title: The modulation of physicochemical characterization of innovative liposomal platforms: the role of the grafted thermoresponsive polymers.
abstract: This study is focused on chimeric advanced drug delivery systems and specifically on thermosensitive liposomes, combining lipids and thermoresponsive polymers. In this investigation, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) chimeric liposomal systems were prepared, incorporating the homopolymer C12H25-poly(N-isopropylacrylamide)-COOH (C12H25-PNIPAM-COOH) and the block copolymer poly(n-butylacrylate-b-N-isoropylacrylamide) (PnBA-PNIPAM), at six different molar ratios. Both of these polymers contain the thermoresponsive PNIPAM block, which exhibits lower critical solution temperature (LCST) at 32 °C in aqueous solutions, changing its nature from hydrophilic to hydrophobic above LCST. During the preparation of liposomes, the dispersions were observed visually, while after the preparation we studied the alterations of the physicochemical characteristics, by measuring the size, size distribution and ζ-potential of prepared liposomes. The presence of polymer, either C12H25-PNIPAM-COOH or PnBA-PNIPAM, resulted in liposomes exhibiting different physicochemical characteristics in comparison to conventional DPPC liposomes. At the highest percentage of the polymeric guest, chimeric liposomes were found to retain their size during the stability studies. The incorporation of the appropriate amount of these novel thermoresponsive polymers yields liposomal stabilization and imparts thermoresponsiveness, due to the functional PNIPAM block.
authors.affiliation: a Department of Pharmaceutical Technology , Faculty of Pharmacy, University of Athens , Panepistimioupolis Zografou , Athens , Greece and.
authors.forename: Maria
authors.initials: M
authors.lastname: Chountoulesi
authors.affiliation: a Department of Pharmaceutical Technology , Faculty of Pharmacy, University of Athens , Panepistimioupolis Zografou , Athens , Greece and.
authors.forename: Aimilia
authors.initials: A
authors.lastname: Kyrili
authors.affiliation: a Department of Pharmaceutical Technology , Faculty of Pharmacy, University of Athens , Panepistimioupolis Zografou , Athens , Greece and.|b Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation , Athens , Greece.
authors.forename: Natassa
authors.initials: N
authors.lastname: Pippa
authors.affiliation: b Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation , Athens , Greece.
authors.forename: Anastasia
authors.initials: A
authors.lastname: Meristoudi
authors.affiliation: b Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation , Athens , Greece.
authors.forename: Stergios
authors.initials: S
authors.lastname: Pispas
authors.affiliation: a Department of Pharmaceutical Technology , Faculty of Pharmacy, University of Athens , Panepistimioupolis Zografou , Athens , Greece and.
authors.forename: Costas
authors.initials: C
authors.lastname: Demetzos
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry*; D000179:Acrylates / Q000737:chemistry*; D000180:Acrylic Resins / Q000737:chemistry*; D055598:Chemical Phenomena; D006358:Hot Temperature; D057927:Hydrophobic and Hydrophilic Interactions; D008081:Liposomes / Q000737:chemistry*; D010316:Particle Size; D011108:Polymers / Q000737:chemistry*; D013678:Technology, Pharmaceutical / Q000379:methods*
chemical_list: D000179:Acrylates; D000180:Acrylic Resins; D008081:Liposomes; D011108:Polymers; C498324:poly(n-butyl acrylate); C052970:poly-N-isopropylacrylamide; D015060:1,2-Dipalmitoylphosphatidylcholine
keywords: Chimeric advanced drug delivery systems; lipids; thermoresponsive polymers; thermosensitive liposomes