Effect of polyphosphoric acid pre-treatment of titanium on attachment, proliferation, and differentiation of osteoblast-like cells (MC3T3-E1).
OBJECTIVE
To evaluate the effect of polyphosphoric acid (PPA) pre-treatment of titanium (Ti) on the initial attachment, proliferation, and differentiation of mouse osteoblast-like cells (MC3T3-E1).


METHODS
Adsorption of PPA to Ti was achieved by immersing Ti disks (15 mm in diameter) into 0, 1, and 10 wt% PPA and 10 wt% orthophosphoric acid (OPA) for 24 h. On each pre-treated Ti disk, 5.0 x 10(4) MC3T3-E1 cells were seeded, and 1, 3, and 5 h later cell attachment was evaluated. Cell proliferation was also determined 1, 3, and 5 days after cell seed. Cell differentiation was evaluated 5, 10, and 15 days after cell seed using osteoblast marker gene expression. Total RNA was purified from each culture and Type-I collagen, alkaline phosphatase, and osteocalcin mRNA expression levels were measured by real-time reverse transcription polymerase chain reaction.


RESULTS
Adsorption of PPA or OPA to Ti significantly accelerated initial cell attachment at every time point (P<0.0001). As with cell attachment, cell proliferation was also accelerated on the PPA-treated Ti disks in a dose-dependent manner at every time point (P<0.0001). However, OPA-treated Ti disks did not enhance the cell proliferation. Regarding osteoblastic differentiation, PPA-treated Ti significantly accelerated the Type-I collagen gene expression at 5 and 10 days after cell seed. Regarding alkaline phosphatase and osteocalcin gene expression, no significant difference was found among the different Ti surface conditions.


CONCLUSIONS
The accelerated cell behavior following Ti pre-treatment with PPA is a promising new strategy to fabricate bioactive Ti implants.
Maekawa
Kenji
K
Department of Oral and Maxillofacial Rehabilitation, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
Yoshida
Yasuhiro
Y
Mine
Atsushi
A
van Meerbeek
Bart
B
Suzuki
Kazuomi
K
Kuboki
Takuo
T
D016475:3T3 Cells; D000134:Acid Etching, Dental; D000469:Alkaline Phosphatase / Q000096:biosynthesis; D000704:Analysis of Variance; D000818:Animals; D002448:Cell Adhesion; D002454:Cell Differentiation; D049109:Cell Proliferation; D024042:Collagen Type I / Q000096:biosynthesis; D015870:Gene Expression; D051379:Mice; D010006:Osteoblasts / Q000378:metabolism / Q000502:physiology*; D015675:Osteocalcin / Q000096:biosynthesis; D010756:Phosphoric Acids / Q000494:pharmacology*; D011108:Polymers / Q000494:pharmacology*; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013499:Surface Properties; D014025:Titanium
D024042:Collagen Type I; D010756:Phosphoric Acids; D011108:Polymers; D012333:RNA, Messenger; D015675:Osteocalcin; C047269:polyphosphoric acid; D014025:Titanium; D000469:Alkaline Phosphatase