Suture materials and surgical knot tying techniques have improved dramatically
since their first use over five millennia ago. However, the approach remains limited by
the ability of the suture to transfer load to tissue at suture anchor points. Here, we
predict that adhesive-coated sutures can improve mechanical load transfer beyond the range
of performance of existing suture methods, thereby strengthening repairs and decreasing
the risk of failure. The mechanical properties of suitable adhesives were identified using
a shear lag model. Examination of the design space for an optimal adhesive demonstrated
requirements for strong adhesion and low stiffness to maximize the strength of the
adhesive-coated suture repair construct. To experimentally assess the model, we evaluated
single strands of sutures coated with highly flexible cyanoacrylates (Loctite 4903 and
4902), cyanoacrylate (Loctite QuickTite Instant Adhesive Gel), rubber cement,
rubber/gasket adhesive (1300 Scotch-Weld Neoprene High Performance Rubber & Gasket
Adhesive), an albumin-glutaraldehyde adhesive (BioGlue), or poly(dopamine). As a
clinically relevant proof-of-concept, cyanoacrylate-coated sutures were then used to
perform a clinically relevant flexor digitorum tendon repair in cadaver tissue. The repair
performed with adhesive-coated suture had significantly higher strength compared to the
standard repair without adhesive. Notably, cyanoacrylate provides strong adhesion with
high stiffness and brittle behavior, and is therefore not an ideal adhesive for enhancing
suture repair. Nevertheless, the improvement in repair properties in a clinically relevant
setting, even using a non-ideal adhesive, demonstrates the potential for the proposed
approach to improve outcomes for treatments requiring suture fixation. Further study is
necessary to develop a strongly adherent, compliant adhesive within the optimal design
space described by the model.