Surgical
sutures are indispensable for a vast majority of operative procedures. An ideal
suture is characterized by high tissue compliance without cutting into the mended tissue and optimal biocompatibility. Therefore, we assessed these mechanical and biological properties for novel elastic thermoplastic
polyurethane (TPU) and cross-sectional modified "snowflake"
sutures. Circular and "snowflake"-shaped TPU threads were manufactured and compared to similar surface modified
polyvinylidene fluoride (
PVDF)
sutures. Regular
PVDF sutures were used as the control group. Single-axis tensile test with and without gelatinous tissue surrogates were performed to evaluate the
suture incision into the specimens. Biocompatibility was evaluated by subcutaneous implantation (n = 18) in rats for 7 and 21 days. Histology and immunohistology was conducted for assessment of the
foreign body reaction. Regular and modified TPU threads showed a significant reduction of incision into the tissue surrogates compared to the control. Both TPU
sutures and the modified
PVDF sutures achieved comparable biocompatibility versus regular
PVDF threads. Detailed histology revealed novel tissue integration into the notches of the surface modified
sutures, we termed this newly shaped
granuloma "intrafilamentous"
granuloma. Elastic TPU threads showed a significant reduction of tissue surrogate incision and
suture tension loss. Biocompatibility did not significantly differ from standard
PVDF. Histology demonstrated tissue ingrowth following the surface modification of the
suture referred to as "intrafilamentous"
granuloma. Further in vivo studies are required to illuminate the exact potential of the new
sutures to optimize intestinal anastomosis.