Adverse remodeling post-myocardial infarction is hallmarked
by
the phenotypic change of cardiac fibroblasts (CFs) into myofibroblasts
(MyoFs) and over-deposition of the fibrotic extracellular matrix (ECM)
mainly composed by fibronectin and collagens, with the loss of tissue
anisotropy and tissue stiffening. Reversing cardiac fibrosis represents
a key challenge in cardiac regenerative medicine. Reliablein vitromodels of human cardiac fibrotic tissue could be
useful for preclinical testing of new advanced therapies, addressing
the limited predictivity of traditional 2D cell cultures and animalin vivomodels. In this work, we engineered a biomimeticin vitromodel, reproducing the morphological, mechanical,
and chemical cues of native cardiac fibrotic tissue. Polycaprolactone
(PCL)-based scaffolds with randomly oriented fibers were fabricated
by solution electrospinning technique, showing homogeneous nanofibers
with an average size of 131 ± 39 nm. PCL scaffolds were then
surface-functionalized with human type I collagen (C1) and fibronectin
(F) by dihydroxyphenylalanine (DOPA)-mediated mussel-inspired approach
(PCL/polyDOPA/C1F), in order to mimic fibrotic cardiac tissue-like
ECM composition and support human CF culture. BCA assay confirmed
the successful deposition of the biomimetic coating and its stability
during 5 days of incubation in phosphate-buffered saline. Immunostaining
for C1 and F demonstrated their homogeneous distribution in the coating.
AFM mechanical characterization showed that PCL/polyDOPA/C1F scaffolds,
in wet conditions, resembled fibrotic tissue stiffness with an average
Young’s modulus of about 50 kPa. PCL/polyDOPA/C1F membranes
supported human CF (HCF) adhesion and proliferation. Immunostaining
for α-SMA and quantification of α-SMA-positive cells showed
HCF activation into MyoFs in the absence of a transforming growth
factor β (TGF-β) profibrotic stimulus, suggesting the
intrinsic ability of biomimetic PCL/polyDOPA/C1F scaffolds to sustain
the development of cardiac fibrotic tissue. A proof-of-concept study
making use of a commercially available antifibrotic drug confirmed
the potentialities of the developedin vitromodel
for drug efficacy testing. In conclusion, the proposed model was able
to replicate the main hallmarks of early-stage cardiac fibrosis, appearing
as a promising tool for future preclinical testing of advanced regenerative
therapies.