A photoresponsive and rod-shape nanocarrier: Single wavelength of light triggered photothermal and photodynamic therapy based on AuNRs-capped & Ce6-doped mesoporous silica nanorods.

Rod-shape nanocarriers have attracted great interest because of their better cell internalization capacity and higher drug loading properties. Besides, the combination of photodynamic therapy (PDT) and photothermal therapy (PTT) holds great promise to overcome respective limitations of the anti-cancer treatment. In this work, we first report Au nanorods-capped and Ce6-doped mesoporous silica nanorods (AuNRs-Ce6-MSNRs) for the single wavelength of near infrared (NIR) light triggered combined phototherapy. AuNRs-Ce6-MSNRs are not only able to generate hyperthermia to perform PTT effect based on the AuNRs, but also can produce singlet oxygen (1O2) for PDT effect based on Ce6 after uncapping of AuNRs under the single NIR wavelength irradiation. In addition, the combined therapy can be dual-imaging guided by taking the photoacoustic (PA) and NIR fluorescence (NIRF) imaging of AuNRs and Ce6, respectively. What's more, by utilizing the special structure of MSNRs, this nanocarrier can serve as a drug delivery platform with high drug loading capacity and enhanced cellular uptake efficiency. The multi-functional nanocomposite is designed to integrate photothermal and photodynamic therapy, in vivo dual-imaging into one system, achieving synergistic anti-tumor effects both in vitro and in vivo.

In-situ second harmonic generation by cancer cell targeting ZnO nanocrystals to effect photodynamic action in subcellular space.

This paper introduces the concept of in-situ upconversion of deep penetrating near infrared light via second harmonic generation from ZnO nanocrystals delivered into cells to effect photo activated therapies, such as photodynamic therapy, which usually require activation by visible light with limited penetration through biological tissues. We demonstrated this concept by subcellular activation of a photodynamic therapy drug, Chlorin e6, excited within its strong absorption Soret band by the second harmonic (SH) light, generated at 409 nm by ZnO nanocrystals, which were targeted to cancer cells and internalized through the folate-receptor mediated endocytosis. By a combination of theoretical modeling and experimental measurements, we show that SH light, generated in-situ by ZnO nanocrystals significantly contributes to activation of photosensitizer, leading to cell death through both apoptotic and necrotic pathways initiated in the cytoplasm. This targeted photodynamic action was studied using label-free Coherent Anti-Stokes Raman Scattering imaging of the treated cells to monitor changes in the distribution of native cellular proteins and lipids. We found that initiation of photodynamic therapy with upconverted light led to global reduction in the intracellular concentration of macromolecules, likely due to suppression of proteins and lipids synthesis, which could be considered as a real-time indicator of cellular damage from photodynamic treatment. In prospective applications this in-situ photon upconversion could be further extended using ZnO nanocrystals surface functionalized with a specific organelle targeting group, provided a powerful approach to identify and consequently maximize a cellular response to phototherapy, selectively initiated in a specific cellular organelle.

Encapsulation efficacy of natural and synthetic photosensitizers by silica nanoparticles for photodynamic applications.

This study analysed the physical effects of Cichorium Pumilum (CP), as a natural photosensitizer (PS), and Protoporphyrin IX (PpIX), as a synthetic PS, encapsulated with silica nanoparticles (SiNPs) in photodynamic therapy. The optimum concentrations of CP and PpIX, needed to destroy Red Blood Cells (RBC), were determined and the efficacy of encapsulated CP and PpIX were compared with naked CP and PpIX was verified. The results confirmed the applicability of CP and PpIX encapsulated in SiNPs on RBCs, and established a relationship between the encapsulated CP and PpIX concentration and the time required to rupture 50% of the RBCs (t50). The CP and PpIX encapsulated in SiNPs exhibited higher efficacy compared with that of naked CP and PpIX, respectively, and CP had less efficacy compared with PpIX.

Apoptosis selectively induced in BEL-7402 cells by folic acid-modified magnetic nanoparticles combined with 100 Hz magnetic field.

OBJECTIVE: To explore the effect of folic acid-modified magnetic nanoparticles (FA-MNPs) combined with a 100 Hz extremely low-frequency electromagnetic field (ELF-EMF) on the apoptosis of liver cancer BEL-7402 cells. MATERIALS AND METHODS: MNPs (20 nm) were prepared by coprecipitation, and then folic acid was coated onto MNPs to prepare FA-MNPs. BEL-7402 cells and HL7702 cells were selected as liver cancer cells and normal liver cells, respectively. The ELF-EMF was generated from a solenoid coil. Cellular uptake of NPs was determined by inductively coupled plasma atomic emission spectroscopy. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to evaluate cell inhibition. Apoptosis was analyzed by flow cytometry. Statistical analyses were performed using two-way analysis of variance. RESULTS: FA-MNPs combined with a 100 Hz magnetic field significantly inhibited cell proliferation and induced higher apoptosis compared to either the ELF-EMF alone or FA-MNPs alone. FA-MNPs showed a better apoptosis effect and higher iron uptake in BEL-7402 cells compared to in HL7702 cells. On the basis of the ELF-EMF, higher doses of FA-MNPs brought higher apoptosis and higher iron uptake in either BEL-7402 cells or HL7702 cells. CONCLUSION: These results suggest that FA-MNPs may induce apoptosis in a cellular iron uptake-dependent manner when combined with an ELF-EMF in BEL-7402 cells.

