TY - JOUR

T1 - Interactions of Functionalized PAMAM Dendrimers with Model Cell Membranes Studied via Spin-Labeling Technique

AU - Carloni, Riccardo

AU - Ottaviani, Maria Francesca

AU - Ficker, Mario

AU - Christensen, Jorn B.

PY - 2022

Y1 - 2022

N2 - Polyamidoamine (PAMAM) dendrimers are exploited as drug carriers in various biomedical research fields, especially cancer therapy. The present study analyzes the interactions occurring between differently functionalized PAMAM dendrimers, namely, amine, acetamide, and 3-methoxy-carbonyl-5-pyrrolidonyl ("pyrrolidone"), and model membranes, namely, sodium dodecyl sulfate (SDS), sodium hexadecylsulfate (SHS) micelles, and egg-lecithin liposomes. For this purpose, the dendrimers were spin-labeled with the 3-carbamoyl-PROXYL radical. 1H-NMR spectra allowed the verification not only that labeling was successful but also that acetamide and (even more so) pyrrolidone functions shield the proton signals from the influence of the neighboring nitroxide groups. The computer-aided analysis of the electron paramagnetic resonance (EPR) spectra showed that the dendrimers with the acetamide function largely (60%) entered the SDS-micelles interface, while the amino-dendrimer electrostatically interacted with both the SDS and SHS surface forming dendrimer aggregates in solution. The pyrrolidone-dendrimers showed an intermediate behavior between those with the amino and acetamide functions. The acetamide-and pyrrolidone-dendrimers weakly interacted with the lecithin liposome surface, with a synergy between hydrophilic and hydrophobic interactions. Conversely, liposomes/amino-dendrimers interactions were quite strong and led to dendrimer aggregation at the liposome surface in solution. This information showed that acetamide-and pyrrolidone-dendrimers may be used as good alternatives to amino-dendrimers for drug delivery.

AB - Polyamidoamine (PAMAM) dendrimers are exploited as drug carriers in various biomedical research fields, especially cancer therapy. The present study analyzes the interactions occurring between differently functionalized PAMAM dendrimers, namely, amine, acetamide, and 3-methoxy-carbonyl-5-pyrrolidonyl ("pyrrolidone"), and model membranes, namely, sodium dodecyl sulfate (SDS), sodium hexadecylsulfate (SHS) micelles, and egg-lecithin liposomes. For this purpose, the dendrimers were spin-labeled with the 3-carbamoyl-PROXYL radical. 1H-NMR spectra allowed the verification not only that labeling was successful but also that acetamide and (even more so) pyrrolidone functions shield the proton signals from the influence of the neighboring nitroxide groups. The computer-aided analysis of the electron paramagnetic resonance (EPR) spectra showed that the dendrimers with the acetamide function largely (60%) entered the SDS-micelles interface, while the amino-dendrimer electrostatically interacted with both the SDS and SHS surface forming dendrimer aggregates in solution. The pyrrolidone-dendrimers showed an intermediate behavior between those with the amino and acetamide functions. The acetamide-and pyrrolidone-dendrimers weakly interacted with the lecithin liposome surface, with a synergy between hydrophilic and hydrophobic interactions. Conversely, liposomes/amino-dendrimers interactions were quite strong and led to dendrimer aggregation at the liposome surface in solution. This information showed that acetamide-and pyrrolidone-dendrimers may be used as good alternatives to amino-dendrimers for drug delivery.

KW - STARBURST DENDRIMERS

KW - DENDRITIC POLYMERS

KW - EPR

KW - SULFATE

U2 - 10.1021/acs.jpcb.2c05123

DO - 10.1021/acs.jpcb.2c05123

M3 - Journal article

C2 - 36354364

VL - 126

SP - 9686−9694

JO - Journal of Physical Chemistry Part B: Condensed Matter, Materials, Surfaces, Interfaces & Biophysical

JF - Journal of Physical Chemistry Part B: Condensed Matter, Materials, Surfaces, Interfaces & Biophysical

SN - 1520-6106

IS - 46

ER -