ABSTRACT
To date, a large number of active compounds have been discovered that serve as therapeutics for curing complex disease. Yet, very few have shown clinical success. One major challenge is the delivery of an effective dose of a given cytotoxic agent to the target site without losing its functionality, while at the same time minimizing unintended harmful side effects [1]. As is well known, during systemic administration, drugs lose functionality very soon and the blood plasma concentration of the drug can quickly drop below an effective level. Readministration is required, leading to an increase in the risk of an overdose. Another problem is that many medications such as peptide and protein, antibody, vaccine, and gene-based drugs, in general, may not be delivered using common routes because they might be susceptible to enzymatic degradation or cannot be absorbed into the systemic circulation ef‰ciently in order to be therapeutically effective, due to molecular size and charge issues [2].
