Non-uniform self-assembly: On the anisotropic architecture of α-synuclein supra-fibrillar aggregates

Although the function of biopolymer hydrogels in nature depends on structural anisotropy at mesoscopic length scales, the self-assembly of such anisotropic structures in vitro is challenging. Here we show that fibrils of the protein α-synuclein spontaneously self-assemble into structurally anisotropic hydrogel particles. While the fibrils in the interior of these supra-fibrillar aggregates (SFAs) are randomly oriented, the fibrils in the periphery prefer to cross neighboring fibrils at high angles. This difference in organization coincides with a significant difference in polarity of the environment in the central and peripheral parts of the SFA. We rationalize the structural anisotropy of SFAs in the light of the observation that αS fibrils bind a substantial amount of counterions. We propose that, with the progress of protein polymerization into fibrils, this binding of counterions changes the ionic environment which triggers a change in fibril organization resulting in anisotropy in the architecture of hydrogel particles

Characterization and plasticity of human fetal-derived cartilage cells: implications for skeletal tissue regeneration

Abstract of paper from TCES (Tissue and Cell Engineering Society) meeting in 2005. The ability of the skin to extend and recoil is mediated by an elastic fibre network comprising elastin molecules deposited on a microfibrillar scaffold. Studies have demonstrated reduced tensile strength in scar tissue following cutaneous wounding, possibly due to decreased amounts of elastic fibres1. The dermal component of artificial skin substitutes also lacks an organised elastic fibre network, which may contribute to excessive contraction and scarring post-grafting. This study aimed to document the temporal and spatial distribution of elastic fibres following incisional and excisional cutaneous wounding in mice