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Zhao AX, Zhu YI, Chung E, Lee J, Morais S, Yoon H, Emelianov S. Factors Influencing the Repeated Transient Optical Droplet Vaporization Threshold and Lifetimes of Phase Change, Perfluorocarbon Nanodroplets. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2238. [PMID: 37570555 PMCID: PMC10421047 DOI: 10.3390/nano13152238] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Revised: 07/24/2023] [Accepted: 07/26/2023] [Indexed: 08/13/2023]
Abstract
Perfluorocarbon nanodroplets (PFCnDs) are sub-micrometer emulsions composed of a surfactant-encased perfluorocarbon (PFC) liquid and can be formulated to transiently vaporize through optical stimulation. However, the factors governing repeated optical droplet vaporization (ODV) have not been investigated. In this study, we employ high-frame-rate ultrasound (US) to characterize the ODV thresholds of various formulations and imaging parameters and identify those that exhibit low vaporization thresholds and repeatable vaporization. We observe a phenomenon termed "preconditioning", where initial laser pulses generate reduced US contrast that appears linked with an increase in nanodroplet size. Variation in laser pulse repetition frequency is found not to change the vaporization threshold, suggesting that "preconditioning" is not related to residual heat. Surfactants (bovine serum albumin, lipids, and zonyl) impact the vaporization threshold and imaging lifetime, with lipid shells demonstrating the best performance with relatively low thresholds (21.6 ± 3.7 mJ/cm2) and long lifetimes (t1/2 = 104 ± 21.5 pulses at 75 mJ/cm2). Physiological stiffness does not affect the ODV threshold and may enhance nanodroplet stability. Furthermore, PFC critical temperatures are found to correlate with vaporization thresholds. These observations enhance our understanding of ODV behavior and pave the way for improved nanodroplet performance in biomedical applications.
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Affiliation(s)
- Andrew X. Zhao
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Emory University School of Medicine, Atlanta, GA 30332, USA;
| | - Yiying I. Zhu
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA (E.C.); (J.L.); (S.M.)
| | - Euisuk Chung
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA (E.C.); (J.L.); (S.M.)
| | - Jeehyun Lee
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA (E.C.); (J.L.); (S.M.)
| | - Samuel Morais
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA (E.C.); (J.L.); (S.M.)
| | - Heechul Yoon
- School of Electronics and Electrical Engineering, Dankook University, Yongin-si 16890, Republic of Korea;
| | - Stanislav Emelianov
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Emory University School of Medicine, Atlanta, GA 30332, USA;
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA (E.C.); (J.L.); (S.M.)
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Zhang W, Metzger H, Vlatakis S, Claxton A, Carbajal MA, Fung LF, Mason J, Chan KLA, Pouliopoulos AN, Fleck RA, Prentice P, Thanou M. Characterising the chemical and physical properties of phase-change nanodroplets. ULTRASONICS SONOCHEMISTRY 2023; 97:106445. [PMID: 37257208 PMCID: PMC10241977 DOI: 10.1016/j.ultsonch.2023.106445] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 05/04/2023] [Accepted: 05/15/2023] [Indexed: 06/02/2023]
Abstract
Phase-change nanodroplets have attracted increasing interest in recent years as ultrasound theranostic nanoparticles. They are smaller compared to microbubbles and they may distribute better in tissues (e.g. in tumours). They are composed of a stabilising shell and a perfluorocarbon core. Nanodroplets can vaporise into echogenic microbubbles forming cavitation nuclei when exposed to ultrasound. Their perfluorocarbon core phase-change is responsible for the acoustic droplet vaporisation. However, methods to quantify the perfluorocarbon core in nanodroplets are lacking. This is an important feature that can help explain nanodroplet phase change characteristics. In this study, we fabricated nanodroplets using lipids shell and perfluorocarbons. To assess the amount of perfluorocarbon in the core we used two methods, 19F NMR and FTIR. To assess the cavitation after vaporisation we used an ultrasound transducer (1.1 MHz) and a high-speed camera. The 19F NMR based method showed that the fluorine signal correlated accurately with the perfluorocarbon concentration. Using this correlation, we were able to quantify the perfluorocarbon core of nanodroplets. This method was used to assess the content of the perfluorocarbon of the nanodroplets in solutions over time. It was found that perfluoropentane nanodroplets lost their content faster and at higher ratio compared to perfluorohexane nanodroplets. The high-speed imaging indicates that the nanodroplets generate cavitation comparable to that from commercial contrast agent microbubbles. Nanodroplet characterisation should include perfluorocarbon concentration assessment as critical information for their development.
