Search results for "PHOTOTHERMAL THERAPY"
showing 10 items of 39 documents
Injectable Hydrogel for Synergetic Low Dose Radiotherapy, Chemodynamic Therapy and Photothermal Therapy
2021
Higher doses of radiotherapy (RT) are associated with resistance induction, therefore highly selective and controllable radiosensitizers are urgently needed. To address this issue, we developed a FeGA-based injectable hydrogel system (FH) that can be used in combination with low-dose radiation. Our FH can deliver FeGA directly to the tumor site via intratumoral injection, where it is a reservoir-based system to conserve FeGA. The photothermal properties of FeGA steadily dissolve FH under laser irradiation, and, simultaneously, FeGA reacts with a large amount of H2O2 in the cell to produce OH (Fenton reaction) which is highly toxic to mitochondria, rendering the cell inactive and reducing ra…
Thermal lens spectrometry in biochemical analysis.
1994
The photothermal spectroscopic techniques, with special emphasis on the thermal lens spectrometry (TLS), are introduced to the non-specialist in laser spectroscopy. The following topics are treated on an elementary basis: fundamentals and analytical characteristics, instrumentation, selectivity and multi-wavelength capability, the models describing the signal-concentration relationship, the sensitivity, background noise and limits of detection, the influence of light scattering and flow. Applications related to the fields of clinical and biochemical analysis and organic pollution are given. The thermal lens circular dichroism and the infrared TLS are also briefly outlined.
Near-Infrared Light Responsive Folate Targeted Gold Nanorods for Combined Photothermal-Chemotherapy of Osteosarcoma.
2017
Folate-targeted gold nanorods (GNRs) are proposed as selective theranostic agents for osteosarcoma treatment. An amphiphilic polysaccharide based graft-copolymer (INU-LA-PEG-FA) and an amino derivative of the α,β-poly(N-2-hydroxyethyl)-d,l-aspartamide functionalized with folic acid (PHEA-EDA-FA), have been synthesized to act as coating agents for GNRs. The obtained polymer-coated GNRs were characterized in terms of size, shape, zeta potential, chemical composition, and aqueous stability. They protected the anticancer drug nutlin-3 and were able to deliver it efficiently in different physiological media. The ability of the proposed systems to selectively kill tumor cells was tested on U2OS…
Gold nanostars co-coated with the Cu(II) complex of a tetraazamacrocyclic ligand
2015
The twelve-membered tetraazamacrocyclic ligand L1 bears an appended lipoic acid unit, whose disulphide ring is an efficient grafting moiety for the surface of gold nanostars (GNS). The GNS that were used featured a localized surface plasmon resonance (LSPR) absorption at ∼800 nm, i.e. in the near infrared (NIR). We investigated different approaches for coating them with the Cu(2+) complex of L1. While the direct reaction of [CuL1](2+) with as-prepared GNS led to aggregation, an initial coating step with polyethyleneglycol-thiol (PEG-SH) was found to be advantageous. Displacement reactions were carried out on pegylated GNS either with [CuL1](2+), directly generating [Cun(L1@GNS)](2n+), or wi…
Characterization of the defect density states in MoOx for c-Si solar cell applications
2021
Thin layers of MoOx have been deposited by thermal evaporation followed by post-deposition annealing. The density of states distributions of the MoOx films were extracted deconvoluting the absorption spectra, measured by a photothermal deflection spectroscopy setup, including the small polaron contribution. Results revealed a sub-band defect distribution centered 1.1 eV below the conduction band; the amplitude of this distribution was found to increase with post-deposition annealing temperature and film thickness.
Folic acid-functionalized graphene oxide nanosheets via plasma etching as a platform to combine NIR anticancer phototherapy and targeted drug deliver…
2020
PEGylated graphene oxide (GO) has shown potential as NIR converting agent to produce local heat useful in breast cancer therapy, since its suitable photothermal conversion, high stability in physiological fluids, biocompatibility and huge specific surface. GO is an appealing nanomaterial for potential clinical applications combining drug delivery and photothermal therapy in a single nano-device capable of specifically targeting breast cancer cells. However, native GO sheets have large dimensions (0.5-5 mu m) such that tumor accumulation after a systemic administration is usually precluded. Herein, we report a step-by-step synthesis of folic acid-functionalized PEGylated GO, henceforth named…
Visible photothermal deflection spectroscopy using microcantilevers
2012
International audience; Photothermal deflection spectroscopy based on bi-material cantilevers combines the sensitivity of miniature sensors and the selectivity of optical spectroscopy. In this paper, we report on the photothermal response of the microcantilevers functionalized with nanometer thin organic films in the visible region. Unlike responses in the infrared regime, in the optical region, light absorption by all the cantilever constituents must be considered for extraction of the physical parameters of the organic layer. A model of photothermal deflection for the optical region has been developed for two absorbing layers consisting of a thick metal (>200 nm) and a thin organic film. …
Photothermal excitation setup for a modified commercial atomic force microscope
2014
High-resolution imaging in liquids using frequency modulation atomic force microscopy is known to suffer from additional peaks in the resonance spectrum that are unrelated to the cantilever resonance. These unwanted peaks are caused by acoustic modes of the liquid and the setup arising from the indirect oscillation excitation by a piezoelectric transducer. Photothermal excitation has been identified as a suitable method for exciting the cantilever in a direct manner. Here, we present a simple design for implementing photothermal excitation in a modified Multimode scan head from Bruker. Our approach is based on adding a few components only to keep the modifications as simple as possible and …
Photothermal Ablation of Cancer Cells Using Folate-Coated Gold/ Graphene Oxide Composite
2017
Objective: A new tumor targeted polymer-coated gold/graphene hybrid has been developed for achieving simultaneously thermoablation and chemoterapy of folate receptor-positive cancer cells. Methods: The gold/graphene hybrid was prepared by depositing gold nanospheres onto graphene oxide and coating it with an inulin-folate conjugate. Paclitaxel was loaded by sonication. The hybrid was characterized by UV-Vis spectroscopy, DSC analysis and SEM microscopy. The cytotoxicity, thermoablation and anticancer activity were evaluated in vitro on MCF-7 and 16 HBE. Results: In vitro tests showed that the paclitaxel-loaded hybrid improved the effectiveness of the drug especially after photothermal treat…