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Li S, Chen C, Lof J, Stolze EA, Sklenar J, Chen X, Pacella JJ, Villanueva FS, Matsunaga TO, Everbach EC, Radio SJ, Westphal S, Xie F, Leng X, Porter TR. Effect of Ambient Conditions on Acoustic Activation of the Perfluoropropane Droplets Within the Infarct Zone. ULTRASOUND IN MEDICINE & BIOLOGY 2024; 50:1232-1239. [PMID: 38760280 PMCID: PMC11189723 DOI: 10.1016/j.ultrasmedbio.2024.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 04/19/2024] [Accepted: 04/22/2024] [Indexed: 05/19/2024]
Abstract
BACKGROUND Acoustically activated perfluoropropane droplets (PD) formulated from lipid encapsulated microbubble preparations produce a delayed myocardial contrast enhancement that preferentially highlights the infarct zones (IZ). Since activation of PDs may be temperature sensitive, it is unclear what effect body temperature (BT) has on acoustic activation (AA). OBJECTIVE We sought to determine whether the microvascular retention and degree of myocardial contrast intensity (MCI) would be affected by BT at the time of intravenous injection. METHODS We administered intravenous (IV) PD in nine rats following 60 min of ischemia followed by reperfusion. Injections in these rats were given at temperatures above and below 36.5°C, with high MI activation in both groups at 3 or 6 min following IV injection (IVI). In six additional rats (three in each group), IV PDs were given only at one temperature (<36.5°C or ≥36.5°C), permitting a total of 12 comparisons of different BT. Differences in background subtracted MCI at 3-6 min post-injection were compared in the infarct zone (IZ) and remote zone (RZ). Post-mortem lung hematoxylin and eosin (H&E) staining was performed to assess the effect potential thermal activation on lung tissue. RESULTS Selective MCI within the IZ was observed in 8 of 12 rats who received IVI of PDs at <36.5°C, but none of the 12 rats who had IVI at the higher temperature (p < 0.0001). Absolute MCI following droplet activation was significantly higher in both the IZ and RZ when given at the lower BT. H&E indicated significant red blood extravasation in 5/7 rats who had had IV injections at higher BT, and 0/7 rats who had IV PDs at <36.5°C. CONCLUSIONS Selective IZ enhancement with AA of intravenous PDs is possible, but temperature sensitive. Thermal activation appears to occur when PDs are given at higher temperatures, preventing AA, and increasing unwanted bioeffects.
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Affiliation(s)
- Shouqiang Li
- Department of Ultrasound, Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, China; Division of Cardiovascular Medicine, University of Nebraska Medical Center, Omaha, NE, USA
| | - Cheng Chen
- University of Pittsburgh Medical Center; Pittsburgh, PA, USA
| | - John Lof
- Division of Cardiovascular Medicine, University of Nebraska Medical Center, Omaha, NE, USA
| | - Elizabeth A Stolze
- Division of Cardiovascular Medicine, University of Nebraska Medical Center, Omaha, NE, USA
| | | | - Xucai Chen
- University of Pittsburgh Medical Center; Pittsburgh, PA, USA
| | - John J Pacella
- University of Pittsburgh Medical Center; Pittsburgh, PA, USA
| | | | - Terry O Matsunaga
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ, USA
| | - E Carr Everbach
- Department of Engineering, Swarthmore College, Swarthmore, PA, USA
| | - Stanley J Radio
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Sherry Westphal
- Division of Cardiovascular Medicine, University of Nebraska Medical Center, Omaha, NE, USA
| | - Feng Xie
- Division of Cardiovascular Medicine, University of Nebraska Medical Center, Omaha, NE, USA
| | - Xiaoping Leng
- Department of Ultrasound, Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, China.
| | - Thomas R Porter
- Division of Cardiovascular Medicine, University of Nebraska Medical Center, Omaha, NE, USA.