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Affiliation(s)
- Weiqi Zhang
- Institute of Cancer & Pharmaceutical Sciences, King's College London, United Kingdom
| | - Hilde Metzger
- School of Engineering, University of Glasgow, United Kingdom
| | - Stavros Vlatakis
- Institute of Cancer & Pharmaceutical Sciences, King's College London, United Kingdom
| | - Amelia Claxton
- Institute of Cancer & Pharmaceutical Sciences, King's College London, United Kingdom
| | | | - Leong Fan Fung
- Department of Surgical & Interventional Engineering, King's College London, United Kingdom
| | - James Mason
- Institute of Cancer & Pharmaceutical Sciences, King's College London, United Kingdom
| | - K L Andrew Chan
- Institute of Cancer & Pharmaceutical Sciences, King's College London, United Kingdom
| | | | - Roland A Fleck
- Centre for Ultrastructural Imaging, King's College London, United Kingdom
| | - Paul Prentice
- School of Engineering, University of Glasgow, United Kingdom
| | - Maya Thanou
- Institute of Cancer & Pharmaceutical Sciences, King's College London, United Kingdom.
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Alcaraz PE, Davidson SJ, Shreeve E, Meuschke R, Romanowski M, Witte RS, Porter TR, Matsunaga TO. Thermal and Acoustic Stabilization Of Volatile Phase-Change Contrast Agents Via Layer-By-Layer Assembly. ULTRASOUND IN MEDICINE & BIOLOGY 2023; 49:1058-1069. [PMID: 36797095 PMCID: PMC10050125 DOI: 10.1016/j.ultrasmedbio.2022.12.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 12/07/2022] [Accepted: 12/08/2022] [Indexed: 05/11/2023]
Abstract
OBJECTIVE Phase-change contrast agents (PCCAs) are perfluorocarbon nanodroplets (NDs) that have been widely studied for ultrasound imaging in vitro, pre-clinical studies, and most recently incorporated a variant of PCCAs, namely a microbubble-conjugated microdroplet emulsion, into the first clinical studies. Their properties also make them attractive candidates for a variety of diagnostic and therapeutic applications including drug-delivery, diagnosis and treatment of cancerous and inflammatory diseases, as well as tumor-growth tracking. However, control over the thermal and acoustic stability of PCCAs both in vivo and in vitro has remained a challenge for expanding the potential utility of these agents in novel clinical applications. As such, our objective was to determine the stabilizing effects of layer-by-layer assemblies and its effect on both thermal and acoustic stability. METHODS We utilized layer-by-layer (LBL) assemblies to coat the outer PCCA membrane and characterized layering by measuring zeta potential and particle size. Stability studies were conducted by; 1) incubating the LBL-PCCAs at atmospheric pressure at 37∘C and 45∘C followed by; 2) ultrasound-mediated activation at 7.24 MHz and peak-negative pressures ranging from 0.71 - 5.48 MPa to ascertain nanodroplet activation and resultant microbubble persistence. The thermal and acoustic properties of decafluorobutane gas-condensed nanodroplets (DFB-NDs) layered with 6 and 10 layers of charge-alternating biopolymers, (LBL6NDs and LBL10NDs) respectively, were studied and compared to non-layered DFB-NDs. Half-life determinations were conducted at both 37∘C and 45∘C with acoustic droplet vaporization (ADV) measurements occurring at 23∘C. DISCUSSION Successful application of up to 10 layers of alternating positive and negatively charged biopolymers onto the surface membrane of DFB-NDs was demonstrated. Two major claims were substantiated in this study; namely, (1) biopolymeric layering of DFB-NDs imparts a thermal stability up to an extent; and, (2) both LBL6NDs and LBL10NDs did not appear to alter particle acoustic vaporization thresholds, suggesting that the thermal stability of the particle may not necessarily be coupled with particle acoustic vaporization thresholds. CONCLUSION Results demonstrate that the layered PCCAs had higher thermal stability, where the half-lifes of the LBLxNDs are significantly increased after incubation at 37∘C and 45∘C. Furthermore, the acoustic vaporization profiles the DFB-NDs, LBL6NDs, and LBL10NDs show that there is no statistically significant difference between the acoustic vaporization energy required to initiate acoustic droplet vaporization.
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Affiliation(s)
- Pedro Enrique Alcaraz
- College of Optical Sciences, University of Arizona, 1630 E University Blvd., Tucson, AZ 85721 United States; Department of Biomedical Engineering, University of Arizona, Tucson, AZ 85719 United States; Department of Medical Imaging, University of Arizona, Tucson, AZ. 85719 United States
| | - Skylar J Davidson
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ 85719 United States
| | - Evan Shreeve
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ 85719 United States
| | - Rainee Meuschke
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ 85719 United States
| | - Marek Romanowski
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ 85719 United States; Department of Materials Science and Engineering, University of Arizona, Tucson, AZ 85719 United States
| | - Russell S Witte
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ 85719 United States; Department of Materials Science and Engineering, University of Arizona, Tucson, AZ 85719 United States; Department of Medical Imaging, University of Arizona, Tucson, AZ. 85719 United States
| | - Thomas R Porter
- Division of Cardiovascular Medicine, University of Nebraska Medical Center, Omaha, Nebraska
| | - Terry O Matsunaga
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ 85719 United States; Department of Medical Imaging, University of Arizona, Tucson, AZ. 85719 United States.
