Chitosan: Key to Bonding Hydrogels and Polymers

Hydrogels are water-swollen polymers that can mimic the properties of various tissues and organs in the body. They have many potential uses in medicine, such as drug delivery, tissue engineering, wound healing, and surgical care. However, one of the challenges of using hydrogels is how to attach them to each other or to other materials without compromising their strength or functionality.

Scientists at Harvard University have found a simple and effective solution to this problem: chitosan. Chitosan is a natural material derived from the shells of shellfish. It has biocompatibility, biodegradability, and low toxicity. It also has the ability to form strong bonds with hydrogels and other polymeric materials by absorbing water and entangling its sugar strands with the polymer chains.

How does chitosan work?

Chitosan is a polysaccharide composed of glucosamine and N-acetylglucosamine units. It has many hydroxyl and amine groups that can interact with other molecules through electrostatic forces and hydrogen bonds. These interactions are non-covalent, meaning they do not involve the sharing of electrons between atoms, but they are still very strong and stable.

To bond hydrogels with chitosan, the scientists used a thin film of chitosan between two layers of hydrogel or other material. They then applied a slight change in pH to trigger the bonding process. The chitosan film rapidly absorbed water from the hydrogel layers and formed multiple bonds with the polymer chains. The resulting bond was so strong that it could resist high tensions and shear forces.

What are the advantages of chitosan bonding?

Chitosan bonding has several advantages over other methods of attaching hydrogels and other materials. Some of these advantages are:

• It is fast and easy. The bonding process takes only a few seconds and does not require any complex equipment or procedures.
• It is versatile. Chitosan can bond different types of hydrogels and other materials, such as metals, ceramics, plastics, and fabrics.
• It is reversible. The bonds can be broken by changing the pH or adding enzymes that degrade chitosan.
• It is biocompatible. Chitosan is derived from natural sources and does not cause any adverse reactions in the body.
• It is functional. Chitosan can enhance the properties of hydrogels and other materials, such as mechanical strength, antibacterial activity, drug delivery, and tissue regeneration.

What are the applications of bonding?

Chitosan bonding can enable many new applications for hydrogels and other materials in biomedical fields. Some examples are:

• Local protective cooling of tissues. Chitosan can bond hydrogels that contain cooling agents to injured or inflamed tissues, such as skin burns or brain trauma, to reduce swelling and pain.
• Sealing of vascular injuries. Chitosan can bond hydrogels that contain hemostatic agents to bleeding vessels, such as arteries or veins, to stop blood loss and promote healing.
• Prevention of surgical adhesions. Chitosan can bond hydrogels that act as barriers between internal body surfaces that should not stick to each other after surgery, such as organs or tissues, to prevent inflammation and scarring.
• Creation of complex biomaterial structures. Chitosan can bond hydrogels that have different shapes, sizes, colors, or functions to create customized devices for various purposes, such as sensors, actuators, or scaffolds.

Chitosan is a key material that can bond hydrogels and other polymeric materials quickly and strongly, opening new possibilities for biomedical applications. By using chitosan films, scientists can create smart devices that can interface with the body in novel ways.

Recent Blog : Mitsubishi Takes 30% Stake in TVS Mobility Spinoff