Viability of Chondrocytes Seeded onto a Collagen I/III Membrane for Matrix-Induced Autologous Chondrocyte Implantation

Cell viability is crucial for effective cell-based cartilage repair. The aim of this study was to determine the effect of handling the membrane during matrix-induced autologous chondrocyte implantation surgery on the viability of implanted chondrocytes. Images were acquired under five conditions: (i) Pre-operative; (ii) Handled during surgery; (iii) Cut edge; (iv) Thumb pressure applied; (v) Heavily grasped with forceps. Live and dead cell stains were used. Images were obtained for cell counting and morphology. Mean cell density was 6.60x10(5) cells/cm(2) (5.74-7.11x10(5)) in specimens that did not have significant trauma decreasing significantly in specimens that had been grasped with forceps (p<0.001) or cut (p=0.004). Cell viability on delivery grade membrane was 75.1%(72.4-77.8%). This dropped to 67.4%(64.1-69.7%) after handling (p=0.002), 56.3%(51.5-61.6%) after being thumbed (p<0.001) and 28.8%(24.7-31.2%) after crushing with forceps (p<0.001). When cut with scissors there was a band of cell death approximately 275 mu m in width where cell viability decreased to 13.7%(10.2-18.2%, p<0.001). Higher magnification revealed cells without the typical rounded appearance of chondrocytes. We found that confocal laser-scanning microscope (CLSM) can be used to quantify and image the fine morphology of cells on a matrix-induced autologous chondrocyte implantation (MACI) membrane. Careful handling of the membrane is essential to minimise chondrocyte death during surgery. (c) 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:1495-1502, 2014.