Preliminary assessment of chitosan nanoparticles for growth factor delivery

The aim of this study was to investigate the synthesis of chitosan nanoparticles for growth factor delivery in bone tissue engineering. Chitosan nanoparticles were synthesized via a modified precipitation process and their morphology and dimensions characterized by means of scanning electron microscopy (SEM) and dynamic light scattering (DLS), respectively. In particular, both chitosan molecular weight and concentration were varied during the synthesis to assess the effect of those variables on the particle size and morphology. The stability of the nanoparticles in aqueous media was also assessed, by measuring the average increase of the particle size with time. A specific particle formulation was then selected and loaded with a model molecule, i.e. an oligopeptide derived from the bone morphogenetic protein BMP2. The effect of the nanoparticles on the viability of osteoblast-like MG63 cells was finally assessed in a cytotoxicity assay. The encouraging results obtained in this study, although preliminary, suggested the possible use of chitosan nanoparticles for bone tissue engineering.