PEGylated chitosan-coated nanophotosensitizers for effective cancer treatment by photothermal-photodynamic therapy combined with glutathione depletion.

The combination of photothermal therapy (PTT) and photodynamic therapy (PDT) has emerged as a promising strategy for cancer treatment. However, the poor photostability and photothermal conversion efficiency (PCE) of organic small-molecule photosensitizers, and the intracellular glutathione (GSH)-mediated singlet oxygen scavenging largely decline the antitumor efficacy of PTT and PDT. Herein, a versatile nanophotosensitizer (NPS) system is developed by ingenious incorporation of indocyanine green (ICG) into the PEGylated chitosan (PEG-CS)-coated polydopamine (PDA) nanoparticles via multiple π-π stacking, hydrophobic and electrostatic interactions. The PEG-CS-covered NPS showed prominent colloidal and photothermal stability as well as high PCE (ca 62.8 %). Meanwhile, the Michael addition between NPS and GSH can consume GSH, thus reducing the GSH-induced singlet oxygen scavenging. After being internalized by CT26 cells, the NPS under near-infrared laser irradiation produced massive singlet oxygen with the aid of thermo-enhanced intracellular GSH depletion to elicit mitochondrial damage and lipid peroxide formation, thus leading to ferroptosis and apoptosis. Importantly, the combined PTT and PDT delivered by NPS effectively inhibited CT26 tumor growth in vivo by light-activated intense hyperthermia and redox homeostasis disturbance. Overall, this work presents a new tactic of boosting antitumor potency of ICG-mediated phototherapy by PEG-CS-covered NPS.

Tumor-activated targetable photothermal chemotherapy using IR780/zoledronic acid-containing hybrid polymeric nanoassemblies with folate modification to treat aggressive breast cancer.

To effectively treat aggressive breast cancer by tumor-activated targetable photothermal chemotherapy, in this work, folate (FA)-modified hybrid polymeric nanoassemblies (HPNs) with a poly(ethylene glycol) (PEG)-detachable capability are developed as vehicles for tumor-targeted co-delivery of IR780, a lipophilic photothermal reagent, and zoledronic acid (ZA), a hydrophilic chemotherapy drug. Through hydrophobic interaction-induced co-assembly, IR780 molecules and ZA/poly(ethylenimine) (PEI) complexes were co-encapsulated into a poly(lactic-co-glycolic acid) (PLGA)-rich core stabilized by the amphiphilic FA-modified D-α-tocopheryl poly(ethylene glycol) succinate (FA-TPGS) and acidity-sensitive PEG-benzoic imine-octadecane (C18) (PEG-b-C18) conjugates. The developed FA-ZA/IR780@HPNs with high ZA and IR780 payloads not only showed excellent colloidal stability in a serum-containing milieu, but also promoted IR780-based photostability and photothermal conversion efficiency. Furthermore, for FA-ZA/IR780@HPNs under simulated physiological conditions, the premature leakage of IR780 and ZA molecules was remarkably declined. In a mimetic acidic tumor microenvironment, the uptake of FA-ZA/IR780@HPNs by FA receptor-overexpressed 4T1 breast cancer cells was remarkably promoted by PEG detachment combined with FA receptor-mediated endocytosis, thus effectively hindering migration of cancer cells and augmenting the anticancer efficacy of photothermal chemotherapy. Notably, the in vivo studies demonstrated that the FA-ZA/IR780@HPNs largely deposited at 4T1 tumor sites and profoundly suppressed tumor growth and metastasis without severe systemic toxicity upon near infrared (NIR)-triggered IR780-mediated hyperthermia integrated with ZA chemotherapy. This work presents a practical strategy to treat aggressive breast tumors with tumor-triggered targetable photothermal chemotherapy using FA-ZA/IR780@HPNs.

The Penetrated Delivery of Drug and Energy to Tumors by Lipo-Graphene Nanosponges for Photolytic Therapy.

Delivery of drug and energy within responsive carriers that effectively target and accumulate in cancer cells promises to mitigate side effects and to enhance the uniquely therapeutic efficacy demanded for personalized medicine. To achieve this goal, however, these carriers, which are usually piled up at the periphery of tumors near the blood vessel, must simultaneously overcome the challenges associated with low tumor penetration and the transport of sufficient cargos to deep tumors to eradicate whole cancer cells. Here, we report a sponge-like carbon material on graphene nanosheet (graphene nanosponge)-supported lipid bilayers (lipo-GNS) that doubles as a photothermal agent and a high cargo payload platform and releases a burst of drug/energy (docetaxel (DTX) and gasified perfluorohexane (PFH)) and intense heat upon near-infrared irradiation. Ultrasmall lipo-GNS (40 nm) modified with a tumor-targeting protein that penetrates tumor spheroids through transcytosis exhibited a 200-fold increase in accumulation relative to a 270 nm variant of the lipo-GNS. Furthermore, a combination of therapeutic agents (DTX and PFH) delivered by lipo-GNS into tumors was gasified and released into tumor spheroids and successfully ruptured and suppressed xenograft tumors in 16 days without distal harm when subjected to a single 10 min near-infrared laser treatment. Moreover, no tumor recurrence was observed over 60 days post-treatment. This sophisticated lipo-GNS is an excellent delivery platform for penetrated, photoresponsive, and combined gasification/chemo-thermotherapy to facilitate tumor treatment and for use in other biological applications.

