Novel Whitlockite/Alginate/C60 Fullerene Composites: Synthesis, Characterization and Properties for Medical Application

The hybrid composite materials in form of spheres based on whitlockite-related calcium phosphate, Alginate (20, 30 or 50 wt.%) and C60 Fullerene (C60; 2 or 5 wt.%) were fabricated. According to XRD, elemental analysis and SEM data, the whitlockite-related (hexagonal system, space group R3c) calcium phosphate containing 0.42 wt.% of sodium was obtained in the form of particles with size 50–80 nm. It has been found that the addition of Alginate (20 wt.%) to prepared calcium phosphate leads to an increase in the compressive strength of composite by two times (from 137 to 358 MPa), and value of Young's modulus on 20% (from 460 to 558 MPa), while the presence of C60 in composition did not significant influence on this characteristic. The antibacterial activity of prepared composites with different composition and amounts (2.5, 5 or 10 mM) against Lactobacillus rhamnosus, Lactobacillus salivarius, Staphylococcus aureus and Pseudomonas aeruginosa was studied. All prepared samples did not effect on Lactobacillus. The addition of 5 wt.% C60 to phosphate-Alginate (30 wt.%) composite resulted in a tenfold decrease in the survival rate of the S. aureus strain at 5 and 10 mM of samples while P. aeruginosa was less sensitive to action of this sample and inhibition of bacteria growth was occurred only at its amount 10 mM. Thus, the results of mechanical properties and impact of created nanostructured hybrid composites on normal human microbiota (Lactobacillus) as well as pathogenic strain (S. aureus and P. aeruginosa) indicate the suitability of these promising materials for further biological test for bone therapy.