phytochlorin and titanium-dioxide

Sonodynamic therapy (SDT) has good targeting and non-invasive advantages in the treatment of solid cancers, and checkpoint blockade immunotherapy is also a promising treatment to cure cancer. However, their antitumor effects are not sufficient due to some inherent factors. Some studies that combined SDT with immunotherapy or nanoparticles have managed to enhance its efficiency to treat cancers.. In this work, an effective therapeutic strategy that can potentiate the antitumor efficacy of anti-PD-L1 antibody (aPD-L1) is developed by the use of cascade immuno-sonodynamic therapy (immuno-SDT). Titanium dioxide (TiO. The characterization tests showed that the nanosonosensitizers are polycrystalline structure with homogeneous sizes, resulting in a good drug loading efficiency. The innovative nanosonosensitizers (TiO. In this study, we present an effective strategy for tumor treatment by combining nanosonosensitizer-augmented SDT and aPD-L1 checkpoint blockade. This work provides a promising strategy and offers a new vision for treating malignant tumors.

Topics: Animals; Cell Death; Cell Line, Tumor; Chlorophyllides; Combined Modality Therapy; Dendritic Cells; Endocytosis; Female; Humans; Immune Checkpoint Inhibitors; Immunity; Immunotherapy; Mice, Inbred BALB C; Mice, Inbred C57BL; Nanoparticles; Neoplasms; Oligodeoxyribonucleotides; Porphyrins; Reactive Oxygen Species; Titanium; Ultrasonic Therapy

Oxygen deficient TiO2-x nanoparticles (NPs) have been recognized as a category of new-fashioned photothermal agents to offer safer PTT. However, the surface of TiO2-x NPs is deficient in free active groups or radicals to conjugate functional therapeutic molecules, which seriously impedes their in-depth development for versatile medical applications. In this study, surface activation of TiO2-x NPs was realized by the facile conjugation of (3-aminopropyl)triethoxysilane (APTES) through the formation of a stable Si-O-Ti bond, and photosensitizer chlorin e6 (Ce6) was successfully modified onto the TiO2-x NP surface and with a considerably high loading content. The resultant TiO2-x@APTES/Ce6 (TAC) NPs displayed decent biosafety, rapid tumor enrichment and outstanding performance in photoacoustic (PA) imaging. Taking advantage of the intense photo-absorption in the near-infrared (NIR) region and high dose of conjugated Ce6, a powerful antitumor effect was realized based on the combination of hyperthermia-induced cell ablation and cytotoxic reactive oxygen species (ROS)-triggered apoptosis both in vitro and in vivo. Moreover, PA imaging guidance was exceptionally useful for locating the tumor position and optimizing the treatment regimens. Apart from Ce6, this elaborate modification strategy for TiO2-x is believed to be universal for steadily binding more versatile therapeutic agents, which would definitely favor the development of multifunctional TiO2-x-based nanocomplexes for enhanced tumor treatment.

Topics: Animals; Chlorophyllides; Female; HeLa Cells; Humans; Hyperthermia, Induced; Mice; Mice, Inbred BALB C; Nanoparticles; Neoplasms, Experimental; Photoacoustic Techniques; Phototherapy; Porphyrins; Titanium; Xenograft Model Antitumor Assays

Black titanium dioxide (TiO2) nanoparticles have attracted great attention due to their application in photothermal therapy (PTT). However, single-mode phototherapy has the risk of recurrence, and the high-dose laser usually imposed to improve the PTT performance can bring a potential threat to security. Here, polydopamine (PDA)-coated black TiO2 (b-P25@PDA) nanoparticles with a core-shell structure were synthesized for enhanced PTT; then, synergistic phototherapy nanoprobes (b-P25@PDA-Ce6 (Mn)) were constructed by coupling chlorin e6 (Ce6) and chelating Mn2+ for simultaneous photodynamic therapy (PDT)/PTT and magnetic resonance (MR) imaging, in which a low-dose laser was used and imaging-guided phototherapy with high efficiency and high safety was achieved. The prepared nanoprobes showed high photothermal conversion efficiency (32.12%), high reactive oxygen generation and excellent MR imaging. In the 4T1 tumor-bearing nude mouse model, the tumors completely disappeared under the combination of PDT/PTT with a low-dose laser but were only partially inhibited by single PDT and single PTT. The current work developed a multifunctional black TiO2-based nanoprobe for enhanced synergistic PDT/PTT and MR imaging, which will be important for the safe and efficient visualized theranostics of cancers.

