Targeted theranostic nanoparticles: receptor-mediated entry into cells, pH-induced signal generation and cytosolic delivery

Efficient combined near-infrared-triggered therapy: Phototherapy over chemotherapy in chitosan-reduced graphene oxide-IR820 dye-doxorubicin nanoplatforms

Significant efforts are currently being funneled into the improvement of therapeutic outcomes in cancer by designing hybrid nanomaterials that synergistically combine chemotherapeutic abilities and near-infrared (NIR) light-activated photothermal (PTT) and photodynamic (PDT) activity. Herein, a nanotherapeutic platform is specifically designed to integrate combinational functionalities: chemotherapy, PTT, PDT and traceable optical properties. The system, based on chitosan-reduced graphene oxide (chit-rGO), incorporates and carries a large payload of IR820 dye with dual PTT and PDT activity and a chemotherapeutic drug, doxorubicin (DOX). The potential of the fabricated nanoplatforms to operate as an NIR activatable therapeutic agent is first assessed in aqueous solution by investigating its ability to generate singlet oxygen and heat under NIR irradiation with 785 nm laser irradiation. The in vitro anticancer activity of chit-rGO-IR820-DOX is evaluated against murine colon carcinoma cells (C26). The fabricated nanosystem exhibits synergistic anticancer activity against C26 cancer cells by combining IR820 induced PDT, simultaneous graphene and IR820 induced PTT and the chemotherapeutic effect of DOX. Notably, the therapeutic performance of chit-rGO-IR820-DOX can be controlled by the ratio between IR820 and DOX. Moreover, chit-rGO-IR820-DOX facilitates localization inside cancer cells correlated with the release of DOX via mapping by confocal Raman microscopy.

Surface-Enhanced Raman Scattering-Fluorescence Dual-Mode Nanosensors for Quantitative Detection of Cytochrome c in Living Cells

During apoptosis process, the release of cytochrome c (Cyt c) is considered to be a key factor in the intrinsic pathway and is often defined as no regression point. Quantitative detection of intracellular Cyt c remains a challenge. Herein, we have developed surface-enhanced Raman scattering (SERS)-fluorescence dual-mode nanosensors for the quantitative assay of Cyt c in living cells. Dual signal detection was achieved by constructing gold nanotriangles (AuNTs) nanosensors capable of specifically recognizing Cyt c. The nanosensors were prepared by modifying the aptamer of Cyt c on AuNTs and connecting the complementary strands modified with Cy5. The AuNTs provided both enhanced SERS signals and fluorescence quenching effects. Once cells were induced by external stimulus (such as toxins) to release Cyt c, Cyt c would specifically bind to its aptamer, and the complementary strands modified with Cy5 would detach which would result in weakened SERS signal and recovery of fluorescence signal. The experimental results showed that the nanosensors not only had excellent selectivity and sensitivity but also realized real-time monitoring of Cyt c translocation event from mitochondria to cytoplasm. The SERS and fluorescence intensity showed good linear relationship with Cyt c concentration ranging from 0.044 to 9.95 μM and achieved a minimum limit of detection (LOD) of 0.02 μM in living cells. The accuracy of intracellular Cyt c quantitative results was more than 90% compared with the ELISA results.

Cancer-Associated, Stimuli-Driven, Turn on Theranostics for Multimodality Imaging and Therapy

Advances in bioinformatics, genomics, proteomics, and metabolomics have facilitated the development of novel anticancer agents that have decreased side effects and increased safety. Theranostics, systems that have combined therapeutic effects and diagnostic capabilities, have garnered increasing attention recently because of their potential use in personalized medicine, including cancer-targeting treatments for patients. One interesting approach to achieving this potential involves the development of cancer-associated, stimuli-driven, turn on theranostics. Multicomponent constructs of this type would have the capability of selectively delivering therapeutic reagents into cancer cells or tumor tissues while simultaneously generating unique signals that can be readily monitored under both in vitro and in vivo conditions. Specifically, their combined anticancer activities and selective visual signal respond to cancer-associated stimuli, would make these theranostic agents more highly efficient and specific for cancer treatment and diagnosis. This article focuses on the progress of stimuli-responsive turn on theranostics that activate diagnostic signals and release therapeutic reagents in response to the cancer-associated stimuli. The present article not only provides the fundamental backgrounds of diagnostic and therapeutic tools that have been widely utilized for developing theranostic agents, but also discusses the current approaches for developing stimuli-responsive turn on theranostics.

Dietary Iron Oxide Nanoparticles Delay Aging and Ameliorate Neurodegeneration in Drosophila

Dietary iron oxide nanoparticles are shown to ameliorate neurodegeneration in a Drosophelia Alzheimer's disease model. Iron oxide nanoparticles can mimic catalase and can decompose reactive oxygen species (ROS). This has potential therapeutic uses for aging, metabolic disorders, and neurodegenerative diseases, in which increased production of ROS is closely implicated.

Micro- and nanotechnologies for intracellular delivery

The majority of drugs and biomolecules need to be delivered into cells to be effective. However, the cell membranes, a biological barrier, strictly resist drugs or biomolecules entering cells, resulting in significantly reduced intracellular delivery efficiency. To overcome this barrier, a variety of intracellular delivery approaches including chemical and physical ways have been developed in recent years. In this review, the focus is on summarizing the nanomaterial routes involved in making use of a collection of receptors for the targeted delivery of drugs and biomolecules and the physical ways of applying micro- and nanotechnologies for high-throughput intracellular delivery.

A unique perylene-based DNA intercalator: localization in cell nuclei and inhibition of cancer cells and tumors

To date, perylene derivatives have not been explored as DNA intercalator to inhibit cancer cells by intercalating into the base pairs of DNA. Herein, a water-soluble perylene bisimide (PBDI) that efficiently intercalates into the base pairs of DNA is synthesized. Excitingly, PBDI is superior to the commercial DNA intercalator, amonafide, for specific nuclear accumulation and effective suppression of cancer cells and tumors.