Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Application of femtosecond ultrashort pulse laser to photodynamic therapy mediated by indocyanine green.

ABSTRACT: BACKGROUND/AIMS: To evaluate treatment with high peak power pulse energy by femtosecond ultrashort pulse laser (titanium sapphire laser) delivered at an 800 nm wavelength for corneal neovascularisation using photodynamic therapy (PDT) mediated by indocyanine green (ICG). METHODS: Using a gelatin solid as an in vitro corneal model, the safety of laser power was studied to determine if it degenerated gelatin with or without ICG. The authors then induced corneal neovascularisation in rabbit eyes by an intracorneal suturing technique. Fluorescein angiography was used to evaluate occlusion before PDT and 0, 1, 3, and 10 days after PDT. The authors performed light microscopy with haematoxylin eosin staining and transmission electron microscopy to determine thrombosis formation in the neovascular regions. RESULTS: The threshold of peak laser power density ranged from 39 to 53 W/cm(2). Laser irradiation was started 30 seconds after a 10 mg/kg ICG injection, and all irradiated segments were occluded at 0, 1, 3, and 10 days at 3.8 J/cm(2). Light and electron microscopy documented thrombosis formation in the neovascular region. CONCLUSION: Femtosecond pulse laser enhanced by ICG can be used for PDT. Because of effective closure of corneal neovascularisation at a low energy level, the high peak power pulse energy of the femtosecond pulse laser might be more efficacious than continuous wave laser for use with PDT.

SUBMITTER: Sawa M

PROVIDER: S-EPMC1772167 | biostudies-other | 2004 Jun

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Indocyanine Green-Mediated Photodynamic Therapy Reduces Methicillin-Resistant Staphylococcus aureus Drug Resistance.

Project description:Methicillin-resistant Staphylococcus aureus (MRSA) skin-wound infections are associated with considerable morbidity and mortality. Indocyanine green (ICG), a safe and inexpensive dye used in clinical imaging, can be activated by near-infrared in photodynamic therapy (PDT) and photothermal therapy (PTT) to effectively kill MRSA. However, how this treatment affects MRSA drug sensitivity remains unknown. The drug-sensitivity phenotypes, bacterial growth rate, and cell-wall thickness of three MRSA strains were analyzed after ICG-PDT. Drug-resistant gene expressions were determined by polymerase chain reaction (PCR) and quantitative reverse transcription (qRT)-PCR. Related protein expressions were examined with immunoblotting. Drug sensitivity was further evaluated in animal models. MRSA that survived the treatment grew faster, and the cell wall became thinner compared to parental cells. These cells became more sensitive to oxacillin, which was partly related to mecA complex gene deletion. Skin necrosis caused by ICG-PDT-treated MRSA infection was smaller and healed faster than that infected with parental cells. With oxacillin therapy, no bacteria could be isolated from mouse lung tissue infected with ICG-PDT-treated MRSA. ICG-PDT drives MRSA toward an oxacillin-sensitive phenotype. It has the potential to develop into an alternative or adjuvant clinical treatment against MRSA wound infections.

| S-EPMC6463108 | biostudies-literature

Indocyanine green-mediated antimicrobial photodynamic therapy as an adjunct to periodontal therapy: a systematic review and meta-analysis.

Project description:ObjectivesThe aim of this systematic review and meta-analysis was to evaluate the efficacy of indocyanine green-mediated photodynamic therapy (ICG-PDT) as an adjunct to non-surgical periodontal therapy (NSPT), in the management of chronic periodontitis.Materials and methodsFour electronic databases (PubMed, Cochrane Central Register of Controlled Trials, Embase via OVID, Web of Science) were searched for randomised controlled trials comparing NSPT with ICG-PDT to NSPT without laser therapy. Primary outcome measures were changes in probing pocket depth (PPD) and clinical attachment level (CAL). Clinical outcomes were extracted and pooled from 7 eligible trials and meta-analyses conducted using mean difference with standard deviations.ResultsFor PPD, adjunctive ICG-PDT resulted in a mean additional reduction of 1.17 mm (95% CI: 0.67-1.66 mm) at 3 months and a mean additional reduction of 1.06 mm (95% CI: 0.54-1.57 mm) at 6 months. For CAL, adjunctive ICG-PDT resulted in a mean additional gain of 0.70 mm (95% CI: 0.17-1.23 mm) at 3 months and a mean additional gain of 1.03 mm (95% CI: 0.83-1.24 mm) at 6 months. No adverse events were reported in any studies.ConclusionsThe adjunctive use of ICG-PDT in NSPT results in improved treatment outcomes at 3 and 6 months post-therapy. Further investigation is needed to evaluate variables such as different photosensitiser concentrations and adjusting parameters associated with the light source.Clinical relevanceIndocyanine green-based photosensitisers may be a novel, clinically efficacious agent for use in the management of periodontitis.

| S-EPMC8443506 | biostudies-literature

Femtosecond pulsed laser photodynamic therapy activates melanin and eradicates malignant melanoma.

