Dataset Information

Tunable fibrin-alginate interpenetrating network hydrogels to support cell spreading and network formation.

ABSTRACT: Hydrogels are effective platforms for use as artificial extracellular matrices, cell carriers, and to present bioactive cues. Two common natural polymers, fibrin and alginate, are broadly used to form hydrogels and have numerous advantages over synthetic materials. Fibrin is a provisional matrix containing native adhesion motifs for cell engagement, yet the interplay between mechanical properties, degradation, and gelation rate is difficult to decouple. Conversely, alginate is highly tunable yet bioinert and requires modification to present necessary adhesion ligands. To address these challenges, we developed a fibrin-alginate interpenetrating network (IPN) hydrogel to combine the desirable adhesion and stimulatory characteristics of fibrin with the tunable mechanical properties of alginate. We tested its efficacy by examining capillary network formation with entrapped co-cultures of mesenchymal stromal cells (MSCs) and endothelial cells (ECs). We manipulated thrombin concentration and alginate crosslinking density independently to modulate the fibrin structure, mesh size, degradation, and biomechanical properties of these constructs. In IPNs of lower stiffness, we observed a significant increase in total cell area (1.7 × 10⁵ ± 7.9 × 10⁴ µm²) and decrease in circularity (0.56 ± 0.03) compared to cells encapsulated in stiffer IPNs (4.0 × 10⁴ ± 1.5 × 10⁴ µm² and 0.77 ± 0.09, respectively). Fibrinogen content did not influence capillary network formation. However, higher fibrinogen content led to greater retention of these networks confirmed via increased spreading and presence of F-actin at 7 days. This is an elegant platform to decouple cell adhesion and hydrogel bulk stiffness that will be broadly useful for cell instruction and delivery. STATEMENT OF SIGNIFICANCE: Hydrogels are widely used as drug and cell delivery vehicles and as artificial extracellular matrices to study cellular responses. However, there are limited opportunities to simultaneously control mechanical properties and degradation while mimicking the complex native adhesion motifs and ligands known to encourage cell engagement with the hydrogel. In this study, we describe a fibrin-alginate interpenetrating network (IPN) hydrogel designed to balance the compliance and provisional qualities of fibrin with the mechanical stability and tunability of alginate to interrogate these contributions on cell response. We used clinically relevant cell sources, a co-culture of endothelial cells and mesenchymal stromal cells, to test its efficacy in supporting capillary formation in vitro. These data demonstrate the promise of this IPN for use in tissue engineering.

SUBMITTER: Vorwald CE

PROVIDER: S-EPMC7198331 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Background3D bioprinting cardiac patches for epicardial transplantation are a promising approach for myocardial regeneration. Challenges remain such as quantifying printability, determining the ideal moment to transplant, and promoting vascularisation within bioprinted patches. We aimed to evaluate 3D bioprinted cardiac patches for printability, durability in culture, cell viability, and endothelial cell structural self-organisation into networks.MethodsWe evaluated 3D-bioprinted double-layer patches using alginate/gelatine (AlgGel) hydrogels and three extrusion bioprinters (REGEMAT3D, INVIVO, BIO X). Bioink contained either neonatal mouse cardiac cell spheroids or free (not-in-spheroid) human coronary artery endothelial cells with fibroblasts, mixed with AlgGel. To test the effects on durability, some patches were bioprinted as a single layer only, cultured under minimal movement conditions or had added fibroblast-derived extracellular matrix hydrogel (AlloECM). Controls included acellular AlgGel and gelatin methacryloyl (GELMA) patches.ResultsPrintability was similar across bioprinters. For AlgGel compared to GELMA: resolutions were similar (200-700 μm line diameters), printing accuracy was 45 and 25%, respectively (AlgGel was 1.7x more accurate; p < 0.05), and shape fidelity was 92% (AlgGel) and 96% (GELMA); p = 0.36. For durability, AlgGel patch median survival in culture was 14 days (IQR:10-27) overall which was not significantly affected by bioprinting system or cellular content in patches. We identified three factors which reduced durability in culture: (1) bioprinting one layer depth patches (instead of two layers); (2) movement disturbance to patches in media; and (3) the addition of AlloECM to AlgGel. Cells were viable after bioprinting followed by 28 days in culture, and all BIO X-bioprinted mouse cardiac cell spheroid patches presented contractile activity starting between day 7 and 13 after bioprinting. At day 28, endothelial cells in hydrogel displayed organisation into endothelial network-like structures.ConclusionAlgGel-based 3D bioprinted heart patches permit cardiomyocyte contractility and endothelial cell structural self-organisation. After bioprinting, a period of 2 weeks maturation in culture prior to transplantation may be optimal, allowing for a degree of tissue maturation but before many patches start to lose integrity. We quantify AlgGel printability and present novel factors which reduce AlgGel patch durability (layer number, movement, and the addition of AlloECM) and factors which had minimal effect on durability (bioprinting system and cellular patch content).

Dataset Information

Tunable fibrin-alginate interpenetrating network hydrogels to support cell spreading and network formation.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets