scholarly journals Photoacoustic Properties of Polypyrrole Nanoparticles

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2457
Author(s):  
Peter Keša ◽  
Monika Paúrová ◽  
Michal Babič ◽  
Tomáš Heizer ◽  
Petr Matouš ◽  
...  
Keyword(s):  
Contrast Agent ◽  
Photoacoustic Imaging ◽  
Particle Surface ◽  
Photoacoustic Signal ◽  
Ammonium Persulphate ◽  
Coated Nanoparticles ◽  
Polypyrrole Nanoparticles ◽  
Signal Dependence

Photoacoustic imaging, an emerging modality, provides supplemental information to ultrasound imaging. We investigated the properties of polypyrrole nanoparticles, which considerably enhance contrast in photoacoustic images, in relation to the synthesis procedure and to their size. We prepared polypyrrole nanoparticles by water-based redox precipitation polymerization in the presence of ammonium persulphate (ratio nPy:nOxi 1:0.5, 1:1, 1:2, 1:3, 1:5) or iron(III) chloride (nPy:nOxi 1:2.3) acting as an oxidant. To stabilize growing nanoparticles, non-ionic polyvinylpyrrolidone was used. The nanoparticles were characterized and tested as a photoacoustic contrast agent in vitro on an imaging platform combining ultrasound and photoacoustic imaging. High photoacoustic signals were obtained with lower ratios of the oxidant (nPy:nAPS ≥ 1:2), which corresponded to higher number of conjugated bonds in the polymer. The increasing portion of oxidized structures probably shifted the absorption spectra towards shorter wavelengths. A strong photoacoustic signal dependence on the nanoparticle size was revealed; the signal linearly increased with particle surface. Coated nanoparticles were also tested in vivo on a mouse model. To conclude, polypyrrole nanoparticles represent a promising contrast agent for photoacoustic imaging. Variations in the preparation result in varying photoacoustic properties related to their structure and allow to optimize the nanoparticles for in vivo imaging.

scholarly journals A General Approach to Convert Hemicyanine Dyes into Highly Optimized Photoacoustic Scaffolds for Analyte Sensing

2021 ◽  
Author(s):  
Sarah Garder ◽  
Catharine Brady ◽  
Cameron Keeton ◽  
Anuj K Yadav ◽  
Sharath C Mallojjala ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Photoacoustic Imaging ◽  
Disease Model ◽  
Photoacoustic Signal ◽  
Model Of Alzheimer’S Disease ◽  
5Xfad Mice ◽  
The Impact

<p>In the context of deep-tissue disease biomarker detection and analyte sensing of biologically relevant species, the impact of photoacoustic imaging has been profound. However, most photoacoustic imaging agents to date are based on the repurposing of existing fluorescent dye platforms that exhibit non-optimal properties for photoacoustic applications (e.g., high fluorescence quantum yield). Herein, we introduce two effective modifications to the hemicyanine dye to afford PA-HD, a new dye scaffold optimized for photoacoustic probe development. We observed a significant increase in the photoacoustic output, representing an increase in sensitivity of 4.8-fold and a red-shift of the λ<sub>abs</sub> from 690 nm to 745 nm to enable ratiometric imaging. Moreover, to demonstrate the generalizability and utility of our remodeling efforts, we developed three probes using common analyte-responsive triggers for beta-galactosidase activity (PA-HD-Gal), nitroreductase activity (PA-HD-NTR), and hydrogen peroxide (PA-HD-H<sub>2</sub>O<sub>2</sub>). The performance of each probe (responsiveness, selectivity) was evaluated <i>in vitro</i> and <i>in cellulo</i>. To showcase the enhance properties afforded by PA-HD for <i>in vivo</i> photoacoustic imaging, we employed an Alzheimer’s disease model to detect H<sub>2</sub>O<sub>2</sub>. In particular, the photoacoustic signal at 735 nm in the brains of 5xFAD mice (a murine model of Alzheimer’s disease) increased by 1.72 ± 0.20-fold relative to background indicating the presence of oxidative stress, whereas the change in wildtype mice was negligible (1.02 ± 0.14). These results were confirmed via ratiometric calibration which was not possible using the parent HD platform.</p>

scholarly journals Photoacoustic pigment relocalization sensor

2018 ◽  
Author(s):  
Antonella Lauri ◽  
Dominik Soliman ◽  
Murad Omar ◽  
Anja Stelzl ◽  
Vasilis Ntziachristos ◽  
...  
Keyword(s):  
Photoacoustic Imaging ◽  
Photoacoustic Signal ◽  
Optoacoustic Imaging ◽  
Molecular Sensors ◽  
Neurohumoral Control ◽  
Microscopy Techniques ◽  
Biological Analytes ◽  
G Protein Coupled

ABSTRACTPhotoacoustic (optoacoustic) imaging can extract molecular information with deeper tissue penetration than possible by fluorescence microscopy techniques. However, there is currently still a lack of robust genetically controlled contrast agents and molecular sensors that can dynamically detect biological analytes of interest with photoacoustics. In this biomimetic approach, we took inspiration from cuttlefish who can change their color by relocalizing pigment-filled organelles in so-called chromatophore cells under neurohumoral control. Analogously, we tested the use of melanophore cells from Xenopus laevis, containing compartments (melanosomes) filled with strongly absorbing melanin, as whole-cell sensors for optoacoustic imaging. Our results show that pigment relocalization in these cells, which is dependent on binding of a ligand of interest to a specific G protein-coupled receptor (GPCR), can be monitored in vitro and in vivo using photoacoustic mesoscopy. In addition to changes in the photoacoustic signal amplitudes, we could furthermore detect the melanosome aggregation process by a change in the frequency content of the photoacoustic signals. Using bioinspired engineering, we thus introduce a photoacoustic pigment relocalization sensor (PaPiReS) for molecular photoacoustic imaging of GPCR-mediated signaling molecules.

scholarly journals PEGylated liposomal photosensitizers as theranostic agents for dual-modal photoacoustic and fluorescence imaging-guided photodynamic therapy

2019 ◽  
Vol 12 (03) ◽  
pp. 1941003 ◽  
Author(s):  
Hao Xu ◽  
Yubin Liu ◽  
Junle Qu ◽  
Zhen Yuan
Keyword(s):  
Photodynamic Therapy ◽  
Contrast Agent ◽  
Fluorescence Imaging ◽  
High Efficiency ◽  
Photoacoustic Imaging ◽  
Treatment Agent ◽  
Theranostic Agents ◽  
Cancer Theranostics

The photosensitizer (PS) as photodynamic therapy (PDT) agent, can also serve as the contrast agent for dual-modal fluorescence imaging (FLI) and photoacoustic imaging (PAI) for precise cancer theranostics. In this study, the PAI capability of commercial PS, benzoporphyrin derivative monoacid ring-A (BPD) were examined and compared with that from the other PSs and dyes such as TPPS4, Cy5 dye and ICG. We discovered that BPD exhibited its advantage as contrast agent for PAI. Meanwhile, BPD can also serve as the contrast agent for enhanced FLI. In particular, the PEGylated nanoliposome (PNL) encapsulated BPD (LBPD) was produced for contrast enhanced dual-modal FLI and PAI and imaging-guided high-efficiency PDT. Enhanced FLI and PAI results demonstrated the significant accumulation of LBPD both within and among individual tumor during 24[Formula: see text]h monitoring for in vivo experiment tests. In-vitro and in-vivo PDT tests were also performed, which showed that LBPD have higher PDT efficiency and can easily break the blood vessel of tumor tissues as compared to that from BPD. It was discovered that LBPD has great potentials as a diagnosis and treatment agent for dual-modal FLI and PAI-guided PDT of cancer.

scholarly journals Clinically translatable quantitative molecular photoacoustic imaging with liposome-encapsulated ICG J-aggregates

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Cayla A. Wood ◽  
Sangheon Han ◽  
Chang Soo Kim ◽  
Yunfei Wen ◽  
Diego R. T. Sampaio ◽  
...  
Keyword(s):  
Contrast Agent ◽  
Photoacoustic Imaging ◽  
Folate Receptor ◽  
High Sensitivity ◽  
Spectral Unmixing ◽  
Estimation Accuracy ◽  
Spatiotemporal Resolution ◽  
Study Results

AbstractPhotoacoustic (PA) imaging is a functional and molecular imaging technique capable of high sensitivity and spatiotemporal resolution at depth. Widespread use of PA imaging, however, is limited by currently available contrast agents, which either lack PA-signal-generation ability for deep imaging or their absorbance spectra overlap with hemoglobin, reducing sensitivity. Here we report on a PA contrast agent based on targeted liposomes loaded with J-aggregated indocyanine green (ICG) dye (i.e., PAtrace) that we synthesized, bioconjugated, and characterized to addresses these limitations. We then validated PAtrace in phantom, in vitro, and in vivo PA imaging environments for both spectral unmixing accuracy and targeting efficacy in a folate receptor alpha-positive ovarian cancer model. These study results show that PAtrace concurrently provides significantly improved contrast-agent quantification/sensitivity and SO2 estimation accuracy compared to monomeric ICG. PAtrace’s performance attributes and composition of FDA-approved components make it a promising agent for future clinical molecular PA imaging.

scholarly journals A General Approach to Convert Hemicyanine Dyes into Highly Optimized Photoacoustic Scaffolds for Analyte Sensing

2021 ◽  
Author(s):  
Sarah Garder ◽  
Catharine Brady ◽  
Cameron Keeton ◽  
Anuj K Yadav ◽  
Sharath C Mallojjala ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Photoacoustic Imaging ◽  
Disease Model ◽  
Photoacoustic Signal ◽  
Model Of Alzheimer’S Disease ◽  
5Xfad Mice ◽  
The Impact

<p>In the context of deep-tissue disease biomarker detection and analyte sensing of biologically relevant species, the impact of photoacoustic imaging has been profound. However, most photoacoustic imaging agents to date are based on the repurposing of existing fluorescent dye platforms that exhibit non-optimal properties for photoacoustic applications (e.g., high fluorescence quantum yield). Herein, we introduce two effective modifications to the hemicyanine dye to afford PA-HD, a new dye scaffold optimized for photoacoustic probe development. We observed a significant increase in the photoacoustic output, representing an increase in sensitivity of 4.8-fold and a red-shift of the λ<sub>abs</sub> from 690 nm to 745 nm to enable ratiometric imaging. Moreover, to demonstrate the generalizability and utility of our remodeling efforts, we developed three probes using common analyte-responsive triggers for beta-galactosidase activity (PA-HD-Gal), nitroreductase activity (PA-HD-NTR), and hydrogen peroxide (PA-HD-H<sub>2</sub>O<sub>2</sub>). The performance of each probe (responsiveness, selectivity) was evaluated <i>in vitro</i> and <i>in cellulo</i>. To showcase the enhance properties afforded by PA-HD for <i>in vivo</i> photoacoustic imaging, we employed an Alzheimer’s disease model to detect H<sub>2</sub>O<sub>2</sub>. In particular, the photoacoustic signal at 735 nm in the brains of 5xFAD mice (a murine model of Alzheimer’s disease) increased by 1.72 ± 0.20-fold relative to background indicating the presence of oxidative stress, whereas the change in wildtype mice was negligible (1.02 ± 0.14). These results were confirmed via ratiometric calibration which was not possible using the parent HD platform.</p>

scholarly journals Study on Establishing Reference Safe Concentrations of MRI Contrast Agents for Optimized Images: Paramagnetic Gd-DTPA-BMEA and Superparamagnetic Ferucarbotran

2021 ◽  
Vol 11 (3) ◽  
pp. 1165
Author(s):  
Wen-Tien Hsiao ◽  
Yi-Hong Chou ◽  
Jhong-Wei Tu ◽  
Ai-Yih Wang ◽  
Lu-Han Lai
Keyword(s):  
Contrast Agent ◽  
Contrast Agents ◽  
Mri Contrast Agents ◽  
Mri Contrast Agent ◽  
In Vitro Experiments ◽  
Mri Contrast ◽  
In Vivo Experiments ◽  
Contrast Agent Injection

