Fast Coprecipitation of Calcium Phosphate Nanoparticles inside Gelatin Nanofibers by Tricoaxial Electrospinning

We present an effective method for fabricating electrospun gelatin nanofibers containing well-dispersed inorganic nanoparticles. The new method encompasses the use of a special triaxial needle where mixing calcium and phosphate aqueous solutions in an intermediate needle yield calcium phosphate (CaP) nanoparticles that immediately after precipitation are dragged by the outer polymeric solution and incorporated directly in the electrospinning jet, before nanofiber formation. Gelatin electrospun mats containing different amounts of CaP nanoparticles were prepared and characterized by SEM, TEM, TGA, and stress-strain measurements. The results demonstrate that CaP particles having diameter of few tens of nanometers were successfully introduced in the gelatin nanofibers during the electrospinning process and that they were well dispersed throughout the fiber length. In addition, the use of the special triaxial needle enabled modulating the CaP amount in the nanofibers.