title: Directed transport of bacteria-based drug delivery vehicles: bacterial chemotaxis dominates particle shape.
abstract: Several attenuated and non-pathogenic bacterial species have been demonstrated to actively target diseased sites and successfully deliver plasmid DNA, proteins and other therapeutic agents into mammalian cells. These disease-targeting bacteria can be employed for targeted delivery of therapeutic and imaging cargos in the form of a bio-hybrid system. The bio-hybrid drug delivery system constructed here is comprised of motile Escherichia coli MG1655 bacteria and elliptical disk-shaped polymeric microparticles. The transport direction for these vehicles can be controlled through biased random walk of the attached bacteria in presence of chemoattractant gradients in a process known as chemotaxis. In this work, we utilize a diffusion-based microfluidic platform to establish steady linear concentration gradients of a chemoattractant and investigate the roles of chemotaxis and geometry in transport of bio-hybrid drug delivery vehicles. Our experimental results demonstrate for the first time that bacterial chemotactic response dominates the effect of body shape in extravascular transport; thus, the non-spherical system could be more favorable for drug delivery applications owing to the known benefits of using non-spherical particles for vascular transport (e.g. relatively long circulation time).
authors.affiliation: School of Biomedical Engineering and Sciences, Virginia Tech-Wake Forest University, Blacksburg, VA, 24061, USA.
authors.forename: Ali
authors.initials: A
authors.lastname: Sahari
authors.forename: Mahama A
authors.initials: MA
authors.lastname: Traore
authors.forename: Birgit E
authors.initials: BE
authors.lastname: Scharf
authors.forename: Bahareh
authors.initials: B
authors.lastname: Behkam
mesh_terms: D001692:Biological Transport; D002633:Chemotaxis; D004337:Drug Carriers; D004926:Escherichia coli / Q000378:metabolism* / Q000648:ultrastructure; D046210:Microfluidic Analytical Techniques; D008954:Models, Biological
chemical_list: D004337:Drug Carriers