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Riemer K, Toulemonde M, Yan J, Lerendegui M, Stride E, Weinberg PD, Dunsby C, Tang MX. Fast and Selective Super-Resolution Ultrasound In Vivo With Acoustically Activated Nanodroplets. IEEE TRANSACTIONS ON MEDICAL IMAGING 2023; 42:1056-1067. [PMID: 36399587 DOI: 10.1109/tmi.2022.3223554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Perfusion by the microcirculation is key to the development, maintenance and pathology of tissue. Its measurement with high spatiotemporal resolution is consequently valuable but remains a challenge in deep tissue. Ultrasound Localization Microscopy (ULM) provides very high spatiotemporal resolution but the use of microbubbles requires low contrast agent concentrations, a long acquisition time, and gives little control over the spatial and temporal distribution of the microbubbles. The present study is the first to demonstrate Acoustic Wave Sparsely-Activated Localization Microscopy (AWSALM) and fast-AWSALM for in vivo super-resolution ultrasound imaging, offering contrast on demand and vascular selectivity. Three different formulations of acoustically activatable contrast agents were used. We demonstrate their use with ultrasound mechanical indices well within recommended safety limits to enable fast on-demand sparse activation and destruction at very high agent concentrations. We produce super-localization maps of the rabbit renal vasculature with acquisition times between 5.5 s and 0.25 s, and a 4-fold improvement in spatial resolution. We present the unique selectivity of AWSALM in visualizing specific vascular branches and downstream microvasculature, and we show super-localized kidney structures in systole (0.25 s) and diastole (0.25 s) with fast-AWSALM outperforming microbubble based ULM. In conclusion, we demonstrate the feasibility of fast and selective imaging of microvascular dynamics in vivo with subwavelength resolution using ultrasound and acoustically activatable nanodroplet contrast agents.
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Xu M, Long W, Ling X, Hu X, Hong H, Peng Y, Cai T. Multifunctional theragnostic ultrasmall gold nanodot-encapsuled perfluorocarbon nanodroplets for laser-focused ultrasound sequence irradiation (LFSI)-based enhanced tumor ablation. J Mater Chem B 2022; 10:9816-9829. [PMID: 36426923 DOI: 10.1039/d2tb01775j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Despite the substantial potential of focused ultrasound therapy, its efficacy in cancer therapy has been limited due to the high cavitation threshold and safety concerns regarding the use of high-intensity energy pulses. Here, ultrasmall Au nanodot-loaded PEG-modified perfluorocarbon nanodroplets (Au-PFCnDs) were prepared and used as a therapeutic enhancer. A LFSI method was designed to achieve enhanced tumor ablation at a mild focused ultrasound (FUS) energy pulse with the assistance of the instinct photothermal effect of intratumor-permeable ultrasmall Au nanodots under 808 nm NIR laser irradiation. In addition to their therapeutic function, Au-PFCnDs can also generate multimodal images to provide information for tumor surveillance and treatment guidance. The experimental results also showed that the cRGD-targeted Au-PFCnDs could be more efficiently delivered into the tumor and selectively destroy tumors with no observable side effects on normal tissue under LFSI treatment.
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Affiliation(s)
- Menghan Xu
- State Key Laboratory of Natural Medicines, Department of Pharmaceutics, China Pharmaceutical University, Nanjing 210009, China.
| | - Wei Long
- State Key Laboratory of Natural Medicines, Department of Pharmaceutics, China Pharmaceutical University, Nanjing 210009, China.
| | - Xiang Ling
- State Key Laboratory of Natural Medicines, Department of Pharmaceutics, China Pharmaceutical University, Nanjing 210009, China.
| | - Xiongwei Hu
- State Key Laboratory of Natural Medicines, Department of Pharmaceutics, China Pharmaceutical University, Nanjing 210009, China.
| | - Hao Hong
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Key Laboratory of Molecular Medicine and School of Medicine, Medical School of Nanjing University, Nanjing 210093, China
| | - Yayun Peng
- State Key Laboratory of Natural Medicines, Department of Pharmaceutics, China Pharmaceutical University, Nanjing 210009, China.
| | - Ting Cai
- State Key Laboratory of Natural Medicines, Department of Pharmaceutics, China Pharmaceutical University, Nanjing 210009, China.
