Svetlana A. Konnova

Silver nanoparticle-coated “cyborg” microorganisms: rapid assembly of polymer-stabilised nanoparticles on microbial cells

Fabrication of “cyborg” cells (biological cells with surfaces functionalised using a variety of nanomaterials) has become a fascinating area in cell surface engineering. Here we report a simple procedure for fabrication of polycation-stabilised 50 nm silver nanoparticles and application of these nanoparticles for fabrication of viable “cyborg” microbial cells (yeast and bacteria). Cationic polymer-stabilised nanoparticles electrostatically adhere to microbial cells producing an even monolayer on the cell walls, as demonstrated using enhanced dark-field microscopy, atomic force microscopy and microelectrophoresis. Our procedure is exceptionally fast, being completed within 20 min after introduction of cells into nanoparticle aqueous suspensions. Polymer-stabilised silver nanoparticles are highly biocompatible, with viability rates reaching 97%. We utilised “cyborg” cells built using bacteria and silver nanoparticles to deliver nanoparticles into C. elegans microworms. We believe that the technique described here will find numerous applications in cell surface engineering.

Magnetic halloysite nanotubes for yeast cell surface engineering

Abstract Halloysite clay nanotubes are safe and biocompatible nanomaterials and their application in biomaterials is very promising. The microencapsulation of yeast cells in the shell of clay nanotubes modifying their properties was demonstrated here. Each cell was coated with a 200-300 nm-thick tube shell and this coating was not harmful for these cells’ reproduction. Synthesis of magnetic nanoparticles on the surfaces of the nanotubes allowed for magnetic-field manipulation of the coated cells, including their separation. Providing nano-designed shells for biological cells is a step forward in development of ‘cyborg’ microorganisms combining their intrinsic properties with functions added through nano-engineering.

CHAPTER 3:Direct Deposition of Nanomaterials onto Cells

Nanomaterials and nanoscale tools have been successfully utilized in diverse biological systems over the past decades. Integrating nanomaterials with living cells attracts considerable interest because it may be possible to provide new functions, control cell phenotype and fate, and also to create cell–nanomaterial hybrids with desirable properties. In this chapter we describe strategies and methods for the direct deposition of nanomaterials onto cells for extracellular surface functionalisation. We emphasize the importance of the cell surface properties and their interactions with nanomaterials. We also discuss the different approaches to deposit nanomaterials onto cells by either aiming at a homogeneous coating of the cells with different types of nanomaterials or ligand-specific binding of nanoparticles to extracellular biomolecules. The importance of the cell viability during the process of nanomaterials deposition, which depends on the field of application, is discussed. We also present some of the recent studies focused on the development of new smart materials for cell surface functionalization, fabrication of 3D nanoparticle–cell hybrids, and utilization of nanomodified cells in emerging technologies.

Hybrid systems based on living organisms, polymers, and nanoparticles

The review sums up the achievements of recent years in the field of hybrid systems containing living microorganisms and single mammalian cells, polymers, nanoparticles, and inorganic bio-mimetic shells. The authors paid special attention to the methods of creating and classifying these systems. Several approaches to the formation of hybrid systems were emphasized, including the direct deposition of nanomaterials onto the surface of organisms, the functionalization of organisms by thin polymer films, the polymer-mediated immobilization of nanomaterials, and biomimetic encapsulation. Methods for the practical applications of hybrid systems are suggested. The final chapter describes, approaches to the formation of multicellular clusters of microorganism single cells via the integration of the cells into a synthetic polymer matrix on a structured surface or their three-dimensional self-assembling onto various templates.