Robust Surgical Suture Inspired by Human Tendons

Innovation: Academia

McGill University

2021

Image: Rishikesh Yogpeeth / Unsplash / CC BY SA - Creative Commons Attribution + ShareAlike

Attach Temporarily

Living systems must sometimes, temporarily, stay in one place, climb or otherwise move around, or hold things together. This entails attaching temporarily with the ability to release, which minimizes energy and material use. Some living systems repeatedly attach, detach, and reattach for an extended time, such as over their lifetimes. Despite being temporary, these attachments must withstand physical and other forces until they have achieved their purpose. Therefore, living systems have adapted attachment mechanisms optimized for the amount of time or number of times they must be used. An example is the gecko, which climbs walls by attaching its toes for less than a second. Other examples include insects that attach their eggs to a leaf until they hatch, and insects whose wings temporarily attach during flight but separate after landing.

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Protect From Loss of Liquids

Water is essential to life. Liquids, mostly water, make up 70 to 90% of all living systems, and the loss of even a small percentage can mean the difference between life and death. Living systems must maintain a proper liquid balance, which is especially difficult in dry conditions. To do so, they must control the movement of liquids across their boundaries. Living systems do this using structures or waterproof materials to prevent or slow liquid movement. For example, when humans receive a cut, they must limit blood loss. Scattered throughout the bloodstream are lens-shaped structures that serve to plug the wound.

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Manage Tension

When a living system is under tension, it means there is a force pulling on it, like a person pulling on a rope tied to a horse. When applied to a living system, unless the system is completely rigid, the result is that it gets stretched. If stretching exceeds the strength of the living system’s material, it can damage it. Living systems manage tension using materials that are flexible and stretchable enough to survive most tension that occurs in their environment. The ocean’s intertidal zone offers a good example. The waves and incoming and outgoing tides put tension on soft-bodied organisms. Mussels resist tension with flexible threads that hold them onto rocks; in contrast, large algae have stretchy fronds.

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Surgical suture from McGill University is slippery yet tough, reducing irritation to healing wounds.

Benefits

Flexible
Stronger
Biocompatible

Applications

Medical treatment
Drug delivery

UN Sustainable Development Goals Addressed

Goal 3: Good Health & Wellbeing

The Challenge

Sutures are frequently used in surgical procedures, but mechanical incompatibility with tissues limits their efficiency . Moreover, existing modification techniques for sutures often weaken the material, leaving it vulnerable to rupture or deterioration.

Innovation Details

The surgical suture is a multifunctional, tough gel-sheathed (TGS) material. It consists of a series of fiber-based strands encompassed in a hydrogel sheath. The fibers reinforce the material by providing strength against tensile forces, while the sheath protects the fibers and adheres to the skin. The suture has high interfacial adhesion, but easily detaches without causing damage.

Biomimicry Story

Tendons are tough, fibrous, rope-like tissues that connect muscle to bone or other structures within the body. Each tendon is protected by a tendon sheath, a membrane-like structure that surrounds the tendon, separating it from the tissue around it and allowing the tendon to move freely inside the sheath.

See Related Strategy

colorful microscopic image of animal muscles

Biological Strategy

Skeletal Muscles Generate Force

Vertebrates (Mammals, Fish, Birds, Reptiles)

Skeletal muscles contract and relax, generating force and enabling movement.

References

Journal article

Bioinspired tough gel sheath for robust and versatile surface functionalization

Science Advances

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