Effect of artificial cell miniaturization on urea degradation by immobilized E. coli DH5α (pKAU17)

Second generation E. coli DH5α (pKAU17) was successfully encapsulated by means of atomization (MA), inkjet printing (MI) and double-encapsulation (DDMI) for the purpose of urea degradation in a simulated uremic medium at 37 °C. Experimentally determined values of the effectiveness factor are 0.83, 0.28 and 0.34 for the MI, MA and DDMI capsules, respectively, suggesting that the catalytic activity of the E. coli DH5α (pKAU17) immobilized in MI capsule (d = 52 μm ± 2.7 μm) is significantly less diffusion-limited than in the case of the MA (d = 1558 μm ± 125 μm) and DDMI (d = 1370 μm ± 60 μm) bio-encapsulation schemes at the 98.3% CI. The proposed novel double encapsulation biofabrication method for alginate-based microspheres, characterized by lower membrane degradation rates due to secondary containment is recommended compared to the standard atomization scheme currently adopted across immobilization-based therapeutic scenarios. A Fickian-based mechanism is proposed with simulations mimicking urea degradation for a single capsule for the atomization and the inkjet schemes.