Biomedical Engineering Reference
In-Depth Information
7
Carbohydrates
Gerald Dr ä ger , Andreas Krause , Lena M ö ller , and Severian Dumitriu
7.1
Introduction
Polysaccharides are an integral part of the living matter. Due to this huge presence
in organisms, they are highly biocompatible and biodegradable and therefore
idealy match the basic characteristics for polymers used as biomaterials.
All polysaccharides used derive from natural sources. Biodegradation is defi ned
as an event which takes place in the natural environment and living organisms.
Since polysaccharides are ubiquitous in nature and present a valuable carbon
and energy source in the life cycle of organisms, their biodegradation is a
highly evolved process using effective and usually specifi c enzymes. This makes
polysaccharides a promiscuous basis for the development of biodegradable
polymers.
Polysaccharide-based biomaterials are of great interest in several biomedical
fi elds such as drug delivery, tissue engineering, or wound healing. Important
properties of the polysaccharides include controllable biological activity, biode-
gradability, and their ability to form hydrogels. Polysaccharides are also used as
additives in the food industry and in many technical applications. Here the main
focus lies on the superb rheological properties of many polysaccharides together
with their biodegradability and their positive environmental and toxicological
effects.
Several important and up-to-date reviews have to be mentioned and should be
considered in order to gain insight in this complex topic. In 2008, Rinaudo sum-
marized the main properties and current applications of some polysaccharides as
biomaterials [1]. The application of biodegradable systems in tissue engineering
and regenerative medicine with a strong focus on carbohydrates is summarized
by Reis and coworkers [2]. Polysaccharides-based nanoparticles as drug-delivery
systems are reviewed by Liu
et al.
[3], whereas Coviello
et al.
focused on polysac-
charide hydrogels for modifi ed release formulations [4]. In this chapter, we sum-
marize the basic properties, modifi cations, and applications of biodegradable
polysaccharides. We deliberately omit starch and pectin since there are numerous
reviews and topics dealing solely with these materials.
