Tianyi Wang,Haitao Jiang,Long Wan,Qinfu Zhao,Tongying Jiang,Bing Wang,Siling Wang
Novel multifunctional porous titanium dioxide (TiO 2 ) nanoparticles modified with polyethylenimine (PEI) were developed to explore the feasibility of exploiting the photocatalytic property of titanium dioxide to achieve ultraviolet (UV) light triggered drug release. Additionally, in order to further realize targeting delivery, folic acid , which chemically conjugated to the surface of the functionalized multifunctional porous TiO 2 nanoparticles through amide linkage with free amine groups of PEI, was used as a cancer-targeting agent to effectively promote cancer-cell-specific uptake through receptor-mediated endocytosis . And a typical poorly water-soluble anti-cancer drug, paclitaxel, was encapsulated in multifunctional porous TiO 2 nanoparticles. The PEI on the surface of multifunctional porous TiO 2 nanoparticles could effectively block the channel to prevent premature drug release, thus providing enough circulation time to target cancer cells. Following UV light radiation, PEI molecules on the surface were cut off by the free radicals (OH and O 2 −) that TiO 2 produced, and then the drug loaded in the carrier was released rapidly into the cytoplasm. Importantly, the amount of drug released from multifunctional porous TiO 2 nanoparticles can be regulated by the UV-light radiation time to further control the anti-cancer effect. This multifunctional porous TiO 2 nanoparticle exhibits a combination of stimuli-triggered drug release and cancer cell targeting. The authors believe that the present study will provide important information for the use of porous TiO 2 nanomaterials in light-controlled drug release and targeted therapy.
TiO 2 nanoparticles have emerged as satisfactory sonosensitizers in sonodynamic therapy over the years, but shortcomings such as poor drug loading capability and inadequate techniques to construct suitable TiO 2 nanoparticles, limit their broader applications. Hence, in this paper, versatile nanocomposites that combine mesoporous TiO 2 nanoparticles (mTiO 2 s) with the promising photothermal material, polypyrrole (PPY) to exert synergistic therapeutic effects on tumors are fabricated. The PPY-coated mesoporous TiO 2 nanocomposites (mTiO 2 @PPYs) act as drug delivery vehicles and ultrasonically activated sonosensitizers as well as photothermal agents. Besides, mTiO 2 @PPY may have potential as an ultrasound/photoacoustic (US/PA) imaging contrast agent. The mTiO 2 @PPY shows a favorable drug loading and good photothermal conversion ability. Moreover, intracellular reactive oxygen species generation is verified. The in vitro cell experiments on HepG2 and 4T1 cells demonstrate that honokiol (HNK)-loaded mTiO 2 @PPY has satisfactory cytotoxicity under laser and US irradiation, and the results are further validated by animal experiments. The ability of mTiO 2 @PPY as a contrast agent for US and PA imaging is investigated both in vitro and in vivo. The results indicate that mTiO 2 @PPY-HNK has multitherapeutic effects and bimodal imaging property, which shows great prospect as a novel nanosystem in antitumor applications.
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