Laser-assisted wet coating of calcium phosphate for surface-functionalization of PEEK

PLoS One. 2018 Oct 31;13(10):e0206524. doi: 10.1371/journal.pone.0206524. eCollection 2018.


Calcium phosphate (CaP) coating is an effective method for surface-functionalization of bioinert materials and for production of osteoconductive implants. Recently, we developed a laser-assisted biomimetic process (LAB process) for facile and area-specific CaP coating. In this study, the LAB process was applied to chemically stable and mechanically durable poly(etheretherketone) (PEEK), which has become widely used as an orthopedic and dental implant material. The LAB process was carried out by irradiating pulsed Nd:YAG laser light (355 nm) onto a PEEK substrate that was immersed in supersaturated CaP solution. The CaP coating applicability depended on laser fluence, i.e., CaP successfully formed on PEEK surface after the LAB process at 2 W/cm2. Further increase in laser fluence did not result in the successful formation. At the optimal fluence of 2 W/cm2, the laser-irradiated PEEK surface was modified and heated to induce heterogeneous CaP precipitation within 10 min in CaP solution, followed by further CaP growth over the irradiation time (tested up to 30 min). The LAB process improved the cytocompatibility of PEEK surface with osteoblastic MC3T3-E1 cells. Furthermore, the LAB-processed CaP-coated PEEK substrate formed a dense hydroxyapatite layer on its surface in the simulated body fluid, suggesting the osteoconductivity of this material. The present LAB process can be a useful new tool to produce osteoconductive PEEK-based implants.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calcium Phosphates*
  • Coated Materials, Biocompatible / chemistry*
  • Ketones / chemistry*
  • Lasers
  • Polyethylene Glycols / chemistry*
  • Prostheses and Implants*
  • Surface Properties


  • Calcium Phosphates
  • Coated Materials, Biocompatible
  • Ketones
  • polyetheretherketone
  • Polyethylene Glycols
  • calcium phosphate

Grant support

This study was supported by JSPS KAKENHI grant numbers JP17H02093, JP15H00906 (funder: Japan Society for the Promotion of Science;; AO received the funding). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.