To foster a green environment, considerable efforts have been made to
replace synthetic polymers with biodegradable materials, such as biopolymers,
particularly for the development of green drug delivery systems. Biopolymers are a
prominent class of functional materials with high-value applications, generated either
by biological systems or derived from biological sources. Natural sources of
biopolymers include plants, animals, microorganisms, and agricultural wastes.
Biopolymers exhibit excellent properties, including flexibility, tensile strength,
stability, reusability, and many more. Biopolymers are composed of repetitive
monomers bound covalently via polymerization reaction or enzyme-catalyzed
assemblies of monomeric units that occur in the biosynthetic pathway within biological
systems. Biopolymers can be classified based on their source, chemical composition,
functional properties, degradability, type of charges, and other factors. The extraction
of biopolymers involves a range of chemical and enzymatic processes that vary
specifically for each biopolymer. Some of the extraction methods include the use of
coagulating agents, hydrolysis, alkali and acid treatments, bleaching, deproteination,
and demineralization, among others. Following extraction, purification, and often
modification, biopolymers are prepared for potential applications. Due to their
renewability, abundance, biodegradability, and unique properties, such as higher
absorption capabilities and ease of functionalization, biopolymers have been explored
for various industrial applications. This chapter examines the sources, chemistry, and
extraction procedures for several important biopolymers, including
polyhydroxyalkanoates, polylactic acid, chitosan, alginate, polyesteramide, starch,
gelatin, polyglycolic acid, and pectin, as well as their biomedical applications.
Keywords: Biopolymers, Bio-based technology, Biodegradable polymers, Chemistry, Extraction.
