539 - Biomineral CaP Coating Promotes Osteostimulatory Responses of PEEK Imp...

Oral Posters: Innovative Technologies

Presented by: L. Jongpaiboonkit - View Audio/Video Presentation (Members Only)

Author(s):

L. Jongpaiboonkit(1), N. Caras(1), V. Mondine(1), W. Murphy(2)

(1) Tissue Regeneration Systems, Inc, Plymouth, MI, United States
(2) The University of Wisconsin, Madison, WI, United States

Abstract

Introduction: Nanostructured calcium phosphate (CaP) coatings have the potential to induce osteostimulatory, bone forming characteristics on the surface of PEEK spinal implants. This study investigated the behavior of MC3T3-E1 osteoblast-like cells cultured on CaP coated and non-coated PEEK and Carbon Fiber Reinforced (CF) PEEK substrates.

Methods: A nanostructured CaP coating was applied to PEEK and CF-PEEK cylinders through a proprietary biomimetic precipitation process. Materials were subjected to surface pre-treatments and subsequently incubated in a pH adjusted mineral solution, referred to as 'modified simulated body fluid' (mSBF). An incubation protocol was followed for 4 days resulting in a continuous, plate-like nanostructure coating that provides high surface area favorable for cell attachment (image 1)
MC3T3-E1 cells were seeded upon coated and uncoated PEEK and CF-PEEK cylinders and incubated under standard cell culture conditions. At day 3, 7 and 10 in culture, we evaluated 1) cell adhesion and proliferation, which are indicative of proper cell function; and 2) alkaline phosphatase (ALP) activity and secreted osteocalcin (OCN) level, which are markers for differentiated function of osteoblast cells.

Results: Overall, a significantly increased number of cells adhered and proliferated on the coated PEEK and CF-PEEK cylinders when compared to non-coated PEEK cylinders. Similarly, ALP activity and OCN levels per cell were substantially increased in the coated PEEK implants. Further, cell attachment to both types of uncoated PEEK showed delayed proliferation and differentiation, and demonstrated a decline in proliferation rate after day 7 (image 2).

Conclusion: These in vitro results indicate that the presence of this CaP coating is osteostimulatory on PEEK implants. These in vitro effects suggest that the coating may enhance the osseointegration of PEEK devices, as well as peri-implant bone formation. The bone forming characteristics are likely related to the combined effect of mineral ion release and the surface area and topography achieved through the plate-like nano features.

Figure 1

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