Biodegradable polymer

Coordinates: 51°16′16″N 0°50′46″W / 51.271°N 0.846°W / 51.271; -0.846

Biodegradable polymers are polymers that break down and lose their initial integrity. Biodegradable polymers are used in medical devices to avoid a second operation to remove them, or to gradually release a drug^[1]

History

Biodegradable polymers were used in the times of the Romans. The first medical use of a biodegradable polymer were Catgut sutures. One desired property of a suture is that it slowly degrades as the wound heals. The Romans used cat gut, however this elicited a bad inflammatory response. Tesco have used biodegradable bags since 2012.

Applications

Applications of biodegradable polymers include sutures, controlled drug release, and tissue engineering. Biodegradable polymers also could be implemented in drug delivery. The polymer slowly degrades into smaller fragments, releasing a natural product, and there is controlled ability to release a drug. The drug slowly releases as polymer degrades.

Biodegradable polymers have been used to coat a stent and release drugs in a controlled way.

A holy grail is to create organs, such as the kidney from basic constituents. A scaffolding is necessary to grow the entity into a functioning organ. The scaffolding should dissolve away and needs to be biocompatible.

Another application involves the breakdown in landfills after being strong during its useful lifetime.

Required properties

Biodegradable polymers should be 1) non-toxic, 2) capable of maintaining good mechanical integrity until degraded, and 3) capable of controlled rates of degradation. A goal is not to illicit the immune response, and the products of degradation also need to not be toxic. With regard to controlled degradation, is it possible to trigger degradation?

A goal is to control the rate at which water can get into polymers. Factors controlling the rate of degradation include: 1) percent crystallinity, 2) molecular weight, 3) hydrophobicity. The degradation rate depends on the location in the body. The environment surrounding the polymer is different depending on the location in the body

Examples

3-hydroxypropionic acid

The market for a bio-based and biodegradable replacement for polyester is expected to grow rapidly during the next five years. The bio-based polyester, P(3-HP), has attractive mechanical properties, such as rigidity, ductility, and exceptional tensile strength in drawn films and can be created using the new lower toxicity method. P(3-HP) has applications in packaging or biodegradable plastics.

Another example of a biodegradable polymer is polylactic acid.

References

External links

• polyketals

• New emerging trends in synthetic biodegradable polymers – Polylactide: A critique. European Polymer Journal 2007 43 4053-4074