Osteoinductive and anti-inflammatory properties of chitosan-based scaffolds for bone regeneration

Current bone implants based on new biomaterials may cause a foreign body reaction (FBR) around the implant itself thus prolonging the healing time following bone fractures. In this paper, biomimetic chitosan-based scaffolds promoting bone tissue regeneration and controlling inflammatory response are proposed. First, the anti-inflammatory potential of scaffolds on hMSCs stimulated by lipopolysaccharide (LPS) was investigated by dosing the levels of some interleukins and oxidative stress metabolites (IL-1β, IL-10 and nitrites) involved in immune response. Then, to mimic the inflammation process at osteoporotic site, the effect of scaffolds was evaluated on in vitro co-culture model based on osteoblasts and macrophages stimulated by LPS. Results demonstrated that bioactivated scaffolds are able to i) inhibit synthesis of inflammatory mediators such as IL-1β; ii) reduce oxidative stress metabolites; and iii) promote anti-inflammatory markers generation (IL-10) in hMSCs. Finally, bioactivated scaffolds show an anti-inflammatory activity also on in vitro co-cultures, which better mimic in vivo damaged bone microenvironment.