title: Prilocaine-cyclodextrin-liposome: effect of pH variations on the encapsulation and topology of a ternary complex using 1H NMR.
abstract: A better comprehension of the prilocaine (PLC)-β-cyclodextrin (β-CD) complex liberation to membranes was provided by studying the architectural supramolecular arrangements of PLC, β-CD and egg phosphatidylcholine (EPC) liposomes, a membrane model. The topologies and possible interactions of mixtures of PLC, β-CD and EPC liposomes were investigated by nuclear magnetic resonances combining experimental (1)H-NMR (1D ROESY, STD and DOSY) at different pHs. The results indicate that in the mixture PLC/β-CD/EPC at pH 10 the PLC molecules are almost totally embedded into the liposomes and little interaction was observed between PLC and β-CD. However, at pH 5.5 not only was PLC imbedded in the EPC bilayer, but PLC was also interacting with β-CD. These results were rationalized as a spontaneous PLC release from β-CD to liposomes vesicles, whereas the PLC/EPC complex formation was higher at pH 10 than pH 5.5.
authors: Institute of Chemistry, UNICAMP, PO Box 6154, 13083-970 Campinas, SP, Brazil.
authors: Luís Fernando
authors: LF
authors: Cabeça
authors: Isis Martins
authors: IM
authors: Figueiredo
authors: Eneida
authors: E
authors: de Paula
authors: Anita Jocelyne
authors: AJ
authors: Marsaioli
mesh_terms: D004531:Eggs; D006863:Hydrogen-Ion Concentration; D008081:Liposomes / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000592:standards; D015394:Molecular Structure; D010713:Phosphatidylcholines / Q000737:chemistry*; D011318:Prilocaine / Q000737:chemistry*; D011522:Protons; D012015:Reference Standards; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D008081:Liposomes; D010713:Phosphatidylcholines; D011522:Protons; D047392:beta-Cyclodextrins; D011318:Prilocaine; C031215:betadex