A three-dimensional anisotropic point process characterization for pharmaceutical coatings

Authors

Affiliations

Henrike Häbel

Chalmers University of Technology and the University of Gothenburg

Tuomas Rajala

Chalmers University of Technology and the University of Gothenburg

Mariagrazia Marucci

UCL

Catherine Boissier

AstraZeneca R&D Mölndal

Katja Schladitz

Fraunhofer Insititute for Industrial Mathematics ITWM

Claudia Redenbach

University of Kaiserslautern

Aila Särkkä

Chalmers University of Technology and the University of Gothenburg

Abstract

While epidermal nerve fiber (ENF) data have been used to study the effects of small fiber neuropathies through the density and the spatial patterns of the ENFs, little research has been focused on the effects on the individual nerve fibers. Studying the individual nerve fibers might give a better understanding of the effects of the neuropathy on the growth process of the individual ENFs. In this study, data from 32 healthy volunteers and 20 diabetic subjects, obtained from suction induced skin blister biopsies, are analyzed by comparing statistics for the nerve fibers as a whole and for the segments that a nerve fiber is composed of. Moreover, it is evaluated whether this type of data can be used to detect diabetic neuropathy, by using hierarchical models to perform unsupervised classification of the subjects. It is found that using the information about the individual nerve fibers in combination with the ENF counts yields a considerable improvement as compared to using the ENF counts only.

Figure 1: Left: Processed CLSM image of a 23.57×23.57×17 µm3 film section. Dark voxels correspond to the EC-rich phase and bright voxels to the HPC-rich phase. Dimension z goes from drum-side to air-side. The pore structure appears anisotropic with large elongated domains in cross-sections (z) compared to the displayed top layer (xy) with smaller domains forming a homogeneous structure. Right: Film cross-section (ca. 30 µm) obtained by SEM after HPC leaching showing more pores on the top (air-side) than on the bottom (drumside). The gray region above and below the pores is the epoxy-glue in which the sample was embedded.