scholarly journals Optimising gold nanorods for photoacoustic imaging in vitro

2019 ◽  
Vol 1 (4) ◽  
pp. 1472-1481 ◽  
Author(s):  
Oscar B. Knights ◽  
Sunjie Ye ◽  
Nicola Ingram ◽  
Steven Freear ◽  
James R. McLaughlan
Keyword(s):  
Gold Nanorods ◽  
Photoacoustic Imaging ◽  
Gold Nanorod ◽  
Aspect Ratios

A study to find the optimum sized gold nanorod for use in PA imaging and/or optical-based theranostics, by comparing four different sizes with similar aspect ratios.

scholarly journals In vitro toxicity and bioimaging studies of gold nanorods formulations coated with biofunctional thiol-PEG molecules and Pluronic block copolymers

2014 ◽  
Vol 5 ◽  
pp. 546-553 ◽  
Author(s):  
Tianxun Gong ◽  
Douglas Goh ◽  
Malini Olivo ◽  
Ken-Tye Yong
Keyword(s):  
Gold Nanorods ◽  
Colloidal Stability ◽  
Dark Field ◽  
Solution Phase ◽  
In Vitro Toxicity ◽  
Visible Absorption ◽  
Aspect Ratios ◽  
Biological Studies

In this work, we investigated the cytotoxicity, colloidal stability and optical property of gold nanorods before and after functionalizing them with thiolated PEG and Pluronic triblock copolymer (PEO–PPO–PEO) molecules. The morphology of functionalized gold nanorods was characterized by UV–visible absorption spectroscopy, transmission electron microscopy, and dynamic light scattering. Solution phase synthesis of gold nanorods has remained the method of choice for obtaining varying shapes and aspect ratios of rod nanoparticles. This method typically involves the use of cetyltrimethylammonium bromide (CTAB) surfactants as directing agents to grow gold nanorods in the solution phase. The as-synthesized gold nanorods surfaces are terminated with CTAB molecules and this formulation gives rise to adverse toxicity in vitro and in vivo. To employ the gold nanorods for biological studies, it is important to eliminate or minimize the exposure of CTAB molecules from the gold nanorods surface to the local environment such as cells or tissues. Complete removal of CTAB molecules from the gold nanorods surface is unfeasible as this will render the gold nanorods structurally unstable, causing the aggregation of particles. Here, we investigate the individual use of thiolated PEG and PEO–PPO–PEO as capping agents to reduce the cytotoxicity of gold nanorods formulation, while maintaining the optical, colloidal, and structural properties of gold nanorods. We found that encapsulating gold nanorods with the thiolated PEG or PEO–PPO–PEO molecules guarantees the stability and biocompatibility of the nanoformulation. However, excessive use of these molecules during the passivation process leads to a reduction in the overall cell viability. We also demonstrate the use of the functionalized gold nanorods as scattering probes for dark-field imaging of cancer cells thereby demonstrating their biocompatibility. Our results offer a unique solution for the future development of safe scattering color probes for clinical applications such as the long term imaging of cells and tissues.

Study on the sensitivity enhancement of fiber SPR sensor by gold nanorods

Sensor Review ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Rui Wang ◽  
Chunlan Liu ◽  
Yong Wei ◽  
Yudong Su
Keyword(s):  
Refractive Index ◽  
Parameter Optimization ◽  
Gold Nanorods ◽  
Sensitivity Enhancement ◽  
Gold Nanorod ◽  
Enhancement Effect ◽  
Content Type ◽  
Spr Sensor ◽  
Aspect Ratios ◽  
Validation Experiments

Purpose This paper aims to study the sensitivity enhancement effect of the gold nanorod on fiber surface plasmon resonance (SPR) sensor. It proposes modeling the sensing effects of fiber SPR sensor decorated with metal nanoparticles. By using simulation and experiment, the sensitivity enhancement effect of the gold nanorod was studied and demonstrated. Design/methodology/approach The paper opted for an exploratory study using simulation approach of finite-difference time-domain. Specifically, the effect of ratios and aspect ratios of gold nanorod on sensing performance are investigated theoretically. Based on the mathematical models, the validation experiments by using the gold nanorod with the aspect ratios of 5.1 were done to verify the sensitivity enhancement effect of the gold nanorod. Findings In conclusion, it is evident that with the increases of the aspect ratios, the sensing sensitivity of the refractive index increases first, then gradually stabilizes or decreases. After parameter optimization, the ratios and aspect ratios of gold nanorod are chosen to be 8 nm and 12.5, respectively, which makes the optimal refractive index sensitivity of 4465.53 nm/RIU be realized. In addition, the validation experiments by using the gold nanorod with the aspect ratios of 5.1 verify the sensitivity enhancement effect of the gold nanorods. Originality/value This paper proposes and demonstrates a new method for the sensitivity enhancement of fiber SPR sensor. After parameter optimization, the maximum sensitivity of 4465.53 nm/RIU was achieved by using 8 nm gold nanorods with the aspect ratios of 12.5. To verify the sensitivity enhancement of the gold nanorods, the authors also did the validation experiments. The testing results indicated that after the decoration of the gold nanorods, the sensitivity of the sensing probe increases from 2190.57 nm/RIU to 2693.24 nm/RIU, which demonstrates the sensitivity enhancement effect of the gold nanorods.

