Biologics have emerged as an exciting and rapidly developing front in pharmaceutical research and development, accounting for approximately $142 billion in sales in 2011 and enabling effective treatment of diseases that have been unresponsive to existing treatments [1]. In contrast to many existing drugs, biologics tend to be high in molecular weight and are often prone to degradation. As a result, typical modes of delivery can lead to destruction of the drug before it can reach its active site. While biologics can be delivered systemically, large quantities of drug have to be delivered to the body in order to maintain sufficiently high concentrations for therapeutic efficacy at the target site [2].
Local delivery has proven highly effective for maintaining therapeutic concentrations while minimizing side effects associated with off-target delivery. These systems produce higher concentrations of drug at the site of action and minimize the amount of...