Abstract
In this paper, we study the interaction of charged polymers with solid-supported 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) membranes by in-situ neutron reflectivity. We observe an enormous swelling of the oligolamellar lipid bilayer stacks after incubation in solutions of poly(allylamine hydrochloride) (PAH) in D2O. The positively charged polyelectrolyte molecules interact with the lipid bilayers and induce a drastic increase in their d-spacing by a factor of ~4. Temperature, time, and pH influence the swollen interfacial lipid linings. From our study, we conclude that electrostatic interactions introduced by the adsorbed PAH are the main cause for the drastic swelling of the lipid coatings. The DMPC membrane stacks do not detach from their solid support at T > Tm. Steric interactions, also introduced by the PAH molecules, are held responsible for the stabilizing effect. We believe that this novel system offers great potential for fundamental studies of biomembrane properties, keeping the membrane’s natural fluidity and freedom, decoupled from a solid support at physiological conditions.
Highlights
Biological cell membranes are selectively permeable for macromolecules and are constantly interacting with their surroundings
The interplay of natural occurring and synthetic polymers with biological membranes is of great interest in the medical field, e.g., in drug delivery [2] and nanotechnology therapeutics [3,4], where for instance positively charged polymer-based nanoparticle (NP) constructs are used in nonviral gene transfection [5]
Membrane, directly adsorbed to the silicon substrate, they host a substantial amount of water within the individual bilayer leaflets varying between 45% and 21% and further changing with treatment (T, t, and pH), see
Summary
Biological cell membranes are selectively permeable for macromolecules and are constantly interacting with their surroundings. The authors used chitosan and hyaluronic acid (HA) as natural occurring molecules of the extra-cellular matrix and investigated their interactions with zwitterionic lipid membranes of vesicles [8] In this context, a numerical study revealed that physiological conditions with a Debye. Singh et al demonstrated the deposition of a free floating DPPC lipid bilayer on a positively charged polyelectrolyte cushion and detected structural differences as a function of the pH of the surrounding solution [12]. These results reveal a strong influence of the free charges in the system. The premise that charged polymers have a profound impact on the morphology and the structure of the supported lipid membrane systems was investigated in-situ by neutron reflectivity
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
