Biomimetic design of bioartificial scaffolds for the in vitro modelling of human cardiac fibrosis

Abstract

In vitro models of pathological cardiac tissue have attracted interest as predictive platforms for preclinical validation of therapies. However, models reproducing specific pathological features, such as cardiac fibrosis size (i.e., thickness and width) and stage of development are missing. This research was aimed at engineering 2D and 3D models of early-stage post-infarct fibrotic tissue (i.e., characterized by non-aligned tissue organization) on bioartificial scaffolds with biomimetic composition, design, and surface stiffness. 2D scaffolds with random nanofibrous structure and 3D scaffolds with 150 µm square-meshed architecture were fabricated from polycaprolactone, surface-grafted with gelatin by mussel-inspired approach and coated with cardiac extracellular matrix (ECM) by 3 weeks culture of human cardiac fibroblasts. Scaffold physicochemical properties were thoroughly investigated. AFM analysis of scaffolds in wet state, before cell culture, confirmed their close surface stiffness to human cardiac fibrotic tissue. Following 3 weeks culture, biomimetic biophysical and biochemical scaffold properties triggered the activation of myofibroblast phenotype. Upon decellularization, immunostaining, SEM and two-photon excitation fluorescence microscopy showed homogeneous decoration of both 2D and 3D scaffolds with cardiac ECM. The versatility of the approach was demonstrated by culturing ventricular or atrial cardiac fibroblasts on scaffolds, thus suggesting the possibility to use the same scaffold platforms to model both ventricular and atrial cardiac fibrosis. In the future, herein developed in vitro models of cardiac fibrotic tissue, reproducing specific pathological features, will be exploited for a fine preclinical tuning of therapies.

Deciphering the fibrotic process: mechanism of chronic radiation skin injury fibrosis

“…Building upon the foundation laid by collagen, fibronectin, another critical ECM component, is upregulated in fibrotic tissues and plays a multifaceted role ( 87 ). It serves as a scaffold for collagen deposition and is involved in the initial stages of fibrosis ( 88 ). The extra domain-A variant of fibronectin interacts with cell surface integrins, facilitating cell adhesion and migration and TGF-β activation ( 89 ).…”

In Vitro Mechanical Stimulation to Reproduce the Pathological Hallmarks of Human Cardiac Fibrosis on a Beating Chip and Predict The Efficacy of Drugs and Advanced Therapies

“…[18,19] Other works focused on modulating the stiffness of human 3D cell culture environment (e.g., by tailoring the scaffold composition) to specifically assess the mechanical contribution to the onset of fibrotic traits and to propose treatments to mitigate them. [20][21][22] Mechano-transduction in cardiac fibrosis has emerged indeed as a fundamental aspect to be considered since mechanical function of CFs actively regulates heart growth, homeostasis, repair and disease. [23] Besides TGF-𝛽, different pathways have been proposed for the cardiac fibrosis process mediated by mechanotransduction: the transcriptional regulation of the Wnt/𝛽-catenin and Hippo pathways are involved in mechanical forces exerted at cell-cell adhesion level, [24] mechanosensitive stimulation activates the RhoA/ROCK pathway [25] and mechanical strain or stress on cardiac tissue, like hypertension, can activate the 𝛽catenin/Wnt signaling pathway.…”

Construction of cardiac fibrosis for biomedical research

“…Fibrosis has been proven to be a serious negative prognostic indicator in cases of heart failure, which can directly worsen disease outcomes 4,6,7 . By simulating the physio‐pathological features in vitro, researchers have developed various experimental systems for investigating the mechanisms of cardiac fibrosis 8–12 . Planar two‐dimensional (2D) culture‐based analysis, such as high‐throughput screening in multi‐well plates, provides image‐based multi‐parameter readout of fibrosis markers 13 .…”

“…In particular, materials with micro‐nano architectures have been proved to induce cell orientation and function, thereby mimicking the tissue‐level morphology and enhancing versatility and practicability 24 . Recently, various microfabrication techniques have been utilized to create ECM simlants that support cell culture and simulate specific disease conditions 8,30–33 . Substantial emphasis has been placed on the following exemplary fabrication methods: microfluidics, 3D printing, template molding, decellularized ECM, and self‐assembly.…”

“…24 Recently, various microfabrication techniques have been utilized to create ECM simlants that support cell culture and simulate specific disease conditions. 8,[30][31][32][33] Substantial emphasis has been placed on the following exemplary fabrication methods: microfluidics, 3D printing, template molding, decellularized ECM, and self-assembly. Integrated cardiac models have emerged as an attractive way of mimicking complex and dynamically changing physical environments, thereby enhancing the longevity and reproducibility of cardiac systems in vitro.…”