PDF(Pubmed)
Abstract：
Poly[2-(methacryloyloxy)ethyl phosphorylcholine] liposomes (pMPC liposomes) gained attention during the last few years because of their potential use in treating osteoarthritis. pMPC liposomes that serve as boundary lubricants are intended to restore the natural lubrication properties of articular cartilage. For this purpose, it is important that the liposomes remain intact and do not fuse and spread as a lipid film on the cartilage surface. Here, we investigate the stability of the liposomes and their interaction with two types of solid surfaces, gold and carbon, by using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). With the aid of a hydrophilic species used as an electroactive probe in the solution, the charge transfer characteristics of the electrode surfaces are obtained. Additionally, from EIS, the capacitance characteristics of the surfaces are derived. No decrease of the peak currents and no displacement of the peak potentials to greater overpotentials are observed in the CV experiments. No decrease in the apparent capacitance and increase in the charge transfer resistance is observed in the EIS experiments. On the contrary, all parameters in both CV and EIS do change in the opposite direction. The obtained results confirm that there is only physical adsorption without fusion and spreading of the pMPC liposomes and without the formation of lipid films on the surfaces of both gold and carbon electrodes.
摘要：
聚[2-(甲基丙烯酰氧基)乙基磷酰胆碱]脂质体(pMPC脂质体)由于其在治疗骨关节炎中的潜在用途而在过去几年中受到关注。用作边界润滑剂的pMPC脂质体旨在恢复关节软骨的自然润滑特性。为此,重要的是,脂质体保持完整并且不融合并作为脂质膜在软骨表面上扩散。这里,我们研究了脂质体的稳定性及其与两种类型的固体表面的相互作用，金和碳,采用循环伏安法(CV)和电化学阻抗谱(EIS)。借助在溶液中用作电活性探针的亲水性物质，获得电极表面的电荷转移特性。此外,从EIS,推导了表面的电容特性。在CV实验中没有观察到峰值电流的降低以及峰值电势到更大的过电势的位移。在EIS实验中没有观察到表观电容的降低和电荷转移电阻的增加。相反,CV和EIS中的所有参数都以相反的方向变化。获得的结果证实，仅存在物理吸附，而没有pMPC脂质体的融合和扩散，也没有在金电极和碳电极的表面上形成脂质膜。
