posted on 2019-03-20, 00:00authored byFrancesca Michela Pramotton, Francesco Robotti, Costanza Giampietro, Tobias Lendenmann, Dimos Poulikakos, Aldo Ferrari
Autologous
epidermis grafts generated in vitro represent a promising
option for the treatment of burn wounds. The procedure relies on of
a sufficient number of cells harvested from healthy tissue, which
are then sparsely seeded on a target surface. The time required to
reconstitute a fully confluent and mature monolayer and the limited
availability of cell seeds hinder the broad clinical application of
this procedure. Here, a novel engineering approach to enhance the
in vitro expansion of epithelial tissues is designed and experimentally
validated. The method combines three independent elements supporting
fast epithelialization. First, the tactical seeding of epithelial
cells at high density in confined channels generated by means of magnetic
silicon stencils. Second, the implementation of a curved interface
along the channels, increasing the edge interface length. Third, a
rationally developed and oriented anisotropic topography, in the form
of gratings, aligned perpendicularly to the channels. Upon removal
of the stencil, unconfined cell monolayers are free to expand and
invade the open space, in a process of epithelialization that fully
exploits the directional migration of epithelial collectives. As compared
to sparse seeding, this approach attains an almost three times faster
full epithelialization of a target surface with the same number of
cells. Molecular signals triggered by cell–cell and cell–substrate
contacts supported this enhanced response. In summary, we introduce
a facile and scalable approach yielding fast in vitro epithelial tissue
expansion with optimized yield.