Characteristics of Hybrid Bioglass-Chitosan Coatings on the Plasma Activated PEEK Polymer

Abstract

Polyetheretherketone (PEEK) is a biocompatible, chemically and physically stable radiolucent polymer that exhibits a similar elastic modulus to the normal human bone, making it an attractive orthopedic implant material. However, PEEK is biologically inert, preventing strong enough bonding with the surrounding bone tissue when implanted in vivo. Surface modification and composite preparation are the two main strategies for the improvement of the bioactivity of PEEK. In this study, the plasma activated PEEK surfaces with the embedded bioglass, chitosan, and bioglass-chitosan mixed layers applying from the solution dip-coating technique were investigated. The most prominent factors affecting the coating biocompatibility are strictly connected with the composition of its outer surface (its charge and functional groups), hydrophilic-hydrophobic character, wettability and surface free energy, and topography (size of pores/substructures, roughness, stiffness), as well as the personal characteristics of the patient. The obtained surfaces were examined in terms of wettability and surface-free energy changes. Additionally, FTIR (Fourier Transformation Infrared Spectrometry) and SIMS (Secondary Ion Mass Spectrometry) were applied to establish and control the coating composition. Simultaneously the structure of coatings was visualized with the aid of SEM (Scanning Electron Microscopy). Finally, the obtained systems were incubated in SBF (Simulated Body Fluid) to verify the modifications’ influence on the bioactivity/biocompatibility of the PEEK surface. Different structures with variable compositions, as well as changes of the wettability, were observed depending on the applied modification. In addition, the incubation in SBF suggested that the bioglass-chitosan ratio influenced the formation of apatite-like structures on the modified PEEK surfaces.

Strategies to improve the performance of polyetheretherketone (PEEK) as orthopedic implants: from surface modification to addition of bioactive materials

“…In addition to directly improving the physicochemical properties, osteogenic activity, and antimicrobial ability of PEEK, the plasma-treated PEEK surface is useful for coating adhesion. 28 3.1.2. Laser treatment.…”

Chitosan-Based Smart Biomaterials for Biomedical Applications: Progress and Perspectives

“…Chitosan preferentially binds with bioglass crystallite, which makes fewer chitosan bind to PEEK if a small chitosan concentration is used. The preferential binding of chitosan impacts the wetting properties that correspond to the host response at the cellular level …”

“…Chitosan can be designed as a stable film form because of the strong hydrogen bonding between chitosan chains . As the film forms, chitosan is usually used to coat the prepared scaffolds to induce physicochemical, mechanical, and antibacterial properties . It is essential to explore the concentration of chitosan coatings on the surfaces of the scaffolds because it can influence scaffold characteristics.…”

“…126 As the film forms, chitosan is usually used to coat the prepared scaffolds to induce physicochemical, mechanical, and antibacterial properties. 127 It is essential to explore the concentration of chitosan coatings on the surfaces of the scaffolds because it can influence scaffold characteristics. For example, in the study of Polyetheretherketone (PEEK) as the polymer for orthopedic implants, coating with bioglass and chitosan films influence the wetting properties.…”

“…The preferential binding of chitosan impacts the wetting properties that correspond to the host response at the cellular level. 127 3.2. Chitosan-Based Smart Biomaterials for Bone Scaffolds.…”