Enhanced Viability of Endothelial Colony Forming Cells in Fibrin Microbeads for Sensor Vascularization

Abstract

Enhanced vascularization at sensor interfaces can improve long-term function. Fibrin, a natural polymer, has shown promise as a biomaterial for sensor coating due to its ability to sustain endothelial cell growth and promote local vascularization. However, the culture of cells, particularly endothelial cells (EC), within 3D scaffolds for more than a few days is challenging due to rapid loss of EC viability. In this manuscript, a robust method for developing fibrin microbead scaffolds for long-term culture of encapsulated ECs is described. Fibrin microbeads are formed using sodium alginate as a structural template. The size, swelling and structural properties of the microbeads were varied with needle gauge and composition and concentration of the pre-gel solution. Endothelial colony-forming cells (ECFCs) were suspended in the fibrin beads and cultured within a perfusion bioreactor system. The perfusion bioreactor enhanced ECFCs viability and genome stability in fibrin beads relative to static culture. Perfusion bioreactors enable 3D culture of ECs within fibrin beads for potential application as a sensor coating.

Chromosome Missegregation and Aneuploidy Induction in Human Peripheral Blood Lymphocytes In vitro by Low Concentrations of Chlorpyrifos, Imidacloprid and α‐Cypermethrin

“…Thus, to minimize the variability of the results, the single donor approach was chosen. The single donor approach was also applied in other studies, for instance, in a study by Collins et al (), Ferk et al (), Gandhi et al (), García et al () and Zeljezic et al (). The OECD (Organization for Economic Co‐operation and Development) testing guidelines TG 487 and TG 473 (OECD, , b) for in vitro testing also suggest that the lymphocytes to be treated may originate from a single donor.…”

iPSC‐Derived Vascular Cell Spheroids as Building Blocks for Scaffold‐Free Biofabrication

“…The limit of oxygenation diffusion in vivo is 200 μm . This finding is not unexpected, also given the known benefit of a stirred bioreactor to keep ECFC alive, when packed within fibrin microspheres …”

“…In addition, they had poor biomechanical consistency, as shown by the inability to be sustain integrity when gently aspirated with the low depression routinely used by the Regenova's robotic arm, and to sustain the implantation in the instrument's microneedles. To prepare more robust spheroids from ECFC only, we could have considered other methods to strengthen their intercellular interactions (such as using magnetic beads), or to incorporate them in biomaterials as additional extracellular matrices . However, we considered that a compact mass of cells, even at the progenitor stage, is an unusual situation for the normal epithelial physiology.…”

“…ECFC of both cord and adult blood or of iPSC origin, are a very promising cell population for cardiovascular medicine . Because their in vivo applications for cell therapy face the same biological constrains as other single‐cell suspensions, it has been proposed to lead cells into alginate/fibrin microspheres . However, this procedure requires complex preparations, followed by specialized bioreactor cultivation.…”

Human Fibrinogen for Maintenance and Differentiation of Induced Pluripotent Stem Cells in Two Dimensions and Three Dimensions

“…Fibrin gels are most synonymous with vascular engineering applications, where a variety of approaches have demonstrated the ability to form vessel‐like structures in vitro and in vivo, angiogenesis in vivo and anastomosis after implantation . Furthermore, fibrin hydrogels have shown potential use as an encapsulant for drug and cell delivery . For example, bone marrow‐derived mesenchymal stromal cells (MSCs) cultured in fibrin hydrogels were implanted in a cranial defect model of a rodent to develop bone mineralization and increased vascularization .…”