Topics: Animals; Cell Line, Tumor; Chlorophyllides; Contrast Media; Female; Indoles; Magnetic Resonance Imaging; Mammary Neoplasms, Animal; Manganese; Mice; Nanoparticles; Phototherapy; Polymers; Porphyrins; Titanium

Despite the advantages of using photodynamic therapy (PDT) for the treatment of head and neck tumors, it can only be used to treat early stage flat lesions due to the limited tissue penetration ability of the visible light. Here, we developed near-infrared (NIR) excitable upconversion nanoparticle (UCN) based PDT agent that can specifically target epithelial growth factor receptor (EGFR) overexpressing oral cancer cells, in a bid to widen the application of PDT against thick and solid advanced or recurrent head and neck cancers. In vivo studies using the synthesized anti-EGFR-PEG-TiO2-UCNs following systemic administration displayed no major sub-acute or long term toxic effects in terms of blood biochemical, hematological or histopathological changes at a concentration of 50 mg/kg. NIR-PDT even in the presence of a 10 mm tissue phantom placed over the xenograft tumor, showed significant delay in tumor growth and improved survival rate compared to conventional chlorin-e6 (Ce6) PDT using 665 nm red light. Our work, one of the longest study till date in terms of safety (120 d), PDT efficacy (35 d) and survival (60 d), demonstrates the usefulness of UCN based PDT technology for targeted treatment of thick and bulky head and neck tumors.

Topics: Animals; Biocompatible Materials; Cell Line, Tumor; Chlorophyllides; Drug Delivery Systems; ErbB Receptors; Female; Humans; Infrared Rays; Mice, Inbred BALB C; Mice, Nude; Mouth Neoplasms; Nanoparticles; Photochemotherapy; Photosensitizing Agents; Porphyrins; Reactive Oxygen Species; Titanium; Xenograft Model Antitumor Assays

A bio-photovoltaic conversion device based on dye-sensitised solar cell (DSSC) using the visible light sensitisation of chlorine-e6 (Chl-e6) derived from chlorophyll from Spirulina adsorbed on a nanocrystalline TiO2 film was developed. Form fluorescence spectrum of Chl-e6 adsorbed on a nanocrystalline TiO2 film, the emission of Chl-e6 was effectively quenched by TiO2 nanocrystalline indicating that the effective electron injection from the excited singlet state of Chl-e6 into the conduction band of TiO2 particles occurred. The short-circuit photocurrent density (Isc). the open-circuit photovoltage (Voc). and the fill factor (FF) of solar cell using Chl-e6 adsorbed on a nanocrystalline TiO2 film electrode were estimated to be 0.305 +/- 0.012 mA cm(-2), 426 +/- 10 mV, and 45.0%, respectively. IPCE values were reached a maximum around the wavelength of absorption maximum (7.40% at 400 nm; 1.44% at 514 nm and 2.91% at 670 nm), indicating that the DSSC using visible light sensitisation of nanocrystalline TiO2 film by Chl-e6 was developed.

Topics: Bacterial Proteins; Chlorophyll; Chlorophyllides; Crystallization; Electric Power Supplies; Electrochemistry; Electrodes; Equipment Design; Equipment Failure Analysis; Light; Nanotechnology; Photochemistry; Porphyrins; Reproducibility of Results; Sensitivity and Specificity; Spirulina; Titanium; Transducers