title: Entrapment of peptidoglycans and adamantyltripeptides into liposomes: an HPLC assay for determination of encapsulation efficiency.
abstract: The encapsulation of different immunomodulating peptides, the peptidoglycan monomer, its semisynthetic derivatives (Adamant-1-yl)-acetyl-peptidoglycan monomer and Boc-Tyr-peptidoglycan monomer, respectively, and of two diastereoisomers of adamantyltripeptides into the large negatively charged multilamellar liposomes was investigated. The reproducible quantitative method using HPLC was established for the determination of the entrapped compounds. It was shown that the tested compounds could be efficiently incorporated into liposomes using either the film or modified film method. The results confirmed that the peptidoglycans with lipophilic substituents and particularly the adamantyltripeptides were incorporated into liposomes with higher efficiency than the peptidoglycan monomer using either of the described methods. Liposome preparations were stable at 4 degrees C up to seven days as shown by minimal leaking of the entrapped material.
authors.affiliation: Research and Development, Institute of Immunology, Inc., Zagreb, Croatia. rfrkanec@imz.hr
authors.forename: Ruza
authors.initials: R
authors.lastname: Frkanec
authors.forename: Dijana
authors.initials: D
authors.lastname: Travas
authors.forename: Marina
authors.initials: M
authors.lastname: Krstanović
authors.forename: Beata Halassy
authors.initials: BH
authors.lastname: Spoljar
authors.forename: Durdica
authors.initials: D
authors.lastname: Ljevaković
authors.forename: Branka
authors.initials: B
authors.lastname: Vranesić
authors.forename: Leo
authors.initials: L
authors.lastname: Frkanec
authors.forename: Jelka
authors.initials: J
authors.lastname: Tomasić
mesh_terms: D000218:Adamantane / Q000031:analogs & derivatives* / Q000737:chemistry*; D000276:Adjuvants, Immunologic / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004339:Drug Compounding / Q000379:methods; D004355:Drug Stability; D008081:Liposomes / Q000737:chemistry*; D015394:Molecular Structure; D009842:Oligopeptides / Q000737:chemistry*; D010457:Peptidoglycan / Q000737:chemistry*; D013997:Time Factors
chemical_list: C405426:(adamant-2-yl)-glycyl-alanyl-isoglutamine; D000276:Adjuvants, Immunologic; D008081:Liposomes; D009842:Oligopeptides; D010457:Peptidoglycan; D000218:Adamantane