Multifunctional polymeric nanocurcumin for cancer therapy.

Nanotechnology-based drug delivery systems have the potential to enhance the efficacy of poorly soluble systemic drugs. Curcumin, a yellow pigment isolated from turmeric, possesses a wide range of pharmacological activities, including anticancer effects. The anticancer potential of curcumin is mediated through the inhibition and modulation of several intracellular signaling pathways, as confirmed in various in vitro and in vivo cancer studies. However, clinical application of dietary curcumin for the treatment of cancer and other chronic diseases have been hindered by poor bioavailability, due to low systemic solubility as well as rapid metabolism and elimination from the body. Different techniques for sustained and efficient curcumin delivery, including nanoparticles, liposomes, micelles, phospholipids, and curcumin-encapsulated polymer nanoparticles are the focus of this study. Previous studies have shown that nanocurcumin has improved anticancer effects as compared to normal curcumin formulations. Among nanoformulations, few composite nanosystems have the simultaneous properties of therapeutic activity and multifunctional nanoparticles as enhanced image contrast agents. We also address the challenges to the development of nanocurcumin delivery platforms by enhancing a steady aqueous dispersion state. Further studies are needed using preclinical and clinical cancer models to recommend nanocurcumin as a drug of choice for cancer therapy.

Self-assembled porphyrin nanodiscs with structure-dependent activation for phototherapy and photodiagnostic applications.

The abilities to deliver and subsequently activate a therapeutic at the intended site of action are two important challenges in the synthesis of novel nanoparticles. Poor tumor permeability as a result of a dense microenvironment can impede the delivery of nanoparticles to the site of action. The design of a sub-40 nm activatable porphyrin nanodisc, based on protein-induced lipid constriction, is described. The biophotonic nanoparticle, self-assembled from aggregated porphyrin-lipid, is stabilized by an amphipathic alpha helical protein and becomes photoactive when its structure is perturbed. Enzymatic cleavage of the constricting protein leads to conversion of the particle from a disc- to a vesicle-shaped structure and provides further evidence that the apolipoprotein serves a functional role on the nanodisc. Fluorescence measurements of these nanodiscs in a detergent show that fluorescence is over 99% quenched in the intact state with a 12-fold increase in singlet oxygen generation upon disruption. Cellular fluorescence unquenching and dose-dependent phototoxicity demonstrate that these nanodiscs can be internalized and unquenched intracellularly. Finally, nanodiscs were found to display a 5-fold increase in diffusion coefficient when compared with the protein-free control ((3.5±0.1)×10(-7) vs (0.7±0.03)×10(-7) cm2 s(-1)). The ability to incorporate large amounts of photosensitizer drugs into its compact structure allows for phototherapeutic action, fluorescence diagnostic applications, and the potential to effectively deliver photosensitizers deep into poorly permeable tumors.

Gold nanorod-covered kanamycin-loaded hollow SiO2 (HSKAu(rod)) nanocapsules for drug delivery and photothermal therapy on bacteria.

A hybrid bactericidal material, gold nanorod-covered kanamycin-loaded hollow SiO(2) (HSKAu(rod)) nanocapsules, is constructed. The hybrid material combines the features of a chemical drug with photothermal physical sterilization which decreases the dosage of broad-spectrum antibiotic and the physical damage of biological systems. Hollow SiO(2) nanocapsules are used as carriers for drug delivery. The nanocapsules load a model drug, kanamycin, and are covered with gold nanorods to avoid drug leakage and realize photothermal treatment. The sterilizing effect on the bacterial strain is investigated by incubating E. coli BL21 with the hybrid nanocapsules and irradiating under near-infrared light (NIR) for 20 min. A bactericidal effect, i.e., a sterilizing rate of 53.47%, is achieved for the HSKAu(rod) nanocapsules under NIR irradiation, with respect to a net sum sterilizing rate of 34.49% for the individual components of the HSKAu(rod) nanocapsules, e.g., carrier nanocapsules, chemical sterilization of kanamycin and physical sterilization due to the gold nanorods under NIR irradiation. It is demonstrated that the combination of chemical drug and physical sterilization results in an obvious synergistic effect and makes the sterilization more effective. This novel hybrid has great potential as an adjuvant therapeutic alternative material for sterilization or even for the control of disease.

Anti-cAngptl4 Ab-conjugated N-TiO(2) /NaYF(4) :Yb,Tm nanocomposite for near infrared-triggered drug release and enhanced targeted cancer cell ablation.

Nanomedicine: NIR-active N-TiO(2) /NaYF(4) :Yb,Tm nanocomposites (NCs) were synthesized for the first time and its potential applications in drug release and targeted cancer cell ablation are explored. Upon 980 nm laser irradiation, the anti-cAngptl4 Ab-conjugated N-TiO(2) /NaYF(4) :Yb,Tm NCs shows a significant increase in apoptotic A-5RT3 cells when compared with that of the unconjugated NCs. The mechanisms for NIR-induced photocatalysis, drug release and targeted cancer cell killing are proposed.