Biomineralized nanostructured biointerfaces mimicking extracellular matrix

Details

Supervisors

Demoustier-Champagne, Sophie ; Dupont-Gillain, Christine C.

Faculty

Ecole polytechnique de Louvain

Degree label

Master [120] : ingénieur civil biomédical, à finalité spécialisée

Abstract

The elaboration of biointerfaces mimicking native tissue environments for tissue engineering applications has attracted growing interest due to the emergence of nanotechnologies in biological research. The particular case of bone tissue engineering is especially challenging due to the complex anatomical structure and the important functions that bones exert in the body. A promising scaffold for bone regeneration would have a composition and structure similar the bone extracellular matrix (ECM), which constitutes a structural framework providing mechanical support to bone cells in vivo. To this end, the subsequent work presents a method to produce biomineralized biointerfaces mimicking the bone ECM. Inspired by the composition and structure of the ECM, the biointerfaces produced consist of intersected nanotubes composed of collagen (Col) and hyaluronic acid (HA). To achieve this, the layer-by-layer (LbL) assembly technique is performed in polycarbonate membranes with a tunable network of intersected nanopores. In order to obtain biointerfaces with suitable mechanical stability, hydroxyapatite, the major component of the inorganic bone ECM, is formed within the nanotubes by the enzymatic-induced mineralization technique using alkaline phosphatase (ALP). The promising results showed that LbL assembly of (Col/HA)3(PAH/ALP)5 multilayers followed by mineralization was successful both on planar surfaces and in nanoporous templates. A predominant role of the collagen-based multilayers on the mineralization process was highlighted by a more pronounced mineralization on silicon wafers and the formation of a higher amount of nanotubes reaching longer lengths. Lowering the temperature of the cross-linking process was shown to lead to a better stabilization of the Col/HA based multilayers and using PC membranes with a pore size of 500 nm allowed to achieve promising results of nanotubes with the expected length of the template thickness. This Master thesis therefore pave the way for future investigations towards the formation of intersected nanotube networks with improved mechanical stability mimicking the bone ECM.