Figure 2
From: Effect of 3D-scaffold formation on differentiation and survival in human neural progenitor cells
AFM images of pure PuraMatrix scaffolds. AFM images of pure PuraMatrix scaffolds; scan size: 0.75 × 0.75 μm2 (left column) or 4 × 4 μm2 (right column). Depending on the PM concentration two kinds of fibres are formed: long and thin beta-sheets (i.e. isolated PM fibres, exemplary marked by white arrows; height ca. 1.3 nm and length > 1 μm) and bundles or aggregates of these sheets (red arrows). Additionally, a crossing of single PM fibres is accompanied by an increase in height (white arrows), indicating that once the PM fibres are created, they do not interdigitate. At low PM concentrations (PM 0.15% and 0.25%, Fig. 2A-D) the samples show a homogeneous distribution of single PM fibres and bundles, whereas an increase in PM concentration rises the numbers of bundles within the network. At 0.5% PM concentration (E, F) the fibres form very dense networks that cannot be penetrated by AFM.