Polypyrrole–methylene blue nanoparticles as a single multifunctional nanoplatform for near-infrared photo-induced therapy and photoacoustic imaging

Abstract

The combination of photothermal therapy (PTT) and photodynamic therapy (PDT) has recently gained much attention due to its selective and localized therapeutic effects by light irradiation. The reagents for phototherapy should have a large absorption coefficient in the near infrared region (NIR) (700 to 2500 nm) to maximize the depth of light penetration in tissues. In this study, we designed multifunctional nanoparticles that can provide strong NIR absorbing capability for the combined treatment of PTT and PDT. For the first time, FDA-approved photosensitizer methylene blue (MB) was conjugated with photothermal material polypyrrole (PPy) to form a novel NIR photo-absorber. The obtained PPy-MB NPs with an average size of 48.5 nm showed excellent biocompatibility, photothermal stability, and high NIR absorbance for the combined PTT and PDT. Under a NIR laser (e.g., 808 nm laser) at 0.5 W cm À2 , the temperature of the aqueous solution containing 50 mg ml À1 PPy-MB NPs reached up to 50 C within a very short time and reactive oxygen species (ROS) were also generated. In vitro investigation confirmed the effectiveness of the PPy-MB NPs in killing the cancer cells under the NIR laser. Further, the phantom test of photoacoustic microscopy (PAM) used in conjunction with PPy-MB NPs showed a strong photoacoustic signal. Therefore, the novel PPy-MB NPs could be considered as promising single multifunctional nanoplatforms for further applications of photo-induced therapy and biomedical imaging.

Molecular Photoacoustic Contrast Agents: Design Principles & Applications

“…These studies have ranged from PAI in tissue phantoms to in vivo PAI of sentinel lymph nodes , to PA lifetime studies for aggregate and in vivo dissolved oxygen quantification, US/PA dual modality imaging of MB/perfluorocarbon microbubbles (Fig. ) and theranostic PAI/PTT studies of polypyrrole‐methylene blue nanoparticles .…”

Synthesis and In Vitro Performance of Polypyrrole-Coated Iron–Platinum Nanoparticles for Photothermal Therapy and Photoacoustic Imaging

“…Polypyrrole (PPy), which has a strong excitation in the NIR region, has received considerable significance in biomedical applications due to its superior inherent features, including photothermal stability, low cost, and biocompatibility [ 11 , 12 ]. Recent studies have reported PPy as a high-performance agent for PTT cancer treatment [ 11 , 13 ] and deep-tissue PAI [ 12 ]. In the present work, we developed PPy-coated FePt NPs (FePt@PPy NPs) as novel agents for the combining PTT and PAI.…”

Fluorescence/photoacoustic imaging-guided nanomaterials for highly efficient cancer theragnostic agent

“…Photothermal therapy agents have a high NIR absorption property which facilitates deeper penetration into the solid tumor without dispersing absorbed photons to the surrounding normal tissues 13 , 14 . Several NIR-absorbing materials have been investigated for photothermal applications, including gold nanorods 15 , 16 , upconversion nanoparticles 17 , carbon nanotubes 18 , graphene 19 , graphene–iron oxide nanoparticles 20 , and polypyrrole nanoparticles (PPy NPs) 21 , 22 . PPy NPs are one of the most effective polymeric photothermal agents among those materials.…”