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Cancer cella??specific protein delivery by optoporation with lasera??irradiated gold nanorods
摘要： The delivery of macromolecules into living cells is challenging since in most cases molecules are endocytosed and remain in the endo-lysosomal pathway where they are degraded before reaching their target. Here, a method is presented to selectively improve cell membrane permeability by nanosecond laser irradiation of gold nanorods (GNRs) with visible or near-infrared irradiation in order to deliver proteins across the plasma membrane, avoiding the endo lysosomal pathway. GNRs were labelled with the anti-EGFR (epidermal growth factor receptor) antibody Erbitux to target human ovarian carcinoma cells OVCAR-3. Irradiation with nanosecond laser pulses at wavelengths of 532 nm or 730 nm is used for transient permeabilization of the cell membranes. As a result of the irradiation, the uptake of an anti-Ki-67 antibody was observed in about 50 % of the cells. The results of fluorescence lifetime imaging show that the GNR detached from the membrane after irradiation.
关键词： gold nanorods,optical window,protein delivery,near infrared radiation,nanosecond pulsed laser
更新于2025-09-23 15:19:57
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Influence of the Fifth-Order Nonlinearity of Gold Nanorods on the Performance of Random Lasers
摘要： We present the first experimental evidence for the influence of the fifth-order nonlinearity on the characteristics of Random Lasers with plasmonic nanoparticles as scatterers. The experiments were performed with gold nanorods suspended in an ethanolic solution of Rhodamine 6G, pumped by a picosecond laser. It is shown that by varying the nanorods aspect-ratio, it is possible to control the cooperative influence of both transverse and longitudinal localized surface plasmons on the fifth-order nonlinear light scattering, a phenomenon that allows to manage the optical feedback causing significant changes in the threshold intensity and emission power of Random Lasers.
关键词： fifth-order nonlinearity,gold nanorods,Random Lasers,optical feedback,plasmonic nanoparticles
更新于2025-09-23 15:19:57
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Dual-Color Plasmonic Nanosensor for Radiation Dosimetry
摘要： Radiation dosimeters are critical for accurately assessing the levels of radiation exposure of tumor sites and surrounding tissues and for optimizing therapeutic interventions as well as for monitoring environmental exposure. To fill the need for a simple, user-friendly and inexpensive dosimeter, we designed an innovative colorimetric nanosensor-based assay for detecting ionizing radiation. We show that hydroxyl radicals generated by ionizing radiation can be used to etch gold nanorods (AuNRs) and silver nanoprisms (AgNPRs), yielding reproducible color changes for radiation dose detection in the range of 50-2000 Rad, broad enough to cover doses used in hyperfractionated, conventional, and hypofractionated radiotherapy. This range of doses detected by this assay correlates with radiation induced DNA damage response in mammalian cells. Furthermore, this AuNR- and AgNPR-based sensing platform has been established in a paper format that can be readily adopted for a wide range of applications and translation.
关键词： Radiation dosimetry,gold nanorods,silver nanoprisms,dual-color nanosensor,colorimetric detection
更新于2025-09-23 15:19:57
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Spatio-Spectral Characterization of Multipolar Plasmonic Modes of Au Nanorods via Tip-Enhanced Raman Scattering
摘要： Tip-enhanced Raman (TER) spectral images of 4-thiobenzonitrile-coated Au nanorods map the spatial profiles and trace the resonances of dipolar and multipolar plasmonic modes that are characteristic of the imaged particles. For any particular rod, we observe sequential transitions between high-order modes at low frequency shifts and lower-order modes at higher frequencies. We also notice that higher order modes (up to m=4) are generally observed for long rods as compared to their shorter analogues, where longitudinal dipolar resonances (m=1) are observable. In effect, this work adds a new dimension to local optical field mapping via TERS, which we have previously explored. Not only can the magnitudes, vector components, local/non-local characters of local optical fields be imaged through molecular TERS, but spatially varying local optical resonances are direct observables.
