Kinetic studies of the interaction between antitumor antibiotics and DNA using quartz crystal microbalance

Objective: Kinetic studies of the interaction process between antitumor antibiotics, Mitomycin C (MMC) and Bleomycin (BLM), and DNA were performed with a novel analytical method, piezoelectric quartz crystal (PQC) impedance analysis. Design and methods: DNA was directly immobilized on the Au-electrode surface of a piezoelectric quartz crystal by adsorption. The DNA-modified piezoelectric sensor was in contact with Mitomycin C and Bleomycin solution, respectively. Results: The experimental results demonstrated that antitumor antibiotics concentration had an effect on the interaction. A pseudo-first-order kinetic model for the interaction between antitumor antibiotics and DNA was derived to describe the process. All fitted results were well in agreement with the corresponding experimental results. The kinetic parameters, the interaction rate constants (kMMC and kBLM), were determined by fitting experimental data to the model. At 37 ± 0.5°C, the kMMC and kBLM values obtained were 4.56 (±0.02) × 10−3 and 9.11 (±0.02) mM−1 s−1, respectively. Conclusion: Piezoelectric quartz crystal impedance (PQCI) analysis is a very powerful method to study the kinetic process of antitumor drugs and DNA interaction.