The integration of diagnosis and
therapy into one nanoplatform, known as
theranostics, has attracted increasing attention in the biomedical areas. Herein, we first present a
cancer cell targeting imaging and drug delivery system based on engineered
thioether-bridged periodic mesoporous organosilica nanoparticles (PMOs). The PMOs are stably and selectively conjugated with near-infrared fluorescence (NIRF)
dye Cyanine 5.5 (
Cy5.5) and anti-Her2 affibody on the outer surfaces to endow them with excellent NIRF imaging and
cancer targeting properties. Also, taking the advantage of the
thioether-group-incorporated mesopores, the release of
chemotherapy drug doxorubicin (DOX) loaded in the PMOs is responsive to the
tumor-related molecule
glutathione (GSH). The drug release percentage reaches 84.8% in 10 mM of GSH
solution within 24 h, which is more than 2-fold higher than that without GSH. In addition, the drug release also exhibits pH-responsive, which reaches 53.6% at pH 5 and 31.7% at pH 7.4 within 24 h. Confocal
laser scanning microscopy and flow cytometry analysis demonstrate that the PMOs-based
theranostic platforms can efficiently target to and enter Her2 positive
tumor cells. Thus, the smart imaging and
drug delivery nanoplatforms induce high
tumor cell growth inhibition. Meanwhile, the
Cy5.5 conjugated PMOs perform great NIRF imaging ability, which could monitor the intracellular distribution, delivery and release of the
chemotherapy drug. In addition, cell viability and histological assessments show the engineered PMOs have good biocompatibility, further encouraging the following biomedical applications. Over all, the systemically engineered PMOs can serve as a novel
cancer cell targeting imaging and
drug delivery platform with NIRF imaging, GSH and pH dual-responsive drug release, and high
tumor cell targeting ability.