Abstract
Optimal treatment of bone fractures with minimal complications requires implant alloys that combine high strength with high ductility. Today, TiAl6V4 titanium and 316L steel are the most applied alloys in bone surgery, whereas both share advantages and disadvantages. The nickel-free, high-nitrogen austenitic steel X13CrMnMoN18-14-3 (1.4452, brand name: P2000) exhibits high strength in combination with superior ductility. In order to compare suitable alloys for bone implants, we investigated titanium, 316L steel, CoCrMo and P2000 for their biocompatibility and hemocompatibility (according to DIN ISO 10993–5 and 10993–4), cell metabolism, mineralization of osteoblasts, electrochemical and mechanical properties. P2000 exhibited good biocompatibility of fibroblasts and osteoblasts without impairment in vitality or changing of cell morphology. Furthermore, investigation of the osteoblasts function by ALP activity and protein levels of the key transcription factor RUNX2 revealed 2x increased ALP activity and more than 4x increased RUNX2 protein levels for P2000 compared to titanium or 316 steel, respectively. Additionally, analyses of osteoblast biomineralization by Alizarin Red S staining exhibited more than 6x increased significant mineralization of osteoblasts grown on P2000 as compared to titanium. Further, P2000 showed no hemolytic effect and no significant influence on hemocompatibility. Nanoindentation hardness tests of Titanium and 316L specimens exposed an indentation hardness (HIT) of about 4 GPa, whereas CoCrMo and P2000 revealed HIT of 7.5 and 5.6 GPa, respectively. Moreover, an improved corrosion resistance of P2000 compared to 316L steel was observed. In summary, we could demonstrate that the nickel-free high-nitrogen steel P2000 appears to be a promising alternative candidate for applications in bone surgery. As to nearly all aspects like biocompatibility and hemocompatibility, cell metabolism, mineralization of osteoblasts and mechanical properties, P2000 was similar to or revealed advantages against titanium, 316L or CoCrMo.
Highlights
For many decades surgical reconstruction plates, nails and screws on the basis of steel and titanium alloys are used for reconstruction of bone defects in orthopedics, trauma, hand, craniofacial surgery [1,2]
To investigate the vitality of fibroblasts and osteoblasts on P2000 compared to other alloys, live/ dead stainings of the cells plated on titanium, 316L, CoCrMo, P2000 and control samples were performed
A significant lower cytotoxicity for P2000 was observed in fibroblasts as well as in osteoblasts compared to titanium and all other samples (Fig 2B)
Summary
For many decades surgical reconstruction plates, nails and screws on the basis of steel and titanium alloys are used for reconstruction of bone defects in orthopedics, trauma-, hand-, craniofacial surgery [1,2]. Stainless steel alloys, such as the commonly used 316L-type of steels, show good properties as to mechanical strength, toughness as well as cyto- and biocompatibility; they are the most frequently used implant materials for internal fixation in orthopedics [1,7,11,12]. Compared to 316L steel, P2000 provides a better corrosion resistance, which is supported by the high nitrogen content [12]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