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Welch PJ, Li DS, Forest CR, Pozzo LD, Shi C. Perfluorocarbon nanodroplet size, acoustic vaporization, and inertial cavitation affected by lipid shell composition in vitro. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2022; 152:2493. [PMID: 36319242 PMCID: PMC9812515 DOI: 10.1121/10.0014934] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 08/17/2022] [Accepted: 10/04/2022] [Indexed: 05/25/2023]
Abstract
Perfluorocarbon nanodroplets (PFCnDs) are ultrasound contrast agents that phase-transition from liquid nanodroplets to gas microbubbles when activated by laser irradiation or insonated with an ultrasound pulse. The dynamics of PFCnDs can vary drastically depending on the nanodroplet composition, including the lipid shell properties. In this paper, we investigate the effect of varying the ratio of PEGylated to non-PEGylated phospholipids in the outer shell of PFCnDs on the acoustic nanodroplet vaporization (liquid to gas phase transition) and inertial cavitation (rapid collapse of the vaporized nanodroplets) dynamics in vitro when insonated with focused ultrasound. Nanodroplets with a high concentration of PEGylated lipids had larger diameters and exhibited greater variance in size distribution compared to nanodroplets with lower proportions of PEGylated lipids in the lipid shell. PFCnDs with a lipid shell composed of 50:50 PEGylated to non-PEGylated lipids yielded the highest B-mode image intensity and duration, as well as the greatest pressure difference between acoustic droplet vaporization onset and inertial cavitation onset. We demonstrate that slight changes in lipid shell composition of PFCnDs can significantly impact droplet phase transitioning and inertial cavitation dynamics. These findings can help guide researchers to fabricate PFCnDs with optimized compositions for their specific applications.
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Affiliation(s)
- Phoebe J Welch
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | | | - Craig R Forest
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - Lilo D Pozzo
- Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, USA
| | - Chengzhi Shi
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
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黄 建, 杨 林, 阳 锐, 阎 锋, 彭 玉, 徐 金. [Fucoidan-Modified Phase-Transitional Contrast Agent for Ultrasound Imaging and Targeting of Hepatoma Cells]. SICHUAN DA XUE XUE BAO. YI XUE BAN = JOURNAL OF SICHUAN UNIVERSITY. MEDICAL SCIENCE EDITION 2022; 53:752-757. [PMID: 36224674 PMCID: PMC10408789 DOI: 10.12182/20220960101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Indexed: 06/16/2023]
Abstract
Objective To prepare a fucoidan-modified phase-transitional contrast agent (FPCA) and to evaluate its in vitro capabilities for ultrasound imaging and targeting of hepatoma cells. Methods Nano-liposomes encapsulated with perfluoropentane were prepared using thin-film hydration and ultrasonic emulsification methods. Then, FPCA nanoparticles were prepared through chemical grafting of fucoidan and the characterization of their physical and chemical properties was performed. After applying external stimuli of heating with hot water bath and microwave irradiation, the phase-transition status of FPCA was observed with microscope. The imaging abilities of phase-transited FPCA on two-dimensional ultrasound and contrast-enhanced ultrasound were observed with ultrasonic diagnostic instrument. The ability of FPCA to target at hepatoma cells was evaluated and verified with fluorescence confocal observation and flow cytometry analysis. Results The FPCA prepared in the study had an average diameter of (222.1±32.5) nm, displaying spherical appearance, good dispersion, good stability, and good biocompatibility. The phase-transition of FPCA was induced by both heating with hot water bath and microwave irradiation. For phase transition, the optimal temperature was found to be 50 ℃ and the preferred microwave power was 1.5 W/cm 2. Moreover, after phase transition, FPCA showed significant imaging enhancement on both two-dimensional ultrasonography and contrast-enhanced ultrasonography. Through fluorescein isothiocyanate (FITC) labeling, FPCA could specifically bind with hepatoma cells at a high binding rate of (96.19±1.62)%, while it rarely bound with normal liver cells, showing a binding rate of less than 10%. Conclusion A new type of phase-transitional ultrasound contrast agent with good stability and biocompatibility was successfully prepared. It not only could enhance ultrasound imaging through phase transition, but also had specific active hepatoma cell-targeting properties.
