Background Leukaemia is the most prevalent form of
cancer-causing death in a large number of populations and
needs prompt and effective treatment. Chemotherapeutics
can be used to treat leukaemia, but their pronounced killing
effects to other living cells is still an issue. Active targeting to
certain specific receptors in leukaemic cells is the best way to
avoid damage to other living cells. Leukaemic cells can be
targeted using novel nanoparticles (NPs) coated with a specific
ligand, such as octreotide (OCD), to target somatostatin receptor
type 2 (SSTR2), which is expressed in leukaemic cells.
Methods Amino-PEGylated quantum dots (QDs) were chosen
as model NPs. The QDs were first succinylated using
succinic anhydride and then coated with OCD. The reactivity
and selectivity of the formulated QDs-OCD were studied in
cell lines with well-expressed SSTR2, while fluorescence was
detected using confocal laser scanning microscopy (CLSM)
and flow cytometry (FACS). Conclusively, QD-OCD targeting
to blood cells was studied in vivo in mice and detected using
inductively coupled plasma mass spectrometry and CLSM in
tissues.
Results Highly stable QDs coated with OCD were prepared.
FACS and CLSM showed highly definite interactions with
overexpressed SSTR2 in the investigated cell lines.
Moreover, the in vivo results revealed a higher concentration
of QDs-OCD in blood cells. The fluorescence intensity of the
QDs-OCD was highly accumulated in blood cells, while the
unmodified QDs did not accumulate significantly in blood
cells. Conclusion: The formulated novel QDs-OCD can target
SSTR2 overexpressed in blood cells with great potential
for treating blood cancer.