Szafran Klaudia, Jurak Małgorzata, Mroczka Robert, Wiącek Agnieszka Ewa
Department of Interfacial Phenomena, Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Skłodowska University, 20-031 Lublin, Poland.
Laboratory of X-ray Optics, Department of Chemistry, Institute of Biological Sciences, Faculty of Medicine, The John Paul II Catholic University of Lublin, 20-708 Lublin, Poland.
Pharmaceutics. 2022 Dec 15;14(12):2815. doi: 10.3390/pharmaceutics14122815.
Surface properties of polyethylene terephthalate (PET) coated with the ternary monolayers of the phospholipid 1,2-dioleoyl--glycero-3-phosphocholine (DOPC), the immunosuppressant cyclosporine A (CsA), and the antioxidant lauryl gallate (LG) were examined. The films were deposited, by means of the Langmuir-Blodgett (LB) technique, on activated by air low temperature plasma PET plates (PET). Their topography and surface chemistry were determined with the help of atomic force microscopy (AFM) and time-of-flight secondary ion mass spectrometry (TOF-SIMS), respectively, while wettability was evaluated by the contact angle measurements. Then, the surface free energy and its components were calculated from the Lifshitz-van der Waals/Acid-Base (LWAB) approach. The AFM imaging showed that the Langmuir monolayers were transferred effectively and yielded smoothing of the PET surface. Mass spectrometry confirmed compatibility of the quantitative and qualitative compositions of the monolayers before and after the transfer onto the substrate. Moreover, the molecular arrangement in the LB films and possible mechanisms of DOPC-CsA-LG interactions were determined. The wettability studies provided information on the type and magnitude of the interactions that can occur between the biocoatings and the liquids imitating different environments. It was found that the changes from open to closed conformation of CsA molecules are driven by the hydrophobic environment ensured by the surrounding DOPC and LG molecules. This process is of significance to drug delivery where the CsA molecules can be released directly from the biomaterial surface by passive diffusion. The obtained results showed that the chosen techniques are complementary for the characterization of the molecular organization of multicomponent LB films at the polymer substrate as well as for designing biocompatible coatings with precisely defined wettability.
对涂覆有磷脂1,2 - 二油酰 - sn - 甘油 - 3 - 磷酸胆碱（DOPC）、免疫抑制剂环孢素A（CsA）和抗氧化剂没食子酸月桂酯（LG）三元单分子层的聚对苯二甲酸乙二酯（PET）的表面性质进行了研究。通过朗缪尔 - 布洛杰特（LB）技术将这些薄膜沉积在经空气低温等离子体活化的PET板（PET）上。分别借助原子力显微镜（AFM）和飞行时间二次离子质谱（TOF - SIMS）确定了它们的形貌和表面化学性质，同时通过接触角测量评估了润湿性。然后，根据 Lifshitz - 范德华/酸碱（LWAB）方法计算了表面自由能及其组分。AFM成像表明，朗缪尔单分子层被有效地转移，使PET表面变得平滑。质谱证实了单分子层在转移到基底前后定量和定性组成的兼容性。此外，还确定了LB膜中的分子排列以及DOPC - CsA - LG相互作用的可能机制。润湿性研究提供了关于生物涂层与模拟不同环境的液体之间可能发生的相互作用类型和强度的信息。研究发现，CsA分子从开放构象到封闭构象的变化是由周围DOPC和LG分子确保的疏水环境驱动的。这一过程对于药物递送具有重要意义，因为CsA分子可以通过被动扩散直接从生物材料表面释放。所得结果表明，所选择的技术对于表征聚合物基底上多组分LB膜的分子组织以及设计具有精确确定润湿性的生物相容性涂层是互补的。
