Magento-fluorescent uniform sub-micron up-conversion capsules for potential simultaneous MRI/PL imaging and drug delivery capabilities

[Display omitted] •Monodisperse, highly uniform hollow capsules were synthesized.•The hollow capsules exhibit paramagnetic and upconversion properties.•The DOX loaded capsules are capable of pH triggered drug release.•The DOX loaded capsules effectively kill MCF-7 cancer cells. The study reports the facile synthesis of upconversion porous shell based hollow capsules with magnetic and luminescent properties. The upconversion shell was composed of composite structure of NaYF4:Yb/Er and NaMnF3:Yb/Er upconversion nanocrystals. The as-synthesized capsules exhibit simulations photoluminescence and magnetic character thus rendering these an ideal candidate for bi-modal MRI and photoluminescence imaging. The drug carrying potential of the capsules was elucidated using doxorubicin as model drug, with its release behavior found to be pH-dependent. Cytotoxicity tests of unloaded and drug-loaded capsules showed excellent biocompatibility and promising cytotoxicity, respectively. The results indicate upconversion hollow capsules to be a promising theranostic platform equipped with bi-modal imaging and drug delivery capabilities.