A major challenge in the drug delivery field is to enhance transport of (bio)therapeutics across biological barriers. First and foremost the blood-brain barrier (BBB), composed of a unique highly selective vascular/endothelial system, remains a major hurdle for the development of Central Nervous System (CNS) drugs as it prevents the vast majority of (bio)therapeutics from penetrating into the nervous tissue. This leads to low efficacy and high attrition rates for CNS drug developers and remains a major industrial challenge of the 21st century.

Another challenge is to improve therapeutic or diagnostic benefits while minimizing both dose-levels and off-target effects of newly developed molecules. Growth drivers molecules for pharmaceutical industry such as theragnostic agents and ASOs can be trapped in liver and kidneys, which will hamper their distribution to intended cells and tissues. Targeted drug delivery to tissues of interest should enable administration of minimal drug doses with maximal treatment efficacy.