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Engineering the Biointerface of Nanowires to Direct Stem Cell Differentiation

Periodic Reporting for period 2 - EnBioN (Engineering the Biointerface of Nanowires to Direct Stem Cell Differentiation)

Reporting period: 2019-08-01 to 2021-01-31

The reduced functionality or failure of organs due to disease or old age is a major societal and healtcare burden in our aging society. Regenerative medicine and tissue engineering approaches aim to combine materials, cells and instructive signals to repair and restore organ functionality. In particular, Regenerative medicine aims to recover lost tissue/organ function by directing the behaviour and organization of cells. Stem cells are ideal candidates for regenerative approaches owing to their potential to orchestrate tissue reconstruction through self-renewal, differentiation and recruitment of specialized cells. Stem cells reside within a microenvironment (the niche) that provides the biochemical and biophysical cues to support and modulate their physiological functions throughout development, quiescence and regeneration. There is a need to engineer materials that can direct the regenerative potential of stem cells combining regulatory stimuli ranging from gene therapy to biochemical and biophysical niche engineering.
ENBION is a first-in-class approach to integrate three core regulatory strategies to direct stem cell differentiation. ENBION engineers the unique biointerface of nanowires to (i)regulate gene transfection, (ii) directly stimulate the nucleus to direct epigenetic remodelling, (iii) pattern and localize presentation and delivery of biochemical stimuli. Engineering these aspects will enable to spatiotemporally regulate the differentiation of stem cells by developing principles for the rational design of the nanowire biointerface.
To this point we have identified the mechanisms that nanowires use to regulate gene transfection and we have effectively used those mechanisms to control gene expression in stem cells. We have identified strategies to deliver nucleic acids to individual cells. We have determined how to pattern signals on to the nanowires and to expose cell colonies to a coordinated pattern of these signals. Furthermore we have identified the mechanisms that nanowires engage to directly stimulate the nucleus, and have assessed their effect on the ability to promote the differentiation of stem cells.
We have established new methods for cell transfection mediated by porous silicon nanostructured materials. We have identified new mechanisms for the delivery of payloads from nanowires and leveraged those for efficient delivery of nucleic acids. We have developed new methods and protocols to investigate the cell-material interface in three dimensions with nanoscale resolution combining both structural and functional information. We have determined the mechanisms of nanowire interaction with the cells, including their direct interaction with the nucleus, the cytoskeleton and the cell membrane, and observed the mechanosensory response of the cells to this stimuli. We have provided new approaches to control the delivery of soluble differentiation sitmuli using porous silicon nanostructures, and devised strategies to pattern both ECM cues and payload for intracellular delivery with single cell resolution.