scholarly journals In Vitro and In Vivo Multispectral Photoacoustic Imaging for the Evaluation of Chromophore Concentration

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3366
Author(s):  
Aneline Dolet ◽  
Rita Ammanouil ◽  
Virginie Petrilli ◽  
Cédric Richard ◽  
Piero Tortoli ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Photoacoustic Imaging ◽  
Hyperspectral Remote Sensing ◽  
Reference Spectrum ◽  
In Vivo Experiments ◽  
Mouse Tumors ◽  
Chromophore Concentration ◽  
Saturation Rate

Multispectral photoacoustic imaging is a powerful noninvasive medical imaging technique that provides access to functional information. In this study, a set of methods is proposed and validated, with experimental multispectral photoacoustic images used to estimate the concentration of chromophores. The unmixing techniques used in this paper consist of two steps: (1) automatic extraction of the reference spectrum of each pure chromophore; and (2) abundance calculation of each pure chromophore from the estimated reference spectra. The compared strategies bring positivity and sum-to-one constraints, from the hyperspectral remote sensing field to multispectral photoacoustic, to evaluate chromophore concentration. Particularly, the study extracts the endmembers and compares the algorithms from the hyperspectral remote sensing domain and a dedicated algorithm for segmentation of multispectral photoacoustic data to this end. First, these strategies are tested with dilution and mixing of chromophores on colored 4% agar phantom data. Then, some preliminary in vivo experiments are performed. These consist of estimations of the oxygen saturation rate (sO2) in mouse tumors. This article proposes then a proof-of-concept of the interest to bring hyperspectral remote sensing algorithms to multispectral photoacoustic imaging for the estimation of chromophore concentration.

scholarly journals Effective replacement of cetyltrimethylammonium bromide (CTAB) by mercaptoalkanoic acids on gold nanorod (AuNR) surfaces in aqueous solutions

Nanoscale ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 658-668 ◽  
Author(s):  
Rafael del Caño ◽  
Jose M. Gisbert-González ◽  
Jose González-Rodríguez ◽  
Guadalupe Sánchez-Obrero ◽  
Rafael Madueño ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Gold Nanorods ◽  
Ligand Exchange ◽  
Cetyltrimethylammonium Bromide ◽  
Gold Nanorod ◽  
Experimental Conditions ◽  
Seed Mediated ◽  
The Stability

The highly packed cetyltrimethylammonium bromide bilayer on the surface of gold nanorods synthesized by the seed-mediated procedure hampers the complete ligand exchange under experimental conditions that preserves the stability of the dispersions.

The influence of different geometries of matrix/scaffold on the remodeling process of a bone and bioresorbable material mixture with voids

2015 ◽  
Vol 22 (5) ◽  
pp. 969-987 ◽  
Author(s):  
Ivan Giorgio ◽  
Ugo Andreaus ◽  
Tomasz Lekszycki ◽  
Alessandro Della Corte
Keyword(s):  
Bone Growth ◽  
Matrix Material ◽  
Porous Solids ◽  
Artificial Material ◽  
Matrix Deposition ◽  
Aspect Ratios ◽  
Adopted Model ◽  
The Matrix ◽  
Bioresorbable Material

Since internal architecture greatly influences crucial factors for tissue regeneration, such as nutrient diffusion, cell adhesion and matrix deposition, scaffolds have to be carefully designed, keeping in mind case-specific mechanical, mass transport and biological requirements. However, customizing scaffold architecture to better suit conflicting requirements, such as biological and mechanical ones, remains a challenging issue. Recent advances in printing technologies, together with the synthesis of novel composite biomaterials, have enabled the fabrication of various scaffolds with defined shape and controlled in vitro behavior. Thus, the influence of different geometries of the assemblage of the matrix and scaffold on the remodeling processes of living bone and artificial material should be investigated. To this end, two implant shapes are considered in this paper, namely a circular inclusion and a rectangular groove of different aspect ratios. A model of a mixture of bone tissue and bioresorbable material with voids was used to numerically analyze the physiological balance between the processes of bone growth and resorption and artificial material resorption in a plate-like sample. The adopted model was derived from a theory for the behavior of porous solids in which the matrix material is elastic and the interstices are void of material.

scholarly journals Direct formation of gold nanorods on surfaces using polymer-immobilised gold seeds

2016 ◽  
Vol 7 ◽  
pp. 809-816 ◽  
Author(s):  
Majid K Abyaneh ◽  
Pietro Parisse ◽  
Loredana Casalis
Keyword(s):  
Gold Nanorods ◽  
Growth Control ◽  
Weight Ratio ◽  
Polymer Nanocomposite ◽  
Gold Salt ◽  
Aspect Ratios ◽  
Direct Formation ◽  
Growth Method ◽  
Direct Growth ◽  
Gold Seed