关键词： Tip-Enhanced Raman,Nano-Spectroscopy,Local Optical Fields,Gold Nanorods,Multipolar Plasmons
更新于2025-09-23 15:19:57
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Electro-optical switching in twisted nematic samples doped with gold nanorods
摘要： The present study is devoted to the investigation of reorientation properties of 8CB liquid crystal samples doped with gold nanorods with distinct aspect ratios. By using an optical experimental setup to probe the electro-optic response of twist cells under an AC electric field, we measure the characteristic switch times and Freedericksz threshold of doped nematic liquid crystals. The effects associated with the surface plasmon resonance and disorder induced by the metallic guest particles are analyzed. Further, we exploit the Gooch-Tarry conditions and Mauguin minima to account the thermal dependence of nematic birefringence in pristine and doped samples. Our results show that the electro-optical and thermal parameters of twisted nematic cells are strongly affected by the addition of gold nanorods.
关键词： Nematic liquid crystals,Gold nanorods,Reorientation
更新于2025-09-19 17:13:59
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Combination of light-driven co-delivery of chemodrugs and plasmonic-induced heat for cancer therapeutics using hybrid protein nanocapsules
摘要： Background: Improving the water solubility of hydrophobic drugs, increasing their accumulation in tumor tissue and allowing their simultaneous action by different pathways are essential issues for a successful chemotherapeutic activity in cancer treatment. Considering potential clinical application in the future, it will be promising to achieve such purposes by developing new biocompatible hybrid nanocarriers with multimodal therapeutic activity. Results: We designed and characterised a hybrid nanocarrier based on human serum albumin/chitosan nanoparticles (HSA/chitosan NPs) able to encapsulate free docetaxel (DTX) and doxorubicin?modified gold nanorods (DOXO?GNRs) to simultaneously exploit the complementary chemotherapeutic activities of both antineoplasic compounds together with the plasmonic optical properties of the embedded GNRs for plasmonic?based photothermal therapy (PPTT). DOXO was assembled onto GNR surfaces following a layer?by?layer (LbL) coating strategy, which allowed to partially control its release quasi?independently release regarding DTX under the use of near infrared (NIR)?light laser stimulation of GNRs. In vitro cytotoxicity experiments using triple negative breast MDA?MB?231 cancer cells showed that the developed dual drug encapsulation approach produces a strong synergistic toxic effect to tumoral cells compared to the administration of the combined free drugs; additionally, PPTT enhances the cytostatic efficacy allowing cell toxicities close to 90% after a single low irradiation dose and keeping apoptosis as the main cell death mechanism. Conclusions: This work demonstrates that by means of a rational design, a single hybrid nanoconstruct can simultaneously supply complementary therapeutic strategies to treat tumors and, in particular, metastatic breast cancers with good results making use of its stimuli?responsiveness as well as its inherent physico?chemical properties.
关键词： Multimodal therapy,Gold nanorods,Photo?therapy,Stimuli?responsiveness,Human serum albumin nanoparticles
更新于2025-09-19 17:13:59
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Single-Cell ATP Content Monitoring during Hyperthermia Cell Death by using Plasmonic Fluorescent Nanoflare
摘要： Gold nanorods-based plasmonic photothermal therapy (AuNRs-PPTT) has been a prospective anti-cancer approach in which AuNRs absorbs near-infrared (NIR) light and converts it into heat, leading to cell death. Investigating molecular energy metabolism of single cells, especially cancer cells, during hyperthermia cell death process is therefore of great significance, as it can help us to better understand the photothermal lethal mechanism of cancer cells and design new photothermal probes more rationally. However, during the AuNRs-PPTT process, how the cells respond to heat stimulation, and how their energy metabolism changes, these basic issues have rarely been studied. Herein, we selected adenosine triphosphate (ATP) as a target molecule, and by preparing a plasmonic and turn-on type fluorescent nanoprobe we examined the ATP metabolism difference between cancerous cells and normal cells during the AuNRs-PPTT process. We found that the fluorescence intensity increased ~ 60% after 5 min laser irradiation as compared to the initial intensity in single HeLa cells, but only ~ 20% increasement was observed for single H8 cells; obviously the increase of ATP content in cancerous cells was notably higher than that in normal cells during the hyperthermia cell death.
