Interaction of polyhedral oligomeric silsesquioxanes and dipalmitoylphosphatidylcholine at the air/water interface: Thermodynamic and rheological study

M Skrzypiec; G As Georgiev; M Rojewska; K Prochaska

doi:10.1016/j.bbamem.2017.06.012

Interaction of polyhedral oligomeric silsesquioxanes and dipalmitoylphosphatidylcholine at the air/water interface: Thermodynamic and rheological study

Biochim Biophys Acta Biomembr. 2017 Oct;1859(10):1838-1850. doi: 10.1016/j.bbamem.2017.06.012. Epub 2017 Jun 20.

Authors

M Skrzypiec¹, G As Georgiev², M Rojewska¹, K Prochaska³

Affiliations

¹ Institute of Chemical Technology and Engineering, Poznan University of Technology, Berdychowo str. 4, 60-965 Poznan, Poland.
² Department of Optics and Spectroscopy, Faculty of Physics, University of Sofia, Sofia, Bulgaria.
³ Institute of Chemical Technology and Engineering, Poznan University of Technology, Berdychowo str. 4, 60-965 Poznan, Poland. Electronic address: krystyna.prochaska@put.poznan.pl.

PMID: 28642041
DOI: 10.1016/j.bbamem.2017.06.012

Abstract

Polyhedral oligomeric silsesquioxanes (POSS) derivatives containing open silsesquioxane cage bear great potential for biomedical applications and therefore their lateral interactions with phospholipids, major biomembranes and drug vehicles constituent, should be studied in detail. That is why the properties of surface films by two POSS-derivatives, POSS-polyethylene glycol (POSS-PEG) and POSS-perfluoroalkyl (POSS-OFP), pure and in presence of 1,2-dipalmitoyl-sn-glycerol-3-phosphocholine (DPPC) were studied using Langmuir surface balance. Side chains of opposite nature (PEG is hydrophilic; OFP is hydrophobic) were selected, so that to evaluate their impact on polymers' surface properties. Two types of measurements were performed: (i) the miscibility of POSS-derivatives with DPPC was evaluated via thermodynamic analysis of the surface pressure (π)-area (A) isotherms and (ii) the dilatational rheology of selected POSS-polymer containing films was studied by the stress relaxation method. Fourier transformation analysis of the relaxation transients allows to access films' dynamic interfacial properties in broad frequency range (10^-5-1Hz). Film morphology was monitored with Brewster Angle Microscopy. PEG moiety enabled POSS-PEG to stably incorporate in DPPC films, modifying their equilibrium and dynamic properties. In contrast OFP chains excluded from interactions with other molecules and diminished PEG-OFP amphiphilicity. Therefore at high packing densities (π≥25mN/m) PEG-OFP was expelled from the air/water interface in DPPC/PEG-OFP mixtures, and the binary films equilibrium and dynamic surface properties were determined primarily by DPPC. Thus the choice of POSS side chains can play key role in biomedical applications depending on whether strong or weak incorporation of POSS-polymers in lipid environment is aimed for.

Keywords: Cole-Cole plot; Dilatational rheology; Langmuir monolayer; Phospholipid (DPPC); Polyhedral oligomeric silsesquioxanes (POSS); Stress-relaxation.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

1,2-Dipalmitoylphosphatidylcholine / chemistry*
Air
Hydrophobic and Hydrophilic Interactions
Organosilicon Compounds / chemistry*
Phospholipids / chemistry
Polyethylene Glycols / chemistry
Polymers / chemistry*
Pressure
Rheology
Surface Properties
Thermodynamics
Water / chemistry*

Substances

Organosilicon Compounds
Phospholipids
Polymers
polyhedraloligosilsesquioxane
Water
1,2-Dipalmitoylphosphatidylcholine
Polyethylene Glycols