Luminescent silicon-based nanocarrier for drug delivery in colorectal cancer cells

Nanocarriers sensitive to exogenous or endogenous stimuli emerged as an attractive alternative to target drug delivery, with inorganic silica mesoporous nanoparticles (MNs) playing a core role in the development of a new generation of non-toxic and tuneable nanocarriers. A sensitive nanovector (NANO1) comprising luminescent silicon quantum dots (SiQDs) and functionalized with MNs was synthesised and loaded with doxorubicin (DOX). NANO1 nanoparticles have a size of 74 ± 10 nm and DOX loading percentages of ca. 43%. As a control sample, a similar nanocarrier (NANO2), without SiQDs, was also synthesised and loaded with DOX. Release profile studies, in PBS, revealed the strong NANO1@DOX pH-dependant behaviour, with a pH 5.0 favouring the release of DOX to percentages of ca. 70%. Cytotoxicity assessments of both free and DOX-loaded nanocarriers were evaluated in human cell lines of colon, revealing both free drug and drug-loaded nanoparticles to be concentration-dependent.This work was supported by the Associate Laboratory Research Unit for Green Chemistry - Clean Processes and Technologies - LAQV which is financed by national funds from FCT/MEC (UID/QUI/50006/2013) and co-financed by the ERDF under the PT2020 Partnership Agreement (POCI-01-0145-FEDER- 007265); by the Scientific Society PROTEOMASS (Portugal) (General Funding Grant) and by the Spanish Ministry of Science, Innovation and Universities project RTI2018-098027-B-C22. This work was also supported by grant RTI2018-098027-B-C21 and RTI2018-088027-B-C22 from the Spanish Government funds and by the European Regional Development Fund (ERDF). The ICN2 is funded by the CERCA programme/Generalitat de Catalunya. The ICN2 is supported by the Severo Ochoa Centres of Excellence programme, funded by the Spanish Research Agency (AEI, grant no. SEV-2017-0706). F. N thanks to COST Action CA17121. F. N and J. L thanks to COST Action CA15138. G.M thanks to FCT/MEC (Portugal) for his doctoral grant PD/BD/142865/2018. E. O thanks FCT/MEC (Portugal) for the individual contract, CEECIND/00648/2017.Peer reviewe