pH triggered in vivo photothermal therapy and fluorescence nanoplatform of cancer based on responsive polymer-indocyanine green integrated reduced graphene oxide

Near-IR responsive nanostructures for nanobiophotonics: emerging impacts on nanomedicine

Nanobiophotonics is an emerging field at the intersection of nanoscience, photonics, and biotechnology. Harnessing interactions of light with nanostructures enables new types of bioimaging, sensing, and light-activated therapy which can make a major impact on nanomedicine. Low penetration through tissue limits the use of visible light in nanomedicine. Near infrared (NIR) light (~780-1100 nm) can penetrate significantly further, enabling free-space delivery into deep tissues. This review focuses on interactions of NIR light with nanostructures to produce three effects: direct photoactivation, photothermal effects, and photochemical effects. Applications of direct photoactivation include bioimaging and biosensing using NIR-emitting quantum dots, materials with localized surface plasmon resonance (LSPR) in the NIR, and upconverting nanoparticles. Two key nanomedicine applications using photothermal effects are photothermal therapy (PTT), and photoacoustic (PA) imaging. For photochemical effects, we present the latest advances in in-situ upconversion and upconverting nanostructures for NIR activation of photodynamic therapy (PDT).

FROM THE CLINICAL EDITOR

Nanobiophotonics is a relatively new field applying light for the interactions with nanostructures, which can be used in bioimaging, sensing, and therapy. As near infrared (NIR) light (~780-1100 nm) can have better tissue penetration, its clinical potential is far greater. In this review, the authors discussed the latest research on the applications of NIR light in imaging and therapeutics.

In Vitro and In Vivo Tumor Targeted Photothermal Cancer Therapy Using Functionalized Graphene Nanoparticles

Despite the tremendous progress that photothermal therapy (PTT) has recently achieved, it still has a long way to go to gain the effective targeted photothermal ablation of tumor cells. Driven by this need, we describe a new class of targeted photothermal therapeutic agents for cancer cells with pH responsive bioimaging using near-infrared dye (NIR) IR825, conjugated poly(ethylene glycol)-g-poly(dimethylaminoethyl methacrylate) (PEG-g-PDMA, PgP), and hyaluronic acid (HA) anchored reduced graphene oxide (rGO) hybrid nanoparticles. The obtained rGO nanoparticles (PgP/HA-rGO) showed pH-dependent fluorescence emission and excellent near-infrared (NIR) irradiation of cancer cells targeted in vitro to provide cytotoxicity. Using intravenously administered PTT agents, the time-dependent in vivo tumor target accumulation was exactly defined, presenting eminent photothermal conversion at 4 and 8 h post-injection, which was demonstrated from the ex vivo biodistribution of tumors. These tumor environment responsive hybrid nanoparticles generated photothermal heat, which caused dominant suppression of tumor growth. The histopathological studies obtained by H&E staining demonstrated complete healing from malignant tumor. In an area of limited successes in cancer therapy, our translation will pave the road to design stimulus environment responsive targeted PTT agents for the safe eradication of devastating cancer.

Light controllable surface coating for effective photothermal killing of bacteria

Although the electronic properties of conducting films have been widely explored in optoelectronic fields, the optical absorption abilities of surface-coated films for photothermal conversion have been relatively less explored in the production of antibacterial coatings. Here, we present catechol-conjugated poly(vinylpyrrolidone) sulfobetaine (PVPS) and polyaniline (PANI) tightly linked by ionic interaction (PVPS:PANI) as a novel photothermal antibacterial agent for surface coating, which can absorb broadband near-infrared (NIR) light. Taking advantage of the NIR light absorption, this coating film can release eminent photothermal heat for the rapid killing of surface bacteria. The NIR light triggers a sharp rise in photothermal heat, providing the rapid and effective killing of 99.9% of the Gram-positive and -negative bacteria tested within 3 min of NIR light exposure when used at the concentration of 1 mg/mL. Although considerable progress has been made in the design of antibacterial coatings, the user control of NIR-irradiated rapid photothermal destruction of surface bacteria holds increasing attention beyond the traditional boundaries of typical antibacterial surfaces.

Target delivery of β-cyclodextrin/paclitaxel complexed fluorescent carbon nanoparticles: externally NIR light and internally pH sensitive-mediated release of paclitaxel with bio-imaging

The carbonized fluorescence hyaluronic acid (HA-FCN) for triggered target bioimaging ability have conjugated with β-cyclodextrin (CD) to release PTX by intracellular pH as well as remote photothermal NIR light control.