High tear strength artificial suture pads for hand skin model from degummed silk fiber-reinforced polydimethylsiloxane

The objective of this research is to develop a high tear strength suture pads from a polydimethylsiloxane (PDMS) composite reinforced with degummed silk fibers (DSFs) as artificial hand skin for suturing practice. The influences of fiber diameters, lengths, and contents of DSFs on mechanical properties of the prepared PDMS/DSFs composites were systematically investigated. In composite preparation, PDMS resin and silicone oil were mixed, followed by the gradual addition of DSFs with continuous stirring. The uncured mixture was then cast in molds and cured at room temperature for 4 hours. The results demonstrated that DSFs with a smaller diameter of 170 μm significantly improved tensile strength, elastic modulus, hardness, and, most notably, tear strength—an important property for resisting cuts from medical sutures. The morphology of the composites revealed that the DSFs have uniform dispersion and good adhesion in the PDMS matrix. Additionally, the lengths and contents of DSFs contributed to the enhancement of the mechanical properties of the PDMS/DSFs composites. The developed PDMS/DSFs composites exhibited mechanical properties and texture relatively close to those of real human skin as evaluated by experienced orthopedic surgeons. This indicates that a PDMS/DSFs composite is an effective artificial hand skin model for suture practice.