biotemplates

“…Microorganisms, including viruses, bacteria, and fungi, grow in unique and interesting structures that can be combined with the functional properties of noble metal nanoparticles to generate new smart materials [13,16,22,23]. Usually, it is necessary to modify the surface of nanoparticles in order to increase their affinity for the mycelium [47]. However, in this study, we successfully exposed the fungi directly to colloidal suspensions of unmodified gold and silver nanoparticles, resulting in a stable hybrid material [22].…”

Development of X-ray micro-focus computed tomography to image and quantify biofilms in central venous catheter models in vitro

“…Importantly, studies have demonstrated X-ray µCT identification of Gram-negative bacteria using silver microspheres as a contrast agent , and multispecies water biofilms using barium sulfate and propidium iodide (Davit et al, 2011). Other studies have also used gold and silver nanoparticles to identify yeast species by surface-enhanced Raman scattering (Fakhrullin et al, 2009), highlighting that these contrast stains, combined with X-ray µCT, are applicable across a wide range of potential pathogens. Importantly, also for clinical application, silver and gold nanoparticles also lend themselves to conjugation with oligonucleotides, which may allow bacterial-specific labelling capable of resolving bacteria from thrombus and other occlusions, which future studies into clinical application will need to address (Tauran et al, 2013).…”