Platelet adhesion on commercially pure titanium plates in vitro I: effects of plasma components and involvement of the von Willebrand factor and fibronectin

Abstract

Background Platelet-rich plasma (PRP) is widely used in regenerative dentistry. Furthermore, it is often applied in the pretreatment of titanium implants to improve their surface bioaffinity and initial stability. However, effects of PRP application on implant surface at cellular and molecular levels remain poorly understood. Therefore, we examined platelet adhesion on commercially pure titanium ( cp -Ti) plates, with a particular focus on fibrinogen (FGN), von Willebrand factor (vWF), and fibronectin (FN), in the presence or absence of plasma components. Methods Citrated blood samples were obtained from six healthy male volunteers, and pure-PRP (P-PRP) and pure platelet suspensions in phosphate-buffered saline (PBS) were prepared. Platelet adhesion on cp -Ti plate surface was evaluated by phalloidin staining and tetrazolium dye assay. Distribution of FGN, vWF, FN, albumin, CD62P, and CD63 was examined by immunocytochemical analysis. Results Platelets in PBS suspensions rapidly and time-dependently adhered to cp -Ti plate surface, but this adhesion was substantially disturbed by the presence of plasma components. FGN was most preferably adsorbed regardless of the presence or absence of plasma components, while vWF and FN showed greater accumulation on platelet adhesion area. Conclusions Although FGN is rapidly and abundantly adsorbed on cp -Ti plate surface, vWF and FN function as major platelet adhesion molecules in citrated blood samples. After pretreatment with P-PRP, however, platelets adhered to cp -Ti much less efficiently. Therefore, P-PRP pretreatment might not directly contribute to surface functionalization, initial stabilization, and osseointegration of machined or similar types of implants. Electronic supplementary material The online version of this article (10.1186/s40729-019-0160-z) contains supplementary material, which is available to authorized users.

Platelet Adhesion on Commercially Pure Titanium Plates in Vitro II. Immunofluorescence Visualization of PDGF-B, TGFβ1, and PPARγ Released from Activated Adherent Platelets

“…In the previous study [19], we demonstrated the time-dependent adhesion of platelets onto the cp-Ti platelets and the adhesion molecules mainly involved in this initial adhesion. To add new findings to the previous data, this study was performed to visualize the release of growth factors and a transcription factor.…”

“…As described previously [19],~9 mL of peripheral blood was collected from non-smoking healthy male volunteers (N = 6; age: 23 to 58 years old) in plain plastic blood-collection tubes (Neotube; NIPRO, Osaka, Japan) containing 1 mL of A formulation of acid-citrate-dextrose (ACD-A; Terumo, Tokyo, Japan) [22,23]. These blood samples were stored in a rotating agitator at ambient temperature until use (~48 h) [24,25].…”

“…The plain cp-Ti plates (Nilaco, Tokyo, Japan) were used in this study: the cp-Ti plates were cut into square 10 × 10 mm 2 pieces, washed serially with acetone, ethanol, and distilled water in an ultrasonic cleaner (Citizen, Tokyo, Japan) and air-dried [19].…”

“…To investigate the interaction between the titanium surface and the PRP, especially the platelets, and validate the use of PRP for surface modification, in a previous study [19], we identified the major adhesion molecules involved in human platelet adhesion and activation on commercially pure titanium (cp-Ti) plates. To further investigate these interactions, in this study, we visualized the distribution of the growth factors, PDGF-B and TGFβ1, and the transcription factor, peroxisome proliferator-activated receptor γ (PPARγ), which is recently thought to be an anti-inflammatory factor [20,21], and evaluated the biomolecule releasing activity of platelets activated and adhered on cp-Ti plates.…”

The Platelet Concentrates Therapy: From the Biased Past to the Anticipated Future

“…Kawase and his group successfully found that exogenously added Ca 2+ directly activated platelets in order to facilitate adhesion to a titanium surface and release microparticles and growth factors. To fill gaps in their knowledge, these researchers have further accumulated basic knowledge related to platelet biology in a series of studies [ 72 , 91 , 92 , 93 , 94 , 95 , 96 ]. However, many platelet functions that are closely related to PC therapy are still poorly understood and have not yet been clarified.…”