ABSTRACT
Common modes of drug administration, such as oral ingestion or intravenous and intramuscular injections, often produce suboptimal therapeutic ef cacy because of §uctuating drug concentrations in the body and off-target effects. Polymeric biomaterials can serve as carriers to more ef - ciently deliver bioactive pharmaceuticals, such as low-molecular-weight drugs, peptides, proteins, and nucleic acids, to the target tissue. Natural, synthetic, and bioengineered polymers have all been applied as drug carriers. Their physiochemical characteristics such as size, hydrophobicity, and biodegradability can be modulated as a function of polymer design, thereby offering versatility in tailoring their drug release pro les and biological behaviors to speci c applications. Their targeting properties can also be augmented by the route of administration, functionalizing ligands, and stimuli-responsive release characteristics. Precise delivery maximizes the therapeutic ef cacy of the drug and minimizes the undesirable side effects. Many excellent reviews cover the advanced aspects of polymeric controlled release.1-8 In this chapter, the fundamentals of drug delivery and methods of achieving controlled, targeted drug release are covered. The use of biomaterials in manipulating drug release pro les via different routes of drug administration and device designs are also brie§y described.