关键词： Plasmonic photothermal therapy,Fluorescent nanoprobe,ATP,Gold nanorods,Hyperthermia cell death
更新于2025-09-19 17:13:59
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Fabrication of gold nanorod arrays on a cylindrical surface of optical fibers by using in-situ electrodeposition
摘要： Optical fiber is an excellent light-coupled substrate, which has the characteristics of large a length-diameter ratio with a cylindrical surface. Recently, various methods have been reported in order to improve the ability of local optical fields. In particular, methods aimed to address the efficient coupling and optical resonances by modifying metal nanostructures on the light-coupled substrate have been developed. However, existing methods are largely applicable to planar or tip substrates, and it remains a significant challenge to prepare metal nanostructures on a cylindrical substrate. In this study, we proposed a novel strategy to fabricate gold nanorods arrays (AuNRs) by electrodepositing them in anodized aluminum oxide (AAO) templates on the cylindrical surface of optical fibers. Briefly, AAO templates were prepared in-situ by using a constant current density secondary oxidation method on the cylindrical surface of optical fibers, and then the AuNRs were in-situ deposited in the AAO templates by electrodeposition. The features of the AuNRs such as diameter, nanorod pitch, and height could be easily regulated by adjusting the parameters of electrodeposition and the anode oxidation. The SEM images demonstrates that AuNRs exhibit a satisfactory consistency with a uniform diameter and favorable self-supporting properties. The relationships between the current density, pore diameter and pore distribution were explored, combined with the voltage-time curve during anodic oxidation. Furthermore, the surface plasmon resonance (SPR) optical properties of the AuNRs on the cylindrical surface were analyzed using the Finite-difference Time-domain Algorithm (FDTD) method. Results suggest that this alternative in-situ electrodeposition strategy has the potentials to be applied to SPR optical fiber sensing.
关键词： Gold nanorods arrays,Finite-difference time-domain algorithm,In-situ electrodeposition,Cylindrical surface of optical fibers,Anodized aluminum oxide templates
更新于2025-09-19 17:13:59
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Erythrocyte membrane nano-capsules: biomimetic delivery and controlled release of photothermala??photochemical coupling agents for cancer cell therapy
摘要： Photothermal therapy (PTT), which involves an increase in temperature triggered only by light signals at tumor sites to remove cancer cells, has been considered an attractive strategy in cancer therapy. Nevertheless, the in vivo applications of photosensitizer-based PTT are limited due to the poor biocompatibility of photothermal agents. Employing red blood cell (RBC) membranes to encapsulate photothermal agents can solve this issue, but the extra surface coating will suppress heat dissipation, which is unfavorable for the subsequent treatment. Herein, biomimetic nano-capsules have been fabricated for light signal-activated cancer therapy by encapsulating photocatalyst titanium dioxide colloid and photothermal agent gold nanorods (Au NRs) in erythrocyte membrane vesicles. The fabricated Au/TiO2@RBC nano-capsules can achieve the controlled release of Au NRs upon the photocatalytic degradation of their surface cell membrane coatings, and generate therapeutic signals after the released Au NRs are irradiated by an NIR laser. Meanwhile, the reactive oxygen species (ROS) produced by photocatalysis are helpful for killing tumor cells photodynamically. Thus, the biomimetic nano-capsules prepared herein will contribute to the research and development in cancer cell therapy.
关键词： cancer therapy,titanium dioxide,red blood cell membranes,biomimetic nano-capsules,gold nanorods,Photothermal therapy
更新于2025-09-19 17:13:59
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Freeze‐Facilitated Ligand Binding to Plasmonic Gold Nanorods
摘要： Gold nanorods (AuNRs) are an important class of advanced plasmonic materials, but unlike gold nanospheres (AuNSs) their surface modification is difficult due to the specific surfactant layer of cetyltrimethylammonium bromide (CTAB) resulted from the synthesis. In this paper, a freeze-induced surface modification strategy is proposed for AuNRs. Freezing AuNRs right after a simple wash step can facilitate binding of surface ligands and allow assembly of functional biointerface in a fast time scale. This strategy is simple, fast, versatile, and robust, allowing attachments of different ligand molecules, including organic dyes, poly(ethylene glycol)s (PEGs), and DNAs onto AuNRs without additional reagent. An optimal condition for DNA loading is determined with a matrix driven approach. It is shown that the attached ligand molecules are functional, allowing formation of core–satellite type structures using DNAs linking to AuNSs, or high-density vertical superlattice arrays using PEGylated AuNRs.
关键词： DNA,surface modification,gold nanorods,surface ligands
更新于2025-09-19 17:13:59