Peek Malzemenin Osteojenik Aktivitesinin Artırılmasında Çeşitli Yüzey Modifikasyonlarının Rolü
Özet
This study was prepared with a support of TÜBİTAK 2210-C Primary Subject National Scholarship Program for MSc Students. The aim of the present study is to eliminate the bioinert nature of Polyetheretherketone (PEEK) material and to increase its osteogenic activity by using various surface modifications. In order to provide osteogenic activity on mechanically and/or physically modified PEEK samples, boron doped nano-hydroxyapatite (B-nHAp) was coated by microwave-assisted method and material characterization studies were carried out. After that, osteogenic activities of PEEK material surfaces were investigated by in-vitro cell culture studies.
In the first step of the study, the PEEK surfaces were polished with 800-grid sandpaper after cutting. Then, surfaces were mechanically modified by sandblasting and physically modified by NaOH etching. After modification, sample groups were labeled as B-PEEK (Bare PEEK), S-PEEK (Sand-blasted PEEK), N-PEEK (NaOH etched PEEK) and S, N-PEEK (Sand-blasted and NaOH etched PEEK) and the surface properties of the samples were investigated via profilometer and water contact angle measurements. Roughness values were found to be 982.7±23.3, 5051.0±27.3, 2884.0±3.4, and 4404.0±21.2 nm for B-PEEK, S-PEEK, N-PEEK and S, N-PEEK samples, respectively. The water contact angle values of the surfaces were also measured as 62.8±2.9, 90.8±3.3, 71.0±9.6 and 108.6±1.7° in the same order. It was found that the sandblasting caused the greatest roughness on the surface and thus it was increased the hydrophobicity of the surfaces, but the highest hydrophobicity was seen in both mechanically and physically modified samples.
In the second part of the study, boron-nanohydroxyapatite (B-nHAp) was used to coat the surface of the listed samples above with a boron doped 10 times concentrated simulated body fluid (10xSBF)-like solution by using microwave-assisted biomimetic method to support osseointegration and the reduced water contact angle values of the samples (24.4±5.9, 29.5±5.5, 22.8±5.7, and 25.8±5.6°, respectively), indicated that increased hydrophilicity.
The MC3T3-E1 preosteoblastic cell line was used for cell culture studies of modified PEEK samples. PrestoBlue® analysis for cell viability studies, Scanning Electron Microscopy (SEM) and Confocal Microscopy analyses for morphological observations, measurements of Alkaline Phosphatase (ALP) activity and collagen amount and Real Time Polymerase Chain Reaction (RT-PCR) analyses were used to investigate the osteogenic activities of cells cultured on PEEK samples. Cell culture results demonstrated that mechanical or physical modifications provide an increase in osteogenic activity, but the B-nHAp coating significantly increased the adhesion, proliferation and differentiation capacities of MC3T3-E1 cells on the surface compared to uncoated specimens.
As a result, it was determined that the bioactivity was increased on the PEEK surfaces modified mechanically or physically, but the most effective method for increasing osteogenic activity was provided with B-nHAp coatings.
