Multimodal Particle-Size Distribution or Fractal Surface of Acrylic Acid Copolymer Nanoparticles: A Small-Angle X-ray Scattering Study using Direct Fourier and Indirect Maximum-Entropy Methods

Abstract

Acrylic acid copolymers are potential carriers for drug delivery. The surface, surface rugosity and the absolute dimension of the particles are parameters that determine the binding of drugs or detergents, diffusion phenomena at the surface and the distribution of the carrier within the human body. The particle-size distribution and surface rugosity of the particles have been investigated by smallangle X-ray scattering and dynamic light scattering. Direct Fourier transform as well as a new strategy for the indirect maximum-entropy method MAXENTare used for data evaluation. Scattering equivalence of a pure multimodal distribution of hard spheres (five populations) and a mixed multimodal-surface-fractal model (four populations) was found. Model calculations and dynamic lightscattering experiments gave evidence of the multimodal particle-size distribution combined with the fractal surface of the carrier. The main moiety consists of particles 90 nm in diameter which are surface fractals in the 10 nm region.

Measurement of lipoprotein particle sizes using dynamic light scattering

“…The latter has been reported to give larger mean sizes than the former. 15,16,19…”

“…The latter has been reported to give larger mean sizes than the former. 15,16,19 The measurement of lipoprotein particle sizes has been conducted using GGE in many reports and by DLS in few reports. In a previous study using DLS, the LDL fraction isolated by ultracentrifugation was determined to have diameters of 22.9 + 1.0 nm.…”

An iterative method to extract the size distribution of non-interacting polydisperse spherical particles from small-angle scattering data

“…An iterative method using the above procedure was implemented by Mulato & Chambouleyron (1996). Further, using the maximum entropy method, the estimation of a PSD from SAS data was introduced initially by Potton et al (1988) and subsequently modified by several groups (Tatchev & Kranold, 2004;Morrison et al, 1992;Jemian & Allen, 1994;Tsao & Lin, 1997;Mü ller et al, 1995).…”