Presentation Information
[P03-424]Cell caging for photo-regulation of mammalian cell functions
○Satoshi Yamaguchi1,2 (1. The University of Osaka (Japan), 2. The University of Tokyo (Japan))
Keywords:
Mammalian cells,Photo-regulation,Caging
[Purpose] In recent years, the technology for controlling cellular behaviors and functions by external stimuli has become increasingly important in a variety of fields, from therapeutic cell delivery to regenerative medicine. Optogenetics, based on genetically encoded light-responsive proteins, has recently been actively studied as a photo-controllable tool. However, the application range is limited by the requirement for cell gene engineering. Moreover, most cell behaviors are regulated by multiple genes in a complex manner. Therefore, they cannot be controlled only by changing the functions of a few proteins through optogenetics. To overcome these limitations, we developed a chemical approach, ‘cell caging’, to regulate cellular behaviors and functions by coating entire cell surfaces with photodegradable materials, thereby achieving photo-regulation of cellular functions via steric hindrance imposed by the coating materials.
[Method] Recently, we developed a sterically bulky caging approach for protein photo-regulation, in which the entire protein surface is sterically hindered by the conjugation of photodegradable bulky molecules. In this study, this caging strategy, based on photodegradable sterically bulky protecting groups, was extended from proteins to mammalian cells. To achieve cell caging, the cell surface was fully coated with photodegradable protein–polymer hybrid materials via layer-by-layer assembly. Specifically, a layer-by-layer assembly of photocleavable synthetic materials based on biotin–streptavidin (SA) interactions was employed for cell coating. The cell surface was first biotinylated using a photocleavable biotinylated poly(ethylene glycol) (PEG)–lipid, and then coated by alternately layering SA and micelles composed of PEG–lipid and photocleavable biotinylated four-armed PEG. For light-induced uncaging, the caged cells were exposed to light at wavelengths of 365–405 nm at biocompatible light amounts.
[Results & Discussion] A model adherent cell, HeLa was caged and uncaged in the designed procedure. HeLa cells were coated with the photodegradable materials in a layer-by-layer manner. After layering three times, all cells were observed to be coated with thick fluorescent shells on the cell surfaces. Subsequently, the coated cells were exposed to light. After light exposure (4.0 J/cm2), the fluorescent shells disappeared from the cell surface, and the fluorescence intensity nearly decreased to the baseline. This result quantitatively indicates that the photodegradable shell on the cell surface could be almost completely removed by light. Next, using this cell caging technique, we demonstrated controlling cell functions. The cell extension and adhesion of HeLa cells were suppressed with the shells and then triggered with the degradation of the shells by light exposure. Macrophage phagocytosis was also stopped by caging with the shells and restarted by light-guided uncaging. This study provides the first proof of principle that cellular functions can be remotely controlled by steric hinderance of cell surfaces with photodegradable materials.
[Conclusion] Cellular adhesion, extension, and phagocytosis were suppressed by caging and then re-activated by uncaging through light-guided shell degradation. The present cell caging is promising for application to selective delivery of therapeutic cells in vivo.
[Method] Recently, we developed a sterically bulky caging approach for protein photo-regulation, in which the entire protein surface is sterically hindered by the conjugation of photodegradable bulky molecules. In this study, this caging strategy, based on photodegradable sterically bulky protecting groups, was extended from proteins to mammalian cells. To achieve cell caging, the cell surface was fully coated with photodegradable protein–polymer hybrid materials via layer-by-layer assembly. Specifically, a layer-by-layer assembly of photocleavable synthetic materials based on biotin–streptavidin (SA) interactions was employed for cell coating. The cell surface was first biotinylated using a photocleavable biotinylated poly(ethylene glycol) (PEG)–lipid, and then coated by alternately layering SA and micelles composed of PEG–lipid and photocleavable biotinylated four-armed PEG. For light-induced uncaging, the caged cells were exposed to light at wavelengths of 365–405 nm at biocompatible light amounts.
[Results & Discussion] A model adherent cell, HeLa was caged and uncaged in the designed procedure. HeLa cells were coated with the photodegradable materials in a layer-by-layer manner. After layering three times, all cells were observed to be coated with thick fluorescent shells on the cell surfaces. Subsequently, the coated cells were exposed to light. After light exposure (4.0 J/cm2), the fluorescent shells disappeared from the cell surface, and the fluorescence intensity nearly decreased to the baseline. This result quantitatively indicates that the photodegradable shell on the cell surface could be almost completely removed by light. Next, using this cell caging technique, we demonstrated controlling cell functions. The cell extension and adhesion of HeLa cells were suppressed with the shells and then triggered with the degradation of the shells by light exposure. Macrophage phagocytosis was also stopped by caging with the shells and restarted by light-guided uncaging. This study provides the first proof of principle that cellular functions can be remotely controlled by steric hinderance of cell surfaces with photodegradable materials.
[Conclusion] Cellular adhesion, extension, and phagocytosis were suppressed by caging and then re-activated by uncaging through light-guided shell degradation. The present cell caging is promising for application to selective delivery of therapeutic cells in vivo.
Comment
To browse or post comments, you must log in.Log in