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Affiliation(s)
- 建波 黄
- 四川大学华西医院 超声医学科/超声医学研究室 (成都 610041)Department & Institute of Ultrasound Medicine, West China Hospital, Sichuan University, Chengdu 610041, China
| | - 林 杨
- 四川大学华西医院 超声医学科/超声医学研究室 (成都 610041)Department & Institute of Ultrasound Medicine, West China Hospital, Sichuan University, Chengdu 610041, China
| | - 锐 阳
- 四川大学华西医院 超声医学科/超声医学研究室 (成都 610041)Department & Institute of Ultrasound Medicine, West China Hospital, Sichuan University, Chengdu 610041, China
| | - 锋 阎
- 四川大学华西医院 超声医学科/超声医学研究室 (成都 610041)Department & Institute of Ultrasound Medicine, West China Hospital, Sichuan University, Chengdu 610041, China
| | - 玉兰 彭
- 四川大学华西医院 超声医学科/超声医学研究室 (成都 610041)Department & Institute of Ultrasound Medicine, West China Hospital, Sichuan University, Chengdu 610041, China
| | - 金顺 徐
- 四川大学华西医院 超声医学科/超声医学研究室 (成都 610041)Department & Institute of Ultrasound Medicine, West China Hospital, Sichuan University, Chengdu 610041, China
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Jandhyala S, Van Namen A, Spatarelu CP, Luke GP. EGFR-Targeted Perfluorohexane Nanodroplets for Molecular Ultrasound Imaging. NANOMATERIALS 2022; 12:nano12132251. [PMID: 35808089 PMCID: PMC9268413 DOI: 10.3390/nano12132251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 06/27/2022] [Accepted: 06/28/2022] [Indexed: 02/01/2023]
Abstract
Perfluorocarbon nanodroplets offer an alternative to gaseous microbubbles as contrast agents for ultrasound imaging. They can be acoustically activated to induce a liquid-to-gas phase transition and provide contrast in ultrasound images. In this study, we demonstrate a new strategy to synthesize antibody-conjugated perfluorohexane nanodroplet (PFHnD-Ab) ultrasound contrast agents that target cells overexpressing the epidermal growth factor receptor (EGFR). The perfluorohexane nanodroplets (PFHnD) containing a lipophilic DiD fluorescent dye were synthesized using a phospholipid shell. Antibodies were conjugated to the surface through a hydrazide-aldehyde reaction. Cellular binding was confirmed using fluorescence microscopy; the DiD fluorescence signal of the PFHnD-Ab was 5.63× and 6× greater than the fluorescence signal in the case of non-targeted PFHnDs and the EGFR blocking control, respectively. Cells were imaged in tissue-mimicking phantoms using a custom ultrasound imaging setup consisting of a high-intensity focused ultrasound transducer and linear array imaging transducer. Cells with conjugated PFHnD-Abs exhibited a significantly higher (p < 0.001) increase in ultrasound amplitude compared to cells with non-targeted PFHnDs and cells exposed to free antibody before the addition of PFHnD-Abs. The developed nanodroplets show potential to augment the use of ultrasound in molecular imaging cancer diagnostics.
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Affiliation(s)
- Sidhartha Jandhyala
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA; (S.J.); (A.V.N.); (C.-P.S.)
| | - Austin Van Namen
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA; (S.J.); (A.V.N.); (C.-P.S.)
| | - Catalina-Paula Spatarelu
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA; (S.J.); (A.V.N.); (C.-P.S.)
| | - Geoffrey P. Luke
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA; (S.J.); (A.V.N.); (C.-P.S.)
- Translational Engineering in Cancer Program, Dartmouth Cancer Center, Lebanon, NH 03756, USA
- Correspondence:
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Zhang W, Shi Y, Abd Shukor S, Vijayakumaran A, Vlatakis S, Wright M, Thanou M. Phase-shift nanodroplets as an emerging sonoresponsive nanomaterial for imaging and drug delivery applications. NANOSCALE 2022; 14:2943-2965. [PMID: 35166273 DOI: 10.1039/d1nr07882h] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Nanodroplets - emerging phase-changing sonoresponsive materials - have attracted substantial attention in biomedical applications for both tumour imaging and therapeutic purposes due to their unique response to ultrasound. As ultrasound is applied at different frequencies and powers, nanodroplets have been shown to cavitate by the process of acoustic droplet vapourisation (ADV), causing the development of mechanical forces which promote sonoporation through cellular membranes. This allows drugs to be delivered efficiently into deeper tissues where tumours are located. Recent reviews on nanodroplets are mostly focused on the mechanism of cavitation and their applications in biomedical fields. However, the chemistry of the nanodroplet components has not been discussed or reviewed yet. In this review, the commonly used materials and preparation methods of nanodroplets are summarised. More importantly, this review provides examples of variable chemistry components in nanodroplets which link them to their efficiency as ultrasound-multimodal imaging agents to image and monitor drug delivery. Finally, the drawbacks of current research, future development, and future direction of nanodroplets are discussed.