Functionalized graphene nanocomposites for enhancing photothermal therapy in tumor treatment.

Graphene and its derivatives have unique physical and chemical properties that make them promising vehicles for photothermal therapy (PTT)-based cancer treatment. With intrinsic near-infrared (NIR) absorption properties, graphene-based nanomaterials can be used for PTT and other therapeutics, particularly in combination therapy, to provide successful thermal ablation of cancer cells. In the recent years, advances in graphene-based PTT have produced efficient and efficacious tumor inhibition via nanomaterial structural design and different functionalizations of graphene-derived nanocomposites. Graphene-based nanosystems exhibit multifunctional properties that are useful for PTT applications including enhancement of multimodalities, guided imaging, enhanced chemotherapy and low-power efficient PTT for optimum therapeutic efficiency. Therefore, in this review, we address critical issues and future aspects of PTT-based combination therapy.

Enhanced Targeted Delivery of Cyclodextrin-Based Supermolecules by Core-Shell Nanocapsules for Magnetothermal Chemotherapy.

In this study, double-emulsion capsules (DECs) capable of concealing drug-incorporated targeted-supermolecules are developed to achieve "on-demand" supermolecule release and enhanced sequential targeting for magneto-chemotherapy. These water-in-oil-in-water DECs less than 200 nm in diameter are synthesized using a single component of PVA (polyvinyl alcohol) polymer and the magnetic nanoparticles, which are capable of encapsulating large quantities of targeted supermolecules composed of palitaxel-incorporated beta-cyclodextrin decorated by hyaluronic acid (HA, a CD44-targeting ligand) in the watery core. The release profiles (slow, sustained and burst release) of the targeted supermolecules can be directly controlled by regulating the high-frequency magnetic field (HFMF) and polymer conformation without sacrificing the targeting ability. Through an intravenous injection, the positive targeting of the supermolecules exhibited a 20-fold increase in tumor accumulation via the passive targeting and delivery of DECs followed by positive targeting of the supermolecules. Moreover, this dual-targeting drug-incorporated supermolecular delivery vehicle at the tumor site combined with magneto-thermal therapy suppressed the cancer growth more efficiently than treatment with either drug or supermolecule alone.

Dual-Targeting Lactoferrin-Conjugated Polymerized Magnetic Polydiacetylene-Assembled Nanocarriers with Self-Responsive Fluorescence/Magnetic Resonance Imaging for In Vivo Brain Tumor Therapy.

Maintaining a high concentration of therapeutic agents in the brain is difficult due to the restrictions of the blood-brain barrier (BBB) and rapid removal from blood circulation. To enable controlled drug release and enhance the blood-brain barrier (BBB)-crossing efficiency for brain tumor therapy, a new dual-targeting magnetic polydiacetylene nanocarriers (PDNCs) delivery system modified with lactoferrin (Lf) is developed. The PDNCs are synthesized using the ultraviolet (UV) cross-linkable 10,12-pentacosadiynoic acid (PCDA) monomers through spontaneous assembling onto the surface of superparamagnetic iron oxide (SPIO) nanoparticles to form micelles-polymerized structures. The results demonstrate that PDNCs will reduce the drug leakage and further control the drug release, and display self-responsive fluorescence upon intracellular uptake for cell trafficking and imaging-guided tumor treatment. The magnetic Lf-modified PDNCs with magnetic resonance imaging (MRI) and dual-targeting ability can enhance the transportation of the PDNCs across the BBB for tracking and targeting gliomas. An enhanced therapeutic efficiency can be obtained using Lf-Cur (Curcumin)-PDNCs by improving the retention time of the encapsulated Cur and producing fourfold higher Cur amounts in the brain compared to free Cur. Animal studies also confirm that Lf targeting and controlled release act synergistically to significantly suppress tumors in orthotopic brain-bearing rats.

Magnetic core-shell nanocapsules with dual-targeting capabilities and co-delivery of multiple drugs to treat brain gliomas.

