Biotechnology and therapeutic approaches of protein-based drug delivery system

Proteins and peptides are starting to play a pivotal role as drug carriers also due to advances in recombinant macromolecules techniques with the development of genetically engineered polymers characterized by fixed polymer length and amino acid sequence [1]. Their mechanisms of action are basically found on three main drug delivery technologies: coupling of low-molecular weight drugs to exogenous or endogenous proteins, conjugation with bioactive proteins and encapsulation of drugs into protein nanoparticles. Many proteins accumulate in target tissues, making them a high selective drug delivery systems with various applications including oncology, diabetes, hepatitis C and rheumatoid arthritis. Moreover, they show several advantages (principally the endogenous proteins that are native to the body) as carrier due to their nontoxic, non-immunogenic and metabolizable nature [2]. Promising is also the strategy to bind a therapeutic molecule (mainly bioactive peptides) covalently or physically to protein to enhance its availability, stability, efficacy and half-life such as with antinociceptive, antidiabetes, antitumor or antiviral activity peptides. Nowadays proteins are the frontier for drug delivery system nanocarriers due to their uniform sizes, biodegradability and unique structure that offers the possibility of site-specific drug conjugation.