What Is Polyglycolic Acid?

Polyglycolic acid, also referred to Polyglycolide or PGA, is a simple yet durable fiber-based polymer first discovered in 1954. It is derived from chitin, a biological material responsible for the strength and rigidity of the exoskeletons aquatic life, such as crabs and shrimp, as well as the thick walls of fungi growths. PGA is used predominately as an absorbable surgical suture; however, due to the malleable chemical structure of the basic PGA molecule, the complete range of use for this compound is as yet unknown.

Uses

• The most well known use of PGA is as an absorbable medical suture. An absorbable suture means the material used to close a wound does not need to be removed as it will eventually dissolve into the surrounding tissue. The rigid yet natural properties of PGA make it an ideal absorbable suture; it is commonly used to close internal incisions during bariatric, abdominal and cardiac surgeries. Its success as a suture has also led to the development of other PGA-based medical implants, such as temporary pins, plates, rods and connective rings. There is also the potential that PGA in mesh form can advance the field of synthetic tissue engineering.

Potential

• One of the key aspects of PGA's potential is the ability for additional chemical chains to be attached to the basic polyglycolic compound. This means that additional properties can be integrated into the basic absorbable fiber makeup of the compound, increasing its range of applications. Some research has already been performed regarding the addition of side chains, resulting in varied elasticity, longevity and strengths of sutures and other devices.

Creation and Degradation

• PGA is most commonly derived from the process of the polymerization of glycolic acid, which involves using zinc-based compounds to catalyst a reaction between a polymer and a sodium-based acid. Sodium chloride, also known as table salt, is a byproduct of the reaction and can be easily removed from the resulting PGA fibers. Over time, PGA can be broken down by various biological enzymes and will eventually degrade into the simple and non-toxic components of glycolic acid, water, and carbon dioxide. Inside the human body, it will take four to six months for PGA to be totally absorbed.

Physical Properties

• As a chemical compound, polyglycolic acid has several distinct physical properties that support its use as an absorbable medical tool. First, and perhaps most important, due to its crystalline structure, PGA is water insoluble, which means it will not disintegrate in the human body. However, the pliability of PGA fibers increases when wet, allowing them to be shaped easily. Second, the melting point of PGA is estimated to be between 225 and 230 degrees Celsius, far above even the highest temperature possible in the human body. A final key physical property of PGA is the flexible rigidity of the fibers, which allows them a degree of movement while still maintaining a firm shape.

Benefits

• Materials made from polyglycolic acid are preferable to standard, non-biodegradable surgical alternatives due to the many benefits they yield. One major benefit of PGA sutures is that they support faster wound healing than traditional synthetic sutures that can slow or even jeopardize proper healing. Similarly, the enzyme reaction that occurs between tissue and the PGA is negligible and does not produce any adverse effect for the wound or surrounding tissue. Also, as they are absorbed into the surrounding tissue, there is no need to further traumatize the area with their removal.