Chemically Modified Diatoms Biosilica for Bone Cell Growth with Combined Drug-Delivery and Antioxidant Properties

Nanostructured biosilica produced by Thalassiosira weissflogii diatoms is covalently functionalized with the cyclic nitroxide 2,6,6-tetramethylpiperidine-N-oxyl (TEMPO), an efficient scavenger of reactive oxygen species (ROS) in biological systems. Drug delivery properties of the TEMPO-functionalized biosilica are studied for Ciprofloxacin, an antimicrobial thoroughly employed in orthopedic or dental implant related infections. The resulting TEMPO-biosilica, combining Ciprofloxacin drug delivery with anti-oxidant properties, is demonstrated to be a suitable material for fibroblasts and osteoblast-like cells growth. Them bones gonna rise again: Covalent functionalization of nanostructured silica shells from diatoms with TEMPO radical endows biosilica with both drug-delivery properties and antioxidant activity. The resulting functional biosilica is demonstrated to be a suitable substrate for bone cell growth.