Herein, we present the formation of gold nanorods (GNRs) on novel gold–poly(methyl methacrylate) (Au–PMMA) nanocomposite substrates with unprecedented growth control through the polymer molecular weight (M w) and gold-salt-to-polymer weight ratio. For the first time, GNRs have been produced by seed-mediated direct growth on surfaces that were pre-coated with polymer-immobilised gold seeds. A Au–PMMA nanocomposite formed by UV photoreduction has been used as the gold seed. The influence of polymer M w and gold concentration on the formation of GNRs has been investigated and discussed. The polymer nanocomposite formed with a lower M w PMMA and 20 wt % gold salt provides a suitable medium for growing well-dispersed GNRs. In this sample, the average dimension of produced GNRs is 200 nm in length with aspect ratios up to 10 and a distribution of GNRs to nanoparticles of nearly 22%. Suitable characterization techniques such as AFM and SEM have been used to support concept of the proposed growth method.

Optimum morphology of gold nanorods for light-induced hyperthermia

Nanoscale ◽  
2018 ◽  
Vol 10 (5) ◽  
pp. 2632-2638 ◽  
Author(s):  
Jordi Morales-Dalmau ◽  
Clara Vilches ◽  
Ignacio de Miguel ◽  
Vanesa Sanz ◽  
Romain Quidant
Keyword(s):  
Gold Nanorods ◽  
Systematic Study ◽  
Gold Nanorod ◽  
Cellular Toxicity ◽  
Induced Hyperthermia

A systematic study of the influence of gold nanorod morphology on cellular toxicity, uptake and light to heat conversion.

Polymeric/Inorganic Multifunctional Nanoparticles for Simultaneous Drug Delivery and Visualization

2010 ◽  
Vol 1257 ◽  
Author(s):  
Andrea Fornara ◽  
Alberto Recalenda ◽  
Jian Qin ◽  
Abhilash Sugunan ◽  
Fei Ye ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Fluorescence Microscopy ◽  
Contrast Agents ◽  
Gold Nanorods ◽  
In Vitro Cytotoxicity ◽  
In Vivo Studies ◽  
Multifunctional Nanoparticles ◽  
Cytotoxicity Studies

AbstractNanoparticles consisting of different biocompatible materials are attracting a lot of interest in the biomedical area as useful tools for drug delivery, photo-therapy and contrast enhancement agents in MRI, fluorescence and confocal microscopy. This work mainly focuses on the synthesis of polymeric/inorganic multifunctional nanoparticles (PIMN) based on biocompatible di-block copolymer poly(L,L-lactide-co-ethylene glycol) (PLLA-PEG) via an emulsion-evaporation method. Besides containing a hydrophobic drug (Indomethacin), these polymeric nanoparticles incorporate different visualization agents such as superparamagnetic iron oxide nanoparticles (SPION) and fluorescent Quantum Dots (QDs) that are used as contrast agents for Magnetic Resonance Imaging (MRI) and fluorescence microscopy together. Gold Nanorods are also incorporated in such nanostructures to allow simultaneous visualization and photodynamic therapy. MRI studies are performed with different loading of SPION into PIMN, showing an enhancement in T2 contrast superior to commercial contrast agents. Core-shell QDs absorption and emission spectra are recorded before and after their loading into PIMN. With these polymeric/inorganic multifunctional nanoparticles, both MRI visualization and confocal fluorescence microscopy studies can be performed. Gold nanorods are also synthesized and incorporated into PIMN without changing their longitudinal absorption peak usable for lased excitation and phototherapy. In-vitro cytotoxicity studies have also been performed to confirm the low cytotoxicity of PIMN for further in-vivo studies.

scholarly journals Efficient Photoacoustic Imaging With Biomimetic Mesoporous Silica-Based Nanoparticles

2021 ◽  
Vol 9 ◽  
Author(s):  
Chuangjia Huang ◽  
Xiaoling Guan ◽  
Hui Lin ◽  
Lu Liang ◽  
Yingling Miao ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Near Infrared ◽  
Ex Vivo ◽  
Photoacoustic Imaging ◽  
Mesoporous Silica Nanoparticles ◽  
Good Biocompatibility ◽  
Targeting Ability ◽  
Body Clearance

Indocyanine green (ICG), a near-infrared (NIR) fluorescent dye approved by the Food and Drug Administration (FDA), has been extensively used as a photoacoustic (PA) probe for PA imaging. However, its practical application is limited by poor photostability in water, rapid body clearance, and non-specificity. Herein, we fabricated a novel biomimetic nanoprobe by coating ICG-loaded mesoporous silica nanoparticles with the cancer cell membrane (namely, CMI) for PA imaging. This probe exhibited good dispersion, large loading efficiency, good biocompatibility, and homologous targeting ability to Hela cells in vitro. Furthermore, the in vivo and ex vivo PA imaging on Hela tumor-bearing nude mice demonstrated that CMI could accumulate in tumor tissue and display a superior PA imaging efficacy compared with free ICG. All these results demonstrated that CMI might be a promising contrast agent for PA imaging of cervical carcinoma.

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