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Affiliation(s)
- Weiqi Zhang
- School of Cancer & Pharmaceutical Sciences, King's College London, UK.
| | - Yuhong Shi
- School of Cancer & Pharmaceutical Sciences, King's College London, UK.
| | | | | | - Stavros Vlatakis
- School of Cancer & Pharmaceutical Sciences, King's College London, UK.
| | - Michael Wright
- School of Cancer & Pharmaceutical Sciences, King's College London, UK.
| | - Maya Thanou
- School of Cancer & Pharmaceutical Sciences, King's College London, UK.
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10
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Mitcham TM, Nevozhay D, Chen Y, Nguyen LD, Pinton GF, Lai SY, Sokolov KV, Bouchard RR. Effect of Perfluorocarbon Composition on Activation of Phase-Changing Ultrasound Contrast Agents. Med Phys 2022; 49:2212-2219. [PMID: 35195908 PMCID: PMC9041204 DOI: 10.1002/mp.15564] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 02/16/2022] [Accepted: 02/16/2022] [Indexed: 11/29/2022] Open
Abstract
Background While microbubble contrast agents (MCAs) are commonly used in ultrasound (US), they are inherently limited to vascular targets due to their size. Alternatively, phase‐changing nanodroplet contrast agents (PNCAs) can be delivered as nanoscale agents (i.e., small enough to extravasate), but when exposed to a US field of sufficient mechanical index (MI), they convert to MCAs, which can be visualized with high contrast using nonlinear US. Purpose To investigate the effect of perfluorocarbon (PFC) core composition and presence of cholesterol in particle coatings on stability and image contrast generated from acoustic activation of PNCAs using high‐frequency US suitable for clinical imaging. Methods PNCAs with varied core compositions (i.e., mixtures of perfluoropentane [C5] and/or perfluorohexane [C6]) and two coating formulations (i.e., with and without cholesterol) were characterized and investigated for thermal/temporal stability and postactivation, nonlinear US contrast in phantom and in vivo environments. Through hydrophone measurements and nonlinear numerical modeling, MI was estimated for pulse sequences used for PNCA activation. Results All PNCA compositions were characterized to have similar diameters (249–267 nm) and polydispersity (0.151–0.185) following fabrication. While PNCAs with majority C5 core composition showed higher levels of spontaneous signal (i.e., not due to US activation) in phantoms than C6‐majority PNCAs, all compositions were stable during imaging experiments. When activating PNCAs with a 12.3‐MHz US pulse (MI = 1.1), C6‐core particles with cholesterol‐free coatings (i.e., CF‐C6‐100 particles) generated a median contrast of 3.1, which was significantly higher (p < 0.001) than other formulations. Further, CF‐C6‐100 particles were activated in a murine model, generating US contrast ≥3.4. Conclusion C6‐core PNCAs can provide high‐contrast US imaging with minimal nonspecific activation in phantom and in vivo environments.
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Affiliation(s)
- Trevor M Mitcham
- Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, TX, USA.,MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX, USA
| | - Dmitry Nevozhay
- Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Yunyun Chen
- Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Linh D Nguyen
- Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Gianmarco F Pinton
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, NC, USA
| | - Stephen Y Lai
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX, USA.,Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Konstantin V Sokolov
- Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, TX, USA.,MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX, USA.,Department of Bioengineering, Rice University, Houston, TX, USA.,Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Richard R Bouchard
- Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, TX, USA.,MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX, USA
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11
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Lu S, Zhao P, Deng Y, Liu Y. Mechanistic Insights and Therapeutic Delivery through Micro/Nanobubble-Assisted Ultrasound. Pharmaceutics 2022; 14:pharmaceutics14030480. [PMID: 35335857 PMCID: PMC8954263 DOI: 10.3390/pharmaceutics14030480] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 02/12/2022] [Accepted: 02/19/2022] [Indexed: 02/05/2023] Open
Abstract
Ultrasound with low frequency (20–100 kHz) assisted drug delivery has been widely investigated as a non-invasive method to enhance the permeability and retention effect of drugs. The functional micro/nanobubble loaded with drugs could provide an unprecedented opportunity for targeted delivery. Then, ultrasound with higher intensity would locally burst bubbles and release agents, thus avoiding side effects associated with systemic administration. Furthermore, ultrasound-mediated destruction of micro/nanobubbles can effectively increase the permeability of vascular membranes and cell membranes, thereby not only increasing the distribution concentration of drugs in the interstitial space of target tissues but also promoting the penetration of drugs through cell membranes into the cytoplasm. These advancements have transformed ultrasound from a purely diagnostic utility into a promising theragnostic tool. In this review, we first discuss the structure and generation of micro/nanobubbles. Second, ultrasound parameters and mechanisms of therapeutic delivery are discussed. Third, potential biomedical applications of micro/nanobubble-assisted ultrasound are summarized. Finally, we discuss the challenges and future directions of ultrasound combined with micro/nanobubbles.
