Cell Concentration Modulates Pulsed Electric Fields’ Bioeffects: Integrated Electrical, Viability, and Metabolic Analysis

Pulsed electric field (PEF) technology shows great promise for non-thermal biomedical applications, including gene electrotransfer and tissue engineering. However, the influence of cell concentration and density on the electrical and biological responses to PEFs remains insufficiently characterized. This study evaluated the association between cell concentration, electrical response, viability, post-treatment recovery, and FTIR spectral profiles following microsecond PEF exposure. L929 fibroblasts were exposed to a fixed protocol of 10 kV/cm, with five 5 μs pulses at 1 Hz, using five concentrations ranging from 5.0×104 to 1.0×106 cells in 0.8 mL of DPBS. Higher cell concentrations were associated with lower peak current and temperature increases, with the peak current decreasing from 429 A at 5.0×104 cells to 269 A at 1.0×106 cells and the maximum temperature decreasing from 12.8 to 8.0 °C. Immediate post-PEF viability was lower at the two lowest concentrations, whereas all groups showed substantial recovery after 72 h, with viability ranging from 73.5% to 98.0%. FTIR and principal component analysis identified treatment-associated changes in spectral profiles, followed by partial convergence toward the non-PEF condition after recovery. These findings indicate that cell concentration is an important process parameter in this experimental PEF model, with direct implications for scaling biomedical PEF applications and tissue engineering protocols.