Enhancing the Stability, Hydrophilicity, Mechanical and Biological Properties of Electrospun Polycaprolactone in Formic Acid/Acetic Acid Solvent System

Abstract

Electrospun polycaprolactone is widely used in the medical field. Formic acid/acetic acid (FA/AA) solvent system is one of the safest solvents used for the production of nano-range polycaprolactone (PCL) fibers, although it has a very low stability. In the present study, the stability of PCL in FA/AA system was enhanced by sodium hydrogen carbonate (NaHCO3) addition with three different concentrations (1, 5 and 10 wt%). The resultant electrospun fiber properties were compared to that treated by alkaline hydrolysis. The viscosity and conductivity of PCL solutions were measured before the electrospinning process. Moreover, the obtained electrospun PCL mats were characterized by SEM, FT-IR, XRD, contact angle measurements, degradability, swelling, and mechanical properties, as well as their ability to enhance the proliferation and adhesion of mesenchymal stem cells (MSCs). It was found that NaHCO not only enhanced the fiber properties, such as hydrophilicity, degradability and mechanical properties but also had a significant effect on the stability of polycaprolactone in FA/AA solvent system, as well as an enhanced MSCs proliferation and adhesion. Although hydrolyzed PCL showed high cell viability and adhesion, it showed much lower mechanical properties (0.7 MPa) compared to neat PCL (1.3 MPa) and PCL-NaHCO3 (5.1 MPa). In conclusion, the addition of NaHCO3 to PCL solution prior to the electrospinning process represents a novel and an effective approach to improve the physicochemical properties and biological behavior of electrospun PCL mats for tissue engineering application.