Post Processing and Biological Evaluation of the Titanium Scaffolds for Bone Tissue Engineering
Bartłomiej Wysocki , Joanna Idaszek , Karol Szlązak , Karolina Strzelczyk , Tomasz Brynk , Krzysztof Kurzydłowski , Wojciech Święszkowski
AbstractNowadays, post-surgical or post-accidental bone loss can be substituted by custom-made scaffolds fabricated by additive manufacturing (AM) methods from metallic powders. However, the partially melted powder particles must be removed in a post-process chemical treatment. The aim of this study was to investigate the effect of the chemical polishing with various acid baths on novel scaffolds' morphology, porosity and mechanical properties. In the first stage, Magics software (Materialise NV, Leuven, Belgium) was used to design a porous scaffolds with pore size equal to (A) 200 mu m, (B) 500 mu m and (C) 200 + 500 mu m, and diamond cell structure. The scaffolds were fabricated from commercially pure titanium powder (CP Ti) using a SLM50 3D printing machine (Realizer GmbH, Borchen, Germany). The selective laser melting (SLM) process was optimized and the laser beam energy density in range of 91-151 J/mm(3) was applied to receive 3D structures with fully dense struts. To remove not fully melted titanium particles the scaffolds were chemically polished using various HF and HF-HNO3 acid solutions. Based on scaffolds mass loss and scanning electron (SEM) observations, baths which provided most uniform surface cleaning were proposed for each porosity. The pore and strut size after chemical treatments was calculated based on the micro-computed tomography (mu-CT) and SEM images. The mechanical tests showed that the treated scaffolds had Young's modulus close to that of compact bone. Additionally, the effect of pore size of chemically polished scaffolds on cell retention, proliferation and differentiation was studied using human mesenchymal stem cells. Small pores yielded higher cell retention within the scaffolds, which then affected their growth. This shows that in vitro cell performance can be controlled to certain extent by varying pore sizes.
|Journal series||Materials , ISSN 1996-1944|
|Publication size in sheets||0.9|
|Keywords in English||chemical polishing; CP Ti; powder metallurgy; selective laser melting; scaffolds; cellular solids|
|Score|| = 35.0, 28-11-2017, ArticleFromJournal|
= 35.0, 28-11-2017, ArticleFromJournal
|Publication indicators||: 2016 = 2.654 (2) - 2016=3.236 (5)|
|Citation count*||12 (2018-02-16)|
* presented citation count is obtained through Internet information analysis and it is close to the number calculated by the Publish or Perish system.