The plasma membrane

The plasma membrane: Nature's touch screen?

Dobbenga, S.

Fratila-Apachitei, L. (mentor)

Mechanical, Maritime and Materials Engineering

BioMechanical Engineering (BME)

Biomaterials & Tissue Biomechanics

2017-04-11

Nanotopography has the ability to induce osteogenic differentiation of human Mesenchymal Stem Cells (hMSCs) without the addition of chemical supplements. Understanding of the early mechanisms that interact at the membrane-topography interface and subsequently induce the osteogenic differentiation of hMSCs as a result of nanotopography is key to facilitating a rational design of e.g. multi-functional implant surfaces. Nevertheless, these early mechanisms are yet to be elucidated and systematic approaches in the variation of pattern dimensions and arrangements that are essential in their discovery, are deficient in literature. Electron Beam Induced Deposition (EBID) is a bottom-up, direct writing technique capable of producing high-resolution nanoscale structures and is proposed in this thesis as a fitting technique for facilitating a systematic approach in the variation of pattern dimensions and arrangements. In this thesis, EBID’s potential has been demonstrated by producing osteogenic patterns from literature with a higher degree of control in feature dimension and position, as well as a series of additional patterns and complex structure shapes that further demonstrate the high positioning accuracy of EBID. Furthermore, mechanisms that potentially act at early membrane-topography interactions are explored in this thesis. One mechanism that could potentially play a role in these early interactions is the proposed ability of membrane curvature to mediate lipid and protein composition and subsequently induce curvature-induced diffusion barriers in the membrane. By forming non-phase separating- and phase-separating Supported Lipid Bilayers (SLB) onto ring-like structures we have demonstrated the potential of curvature to bring about diffusion barriers in lipid bilayers through the induction of lipid phase separation at sites of curvature. In addition, this effect was further amplified upon the introduction of a curvature-sensing protein: Cholera-Toxin subunit B. Combined, the high-resolution patterning properties of Electron Beam Induced Deposition and the ability of Supported Lipid Bilayers to study the effect of shapes on lipid- and protein composition within the membrane in a bottom-up approach propose a platform suitable for scrutinizing the mechanisms that act at the membrane-topography interface.

http://resolver.tudelft.nl/uuid:f27fb030-dd1f-492f-af47-2881fe6eee4f

2022-04-11

Student theses

master thesis

(c) 2017 Dobbenga, S.