Manipulating the genetic identity and biochemical surface properties of individual cells with electric-field-induced fusion

An approach to electrical modeling of single and multiple cells

“…Small external fields from dc to ϾϷ1 GHz are of interest with respect to sensory systems, medical applications, and possible human health hazards (3-12). Larger pulsed fields are involved in stimulation of excitable cells (13,14) and electroporation and heating of tissue in vivo (15)(16)(17)(18)(19) and cells in vitro (20)(21)(22)(23) or ex vivo (24).Biological cells contain highly conductive aqueous electrolytes separated by thin, low-conductivity membranes populated with electrically active macromolecules. As a result, multicellular systems are extremely heterogeneous with respect to their passive electrical properties (local resistance and capacitance) and both passive and active interaction mechanisms (ion pumps, voltage-gated channels, and electroporatable membrane regions).…”

Nanoparticle Synthesis in Vesicle Microreactors

“…In nature, fusion is a spontaneous and important event, by which a myriad of physicochemical processes occur (Leabu et al, 2006;Chernomordik et al, 2006;Jahn et al, 2006Tsaadon et al, 2006;Ogura et al, 1995;Wilmut et al, 1997) such as fertilization from egg-sperm fusion, formation of multinucleated muscle cells from fusion of myoblasts during embryonic development, signaling cascades. Fusion has been also widely observed in artificial and natural colloidal systems from crystal growth via droplet condensation to lipid vesicle (Strömberg et al, 2000;Riske et al, 2006) or polymersome Yan et al, 2004;Vriezema et al, 2003) recombination. For fusion-initiated nanoparticle synthesis, the starting complementary reactants are separately loaded into different colloids, and then the reaction is triggered by the fusion of these reactive colloids to make the reactants meet each other.…”

“…The process is completed within milliseconds. Due to its general applicability and mild conditions, electrofusion has been extensively used and the procedures further developed for many years (Strömberg et al, 2000) in a wide variety of biological experiments with cells and vesicles, from the creation of hybridomas and new cell lines to in vitro fertilization and the production of cloned offspring, like the sheep Dolly and her equals (Zimmermann et al, 1986). Genetic and biochemical reactions, such as DNA transcription, translation and gene expression, are often achieved by fusion.…”

“…An important condition for successful fusion-initiated reactions is to stimulate the vesicles in order to obtain an effective fusion event since vesicle fusion is inefficient in the absence of external stimuli. Fusion can be induced artificially by means of membrane stress (Cohen et al, 1982;Shillcock et al, 2005), ions or organic reagents (Estes et al, 2006;Neil et al, 1993;Lentz, 2007;Haluska et al, 2006;Kunishima et al, 2006), DNA (Stengel et al, 2007), proteins (Jahn et al, 2006;Peters et al, 1999 and summary by Walde et al, 2001), laser beams (Steubing et al, 1991;Weber et al, 1992;Kulin et al, 2003) or electric fields (Strömberg et al, 2000). The last one is termed electrofusion.…”

Optical delivery of liposome encapsulated chemical stimuli to neuronal cells

“…13,[16][17][18][19] Here, alternatively, using micrometric vesicles as vectors, we extended a technique previously introduced by Sun et al 9 to deliver extracellular chemical stimuli to morphologically complex cells as neurons are. We demonstrate the possibility of local stimulation of hippocampal primary neuronal cultures, a model system composed of cells of complex morphology, synaptically connected in a network.…”