Locally reversible barbed sutures

A wound closure device comprising:

• a flexible filament having a first end, a second end, and a longitudinal axis extending between said first and second ends;
• a plurality of barbs projecting outwardly from said flexible filament, each said barb having a base connected with said flexible filament, a blunt tip spaced from said base, a leading edge extending between said base and said blunt tip and facing toward said first end of said flexible filament, a trailing edge extending between said base and said tip and facing toward said second end of said flexible filament, and a transition surface extending between said trailing edge and said flexible filament, wherein said leading edge defines a concave surface having a radius of about 0.090 inches, said blunt tip defines a convex surface having a radius of about 0.004 inches and said transition surface defines a concave surface having a radius of about 0.004 inches, and wherein said trailing edge of said barb and the longitudinal axis of said flexible filament define an angle of at least 68°;
• the convex surface of said blunt tip and the concave surface of said transition surface being aligned with one another along the longitudinal axis of said flexible filament so that a line passing perpendicularly through the longitudinal axis of said flexible filament contacts the convex surface of said blunt tip tangentially and contacts the concave surface of said transition surface.