  Hypothesis The treatment of bone fractures still represents a challenging
clinical issue when complications due to impaired bone remodelling (i.e.
osteoporosis) or infections occur. These clinical needs still require a radical
improvement of the existing therapeutic approach through the design of advanced
biomaterials combining the ability to promote bone regeneration with
anti-fouling/anti-adhesive properties able to minimise unspecific biomolecules
adsorption and bacterial adhesion. Strontium-containing mesoporous bioactive
glasses (Sr-MBG), able to exert a pro-osteogenic effect by releasing Sr2+ ions,
have been successfully functionalised to provide mixed-charge surface groups
with low-fouling abilities. Experiments Sr-MBG have been post-synthesis
modified by co-grafting hydrolysable short chain silanes containing amino
(aminopropylsilanetriol) and carboxylate (carboxyethylsilanetriol) moieties to
achieve a zwitterionic zero-charge surface and then characterised in terms of
textural-structural properties, bioactivity, cytotoxicity, pro-osteogenic and
low-fouling capabilities. Findings After zwitterionization the in vitro
bioactivity is maintained, as well as the ability to release Sr2+ ions capable
to induce a mineralization process. Irrespective of their size, Sr-MBG
particles did not exhibit any cytotoxicity in pre-osteoblastic MC3T3-E1 up to
the concentration of 75 ug/mL. Finally, the zwitterionic Sr-MBGs show a
significant reduction of serum protein adhesion with respect to pristine ones.
These results open promising future expectations in the design of nanosystems
combining pro-osteogenic and anti-adhesive properties.
