FIG. 6.

Proof of concept for the use of _mfPA as a template to induce the biofabrication and control the self-release of tissues by donor-derived cells. (a) Schematic diagram depicting how cells isolated from human donors were seeded and grown on low-attachment plates coated with 1.25 mM _mfPA:_dPA at the 15:85 mol/mol ratio (green) in retinoic acid (RA)-supplemented SFM (blue). Tissues fabricated in the course of the 90-day culture period were induced to express MMPs into the culture supernatant after RA removal from the medium (orange), thus providing the cue to degrade the adhesive PA coating and induce their self-release (blue arrows). Lifted tissues were then easily recoverable for downstream applications, namely for thrice-repeated reattachment and relifting processes, using only RA-induced regulation of endogenous MMP expression. (b) Phase-contrast micrographs of hCSFs growing as a monolayer on _mfPA:_dPA templates (day [d]7) and integrating the tissue formed by PA-induced ECM deposition and accumulation before (d30–d90), during (+3), and after tissue self-release (R1). Scale bars, 100 μm. (c) Proliferation of hCSFs grown on _mfPA:_dPA templates. Cell proliferation in RA-containing SFM (blue bars) increased up to day 60, and then decreased at day 90 and in the following 3 days, when incubated in SFM without RA (white bars, +1, +2, and +3). Data are expressed as average±SD of three independent experiments (n=3); * and ** corresponded to p<0.05 and 0.01, respectively. Color images available online at www.liebertpub.com/tea