Nanoparticle Size Effects in Biomedical Applications

Nanoparticle size plays a central role in determining material properties and performance in biomedical applications. A wide variety of functional nanomaterials and nano-bioconjugates have been developed for monitoring biochemical activity, controlling biological functions, and therapeutic applications. This review focuses on the role of nanoparticle size (typically in the range of 1–100 nm) in various biomedical applications, the origin of such a size effect, and the optimum size requirement for the best performance in different biomedical applications. First, we discuss various nanoscale units present in life processes along with their size and functional role. Next, we discuss the size-dependent properties of some well-known nanoparticles and how those properties are exploited in different biomedical applications. Next, we discuss the size-dependent performance of functional nanomaterials and nano-bioconjugates that are used in various biomedical applications. Then, we highlight some of the best designed nanoparticles of optimum size for specific biomedical applications. Finally, we attempt to correlate the origin of the evolutionary selection of various nanoscale units in life processes toward specific biological functions.