Drug delivery from engineered organisms and nanocarriers as monitored by multimodal imaging technologies

In recent years, while the research budget and development times increased for different phases of drug development, the number of clinically approved new medicines declined. In fact, many promising drug candidates failed to demonstrate their full therapeutic potential in vivo. Reasons for unfavorable outcome include some intrinsic properties of drugs, like biodegradation, solubility, and systemic toxicity, as well as the ways in which they are administered or the time elapsed until therapeutic efficiency is demonstrated. Therefore, to develop the full therapeutic potential of drug candidates in vivo, there is a need for advanced drug delivery systems that would carry the drug specifically to the target and release it there at desired concentrations. In addition, there is a requirement for non-invasive biomedical imaging technologies allowing for rapid and sensitive evaluations of drug performance in vivo. This review will present recent developments in bioengineered drug delivery systems, highlighting the biomedical imaging tools needed to evaluate the success of drug delivery strategies