The role of well-defined nanotopography of titanium implants on osseointegration: cellular and molecular events in vivo
Artikel i vetenskaplig tidskrift, 2016

Purpose: Mechanisms governing the cellular interactions with well-defined nanotopography are not well described in vivo. This is partly due to the difficulty in isolating a particular effect of nanotopography from other surface properties. This study employed colloidal lithography for nanofabrication on titanium implants in combination with an in vivo sampling procedure and different analytical techniques. The aim was to elucidate the effect of well-defined nanotopography on the molecular, cellular, and structural events of osseointegration. Materials and methods: Titanium implants were nanopatterned (Nano) with semispherical protrusions using colloidal lithography. Implants, with and without nanotopography, were implanted in rat tibia and retrieved after 3, 6, and 28 days. Retrieved implants were evaluated using quantitative polymerase chain reaction, histology, immunohistochemistry, and energy dispersive X-ray spectroscopy (EDS). Results: Surface characterization showed that the nanotopography was well defined in terms of shape (semispherical), size (79 +/- 6 nm), and distribution (31 +/- 2 particles/mu m(2)). EDS showed similar levels of titanium, oxygen, and carbon for test and control implants, confirming similar chemistry. The molecular analysis of the retrieved implants revealed that the expression levels of the inflammatory cytokine, TNF-alpha, and the osteoclastic marker, CatK, were reduced in cells adherent to the Nano implants. This was consistent with the observation of less CD163-positive macrophages in the tissue surrounding the Nano implant. Furthermore, periostin immunostaining was frequently detected around the Nano implant, indicating higher osteogenic activity. This was supported by the EDS analysis of the retrieved implants showing higher content of calcium and phosphate on the Nano implants. Conclusion: The results show that Nano implants elicit less periimplant macrophage infiltration and downregulate the early expression of inflammatory (TNF-alpha) and osteoclastic (CatK) genes. Immunostaining and elemental analyses show higher osteogenic activity at the Nano implant. It is concluded that an implant with the present range of well-defined nanocues attenuates the inflammatory response while enhancing mineralization during osseointegration.

colloidal lithography

anodized titanium

response

inflammatory

surface

model

immunohistochemistry

gene expression

dioxide nanotubes

bone-formation

different diameters

energy dispersive X-ray spectroscopy

nanofabrication

differentiation

gene-expression

Författare

Dimitrios Karazisis

Göteborgs universitet

Ahmed Ballo

Göteborgs universitet

Sarunas Petronis

Hossein Agheli

Göteborgs universitet

Lena Emanuelsson

Göteborgs universitet

Peter Thomsen

Göteborgs universitet

Omar Omar

Göteborgs universitet

International journal of nanomedicine

1176-9114 (ISSN) 1178-2013 (eISSN)

Vol. 11 1367-1381

Ämneskategorier

Biomaterialvetenskap

DOI

10.2147/ijn.s101294