Mechanical properties and cellular proliferation of electrospun collagen type II

Abstract

A suitable technique for articular cartilage repair and replacement is necessitated by inadequacies of current methods. Electrospinning has potential in cartilage repair by producing scaffolds with fiber diameters in the range of native extracellular matrix. Chondrocytes seeded onto such scaffolds may prefer this environment for differentiation and proliferation, thus approaching functional cartilage replacement tissue. Scaffolds of collagen type II were created by an electrospinning technique. Individual scaffold specimens were prepared and evaluated as uncross-linked, cross-linked, or crosslinked/seeded. Uncross-linked scaffolds contained a minimum and average fiber diameter of 70 and 496 nm, respectively, whereas cross-linked scaffolds possessed diameters of 140 nm and 1.46 microm. The average thickness for uncross-linked scaffolds was 0.20 +/- 0.02 mm and 0.52 +/- 0.07 mm for cross-linked scaffolds. Uniaxial tensile tests of uncross-linked scaffolds revealed an average tangent modulus, ultimate tensile strength, and ultimate strain of 172.5 +/- 36.1 MPa, 3.3 +/- 0.3 MPa, and 0.026 +/- 0.005 mm/mm, respectively. Scanning electron microscopy of cross-linked scaffolds cultured with chondrocytes demonstrated the ability of the cells to infiltrate the scaffold surface and interior. Electrospun collagen type II scaffolds produce a suitable environment for chondrocyte growth, which potentially establishes the foundation for the development of articular cartilage repair.