Figure 1.
The number of research articles indexed in the Web of Science Core Collection (in Science Citation Index Expanded) was determined through a search using the following keywords: (a) “nanoparticle AND drug delivery” OR “nanoparticle AND imaging”, and (b) combinations of “hybrid”, “organic”, “inorganic”, and “nanoparticle” AND “drug delivery” OR “imaging” in the title or abstract.
