Interest in functional materials,nanocarriers,and formulations for targeted therapy,which can selectively deliver therapeutic or diagnostic payloads to target sites such as organs,tissues,cells,and subcellular organelles,is continuously growing because such a targeted strategy may facilitate greater accumulation of the delivered payloads at sites of interest and less accumulation at non-target sites,which can then result in maximized therapeutic efficacy and minimized undesirable effects.In addition,controlling drug releasing rates from nanocarriers and formulations could be included in targeted therapy:fast release,sustained/prolonged release,timed release,controlled release,and site-specific release.