A mechanistic view of lipid membrane disrupting effect of PAMAM dendrimers.
The effect of 5th generation polyamidoamine (PAMAM G5) dendrimers on multilamellar dipalmitoylphosphocholine (DPPC) vesicles was investigated. PAMAM was added in two different concentrations to the lipids (10(-3) and 10(-2) dendrimer/lipid molar ratios). The thermal behavior of the evolved systems was characterized by DSC; while the structure and the morphology were investigated with small- and wide-angel X-ray scattering (SWAXS), freeze-fracture electron microscopy (FFTEM) and phosphorus-31 nuclear magnetic resonance ((31)P NMR) spectroscopy, respectively. IR spectroscopy was used to study the molecular interactions between PAMAM and DPPC. The obtained results show that the dendrimers added in 10(-3) molar ratio to the lipids generate minor perturbations in the multilamellar structure and thermal character of liposomes, while added in 10(-2) molar ratio dendrimers cause major disturbance in the vesicular system. The terminal amino groups of the dendrimers are in strong interaction with the phosphate headgroups and through this binding dendrimers disrupt the regular multilamellar structure of DPPC. Besides highly swollen, fragmented bilayers, small vesicles are formed.
Dept. of Biological Nanochemistry, Institute of Molecular Pharmacology, Research Centre of Natural Sciences, Hungarian Academy of Sciences, Magyar Tudósok körútja 2. 1117 Budapest, Hungary. Electronic address: berenyi.szilvia@mail.bme.hu.
Szilvia
S
Berényi
Dept. of Biological Nanochemistry, Institute of Molecular Pharmacology, Research Centre of Natural Sciences, Hungarian Academy of Sciences, Magyar Tudósok körútja 2. 1117 Budapest, Hungary.
Judith
J
Mihály
Dept. of Biological Nanochemistry, Institute of Molecular Pharmacology, Research Centre of Natural Sciences, Hungarian Academy of Sciences, Magyar Tudósok körútja 2. 1117 Budapest, Hungary.
András
A
Wacha
Dept. of Structural Chemistry, Institute of Organic Chemistry, Research Centre of Natural Sciences, Hungarian Academy of Sciences, Magyar Tudósok körútja 2. 1117 Budapest, Hungary.
Orsolya
O
Tőke
Dept. of Biological Nanochemistry, Institute of Molecular Pharmacology, Research Centre of Natural Sciences, Hungarian Academy of Sciences, Magyar Tudósok körútja 2. 1117 Budapest, Hungary.
Attila
A
Bóta
D002152:Calorimetry, Differential Scanning; D050091:Dendrimers / Q000737:chemistry*; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008563:Membrane Lipids / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D013055:Spectrophotometry, Infrared; D013696:Temperature; D014961:X-Ray Diffraction
D050091:Dendrimers; D008563:Membrane Lipids; C104700:PAMAM Starburst; D004134:Dimyristoylphosphatidylcholine
DPPC; Dendrimer; Infrared spectroscopy; Model membrane; SAXS