title: Interaction of a partially fluorinated long-chain nicotinate with dipalmitoylphosphatidylcholine.
abstract: The interaction of a partially fluorinated long-chain nicotinate, F-NA18, a compound of interest as a chemopreventive agent, with dipalmitoylphosphatidylcholine (DPPC) was investigated in monolayers at the air-water interface and in fully hydrated bilayers and compared with its hydrocarbon analog, NA18. For the monolayer studies, the compression isotherms of mixtures of F-NA18 with DPPC were recorded at various compositions on a hydrochloric acid subphase (pH = 1.9-2.1, 32 +/- 2 degrees C). Analysis of the composition dependence of the average molecular area at constant film pressure and of the dependence of the breakpoints of the phase transitions suggests that F-NA18 is miscible with DPPC at the air-water interface, whereas NA18 shows some degree of immiscibility. In differential scanning calorimetry studies, only one major phase transition was observed for F-NA18-DPPC mixtures, whereas NA18-DPPC mixtures exhibited a complex phase behavior. The differences in the phase behavior of the respective mixtures may be the result of the geometric packing constraints of F-NA18 versus NA18. Therefore, for biomedical applications, the use of a partially fluorinated tail may offer advantages over simple hydrocarbon systems because, in addition to the chain length, the position and degree of fluorination can be adjusted.
authors.affiliation: Department of Occupational and Environmental Health, University of Iowa, Iowa City, IA 52242, USA. hans-joachim-lehmler@uiowa.edu
authors.forename: Hans-Joachim
authors.initials: HJ
authors.lastname: Lehmler
authors.forename: Paul M
authors.initials: PM
authors.lastname: Bummer
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry*; D000388:Air; D002151:Calorimetry; D002152:Calorimetry, Differential Scanning; D002621:Chemistry / Q000379:methods; D005461:Fluorine / Q000737:chemistry*; D006838:Hydrocarbons / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008051:Lipid Bilayers / Q000737:chemistry; D008956:Models, Chemical; D009525:Niacin / Q000737:chemistry*; D011312:Pressure; D011485:Protein Binding; D013499:Surface Properties; D013696:Temperature; D014867:Water
chemical_list: D006838:Hydrocarbons; D008051:Lipid Bilayers; D014867:Water; D015060:1,2-Dipalmitoylphosphatidylcholine; D009525:Niacin; D005461:Fluorine