Engineering multifunctional nanocarriers for targeted drug delivery shows promising potentials to revolutionize the cancer chemotherapy.Simple methods to optimize physicochemical characteristics and surface composition of the drug nanocarriers need to be developed in order to tackle major challenges for smooth translation of suitable nanocarriers to clinical applications.Recently, we have developed a new class of multifunctional mesoporous silica nanoparticles (MSNPs) based systems to deliver anticancer drugs to specific cancer cells in a targeted and controlled manner.[1] The multifunctional MSNPs have been evaluated in vitro with cooperative effects of specific targeting to cancer cells and stimulus-triggered drug release.Guided by our successful in vitro studies, the objectives of present research were to optimize the size and surface decoration of multifunctional MSNPs with suitable physiochemical properties required for targeting folate receptor overexpressed cancer cells in vivo (Figure 1).