Project Title: Characterization of Nanoparticle-Membrane Interactions

Project Duration: May 23 – July 29, 2016 (10 weeks), 40 hours per week.

Project Mentors

• Primary Faculty Mentor (Name, Affiliation, website and Email/Phone):
  • Eric Freeman, College of Engineering, http://freemangroup.wordpress.com, ecfreema@uga.edu

• Secondary Faculty Mentor (Name, Affiliation, website and Email/Phone):
  • Xianqiao Wang, College of Engineering, http://xqwang.engr.uga.edu/index.htm, xqwang@uga.edu

Project Description: Biomembranes are self-assembled lipid bilayer membranes that mimic the naturally occurring membranes surrounding living cells. These membranes may be assembled through microfluidic techniques, and serve as scaffolds for the insertion of various biomolecules such as mechanically-sensitive ion channels. The result is a biological material capable of mimicking cellular functionality while remaining relatively simple to assemble, with applications ranging from drug delivery to chemical sensing.

A previous study performed by REU student Nicole Gay showed that a biocompatible suspension of superparamagnetic nanoparticles may be used to deform a lipid membrane through an externally supplied magnetic field. Tentatively dubbed “magnetowetting,” this behavior may be used to activate (or gate) embedded mechanosensitive ion channels such as MscL, allowing for magnetically-driven mixing of species separated by the thin biomolecular membrane. This may be useful for the development of magnetically-responsive chemical sensors and actuators, and will be explored further through the REU program.

The nature of the deformation must be interpreted from the axon data through current-voltage relations. While convenient, this does not provide the complete picture – comparison to results obtained from coarse-grained molecular dynamics simulations helps fill in the gaps, and provide a more in-depth look at the underlying mechanics of the membrane deformation.

REU Student Role and Responsibility: The selected REU student will investigate whether the ferrofluid may be used to activate embedded mechanosensitive channels in the membrane. The student will be responsible for substrate design and creation through PDMS and soft lithography techniques, creation of suitable buffer and lipid solutions for membrane creation, careful recordings of transmembrane currents through electrophysiology equipment, and comparison to computational results provided by Dr. Wang’s group.

Expected Outcome for REU student: The selected REU student will be listed as co-author on any resulting publications and will have the opportunity to present their work at BMES meetings.