Characteristics of Polypeptide/Phospholipid Monolayers on Water and the Plasma‐Activated Polyetheretherketone Support

Abstract

Polyetheretherketone (PEEK) is a highly biocompatible polymer widely used in medicine as an implant production material. In this article, the PEEK surface was characterized in terms of its wettabillity properties after the physicochemical modifications by treatment with the low‐temperature air plasma and covering with the Langmuir–Blodgett (LB) monolayers of polypeptide (cyclosporine A, CsA) and/or phospholipid (1,2‐dipalmitoyl‐sn‐glycero‐3‐phosphocholine, DPPC). The LB deposition was preceded by the analysis of miscibility and morphology of monolayers at the air/water interface by means of the Langmuir technique and Brewster angle microscopy (BAM). Then, wettability of the polymer‐supported films was evaluated by the contact angle measurements of three probe liquids of different characters (two polar—water and formamide, one apolar—diiodomethane). The measured contact angles allowed for determination of the surface free energy and its components based on the Lifshitz‐van der Waals/acid–base (LWAB) approach. Some relations between the kind and magnitude of interactions within the model membranes on the water subphase and those of the PEEK‐supported membranes with the liquids were found out. The results allowed obtaining the interesting models of biological coatings with potential applications.

Analysis of Molecular Interactions between Components in Phospholipid-Immunosuppressant-Antioxidant Mixed Langmuir Films

“…Each of the compounds studied here (DOPC, CsA, and LG) forms true Langmuir monolayers at the air−water interface, as shown in Figure 1, with the isotherms being consistent with the data published previously. 3,34 Here, the "true" term means that the layer-forming molecules are practically insoluble in the water subphase and these molecules are capable of forming a two-dimensional film at the interface upon the compression process. The π−A curves exhibit a small slope, which is characteristic of high monolayer compressibility.…”

“…Using such a less complicated system is very useful to gain information on the binding of proteins to membranes highly dependent on the mutual interactions. Several studies have shown that the poorly water-soluble CsA penetrates lipid membranes showing affinity to the gel/fluid boundaries and disrupts the order of acyl chains, especially around the polar heads. , Its interactions with phospholipids (DPPC, POPC, DPPE, DPPS, DPPG) ,− with a dominant repulsive character generate no miscibility or only partial miscibility. Therefore, the incorporation of the LG antioxidant, which interacts with both DOPC and CsA, can increase the miscibility of these two components and improve the mixture stability.…”

“…4 One of the ways to improve biocompatibility is to modify the implant surface with a biocompatible living tissue layer of the desired physicochemical properties, which would prevent activation of the immune system, infection, and rejection of the implant. 2,3 In this aspect, there is a need for the preparation and characterization of multicomponent Langmuir films containing cell-friendly components of natural biological membranes (phospholipids, PL), as well as compounds with immunosuppressive activity (cyclosporine A, CsA) and antioxidant (lauryl gallate, LG). Their chemical structures are presented in Scheme 1.…”

“…Ultrathin films characterized by high homogeneity, continuity, defined composition, and chemical structure as well as defined stability and wettability are used to modify the surface properties of implants. In this context, the physicochemical characteristics of Langmuir (L) and Langmuir-Blodgett (LB) monolayers, well-known ultrathin films, are part of intensive research in biomimetic systems. − The integration of these ultrathin films with the tissue strictly depends on the immune response of the organism, which is determined, among others, by the degree of biocompatibility of the material with cells . One of the ways to improve biocompatibility is to modify the implant surface with a biocompatible living tissue layer of the desired physicochemical properties, which would prevent activation of the immune system, infection, and rejection of the implant. , In this aspect, there is a need for the preparation and characterization of multicomponent Langmuir films containing cell-friendly components of natural biological membranes (phospholipids, PL), as well as compounds with immunosuppressive activity (cyclosporine A, CsA) and antioxidant (lauryl gallate, LG).…”

Poly (Ether-Ether-Ketone) for Biomedical Applications: From Enhancing Bioactivity to Reinforced-Bioactive Composites—An Overview

“…The dual-modified PEEK was more favorable for pre-osteoblast adhesion, spreading, and proliferation. Plasma and laser techniques can also be used to immobilize biomolecules on the PEEK surface [ 74 , 82 , 83 , 84 , 85 , 86 ]. Terpiłowski et al [ 74 ] pre-treated PEEK with nitrogen plasma to further immobilize chitosan on its surface.…”