Regulating Stem Cell Functions Through Light Switchable Protein

  • Siu Hong Wong



Regulating stem cell functions by precisely controlling the nanoscale presentation of bioactive ligands has a substantial impact on tissue engineering and regenerative medicine but remains a major challenge. Here it is shown that bioactive ligands can become mechanically “invisible” by increasing their tether lengths to the substrate beyond a critical length, providing a way to regulate mechanotransduction without changing the biochemical conditions. Building on this finding, light switchable tethers are rationally designed, whose lengths can be modulated reversibly by switching a light-responsive protein, pdDronpa, in between monomer and dimer states. This allows the regulation of the adhesion, spreading, and differentiation of stem cells by light on substrates of well-defined biochemical and physical properties. Spatiotemporal regulation of differential cell fates on the same substrate is further demonstrated, which may represent an important step toward constructing complex organoids or mini tissues by spatially defining the mechanical cues of the cellular microenvironment with light.

Period4 Aug 2022

Media coverage


Media coverage

  • TitleRegulating Stem Cell Functions Through Light Switchable Protein
    Degree of recognitionLocal
    Media name/outletPolyU Vibrant@FENG eNewsletter Issue 3
    Media typeWeb
    Country/TerritoryHong Kong
    DescriptionRegulating stem cell functions by controlling ligand presentation can have an impact on tissue engineering and regenerative medicine. Dr Siu Hong Dexter WONG, Research Assistant Professor of Biomedical Engineering, alongside his collaborators, has developed light switchable tethers that are rationally designed and with lengths modulated by switching a light-responsive protein called pdDronpa in between monomer and dimer states.

    This new approach enables consistent, stable control of the bioactive ligand presentation, without the spontaneous dissociation and translocation of ligands over a long cell culture period. The signaling of stem cells can be fine-tuned, by adjusting the tether lengths using selected wavelength lights. The approach does not change the biochemical environment and can decouple the effect of macroscopic matrix elasticity and local mechanical signal transduction, providing a bio-orthogonal, reversible, and spatiotemporally controlled strategy for bioactivity manipulations and a new route to control stem cell fate noninvasively.

    Dr WONG successfully published his findings in the international journal, Advanced Materials.

    To learn more:
    PersonsSiu Hong Wong