Comparative evaluation of macroscopic carriers for Vero cell expansion: Influence of surface properties, incubation parameters, and nutrient media

The aim of this study was to identify optimal conditions for maximising biomass yield and preserving the viability of Vero cells cultured on different macroscopic carriers. The macroscopic carriers, including cellulose, composite, polystyrene (standard and modified), and polyethylene, were analysed in terms of adhesion, cell mass accumulation, doubling time, and morphological stability as well as the effects of incubation parameters and nutrient medium composition. After 48 h of cultivation, cellulose and composite carriers showed the highest adhesion levels (90-94%), followed by modified and standard polystyrene carriers (76-92%), whereas polyethylene carriers were the least effective (50-55%). Optimal growth was observed at 37°C, 21% O2, and pH 7.2, resulting in a 3.5-fold increase in cell density (4.2 x 105/cm2) and viability of 95-96%. Moderate deviations from these conditions led to reduced cell growth (2.6-3.2-fold; 3.3-4.0 x 105 /cm2) and viability (89-93%). However, extreme deviations (35 °C, 15% O2, pH 6.8-7.0) significantly reduced growth to 2.1-2.4-fold, with cell densities of 2.6-2.8 x 105 /cm2 and viability of 83-85%. The nutrient medium composition significantly influenced culture performance; the addition of L-glutamine (4 mmol/l) resulted in the highest cell biomass (4.6-fold) with final cell density of 9.2×105/cm2 and viability of 95% after 48 h. In contrast, glucose deficiency or serum deprivation reduced cell growth (2.0-2.5-fold) and cell layer uniformity. A comparison of cultivation systems showed that macroscopic carriers provided 20-25% greater adhesion levels and effective surface coverage compared to suspension culture. The study demonstrated that cellulose and composite carriers provided the highest adhesion and cell viability, while optimal growth was achieved at 37 °C, 21% O2, and pH 7.2. Nutrient medium composition, particularly L-glutamine supplementation, further enhanced cell proliferation and final cell density.