Near‐Infrared Light and pH‐Responsive Polypyrrole@Polyacrylic acid/Fluorescent Mesoporous Silica Nanoparticles for Imaging and Chemo‐Photothermal Cancer Therapy

Abstract

We have rationally designed a new theranostic agent by coating near-infrared (NIR) light-absorbing polypyrrole (PPY) with poly(acrylic acid) (PAA), in which PAA acts as a nanoreactor and template, followed by growing small fluorescent silica nanoparticles (fSiO2 NPs) inside the PAA networks, resulting in the formation of polypyrrole@polyacrylic acid/fluorescent mesoporous silica (PPY@PAA/fmSiO2 ) core-shell NPs. Meanwhile, DOX-loaded PPY@PAA/fmSiO2 NPs as pH and NIR dual-sensitive drug delivery vehicles were employed for fluorescence imaging and chemo-photothermal synergetic therapy in vitro and in vivo. The results demonstrate that the PPY@PAA/fmSiO2 NPs show high in vivo tumor uptake by the enhanced permeability and retention (EPR) effect after intravenous injection as revealed by in vivo fluorescence imaging, which is very helpful for visualizing the location of the tumor. Moreover, the obtained NPs inhibit tumor growth (95.6 % of tumors were eliminated) because of the combination of chemo-photothermal therapy, which offers a synergistically improved therapeutic outcome compared with the use of either therapy alone. Therefore, the present study provides new insights into developing NIR and pH-stimuli responsive PPY-based multifunctional platform for cancer theranostics.

Graphene Quantum Dots‐Capped Magnetic Mesoporous Silica Nanoparticles as a Multifunctional Platform for Controlled Drug Delivery, Magnetic Hyperthermia, and Photothermal Therapy

“…To date, much effort has been made to construct multifunctional mesoporous silica nanoparticles as a platform for the synergistic therapy with chemotherapy and magnetic hyperthermia/photothermal therapy . For example, Ruiz‐Hernandez et al synthesized γ‐Fe 2 O 3 /mesoporous silica microspheres, and found that these magnetic microspheres showed the sustained drug release behavior and ability to generate heat under a low‐frequency AMF .…”

Comparative Photothermal Performance among Various Sub‐Stoichiometric 2D Oxygen‐Deficient Molybdenum Oxide Nanoflakes and In Vivo Toxicity

“…After just 5 min exposure, the temperatures of the nonfunctionalized BG, B, and G were boosted to 39, 46, and 44 °C, respectively. PPy confers higher photothermal stability and compatibility owing to enhanced NIR absorption up to 1300 nm . These contribute to the better photothermal performance of the nanomaterial.…”

“…Photothermal performanceo fa-MoO 3À Àx Figure 5C and Ds how the temperature enhancement profiles upon exposure to the 808 nm laser.Atotal volume of 0.5 mL of nonfunctionalized and PPy-functionalized BG, B, and Gw as exposed to the laser (808 nm, 0.5 Wcm À2 ). After just 5min exposure,t he temperatures of the nonfunctionalized BG, B, and Gw ere boosted to 39, 46, and 44 8C, respectively.P Py confers higher photothermal stability and compatibility [54] owing to enhanced NIR absorption up to 1300 nm. [55] These contributet o the better photothermal performance of the nanomaterial.…”

Emerging Multifunctional NIR Photothermal Therapy Systems Based on Polypyrrole Nanoparticles

“…Zhang et al [121] also prepared core–shell multifunctional PPy@polyacrylic acid/fluorescent mesoporous silica nanoparticles (designated as PPY@PAA/fmSiO 2 NPs) which integrate the high drug storage capacity, NIR light and pH dual-stimuli controlled drug release property, and strong fluorescence intensity, as shown in Figure 19. Uniform PPy NPs sized about 40 nm were firstly prepared in water through the chemical oxidation polymerization method using PVA as the stabilizer.…”