Hydrodynamic Behavior of Dendrigraft Polylysines in Water and Dimethylformamide

Abstract

Abstract:The four first generations of dendrigraft poly-L-lysine have been studied in dimethylformamide (aprotic solvent) and in 0.2 M NaCl aqueous solutions by isothermal translation diffusion, 1 H NMR and viscometry methods. The relationships between diffusion coefficient, intrinsic viscosity and molar mass have been determined for dendrigraft poly-L-lysines, and the scaling index values have been compared to classical trifunctional dendrimers. Dendrimers and dendrigraft poly-L-lysines exhibited similitudes in their hydrodynamic behaviors. Nevertheless, dendrigraft poly-L-lysines displayed a specific behavior in solution. In contrast to dendrimers, a significant change of hydrodynamic dimension of dendrigraft poly-L-lysines according to the nature of the solvent has been observed. In aprotic solvent, the dendrigraft poly-L-lysine dimensions are about two times lower than in aqueous media (i.e., the hydrodynamic volume is contracted by a factor 8 in dimethylformamide), revealing the softness of dendrigraft poly-L-lysine compared to classical trifunctional dendrimers. OPEN ACCESSPolymers 2012, 4 21

Lysine Dendrigraft Nanocontainers. Influence of Topology on Their Size and Internal Structure

“…The higher the degree of branching, the smaller is the size of the dendrigraft. We found that sizes calculated from the simulations of dendrigrafts 2 and 3 (with three and seven branching points in each side chain, respectively) are in good agreement with the existing experimental data for PLL dendrigrafts [ 28 , 29 ]. At the same time, the size of dendrigraft 1 (with linear side chains) is essentially greater than that of experimental ones and it is likely that this topology is not realized in real lysine dendrigrafts.…”

“…The values of R g calculated from MD simulations of dendrigraft 2 and dendrigraft 3 (2.64 nm and 2.09 nm, respectively) belong to the interval of values R g = 1.65–2.65 nm ( R h = 2.14–3.43 nm) obtained by different experimental methods in [ 28 , 29 ], while our value of R g for dendrigraft 1 is essentially higher than for the experimental ones.…”

“…Thus, the increase of the branching degree from dendrigraft 1 to dendrigraft 3 leads to smaller dendrigraft size due to the decrease of the contour length of the side chains (see Figure 1 ). We can compare values of R g obtained from our simulation with R g calculated from experimental hydrodynamics radius R h [ 28 , 29 ] using theoretical connection of R g and R h for undrained spherical molecules: …”

Peptide mediated active targeting and intelligent particle size reduction-mediated enhanced penetrating of fabricated nanoparticles for triple-negative breast cancer treatment

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“…The physicochemical characterization of dendrimers, and particularly DGLs is crucial for these applications as their macromolecular dimension and behavior in aqueous solution determine their biomedical efficiency . Their average molecular weights (connected to their average degrees of polymerization, DP) are also important for establishing a structure–property relationship.…”