The purpose of this study is to establish the minimal injection doses of magnetic resonance imaging (MRI) contrast agents that can achieve optimized images while improving the safety of injectable MRI drugs. Gadolinium-diethylenetriamine penta-acetic acid (Gd-DTPA) and ferucarbotran, commonly used in clinical practice, were selected and evaluated with in vitro and in vivo experiments. MRI was acquired using T1-weighted (T1W) and T2-weighted (T2W) sequences, and the results were quantitatively analyzed. For in vitro experiments, results showed that T1W and T2W images were optimal when Gd-DTPA-bisamide (2-oxoethyl) (Gd-DTPA-BMEA) and ferucarbotran were diluted to a volume percentage of 0.6% and 0.05%; all comparisons were significant differences in grayscale statistics using one-way analysis of variance (ANOVA). For in vivo experiments, the contrast agent with optimal concentration percentages determined from in vitro experiments were injected into mice with an injection volume of 100 μL, and the images of brain, heart, liver, and mesentery before and after injection were compared. The statistical results showed that the p values of both T1W and T2W were less than 0.001, which were statistically significant. Under safety considerations for MRI contrast agent injection, optimized MRI images could still be obtained after reducing the injection concentration, which can provide a reference for the safety concentrations of MRI contrast agent injection in the future.

scholarly journals In vitro and in vivo biocompatibility study of polyacrylate TiO2@Ag coated nanoparticles for the radiation dose enhancement

2021 ◽  
Vol 49 (1) ◽  
pp. 185-193
Author(s):  
Ateeque Ur Rehman ◽  
Muhammad Hassan ◽  
Sadia Bano ◽  
Khizir Farooq ◽  
Aun Raza ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Dose Enhancement ◽  
Coated Nanoparticles ◽  
Biocompatibility Study

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 Asialoglycoprotein Receptor-Targeted Superparamagnetic Perfluorooctylbromide Nanoparticles

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Yang Li ◽  
Chao Feng Yang ◽  
Hui Zuo ◽  
Ao Li ◽  
Sushant Kumar Das ◽  
...  
Keyword(s):  
Contrast Agent ◽  
Rat Liver ◽  
Liver Parenchyma ◽  
Asialoglycoprotein Receptor ◽  
Enhancement Effect ◽  
Receptor Imaging ◽  
Significant Difference ◽  
Mean Size

Background. The decrease in asialoglycoprotein receptor (ASGPR) levels is observed in patients with chronic liver disease and liver tumor. The aim of our study was to develop ASGPR-targeted superparamagnetic perfluorooctylbromide nanoparticles (M-PFONP) and wonder whether this composite agent could target buffalo rat liver (BRL) cells in vitro and could improve R2 ∗ value of the rat liver parenchyma after its injection in vivo. Methods. GalPLL, a ligand of ASGPR, was synthesized by reductive amination. ASGPR-targeted M-PFOBNP was prepared by a film hydration method coupled with sonication. Several analytical methods were used to investigate the characterization and safety of the contrast agent in vitro. The in vivo MR T2 ∗ mapping was performed to evaluate the enhancement effect in rat liver. Results. The optimum concentration of Fe3O4 nanoparticles inclusion in GalPLL/M-PFOBNP was about 52.79 µg/mL, and the mean size was 285.6 ± 4.6 nm. The specificity of GalPLL/M-PFOBNP for ASGPR was confirmed by incubation experiment with fluorescence microscopy. The methyl thiazolyl tetrazolium (MTT) test showed that there was no significant difference in the optical density (OD) of cells incubated with all GalPLL/M-PFOBNP concentrations. Compared with M-PFOBNP, the increase in R2 ∗ value of the rat liver parenchyma after GalPLL/M-PFOBNP injection was higher. Conclusions. GalPLL/M-PFOBNP may potentially serve as a liver-targeted contrast agent for MR receptor imaging.

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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