Tailored electrospun nanofibrous polycaprolactone/gelatin scaffolds into an acid hydrolytic solvent system

Abstract

Blended nanofibrous scaffolds based on polycaprolactone (PCL) and gelatin (Ge) were successfully prepared. A formic/acetic acid (1:1) mixture was used to dissolve PCL/Ge blends from 100/0 to 20/80 wt% in steps of 10 wt%. The hydrolysis of the PCL diluted in the formic/acetic acid mixture was considered as a method for tailoring the surface morphology and physicochemical features of the nanofibrous PCL/Ge scaffolds as a function of the dissolution time. The fibre diameter remained in the nanoscale range for all the studied scaffolds, which is crucial to mimic the extra-cellular matrix size. The reduction of the intrinsic viscosity, molar mass and hydrodynamic radius found for the PCL molecules as a function of the dissolution time, consequently diminished the entanglement capability of the polymeric chains. Subsequently, the fibre diameter decreased as dissolution time increased for all the studied compositions. While the crystallinity of the scaffolds with high PCL content increased as a function of the dissolution time, the scaffolds with high percentage of Ge showed the lowest crystallinity degree, which was ascribed to the hindering effect of the Ge that diffused among the PCL segments. The wettability increased as a function of the Ge content due to the high hydrophilic behaviour of these molecules. Water affinity also increased as a function of the dissolution time, due to the more hydroxyl groups available in the PCL segments to interact with water molecules. As a whole, the physicochemical assessment of the electrospun scaffolds revealed an effective tailoring procedure to obtain functionalised PCL/Ge scaffolds with specific properties as a function of the dissolution time before electrospinning.