Interactions between PAMAM dendrimers and DOPC lipid multilayers: Membrane thinning and structural disorder

Understanding the structure of hybrid nanoparticle-lipid multilayers is fundamental importance to their bioanalytical applications and nanotoxicity, where nanoparticle-membrane interactions play an important role. Poly(amidoamine) (PAMAM) dendrimers are branched polymeric nanoparticles with potential biomedical due precise tunability physicochemical properties. Here, effect PAMAM (2.9–4.5 nm) either a hydrophilic amine (NH2) or hydrophobic C12 chain surface termination on 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) has been studied for first time. DOPC were created by liposome-rupture method via drop-casting dendrimer-liposome dispersions added at different concentrations three stages. The multilayer was evaluated analysis synchrotron X-ray reflectivity (XRR) curves, obtaining bilayer d-spacing, coherence length from Scherrer (Ls) Bragg peaks, paracrystalline disorder parameter (g). Dendrimer addition led lipid thinning more disordered structures. Larger caused greater structural disruption compared smaller dendrimers. smallest, positively charged highest concentration most pronounced thinning. mixing also affected dendrimer aggregation involved. These results show complexity properties mixed dendrimer-DOPC multilayers. insights useful understanding nanotoxicity future application nanocomposite materials in which enhanced functionality.