The role of CaCO3 nanoparticles as a reinforcing agent in increasing the mechanical properties of electrospun chitosan/poly(vinyl alcohol) (PVA) is inspired by the incorporation of CaCO3 inside a chitin network in nature. The loading concentration of CaCO3 nanoparticles varied from 1 to 5 wt%, and the diameter of fibers ranges from 71.5 +/- 23.4 nm to 140.7 +/- 15.1 nm with an increased loading of CaCO3. A tensile test on 4 wt% CaCO3-reinforced fibers revealed a Young's modulus up to 912.5 +/- 60.6 MPa from 15.7 +/- 3 MPa, which is almost sixty times the value of fibers without CaCO3. The biocompatibilities of the CaCO3-loaded fibers were also tested in a 14-day simulated body fluid (SBF) incubation to induce the formation of apatite minerals and in a 14-day cell proliferation assay with ATDC5 cells. The chitosan/PVA-CaCO3 (4 wt%) was found to provide the most suitable environment for cell growth in comparison with chitosan/PVA and chitosan/PVA-apatite. The CaCO3-reinforced chitosan/PVA has potential to be a promising alternative as an artificial cartilage. (C) 2014 Elsevier Ltd. All rights reserved.