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12
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Ultrasound and Photoacoustic Imaging of Laser-Activated Phase-Change Perfluorocarbon Nanodroplets. PHOTONICS 2021. [DOI: 10.3390/photonics8100405] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Laser-activated perfluorocarbon nanodroplets (PFCnDs) are emerging phase-change contrast agents that showed promising potential in ultrasound and photoacoustic (US/PA) imaging. Unlike monophase gaseous microbubbles, PFCnDs shift their state from liquid to gas via optical activation and can provide high US/PA contrast on demand. Depending on the choice of perfluorocarbon core, the vaporization and condensation dynamics of the PFCnDs are controllable. Therefore, these configurable properties of activation and deactivation of PFCnDs are employed to enable various imaging approaches, including contrast-enhanced imaging and super-resolution imaging. In addition, synchronous application of both acoustic and optical pulses showed a promising outcome vaporizing PFCnDs with lower activation thresholds. Furthermore, due to their sub-micrometer size, PFCnDs can be used for molecular imaging of extravascular tissue. PFCnDs can also be an effective therapeutic tool. As PFCnDs can carry therapeutic drugs or other particles, they can be used for drug delivery, as well as photothermal and photodynamic therapies. Blood barrier opening for neurological applications was recently demonstrated with optically-triggered PFCnDs. This paper specifically focuses on the activation and deactivation properties of laser-activated PFCnDs and associated US/PA imaging approaches, and briefly discusses their theranostic potential and future directions.
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13
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Guo R, Xu N, Liu Y, Ling G, Yu J, Zhang P. Functional ultrasound-triggered phase-shift perfluorocarbon nanodroplets for cancer therapy. ULTRASOUND IN MEDICINE & BIOLOGY 2021; 47:2064-2079. [PMID: 33992473 DOI: 10.1016/j.ultrasmedbio.2021.04.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 04/02/2021] [Accepted: 04/06/2021] [Indexed: 06/12/2023]
Abstract
In recent years, because of their unique properties, the use of perfluorocarbon nanodroplets (PFC NDs) in ultrasound-mediated tumor theranostics has attracted increasing interest. PFC is one of the most stable organic compounds with high hydrophobicity. Phase-shift PFC NDs can be transformed into highly echogenic microbubbles for ultrasound and photoacoustic imaging by ultrasound and laser light. In addition, in the process of acoustic droplet vaporization, PFC NDs with cavitation nuclei can be combined with a variety of ultrasound technologies to produce cavitation effects for tumor ablation, antivascular therapy and release of therapeutic agents loaded in nanodroplets. Moreover, they can also be used to overcome tumor hypoxia by virtue of high oxygen solubility. In this review, first the preparation and stabilization of PFC NDs are summarized and then the issues and outlook are discussed. More importantly, multifunctional platforms based on PFC NDs for cancer diagnostics, therapy and theranostics are reviewed in detail.
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Affiliation(s)
- Ranran Guo
- Shenyang Pharmaceutical University, Shenyang, China
| | - Na Xu
- Shenyang Pharmaceutical University, Shenyang, China
| | - Ying Liu
- Shenyang Pharmaceutical University, Shenyang, China
| | - Guixia Ling
- Shenyang Pharmaceutical University, Shenyang, China
| | - Jia Yu
- Shenyang Pharmaceutical University, Shenyang, China.
| | - Peng Zhang
- Shenyang Pharmaceutical University, Shenyang, China.
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14
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Li DS, Jeng GS, Pitre JJ, Kim M, Pozzo LD, O’Donnell M. Spatially localized sono-photoacoutic activation of phase-change contrast agents. PHOTOACOUSTICS 2020; 20:100202. [PMID: 32817821 PMCID: PMC7424230 DOI: 10.1016/j.pacs.2020.100202] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 07/13/2020] [Accepted: 07/23/2020] [Indexed: 05/29/2023]
Abstract
Sono-photoacoustic (SPA) activation lowers the threshold of phase-change contrast agents by timing a laser shot to coincide with the arrival of an acoustic wave at a region of interest. The combination of photothermal heating from optical absorption and negative pressure from the acoustic wave greatly reduces the droplet's combined vaporization threshold compared to using laser energy or acoustic energy alone. In previous studies, SPA imaging used a broadly illuminated optical pulse combined with plane wave acoustic pulses transmitted from a linear ultrasound array. Acoustic plane waves cover a wide lateral field of view, enabling direct visualization of the contrast agent distribution. In contrast, we demonstrate here that localized SPA activation is possible using electronically steered/focused ultrasound pulses. The focused SPA activation region is defined axially by the number of cycles in the acoustic pulse and laterally by the acoustic beam width. By reducing the spot size and enabling rapid electronic steering, complex activation patterns are possible, which may be particularly useful in therapeutic applications.