Project description:Photodynamic therapy (PDT) relies on a series of photophysical and photochemical reactions leading to cell death. While effective for various cancers, PDT has been less successful in treating pigmented melanoma due to high light absorption by melanin. Here, this limitation is addressed by 2-photon excitation of the photosensitizer (2p-PDT) using ~100 fs pulses of near-infrared laser light. A critical role of melanin in enabling rather than hindering 2p-PDT is elucidated using pigmented and non-pigmented murine melanoma clonal cell lines in vitro. The photocytotoxicities were compared between a clinical photosensitizer (Visudyne) and a porphyrin dimer (Oxdime) with ~600-fold higher σ2p value. Unexpectedly, while the 1p-PDT responses are similar in both cell lines, 2p activation is much more effective in killing pigmented than non-pigmented cells, suggesting a dominant role of melanin 2p-PDT. The potential for clinical translational is demonstrated in a conjunctival melanoma model in vivo, where complete eradication of small tumors was achieved. This work elucidates the melanin contribution in multi-photon PDT enabling significant advancement of light-based treatments that have previously been considered unsuitable in pigmented tumors.

| S-EPMC10998568 | biostudies-literature

Ultrashort spin-orbit torque generated by femtosecond laser pulses.

Project description:To realize the very objective of spintronics, namely the development of ultra-high frequency and energy-efficient electronic devices, an ultrafast and scalable approach to switch magnetic bits is required. Magnetization switching with spin currents generated by the spin-orbit interaction at ferromagnetic/non-magnetic interfaces is one of such scalable approaches, where the ultimate switching speed is limited by the Larmor precession frequency. Understanding the magnetization precession dynamics induced by spin-orbit torques (SOTs) is therefore of great importance. Here we demonstrate generation of ultrashort SOT pulses that excite Larmor precession at an epitaxial Fe/GaAs interface by converting femtosecond laser pulses into high-amplitude current pulses in an electrically biased p-i-n photodiode. We control the polarity, amplitude, and duration of the current pulses and, most importantly, also their propagation direction with respect to the crystal orientation. The SOT origin of the excited Larmor precession was revealed by a detailed analysis of the precession phase and amplitude at different experimental conditions.

| S-EPMC9747954 | biostudies-literature

Indocyanine Green-Conjugated Magnetic Prussian Blue Nanoparticles for Synchronous Photothermal/Photodynamic Tumor Therapy.

Project description:Indocyanine green (ICG) is capable of inducing a photothermal effect and the production of cytotoxic reactive oxygen species for cancer therapy. However, the major challenge in applying ICG molecules for antitumor therapy is associated with their instability in aqueous conditions and rapid clearance from blood circulation, which causes insufficient bioavailability at the tumor site. Herein, we conjugated ICG molecules with Prussian blue nanoparticles enclosing a Fe3O4 nanocore, which was facilitated by cationic polyethyleneimine via electrostatic adsorption. The nanocarrier-loaded ICG formed stable aggregates that enhanced cellular uptake and prevented fluorescence quenching. Moreover, the strong superparamagnetism of the Fe3O4 core in the obtained nanocomposites further improved cellular internalization of the drugs guided by a localized magnetic field. The therapeutic efficacy of this nanoplatform was evaluated using tumor models established in nude mice, which demonstrated remarkable tumor ablation in vivo due to strong photothermal/photodynamic effects. This study provides promising evidence that this multifunctional nanoagent might function as an efficient mediator for combining photothermal and photodynamic cancer therapy.

| S-EPMC6208784 | biostudies-literature

Indocyanine green assembled free oxygen-nanobubbles towards enhanced near-infrared induced photodynamic therapy.

Project description:Photodynamic therapy (PDT) has shown a promising capability for cancer treatment with minimal side effects. Indocyanine green (ICG), the only clinically approved near-infrared (NIR) fluorophore, has been used as a photosensitizer for PDT in clinical application. However, the main obstacle of directly utilizing ICG in the clinic lies in its low singlet oxygen (1O2) quantum yield (QY) and instability in aqueous solution. To improve the PDT efficacy of ICG, free ICG molecules were assembled with free oxygen nanobubbles (NBs-O2) to fabricate ICG-NBs-O2 by hydrophilic-hydrophobe interactions on the gas-liquid interface. Interestingly, 1O2 QY of ICG-NBs-O2 solution was significantly increased to 1.6%, which was estimated to be 8 times as high as that of free ICG solution. Meanwhile, ICG-NBs-O2 exhibited better aqueous solution stability compared with free ICG. Furthermore, through establishing tumor models in nude mice, the therapeutic efficacy of ICG-NBs-O2 was also assessed in the PDT treatment of oral cancer. The tumor volume in ICG-NBs-O2 treated group on day 14 decreased to 0.56 of the initial tumor size on day 1, while the tumor volume in free ICG treated group increased to 2.4 times. The results demonstrated that ICG-NBs-O2 showed excellent tumor ablation in vivo. Therefore, this facile method provided an effective strategy for enhanced PDT treatment of ICG and showed great potential in clinical application.Electronic supplementary materialSupplementary material (measurements of the singlet oxygen quantum yield of ICG-NBs-O2, time-dependent temperature changes during the laser irradiation, photographs of Cal27 tumor-bearing nude mice and complete blood count of health male balb/c mice analysis) is available in the online version of this article at 10.1007/s12274-022-4085-0.

