Scalable encapsulation of hepatocytes by electrostatic spraying

Area of Science:

• Biomaterials Engineering
• Cell Encapsulation Technologies
• Tissue Engineering

Background:

• Polyelectrolyte complex coacervation enables cell encapsulation at physiological conditions.
• Natural extracellular matrices like collagen support cell viability within microcapsules.
• Producing ultra-thin shelled microcapsules at scale is challenging due to fragility.

Purpose of the Study:

• To develop a scalable method for producing cell-encapsulating microcapsules using electrostatic spraying.
• To investigate the influence of operational parameters on microcapsule characteristics and cell viability.
• To produce microcapsules suitable for bio-artificial liver-assisted device applications.

Main Methods:

• Utilized electrostatic spraying for scalable production of microcapsules via complex coacervation.
• Employed cationic methylated collagen and an anionic terpolymer (HEMA-MMA-MAA).
• Investigated parameters including spraying needle diameter, flow rate, and electrical field voltage.

Main Results:

• Successfully produced microcapsules with diameters of 200-800 microm and narrow size distribution (5-28% std dev).
• Demonstrated that operational parameters significantly influenced microcapsule size, cell viability, and function.
• Achieved high encapsulation rates (up to 55 ml/h per orifice) with cell viability >87%.

Conclusions:

• Electrostatic spraying provides a scalable and efficient method for producing cell-encapsulating microcapsules.
• The developed microcapsules maintain excellent cell viability, mechanical stability, and bio-functionality.
• This technique is promising for applications in bio-artificial liver-assisted devices.