Lactoferrin (Lf)-tethered magnetic double emulsion nanocapsules (Lf-MDCs) are assembled from polyvinyl alcohol (PVA), polyacrylic acid (PAA), and iron oxide (IO) nanoparticles. The core-shell nanostructure of the Lf-MDCs (particle diameters from 100 to 150 nm) can simultaneously accommodate a hydrophilic drug, doxorubicin (Dox), and a hydrophobic drug, curcumin (Cur), in the core and shell, respectively, of the nanocapsules for an efficient drug delivery system. The release patterns of the two drugs can be regulated by manipulating the surface charges and drug-loading ratios, providing the capability for a stepwise adjuvant release to treat cancer cells. The results demonstrate that the dual (Dox+Cur)-drug-loaded nanocapsule can be effectively delivered into RG2 glioma cells to enhance the cytotoxicity against the cells through a synergistic effect. The combined targeting, i.e., magnetic guidance and incorporation of Lf ligands, of these Lf-MDCs results in significantly elevated cellular uptake in the RG2 cells that overexpress the Lf receptor. Interestingly, an intravenous injection of the co-delivered chemotherapeutics follows by magnetic targeting in brain tumor-bearing mice not only achieve high accumulation at the targeted site but also more efficiently suppress cancer growth in vivo than does the delivery of either drug alone.

A novel multifunctional nano-platform with enhanced anti-cancer and photoacoustic imaging modalities using gold-nanorod-filled silica nanobeads.

The novel nano-seaurchin structure is characteristic of high-density and well-dispersed gold nanorods in one mesoporous silica nanobead. This nanoplatform provided increased photothermal stability, stable photoacoustic signal and highly efficient hyperthermia effect both in vitro and in vivo, indicating a powerful theranostic modality.

Core-shell nanocapsules stabilized by single-component polymer and nanoparticles for magneto-chemotherapy/hyperthermia with multiple drugs.

Iron-oxide-containing double emulsion capsules carrying both hydrophilic and hydrophobic therapeutic molecules can deliver drugs and energy on demand in vivo. Magneto-chemotherapy/hyperthermia involves a burst-like release of hydrophilic doxorubicin and hydrophobic paclitaxel, remotely triggered by a high frequency magnetic field, which also releases energy via internalized iron oxide nanoparticles, all contributing to cell kill.

Quantum-dot-tagged reduced graphene oxide nanocomposites for bright fluorescence bioimaging and photothermal therapy monitored in situ.

Quantum-dot-tagged reduced graphene oxide (QD-rGO) nanocomposites (left) internalized into targeted tumor cells display bright fluorescence from the QDs (right); by absorbing NIR radiation incident on the rGO and converting it into heat, they also cause simultaneous cell death and fluorescence reduction (bottom). The nanocomposite is thus capable of tumor imaging, photothermal therapy and in situ monitoring of treatment in progress.

Nanocomposites with spatially separated functionalities for combined imaging and magnetolytic therapy.

Compact nanostructures with highly integrated functionalities are of considerable current interest to drug delivery, multimodality imaging, and electronic devices. A key challenge, however, is how to combine individual components together without interfering or sacrificing their original electronic and optical properties. Here, we demonstrate a new class of nanocomposites with spatially separated functionalities. We further demonstrate magnetic field modulated imaging and an innovative application of this technology in cancer cell treatment, magnetolytic therapy, based on magnetically controlled mechanical damage to cell membranes.

Biofunctional ZnO nanorod arrays grown on flexible substrates.

A square pattern of thioctic acid self-assembled ZnO nanorod arrays was grown on a large 4-in. thermoplastic polyurethane (TPU) flexible substrate via an in situ soluthermal process at low temperature (348 K). With the addition of dimercaptosuccinic acid (DMSA), the surface chemistry forms a disordered ZnO phase, and the morphology of the ZnO-DMSA nanorods changes with various DMSA addition times. As evidenced by the Zn2p3/2, C1s, O1s, S2p, and N-1s scans of X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD), DMSA and proteins were conjugated on the single crystalline ZnO nanorods. The photoluminescence (PL) spectra indicated that the optical properties of ZnO nanorod arrays were changed while the DMSA was inserted, and proteins were conjugated. Furthermore, a control test found that the ZnO nanorods show a significant improvement in sensitive characterization over the ZnO film. As another proteins (e.g., human serum albumin, HSA) were bound onto the ZnO-bovine serum albumin (BSA) nanorod arrays, an enhanced ultraviolet emission intensity was detected. On the basis of these results, one might be expected to conjugate specific biomolecules on the biofunctional ZnO nanorod arrays to detect the complementary biomolecules by PL detecting.