Given the limitations of current surgical approaches to treat articular cartilage injuries, tissue engineering (TE) approaches have been aggressively pursued over the past two decades. Although biochemical and biomechanical properties on the order of the native tissue have been achieved (1–5), several in-vitro and in-vivo studies indicate that increased tissue maturity may limit the ability of engineered constructs to remodel and integrate with surrounding cartilage, although results are highly variable (2, 6–8). Thus, “static” measures of construct maturity (e.g. compressive modulus) upon implantation may not be the best indicators of in-vivo success, which likely requires implanted TE constructs to mature, remodel, and integrate with the host over time to achieve optimal results. We recently introduced the concept of “trajectory-based” tissue engineering (TB-TE), which is based on the general hypothesis that time-dependent increases in construct maturation in-vitro prior to implantation (i.e. positive rates) may provide a better predictor of in-vivo success (9). As a first step in evaluating this concept, in the current study we hypothesized that time-dependent increases in equilibrium modulus (a metric of growth) would be correlated to ability of constructs to integrate to cartilage using an in-vitro assay. To test this hypothesis, the current objective was to determine and model the time course of maturation of TE constructs during in-vitro culture and to assess the ability of these constructs to integrate to cartilage at various points during their maturation.
Effects of staphylococcal infection and aseptic inflammation on bone mass and biomechanical properties in a rabbit model
