Tag Archives: Zinc substituted

Improved cytocompatibility and antibacterial properties of zinc-substituted brushite bone cement based on β-tricalcium phosphate

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By Inna V. Fadeeva, Margarita A. Goldberg, Ilya I. Preobrazhensky, Georgy V. Mamin, Galina A. Davidova, Nadezhda V. Agafonova, Marco Fosca, Fabrizio Russo, Sergey M. Barinov, Simona Cavalu & Julietta V. Rau

Full text at https://link-springer-com.am.e-nformation.ro/article/10.1007%2Fs10856-021-06575-x

Brushite cements based on powders of Zinc (Zn) (1.4 wt%) substituted tricalcium phosphate (β-TCP) and non-substituted β-TCP were prepared and investigated by SEM/XRD, MTT test and microbiology assay. Copyright J. Rau, Simona Cavalu et al.

Zinc (Zn) is an important biological trace element that plays a role in the normal growth and development of the skeleton. Its content in human bones (0.0126–0.0217 wt%) is about 28% of the total amount of Zn in the body (0.0030 wt% of Zn in tissues) [20]. The lack of Zn slows down the growth of the bone mass and has a negative influence on the bone metabolism [21]. On the other hand, Zn deficiency is a factor of risk for bone osteoporosis [22]. 

XRD spectra of: TCP-based cement (A) before and (B) after soaking in physiological solution and Zn-substituted TCP cement (C) before and (D) after soaking in physiological solution. Copyright J. Rau, Simona Cavalu et al.
FTIR spectra of: A non-substituted and Zn-substituted TCP powders, B non-substituted and Zn-substituted TCP cements, and C non-substituted and Zn-substituted TCP cements after soaking in physiological solution. Copyright J. Rau, Simona Cavalu et al.
Comparison of EPR spectra for Zn-TCP powder sample annealed at 900 °C before and after X-ray irradiation. Copyright J. Rau, Simona Cavalu et al.
Bone Cements’ morphology, SEM images: A, B cement based on β-TCP; C, D cement based on Zn-β-TCP; E, F cement based on β-TCP after soaking in physiological solution; G, H cement based on Zn-β-TCP after soaking in physiological solution.
Copyright J. Rau, Simona Cavalu et al.
The inhibition of growth of: E. Coli for A Zn-TCP cement and B TCP cement; C E. faecium, and D P. aeruginosa for Zn-TCP cement (1) and TCP cement (2). The Zn-substituted TCP cement shows a stronger antibacterial activity, which is expressed in a larger bacterial zone of inhibition, with respect to the TCP cement. Copyright J. Rau, Simona Cavalu et al.

In this work, the cement based on the Zn-substituted β-TCP powder with a simplified preparation recipe and improved characteristics was developed. The setting time of cements was 8 min (the ratio of cement powder: hardening liquid = 3:1), which is optimal for preparation and application of the developed cements for bone defects during surgery. The Zn2+ content was selected to be 1.40 wt%. The pH of the cements reached 6.5 within 60 min after setting. After soaking in physiological solution for 60 days, the morphology and composition of cements changed. The final phases were DCPD and HA.The EPR measurements showed the presence of the trapped hydrogen and confirmed that annealing at 900 °C led to the significant reduction of carbonate impurities embedded into the β-TCP structure.The NCTC L929 fibroblast cell viability on the developed Zn-β-TCP cement was 10% higher compared to cement without Zn and possess antibacterial properties against E. coli, E. faecium, and P. aeruginosa.This finding confirms that the novel material could be a valid strategy for a range of biomedical application in humans. Therefore, it could offer promising potential for bone replacement and repair in moderate and non-load-bearing defects that are prone to infection in orthopedic and trauma setting.