4 Conclusions
In the current study, a trilayer tissue engineering scaffold mimicking
the hierarchical structure of native uterine tissue was designed and
trilayer scaffolds of this design were successfully constructed through
4D printing, electrospinning and 3D bioprinting. The trilayer scaffolds
had three distinct layers: 3D printed PTMC/TPU scaffold outlayer with
shape morphing ability and high stretchability, electrospun
PLGA/GelMA-PDA@E2 fibrous interlayer with photothermal effect and
controlled and sustained E2 release, and BMSC-laden hydrogel innerlayer
providing abundant stem cells at the repair/tissue regeneration site.
These trilayer scaffolds were highly stretchable and exhibited
comparable mechanical properties with native uterine tissue.
Additionally, they could deliver E2 controllably and sustainably. The E2
release from trilayer scaffolds was also pH-responsive and could be
tuned by NIR laser irradiation. PLGA/GelMA-PDA@E2 fibers fabricated on
the PTMC/TPU scaffold made the scaffold surface more hydrophilic and
improved biological performance. BMSCs encapsulated in GelMA/Gel bioinks
exhibited high survival rates in the 3D bioprinted hydrogel layer of the
trilayer scaffolds. Importantly, the biomimicking trilayer scaffolds had
the shape morphing ability, transforming from the planar shape to curved
or tubular structures when immersed in the culture medium at 37 ℃. The
biomimicking trilayer tissue engineering scaffolds designed and
fabricated in the current study have the high potential for uterine
tissue regeneration.