Project Description

Lipid bilayers are ubiquitous in cell membranes and play an important role in the encapsulation of nanoparticles and DNA for drug delivery and gene therapy. In this project, we will examine the mechanisms that lead to membrane rupture due to thermal fluctuations, ultrasonication, and/or electroporation, examining specific applications on how to control bacterial inactivation for biotechnology and food industries. We will investigate two stages of rupture: a first stage in which random mechanical perturbations result in initiation of a prepore from bilayer defects, followed by a second stage of nucleation and growth of pores leading to bilayer rupture. We will develop a formalism to predict the evolution of probability distribution of defects using a first passage time analysis. The knowledge of rate of formation of prepores will then be employed in the classical analysis of nucleation to describe bilayer rupture. The models will be employed to predict the effects of intensity of different types of external perturbations as well as bilayer composition on rupture time and probability. We will compare these results to experiments using model lipid bilayers and bacterial cells, as well as MD simulations of lipid bilayers.

Start Date

April 2020

Postdoc Qualifications 

The postdoctoral researcher should have a degree in Chemical Engineering, Mechanical Engineering, Materials Science, or equivalent. The research requires a strong background in colloidal/interfacial sciences. Experience in basic statistical mechanics and MD simulations is desirable. 

Co-advisors 

Vivek Narsimhan
vnarism@purdue.edu
Assistant Professor of Chemical Engineering
https://engineering.purdue.edu/ChE/people/ptProfile?resource_id=169352

Ganesan Narsimhan
narsimha@purdue.edu
Professor of Agricultural and Biological Engineering
https://engineering.purdue.edu/ABE/people/ptProfile?resource_id=7368

References 

J.B. Dahl, V. Narsimhan, B. Gouveia, S. Kumar, E.S.G. Shaqfeh, and S.J. Muller. “Experimental observation of the asymmetric instability of intermediate-reduced-volume vesicles in extensional flow ” Soft Matter, 12, 3787-3796 (2016)

V. Narsimhan*, A.P. Spann*, and E.S.G. Shaqfeh. “Pearling, wrinkling, and buckling of vesicles in elongational flows.” J. Fluid. Mech., 777, 1-26, (2015).

G. Narsimhan and Z. Wang. “Rupture of equilibrium foam films due to random thermal and mechanical perturbations”. Colloids and Surfaces A, 282-283, pp 24-36, (2006)

Z. Wang and G. Narsimhan. “Rupture and draining of foam films due to random pressure fluctuations.” Langmuir, 23, pp 2437-2443, (2007)

Lyu, Y., Xiang, N., Zhu, X., & Narsimhan, G. (2017). Potential of mean force for insertion of antimicrobial peptide melittin into a pore in mixed DOPC/DOPG lipid bilayer by molecular dynamics simulation. The Journal of chemical physics, 146(15), 155101.