ReviewPost screenThe in vivo fate of nanocrystals

- Nanocrystals are unique delivery systems with drug loading up to 100%.
- Nanocrystals made from a definite drug differ in their performance.
- Experience obtained from specific nanocrystals cannot be extrapolated to others.
- Bioimaging of integral nanocrystals is highly challengeable.
- Hybrid nanocrystal is valuable in exploring the in vivo fate of nanocrystals.

There has been significant research interest in, and development of, nanocrystals in recent years for the delivery of poorly water-soluble drugs via various routes. However, there is a common misinterpretation of nanocrystallization as an approach to modulate, and more specifically to enhance, the dissolution of drug crystals. Nevertheless, it is possible for nanocrystals to interact with biological tissues because nanocrystals can survive for a longer duration in vivo compared with solution counterparts. Therefore, understanding the in vivo fate of nanocrystals and determining its contribution to efficacy is of tremendous significance for optimizing the performance of nanocrystals. Here, we critically review the general hypotheses related to the in vivo fate of nanocrystals.