关键词: 聚醚醚酮, 表面改性, 生物活性, 细胞黏附, 成骨分化

Abstract:

Objective To improve the surface bioactivity of polyetheretherketone (PEEK) by constructing a polydopamine (PDA)-mediated recombinant humanized type Ⅲ collagen coating. Methods A composite coating was fabricated using a two-step immersion method. Briefly, PEEK substrates were first immersed in a dopamine (DA) solution to form an in situ self-polymerized PDA intermediate layer (PDA-PEEK), followed by immersion in a recombinant humanized type Ⅲ collagen solution to obtain Col-PEEK. Surface characteristics were analyzed using scanning electron microscopy (SEM), water contact angle measurement, Fourier transform infrared spectrum (FTIR), and X-ray photoelectron spectroscopy (XPS). Human jaw bone marrow mesenchymal stem cells (hjBMMSCs) were used as a model. Cells were cultured either with complete medium (Control group) or with material extracts (PEEK, PDA-PEEK, and Col-PEEK groups), and cell proliferation was then evaluated using the CCK-8 assay. Cell adhesion morphology was observed microscopically. Osteogenic differentiation and mineralization were assessed by quantitative alkaline phosphatase (ALP) activity analysis and semi-quantitative alizarin red S (ARS) staining. The expression levels of osteogenesis-related genes were determined by RT-qPCR. Results SEM observations revealed that the coating was uniformly distributed without altering the microstructure of the substrate. The water contact angle of Col-PEEK was significantly reduced (P<0.05), indicating markedly improved hydrophilicity. FTIR and XPS analyses confirmed the successful immobilization of type Ⅲ collagen onto the PDA layer. CCK-8 assays demonstrated that the modified materials exhibited no cytotoxicity. Cells cultured on Col-PEEK displayed enhanced spreading and more filopodia formation. ALP activity and calcium nodule deposition were significantly increased(P<0.05), accompanied by a marked upregulation of key osteogenic gene expression(P<0.05). Conclusion The PDA-mediated recombinant humanized type Ⅲ collagen composite coating significantly enhances the hydrophilicity, cell adhesion, and osteoinductive activity of PEEK surfaces. This modification strategy provides a novel surface modification approach and experimental evidence for the clinical translation of PEEK in oral implantation and maxillofacial bone regeneration.

Key words: polyetheretherketone, surface modification, bioactivity, cell adhesion, osteogenic differentiation