| Abstract
| - The cell membrane can withstand significant osmotic stress before pores open to relieve the tension. Theamount of stress that the membrane can withstand is determined by the lipid chemistry; we have examinedthe effect of four non-bilayer forming lipids on the stability of phosphatidylcholine (PC, a bilayer forminglipid) membranes. Large unilamellar vesicles were subjected to hypo-osmotic gradients and the leakage oftheir contents was quantified. Three micelle forming lipids, lysophosphatidylcholine (LPC), lysophosphatidylethanolamine (LPE), and lysophosphatidylglycerol (LPG), were studied along with one inverted-micelleforming lipid, phosphatidylethanolamine (PE). The inclusion of the lyso lipids resulted in greater leakagefrom the vesicles, while the inclusion of the PE resulted in less leakage from the vesicles. From the leakagedata, the pressure difference at the point of pore closure was determined along with the critical surface tensionand the line tension. Results will be presented detailing how the shape and percentage of non-bilayer forminglipids affects leakage.
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