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Affiliation(s)
- David S. Li
- Department of Bioengineering, University of Washington, Seattle, WA, 98195 USA
- Department of Chemical Engineering, University of Washington, Seattle, WA, 98195 USA
| | - Geng-Shi Jeng
- Department of Bioengineering, University of Washington, Seattle, WA, 98195 USA
| | - John J. Pitre
- Department of Bioengineering, University of Washington, Seattle, WA, 98195 USA
| | - MinWoo Kim
- Department of Bioengineering, University of Washington, Seattle, WA, 98195 USA
| | - Lilo D. Pozzo
- Department of Chemical Engineering, University of Washington, Seattle, WA, 98195 USA
| | - Matthew O’Donnell
- Department of Bioengineering, University of Washington, Seattle, WA, 98195 USA
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15
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Boerner P, Nevozhay D, Hatamimoslehabadi M, Chawla HS, Zvietcovich F, Aglyamov S, Larin KV, Sokolov KV. Repetitive optical coherence elastography measurements with blinking nanobombs. BIOMEDICAL OPTICS EXPRESS 2020; 11:6659-6673. [PMID: 33282515 PMCID: PMC7687956 DOI: 10.1364/boe.401734] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 09/19/2020] [Accepted: 10/06/2020] [Indexed: 05/04/2023]
Abstract
Excitation of dye-loaded perfluorocarbon nanoparticles (nanobombs) can generate highly localized axially propagating longitudinal shear waves (LSW) that can be used to quantify tissue mechanical properties without transversal scanning of the imaging beam. In this study, we used repetitive excitations of dodecafluoropentane (C5) and tetradecafluorohexane (C6) nanobombs by a nanosecond-pulsed laser to produce multiple LSWs from a single spot in a phantom. A 1.5 MHz Fourier-domain mode-locked laser in combination with a phase correction algorithm was used to perform elastography. Multiple nanobomb activations were also monitored by detecting photoacoustic signals. Our results demonstrate that C6 nanobombs can be used for repetitive generation of LSW from a single spot for the purpose of material elasticity assessment. This study opens new avenues for continuous quantification of tissue mechanical properties using single delivery of the nanoparticles.
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Affiliation(s)
- Paul Boerner
- Department of Biomedical Engineering, University of Houston, Houston, Texas 77204, USA
- Equal contribution
| | - Dmitry Nevozhay
- Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
- Equal contribution
| | | | | | - Fernando Zvietcovich
- Department of Biomedical Engineering, University of Houston, Houston, Texas 77204, USA
| | - Salavat Aglyamov
- Department of Mechanical Engineering, University of Houston, Houston, Texas 77204, USA
| | - Kirill V Larin
- Department of Biomedical Engineering, University of Houston, Houston, Texas 77204, USA
| | - Konstantin V Sokolov
- Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
- Department of Bioengineering, Rice University, Houston, Texas 77030, USA
- Department of Biomedical Engineering, The University of Texas at Austin, 107 W Dean Keeton Street, Austin, Texas 78712, USA
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16
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Hallam KA, Emelianov SY. Toward optimization of blood brain barrier opening induced by laser-activated perfluorocarbon nanodroplets. BIOMEDICAL OPTICS EXPRESS 2019; 10:3139-3151. [PMID: 31360596 PMCID: PMC6640833 DOI: 10.1364/boe.10.003139] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 05/30/2019] [Accepted: 05/30/2019] [Indexed: 05/09/2023]
Abstract
The blood brain barrier (BBB), a component of the brain's natural defense system, is often a roadblock for the monitoring and treatment of neurological disorders. Recently, we introduced a technique to open the blood brain barrier through the use of laser-activated perfluorohexane nanodroplets (PFHnDs), a phase-change nanoagent that undergoes repeated vaporization and recondensation when excited by a pulsed laser. Laser-activated PFHnDs were shown to enable noninvasive and localized opening of the BBB, allowing extravasation of various sized agents into the brain tissue. In this current work, the laser-activated PFHnD-induced BBB opening is further explored. In particular, laser fluence and the number of laser pulses used for the PFHnD-induced BBB opening are examined and evaluated both qualitatively and quantitatively to determine the effect of these parameters on BBB opening. The results of these studies show trends between increased laser fluence and an increased BBB opening as well as between an increased number of laser pulses and an increased BBB opening, however, with limitations on the extent of the BBB opening after a certain number of pulses. Overall, the results of these studies serve as a guideline to choosing suitable laser parameters for safe and effective BBB opening.
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Affiliation(s)
- Kristina A. Hallam
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University School of Medicine, Atlanta, GA, USA
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Stanislav Y. Emelianov
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University School of Medicine, Atlanta, GA, USA
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA
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