Amino-modified carbon dots as a functional platform for drug delivery: Load-release mechanism and cytotoxicity

Abstract Carbon dot (CDs) were prepared for carrying DOX (Doxorubicin) or FAC (Ferric ammonium citrate), and the loading mechanism and release kinetics of CDs-drugs were studied. CDs were prepared using peony pollen and urea, and characterized by TEM, XRD, 13C NMR, XPS, UV, FT-IR, DLS and zeta potential. The obtained CDs were rich of –NH2 group on the surface, amorphous phase, spherical morphology with the diameter about 5 nm, and had a blue fluorescence with the quantum yield (QY) of 12%. Iron disorders can cause cancer or anemia. DOX is used for treating cancer, but has severe side effects. FAC is an iron supplement agent, but had low bioavailability. CDs carried DOX (or FAC) through –N=C– (or –CONH–) bond, had high loading efficiency for DOX (37.2%) and FAC (54.0%) by optimizing mass ratios of mCDs to mdrug and reacted overnight. Cellular experiments showed that CDs-drugs had lower cytotoxicity than free drugs and CDs co-located with the drug. In vitro release indicated that CDs-DOX had pH-targeted property and CDs-FAC could be absorbed easily. CDs-drug release belonged to Weibull model, and release mechanism was determined by the bonding way between CDs and drug. CDs had potential applications in delivery drugs with –C=O or –COOH group.