Microencapsulation of cells in alginate through an electrohydrodynamic process

Abstract

The encapsulation of living cells within a semi-permeable matrix is an attractive process for transplanting nonautologous cells by limiting the interaction with the host immune system. The electrohydrodynamic process is a low-cost and high-throughput system to encapsulate cells by means of a static potential. We evaluated the use of this system for cell entrapment by assessing and then manufacturing capsules that had the best dimensions. The effect of different cell densities on the beads was determined to set up the basic parameters of the encapsulation system. The cell viability inside the beads and as a function of release time was observed for their biological response.

Natural polymers for the microencapsulation of cells

“…Furthermore, when fibrin is used as the matrix to encapsulate stem cells, the concentration of thrombin and fibrinogen can influence their proliferation rate and their differentiation. The results from Catelas et al [185] show that formulations containing a lower concentration of fibrinogen (5 mg ml 21 ) can support human mesenchymal stem cell growth, while a higher concentration (50 mg ml 21 ) has an increased potential for their differentiation into osteoblasts. In mammals, fibrin can degrade rapidly owing to the presence of proteolytic enzymes (fibrinolysis).…”

“…Once the jetting condition is initiated the size of the drop is independent of the voltage applied and the distance from the target anode. Gasperini et al [21] used this technique starting from a suspension of B50 mouse cells and alginate. The cell-laden droplets of the jet were collected in a calcium chloride bath acting as the hardening agent.…”

A comprehensive review on droplet-based bioprinting: Past, present and future

“…Dripping mode is observed at low voltages and flow rates, Although process parameters do not significantly affect the cell viability (see Table 2) and genomic expression immediately after bioprinting, applied voltage, cell concentration and bioink constituents can collectively affect the long-term post-bioprinting cell viability [71]. The applied voltage determines the ejected droplets size [43,71] whereas bioink constituents (such as hydrogels including but not limited to crosslinked alginate, collagen and fibrin) and concentration used for cell encapsulation alter the diffusion of media. Hence, the droplet size and bioink constituents affect media transport to the encapsulated cells.…”

“…The volume of ejected droplets is mediated by several operating parameters such as the bioink material characteristics, the printhead geometry (orifice diameter) and its actuation voltage pulse characteristics [23,32,36,43,46,71,82,83]. For example, the width of each M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 13 coalesced line in Fig.…”

Assessing the Impact of Electrohydrodynamic Jetting on Encapsulated Cell Viability, Proliferation, and Ability to Self-Assemble in Three-Dimensional Structures

“…Cell encapsulation was performed by following a protocol already published. 36 In brief, the encapsulation system was placed under the biological hood, a sterile 3 ml syringe was filled with cells suspended in the alginate solution, This article has been peer-reviewed and accepted for publication, but has yet to undergo copyediting and proof correction. The final published version may differ from this proof.…”