| S-EPMC8800431 | biostudies-literature

Cu-Hemin Nanosheets and Indocyanine Green Co-Loaded Hydrogel for Photothermal Therapy and Amplified Photodynamic Therapy.

Project description:Near-infrared (NIR) organic small molecule indocyanine green (ICG) could respond well to 808 nm laser to promote local high temperature and ROS generation for realizing photothermal therapy (PTT)/photodynamic therapy (PDT). However, the high content of GSH in the tumor microenvironment (TME) limited the further therapeutic performance of ICG. Herein, injectable agarose in situ forming NIR-responsive hydrogels (CIH) incorporating Cu-Hemin and ICG were prepared for the first time. When CIH system was located to the tumor tissue through local injection, the ICG in the hydrogel could efficiently convert the light energy emitted by the 808 nm laser into thermal energy, resulting in the heating and softening of the hydrogel matrix, which releases the Cu-Hemin. Then, the over-expressed GSH in the TME could also down-regulated by Cu-Hemin, which amplified ICG-mediated PDT. In vivo experiments validated that ICG-based PDT/PTT and Cu-Hemin-mediated glutathione depletion could eliminate cancer tissues with admirable safety. This hydrogel-based GSH-depletion strategy is instructive to improve the objective response rate of PDT.

| S-EPMC9280130 | biostudies-literature

Photodynamic therapy using nanoparticle loaded with indocyanine green for experimental peritoneal dissemination of gastric cancer.

Project description:Although there have been multiple advances in the development of novel anticancer agents and operative procedures, prognosis of patients with advanced gastric cancer remains poor, especially in patients with peritoneal metastasis. In this study, we established nanoparticles loaded with indocyanine green (ICG) derivatives: ICG loaded lactosomes (ICGm) and investigated the diagnostic and therapeutic value of photodynamic therapy (PDT) using ICGm for experimental peritoneal dissemination of gastric cancer. Experimental peritoneal disseminated xenografts of human gastric cancer were established in nude mice. Three weeks after intraperitoneal injection of the cancer cells, either ICGm (ICGm-treated mice) or ICG solution (ICG-treated mice) was injected through the tail vein. Forty-eight hours after injection of the photosensitizer, in vivo and ex vivo imaging was carried out. For PDT, 48 h after injection of the photosensitizer, other mice were irradiated through the abdominal wall, and the body weight and survival rate were monitored. In vivo imaging revealed that peritoneal tumors were visualized through the abdominal wall in ICGm-treated mice, whereas only non-specific fluorescence was observed in ICG-treated mice. The PDT reduced the total weight of the disseminated nodules and significantly improved weight loss and survival rate in ICGm-treated mice. In conclusion, ICGm can be used as a novel diagnostic and therapeutic nanodevice in peritoneal dissemination of gastric cancer.

| S-EPMC4317961 | biostudies-literature

Femtosecond-Laser-Pulse Characterization and Optimization for CARS Microscopy.

Project description:We present a simple method and its experimental implementation to determine the pulse durations and linear chirps of the pump-and-probe pulse and the Stokes pulse in a coherent anti-Stokes Raman scattering microscope at sample level without additional autocorrelators. Our approach exploits the delay line, ubiquitous in such microscopes, to perform a convolution of the pump-and-probe and Stokes pulses as a function of their relative delay and it is based on the detection of the photons emitted from an appropriate non-linear sample. The analysis of the non-resonant four-wave-mixing and sum-frequency-generation signals allows for the direct retrieval of the pulse duration on the sample and the linear chirp of each pulse. This knowledge is crucial in maximizing the spectral-resolution and contrast in CARS imaging.

| S-EPMC4880195 | biostudies-literature

Testing of a femtosecond pulse laser in outer space.

Project description:We report a test operation of an Er-doped fibre femtosecond laser which was conducted for the first time in outer space. The fibre-based ultrashort pulse laser payload was designed to meet space-use requirements, undergone through ground qualification tests and finally launched into a low-earth orbit early in 2013. Test results obtained during a one-year mission lifetime confirmed stable mode-locking all the way through although the radiation induced attenuation (RIA) in the Er-doped gain fibre caused an 8.6% reduction in the output power. This successful test operation would help facilitate diverse scientific and technological applications of femtosecond lasers in space and earth atmosphere in the near future.

| S-EPMC4038913 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data