Aqueous two-phase deposition and fibrinolysis of fibroblast-laden fibrin micro-scaffolds. (7th April 2021)

• Record Type: Journal Article
• Authors: Robinson, Stephen; Chang, Jonathan; Parigoris, Eric; Hecker, Louise; Takayama, Shuichi
• Is Part Of: Biofabrication. Volume 13:Number 3(2021)
• Publication Date: 2021-04-07
• Subjects: fibrinolysis -- phenotypic assay -- aqueous two-phase system -- fibrin -- wound healing -- fibrosis; Biomedical engineering -- Periodicals; Tissue engineering -- Periodicals; Biomedical materials -- Microstructure -- Periodicals; Bioengineering -- Periodicals; 610.28
• DOI: 10.1088/1758-5090/abdb85
• Languages: English
• ISSNs: 1758-5082

Abstract

Abstract: This paper describes printing of microscale fibroblast-laden matrices using an aqueous two-phase approach that controls thrombin-mediated enzymatic crosslinking of fibrin. Optimization of aqueous two-phase formulations enabled polymerization of consistent sub-microliter volumes of cell-laden fibrin. When plasminogen was added to these micro-scaffolds, the primary normal human lung fibroblasts converted it to plasmin, triggering gradual degradation of the fibrin. Time-lapse live-cell imaging and automated image analysis provided readouts of time to degradation of 50% of the scaffold as well as maximum degradation rate. The time required for degradation decreased linearly with cell number while it increased in a dose-dependent manner upon addition of TGF- β 1. Fibroblasts isolated from idiopathic pulmonary fibrosis patients showed similar trends with regards to response to TGF- β 1 stimulation. Addition of reactive oxygen species (ROS) slowed fibrinolysis but only in the absence of TGF- β 1, consistent with published studies demonstrating that pro-fibrotic cellular phenotypes induced by TGF- β 1 are mediated, at least in part, through increased production of ROS. FDA-approved and experimental anti-fibrosis drugs were also tested for their effects on fibrinolysis rates. Given the central role of fibrinolysis in both normal and pathogenic wound healing of various tissues, the high-throughput cell-mediated fibrinolysis assay described has broad applicability in the study of many different cell types and diseases. Furthermore, aqueous two-phase printing of fibrin addresses several current limitations of fibrin bio-inks, potentially enabling future applications in tissue engineering and in vitro models.