TDM structure

1. Tetraether Archaeal Liposomes: Remarkable Stability against Surfactants Parkson L. Chong, Temple University, DMR 0706410 • We have studied the effect of surfactant n-tetradecyl-β-d-maltoside (TDM, see below) on liposomes composed of the polar lipid fraction E (PLFE, one kind of archaeal bipolar tetraether lipids) and 1-palmitoyl-2-oleoyl-L-a-phosphatidylcholine (POPC, a monopolardiester lipid). • Dynamic light scattering was used to monitor the changes in particle size as the concentration of TDM was increased (top graph, right panel; not all the data are shown). Experimental temperature = 25 oC • For a given liposome, the particle size drops abruptly at a specific TDM concentration (top graph). The TMD concentration where the vesicle size is reduced to half its original value is designated as C1/2. There is a dramatic increase in C1/2 as the content of PLFE increases to >70 mol% (bottom graph). • According to the C1/2 values, bipolar tetraether (e.g., PLFE) liposomes are ~14 times more stable against the surfactant TDM than monopolar diester (e.g., POPC) liposomes. TDM structure

2. Tetraether Archaeal Liposomes: Remarkable Stability against Surfactants Parkson L. Chong, Temple University School, DMR 0706410 • Broader Impacts • Undergraduate training (this current academic year): • Aldo Fafaj, a senior undergraduate student majoring in chemistry, is the first author of the work described in this highlight. He was a 2010 Temple University Summer Undergraduate Research Program intern. A full manuscript for this experimental work is in preparation. • The other undergraduate students who participated in this project are: Leeandrew Taylor, Nam Tran, Thida Tran, Jenny Lam, Rachel Youjin Lee, Elizabeth Zellhart, Michael Bellano, Chelsea Little, Annie Kavulich, Anna Versage, Kara Thompson, Nicole Haloupek, James Hwang, Vinoth Birabaharan ( 2 out of 14 are minority students and 10 are women). • Technological applications: • The extraordinary stability of PLFE liposomes against surfactants demonstrates that archaeal tetraether liposomes hold great promise for technological applications such as orally administered drug carriers (left panel). bs TG bs Drug Small Intestine PLFE Liposome bs: Bile salts (surfactants) TG: Triglycerides Diagram (not to scale) showing the drug carrying PLFE liposomes inside the small intestine where they are exposed to bile salts (surfactants).