Poly(diol citrate) nanocomposites with enhanced mechanical properties

The mechanical properties of a tissue engineering scaffold are particularly important when engineering soft tissues as it has been shown that mechanical stimulation during in vitro tissue development can modulate cell differentiation, increase extracellular matrix synthesis, and enhance the mechanical properties of cartilaginous, ligamentous, and smooth muscle containing tissues [1-5]. Unfortunately, one of the main limitations with poly(hydroxyortho esters) and other polymers commonly used in tissue engineering is their inability to undergo large reversible elastic deformations when stressed [6]. Due to the stiffness and lack of elasticity of commonly used polymers in tissue engineering, our laboratory has developed a novel family of biodegradable elastomeric polyesters referred to as poly(diol citrates) [7-9]. Their mechanical properties can be adjusted depending on the selection of diols and the post-polymerization conditions [8]. Nevertheless, the mechanical properties that can be obtained may not meet the demanding requirements of musculoskeletal tissues, which are often exposed to relatively large tensile or compressive loading forces. In this study we describe the fabrication and mechanical characterization of novel elastomeric nanocomposite materials in which the macrophase consists of a poly(1,10decanediol-co-citrate) (PDC) elastomer and the nanophase consists of a poly(L-lactic acid) (PLLA) nanofibrous network or poly(lactic-co-glycolic acid) (PLGA) nanoparticles.