Tailoring the physicochemical and shape memory properties of the biodegradable polymer poly(glycerol dodecanoate) via curing conditions

Abstract

A major challenge in the repair and regeneration of soft tissue damage occurring as a result of aging, injury, or disease is recapitulating the biomechanical properties of the native tissue. Ideally, a candidate biomaterial for soft tissue engineering applications should be biocompatible, nonlinearly elastic to match soft tissue mechanical behavior, biodegradable to enable tissue remodeling, and tailorable to achieve a range of nonlinear elastic mechanical properties to match specific soft tissues. In addition, for cardiac and other applications, the biomaterial should have shape memory characteristics to facilitate minimally invasive and/or catheter-based delivery. Poly(glycerol dodecanoate) (PGD) is a shape memory material that has nonlinear elastic properties at body temperature and elastic-plastic behavior at room temperature. In this study, we investigated the effects of curing conditions on the nonlinear elastic, shape memory, and biocompatibility properties of PGD. Increased curing and crosslinking resulted in an increase in both the initial stiffness and the nonlinear strain stiffening behavior of PGD. After shape fixation at 60% strain, 100% shape recovery was achieved within 1 min at body temperature for all conditions tested. Polymer curing had no adverse effects on the cellular biocompatibility or non-hemolytic characteristics of PGD, indicating the potential suitability of these formulations for blood-contacting device applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1618-1623, 2017.

Degradation properties of a biodegradable shape memory elastomer, poly(glycerol dodecanoate), for soft tissue repair

“…Polyglycerol dodecanoate was synthesized as previously described [21,22] (Fig 1A). The R groups form crosslinks.…”

“…Explants were cleared of surrounding tissue, washed in sterile saline, and dried at 40˚C for 7 days as described above. Compression testing was conducted as reported previously [22]. Briefly, 6-mm PGD disks within a custom-built temperature control chamber were tested using an MTS system equipped with a 500 N load cell and a porous metal platen.…”

“…At 37˚C, PGD exhibits nonlinear elastic mechanical properties with tangent moduli between 0.5 to 5 MPa exhibiting 70-80% elastic deformation appropriate for various cardiovascular and orthopedic soft tissue repair applications. By changing the crosslink density, we can further tune the mechanical and shape recovery properties [22]. The primary aims of this study were to investigate the effect of crosslink density on the degradation rate and the ensuing mechanical and thermal properties post-degradation in vitro and in a subcutaneous mouse model.…”

Biodegradable Shape Memory Polymers in Medicine

“…In comparison to the development of methodologies for vascular, skeletal muscle, and nerve tissue, considerable effort has been devoted to the use of BSMPs in bone tissue engineering. Fibrous scaffolds prepared by electrospinning have shown promising results in enhancing osteoblast proliferation, alkaline phosphatase activity, and mineralization .…”

Innovative interventional catheterization techniques for congenital heart disease

“…Polymers, for example poly L-lactic acid, break down by hydrolysis. The material strength and rate of bioabsorption can be altered by engineering the composition of the individual monomers and how they are inter-connected (63,64). Because bioabsorption occurs by hydrolysis and the monomers are commonly occurring and/or inert substances, these are likely to be very safe.…”