In this study, we introduced a targeting polymer poly(ethylene glycol)-folic acid (PEG-FA) on the surface of polydopamine (PDA)-modified mesoporous silica nanoparticles (MSNs) to develop the novel nanoparticles (NPs) MSNs@PDA-PEG-FA, which were employed as a drug delivery system loaded with doxorubicin (DOX) as a model drug for cervical cancer therapy. The chemical structure and properties of these NPs were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, N adsorption/desorption, dynamic light scattering-autosizer, thermogravimetric analysis, and Fourier transform infrared spectroscopy. The pH-sensitive PDA coating served as a gatekeeper. The in vitro drug release experiments showed pH-dependent and sustained drug release profiles that could enhance the therapeutic anticancer effect and minimize potential damage to normal cells due to the acidic microenvironment of the tumor. These MSNs@PDA-PEG-FA achieved significantly high targeting efficiency, which was demonstrated by the in vitro cellular uptake and cellular targeting assay. Compared with that of free DOX and DOX-loaded NPs without the folic targeting ligand, the FA-targeted NPs exhibited higher antitumor efficacy in vivo, implying that they are a highly promising potential carrier for cancer treatments.

Synergistic therapy that combines chemo-, gene-, or photothermal means shows great potential for enhancing the therapeutic effects on cancers. Tumor-targeted nanoparticles based on a doxorubicin (DOX)-gated mesoporous silica nanocore (MSN) encapsulated with permeability glycoprotein (P-gp) small interfering RNA (siRNA) and a polydopamine (PDA) outer layer for DOX loading and folic acid decoration are designed. The multifunctional nanoplatform tactfully integrates chemo-(DOX), gene-(P-gp siRNA), and photothermal (PDA layer) substances in one system. In vitro results reveal that DOX release behaviors are both pH-and thermal-responsive and the release of co-delivered P-gp siRNA is also pH-dependent due to the pH-cleavable DOX gatekeeper on MSN. In addition, due to the near-infrared light-responsive PDA outer layer and folic acid conjugation, the nanoparticles exhibit outstanding photothermal activity and selective cell targeting ability. Subsequently, in vitro and in vivo antitumor experiments both demonstrate the enhanced antitumor efficacy of the multifunctional nanoparticles, indicating the significance of synergistic therapy combining chemo-, gene-, and photothermal treatments in one system. Cancer Therapy

The integration of various therapy strategies into a single nanoplatform for synergistic cancer treatment has presented a great prospect. Herein, docetaxel (DTX)-loaded poly lactic-co-glycolic acid (PLGA)-coated polydopamine modified with d-α-tocopherol polyethylene glycol 1000 succinate (TPGS) was synthesized for chemo-photothermal synergistic therapy against cancer. Firstly, the DTX-loaded PLGA NPs were prepared by a facile and robust nanoprecipitation method. Then, they were coated with dopamine to achieve the photothermal effects and to be further modified with TPGS, which can inhibit the P-glycoprotein-mediated multidrug resistance (MDR). The near-infrared (NIR) laser irradiation triggered DTX release from DTX-loaded PLGA NPs@PDA-TPGS, and then the chemo-photothermal therapy effect could be enhanced. The in vitro experimental results illustrated that DTX-loaded PLGA NPs@PDA-TPGS exhibits excellent photothermal conservation properties and remarkable cell-killing efficiency. In vivo antitumor studies further confirmed that DTX-loaded PLGA NPs@PDA-TPGS could present an outstanding synergistic antitumor efficacy compared with any monotherapy. This work exhibits a novel nanoplatform, which could not only load chemotherapy drugs efficiently, but could also improve the therapeutic effect of chemotherapy drugs by overcoming MDR and light-mediated photothermal cancer therapy.