Platelet adhesion on commercially pure titanium plates in vitro III: effects of calcium phosphate-blasting on titanium plate biocompatibility

Masayuki Nakamura,Yutaka Kitamura,Kazushige Isobe,Hideo Kawabata,Atsushi Sato,Hachidai Aizawa,Taisuke Watanabe,Takaaki Tanaka,Tomoyuki Kawase

doi:10.1186/s40729-020-00270-2

Masayuki Nakamura, Yutaka Kitamura + Show 7 more

Open Access

https://doi.org/10.1186/s40729-020-00270-2

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Abstract

BackgroundPlatelet-rich plasma (PRP) is often used to improve surface biocompatibility. We previously found that platelets rapidly adhere to plain commercially pure titanium (cp-Ti) plates in the absence, but not in the presence, of plasma proteins. To further expand on these findings, in the present study, we switched titanium plates from a plain surface to a rough surface that is blasted with calcium phosphate (CaP) powder and then examined platelet adhesion and activation.MethodsElemental distribution in CaP-blasted cp-Ti plates was analyzed using energy-dispersive X-ray spectroscopy. PRP samples prepared from anticoagulated blood samples of six healthy, non-smoking adult male donors were loaded on CaP-blasted cp-Ti plates for 1 h and fixed for examination of platelet morphology and visualization of PDGF-B and platelet surface markers (CD62P, CD63) using scanning electron microscopy and fluorescence microscopy. Plain SUS316L stainless steel plates used in injection needles were also examined for comparison.ResultsSignificant amounts of calcium and phosphate were detected on the CaP-blasted cp-Ti surface. Platelets rapidly adhered to this surface, leading to higher activation. Platelets also adhered to the plain stainless surface; however, the levels of adhesion and activation were much lower than those observed on the CaP-blasted cp-Ti plate.ConclusionsThe CaP-blasted cp-Ti surface efficiently entraps and activates platelets. Biomolecules released from the activated platelets could be retained by the fibrin matrix on the surface to facilitate regeneration of the surrounding tissues. Thus, PRP immersion could not only eliminate surface air bubbles but also improve the biocompatibility of the implant surface.

Highlights

Platelet-rich plasma (PRP) is widely applied in various fields of regenerative medicine
After calcium phosphate (CaP)-blasting, sub-micron levels of roughness were formed on the surface, and some areas were coated with Ca and P
This study demonstrated that CaP-blasted commercially pure titanium (cp-Ti) plates are more efficient in the entrapment and activation of platelets compared to plain cp-Ti plates examined in previous studies [2, 16]

Summary

Introduction

Platelet-rich plasma (PRP) is widely applied in various fields of regenerative medicine. Its clinical application is based on the evidence that platelets concentrated in PRP provide high levels of growth factors along with fibrinogen/fibrin, both of which are involved in the tissue engineering triangle and are expected to function cooperatively in successful tissue regeneration [1]. Other purposes include functionalization of the implant surface with the biomolecules included in PRP preparations. Platelet-rich plasma (PRP) is often used to improve surface biocompatibility. We previously found that platelets rapidly adhere to plain commercially pure titanium (cp-Ti) plates in the absence, but not in the presence, of plasma proteins. To further expand on these findings, in the present study, we switched titanium plates from a plain surface to a rough surface that is blasted with calcium phosphate (CaP) powder and examined platelet adhesion and activation

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