Ultralong tumor retention of theranostic nanoparticles with short peptide-enabled active tumor homing

Computer tomography (CT) and magnetic resonance imaging (MRI) are noninvasive cancer imaging methods in clinics. Hence, a material that enables MRI/CT dual-modal imaging-guided therapy is in high demand. Currently, the available materials lack active tumor targeting, deep tumor penetration, and ultralong tumor retention and may lose their imaging elements. To overcome these drawbacks, herein, nanoparticles (NPs) were deveopled by integrating an MRI contrast-enhancing chelated gadolinium (Gd) complex within a doxorubicin (DOX)-loaded protective silica shell as well as a CT imaging/photothermal biocompatible bismuth (Bi) nano-core, which surface-displayed an MCF-7 breast tumor-homing peptide (AREYGTRFSLIGGYR, termed AR); we found that the resultant NPs AR-Bi@SiO2-Gd/DOXNPs could home to and penetrate deep into the tumors with the unexpected ultralong retention of at least 14 days (as determined by CT/MRI imaging) and the tumor retention half-life of 104.5 h (as determined by ICP-MS analysis) under the guidance of the AR peptide. These NPs can be further used to image tumors with significantly increased sharp contrasts via both CT and MRI, which are much better than the commercial standard contrast agents; moreover, they significantly inhibit tumor growth via the synergistic action of both Bi-enabled photothermal therapy and DOX-induced chemotherapy. The NPs are cleared by the spleen, liver and kidney and then excreted from the body along with faeces and urine. The precise tumor targeting and ultralong tumor retention of these unique NPs would enable both precise tumor detection for early diagnosis and signal-persistent tumor tracking for monitoring the treatment with only a single injection of these NPs.

Leveraging Engineering of Indocyanine Green-Encapsulated Polymeric Nanocomposites for Biomedical Applications

In recent times, photo-induced therapeutics have attracted enormous interest from researchers due to such attractive properties as preferential localization, excellent tissue penetration, high therapeutic efficacy, and minimal invasiveness, among others. Numerous photosensitizers have been considered in combination with light to realize significant progress in therapeutics. Along this line, indocyanine green (ICG), a Food and Drug Administration (FDA)-approved near-infrared (NIR, >750 nm) fluorescent dye, has been utilized in various biomedical applications such as drug delivery, imaging, and diagnosis, due to its attractive physicochemical properties, high sensitivity, and better imaging view field. However, ICG still suffers from certain limitations for its utilization as a molecular imaging probe in vivo, such as concentration-dependent aggregation, poor in vitro aqueous stability and photodegradation due to various physicochemical attributes. To overcome these limitations, much research has been dedicated to engineering numerous multifunctional polymeric composites for potential biomedical applications. In this review, we aim to discuss ICG-encapsulated polymeric nanoconstructs, which are of particular interest in various biomedical applications. First, we emphasize some attractive properties of ICG (including physicochemical characteristics, optical properties, metabolic features, and other aspects) and some of its current limitations. Next, we aim to provide a comprehensive overview highlighting recent reports on various polymeric nanoparticles that carry ICG for light-induced therapeutics with a set of examples. Finally, we summarize with perspectives highlighting the significant outcome, and current challenges of these nanocomposites.

Near-Infrared-Light-Induced Morphology Transition of Poly(ether amine) Nanoparticles for Supersensitive Drug Release

Near-infrared (NIR)-light-controlled drug release has aroused great interest because of its advantages in spatiotemporal control. Herein, a photothermally induced morphology transition of the nanoparticles (NPs) for supersensitive drug release has been demonstrated. Doxorubicin (DOX)- and cyanine (Cy)-coloaded thermosensitive poly(ether amine) NPs (DOX&Cy@PEA81) were developed. Because of the photothermal activity of Cy upon irradiation, increase in temperature at the tumor site results, which would be used not only for photothermal therapy but also to spur the release of DOX from the NPs for tunable chemotherapy. The NIR-laser-driven DOX release was validated by a series of intracellular and in vivo experiments on animals. Meanwhile, the chemo-photothermal combinatorial therapy results in optimal cytotoxicity and tumor inhibition. This article provides a promising approach to realizing supersensitive drug release and synergistic chemo-photothermal therapy for cancer.

QDs decorated with thiol-monomer ligands as new multicrosslinkers for the synthesis of smart luminescent nanogels and hydrogels

QDs decorated with thiol-monomer ligands as new multicrosslinkers for the synthesis of smart (photoluminescent and pH/temperature sensitive) nanogels and hydrogels.

Breaking the reduced glutathione-activated antioxidant defence for enhanced photodynamic therapy

Photodynamic therapy (PDT) has been applied in cancer treatment by utilizing reactive oxygen species (ROSs) to kill cancer cells.