Bernard Vladan, Fojt Lukás, Skorpíková Jirina, Mornstein Vojtĕch
Department of Biophysics, Faculty of Medicine, Masaryk University, 625 00 Brno, Czech Republic.
Indian J Biochem Biophys. 2011 Feb;48(1):59-62.
The in vitro study was carried out for detection of the cisplatin in free form and in culture medium, depending on various conditions of sonodynamic human ovarian cancer cells A2780 treatment by differential pulse polarography (DPP). For sonodynamic treatment, we used cisplatin alone and combined cisplatin/ultrasound treatments. The ultrasound exposure intensity of 1.0 and 2.0 W x cm(-2) in far field for incubation periods 1, 24 and 48 h was used. The parameters of DPP measurements were--1 s drop time, 5 mV x s(-1) voltage scan rate, 50 mV modulation amplitude and negative scanning direction; platinum wire served as counter electrode and Ag/AgCl/3 M KCl as reference electrode. The results showed the dependence of free platinum quantities in culture medium on incubation time and treatment protocol. We found difference in concentration of free cisplatin between conventional application of cisplatin and sonodynamic treatment. The sonodynamic combined treatment of cisplatin and ultrasound field showed a higher cisplatin content in the culture medium than cisplatin treatment alone; a difference of 20% was observed for incubation time 48 h. The results also showed the influence of a time sequence of ultrasound and cytostatics in the sonodynamic treatment. The highest amount of free cisplatin in the solution was found for primary application of cisplatin and the subsequent ultrasound exposure. The quantity of free cisplatin increased with time, namely for time intervals 1-24 h. There was no difference between the DPP signal of cisplatin in reaction mixture containing cells in small quantities and micro-filtered mixture without cells. Thus, the DPP method is suitable for the detection and quantification of free cisplatin in the culture medium of cell suspension. Ultrasound field can be important factor during cytostatic therapy.
采用差分脉冲极谱法（DPP），根据声动力处理人卵巢癌细胞A2780的不同条件，对游离形式和顺铂在培养基中的情况进行体外研究。对于声动力治疗，我们使用了单独的顺铂以及顺铂/超声联合治疗。在远场中，分别采用1.0和2.0 W·cm⁻²的超声暴露强度，孵育时间为1、24和48小时。DPP测量参数为：滴汞时间1秒、电压扫描速率5 mV·s⁻¹、调制幅度50 mV以及负向扫描方向；铂丝用作对电极，Ag/AgCl/3 M KCl用作参比电极。结果表明，培养基中游离铂的量取决于孵育时间和治疗方案。我们发现顺铂常规应用与声动力治疗之间游离顺铂浓度存在差异。顺铂与超声场的声动力联合治疗在培养基中的顺铂含量高于单独的顺铂治疗；在孵育48小时时观察到20%的差异。结果还显示了超声和细胞抑制剂在声动力治疗中的时间顺序影响。溶液中游离顺铂的最高含量出现在先应用顺铂随后进行超声暴露的情况下。游离顺铂的量随时间增加，即在1 - 24小时的时间间隔内。含有少量细胞的反应混合物和顺铂的DPP信号与无细胞的微滤混合物之间没有差异。因此，DPP方法适用于检测和定量细胞悬液培养基中的游离顺铂。超声场可能是细胞抑制治疗中的一个重要因素。
