Bioactivation Treatment with Mixed Acid and Heat on Titanium Implants Fabricated by Selective Laser Melting Enhances Preosteoblast Cell Differentiation

• Main Authors: Phuc Thi Minh Le, Seine A. Shintani, Hiroaki Takadama, Morihiro Ito, Tatsuya Kakutani, Hisashi Kitagaki, Shuntaro Terauchi, Takaaki Ueno, Hiroyuki Nakano, Yoichiro Nakajima, Kazuya Inoue, Tomiharu Matsushita, Seiji Yamaguchi
• Format: Article
• Language: English
• Published: MDPI AG 2021-04-01
• Series: Nanomaterials
• Subjects: selective laser melting; acid treatment; titanium; apatite formation; cell culture
• Online Access: https://www.mdpi.com/2079-4991/11/4/987

Selective laser melting (SLM) is a promising technology capable of producing individual characteristics with a high degree of surface roughness for implants. These surfaces can be modified so as to increase their osseointegration, bone generation and biocompatibility, features which are critical to their clinical success. In this study, we evaluated the effects on preosteoblast proliferation and differentiation of titanium metal (Ti) with a high degree of roughness (Ra = 5.4266 ± 1.282 µm) prepared by SLM (SLM-Ti) that was also subjected to surface bioactive treatment by mixed acid and heat (MAH). The results showed that the MAH treatment further increased the surface roughness, wettability and apatite formation capacity of SLM-Ti, features which are useful for cell attachment and bone bonding. Quantitative measurement of osteogenic-related gene expression by RT-PCR indicated that the MC3T3-E1 cells on the SLM-Ti MAH surface presented a stronger tendency towards osteogenic differentiation at the genetic level through significantly increased expression of Alp, Ocn, Runx2 and Opn. We conclude that bio-activated SLM-Ti enhanced preosteoblast differentiation. These findings suggest that the mixed acid and heat treatment on SLM-Ti is promising method for preparing the next generation of orthopedic and dental implants because of its apatite formation and cell differentiation capability.