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Riemer K, Tan Q, Morse S, Bau L, Toulemonde M, Yan J, Zhu J, Wang B, Taylor L, Lerendegui M, Wu Q, Stride E, Dunsby C, Weinberg PD, Tang MX. 3D Acoustic Wave Sparsely Activated Localization Microscopy With Phase Change Contrast Agents. Invest Radiol 2024; 59:379-390. [PMID: 37843819 DOI: 10.1097/rli.0000000000001033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2023]
Abstract
OBJECTIVE The aim of this study is to demonstrate 3-dimensional (3D) acoustic wave sparsely activated localization microscopy (AWSALM) of microvascular flow in vivo using phase change contrast agents (PCCAs). MATERIALS AND METHODS Three-dimensional AWSALM using acoustically activable PCCAs was evaluated on a crossed tube microflow phantom, the kidney of New Zealand White rabbits, and the brain of C57BL/6J mice through intact skull. A mixture of C 3 F 8 and C 4 F 10 low-boiling-point fluorocarbon gas was used to generate PCCAs with an appropriate activation pressure. A multiplexed 8-MHz matrix array connected to a 256-channel ultrasound research platform was used for transmitting activation and imaging ultrasound pulses and recording echoes. The in vitro and in vivo echo data were subsequently beamformed and processed using a set of customized algorithms for generating 3D super-resolution ultrasound images through localizing and tracking activated contrast agents. RESULTS With 3D AWSALM, the acoustic activation of PCCAs can be controlled both spatially and temporally, enabling contrast on demand and capable of revealing 3D microvascular connectivity. The spatial resolution of the 3D AWSALM images measured using Fourier shell correlation is 64 μm, presenting a 9-time improvement compared with the point spread function and 1.5 times compared with half the wavelength. Compared with the microbubble-based approach, more signals were localized in the microvasculature at similar concentrations while retaining sparsity and longer tracks in larger vessels. Transcranial imaging was demonstrated as a proof of principle of PCCA activation in the mouse brain with 3D AWSALM. CONCLUSIONS Three-dimensional AWSALM generates volumetric ultrasound super-resolution microvascular images in vivo with spatiotemporal selectivity and enhanced microvascular penetration.
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Affiliation(s)
- Kai Riemer
- From the Department of Bioengineering, Imperial College London, London, United Kingdom (K.R., Q.T., S.M., M.T., J.Y., J.Z., B.W., L.T., M.L., P.D.W., M.-X.T.); NDORMS, University of Oxford, Oxford, United Kingdom (L.B., Q.W., E.S.); and Department of Physics, Imperial College London, London, United Kingdom (C.D.)
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Chen J, Zhao C, Liu H, Wang Z, Ma L, Zhang J, Xu N, Hu K, Duan L. Integrated micro/nano drug delivery system based on magnetically responsive phase-change droplets for ultrasound theranostics. Front Bioeng Biotechnol 2024; 12:1323056. [PMID: 38665816 PMCID: PMC11043469 DOI: 10.3389/fbioe.2024.1323056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 03/29/2024] [Indexed: 04/28/2024] Open
Abstract
Phase-change droplets (PCDs) are intelligent responsive micro and nanomaterials developed based on micro/nano bubbles. Subject to external energy inputs such as temperature and ultrasound, the core substance, perfluorocarbon (PFC), undergoes a phase transition from liquid to gas. This transformation precipitates alterations in the PCDs' structure, size, ultrasound imaging capabilities, drug delivery efficiency, and other pertinent characteristics. This gives them the ability to exhibit "intelligent responses". This study utilized lipids as the membrane shell material and perfluorohexane (PFH) as the core to prepare lipid phase-change droplets. Superparamagnetic nanoparticles (PEG-functionalized Fe3O4 nanoparticles) and the anti-tumor drug curcumin (Cur) were loaded into the membrane shell, forming magnetic drug-loaded phase-change droplets (Fe-Cur-NDs). These nanoscale phase-change droplets exhibited excellent magnetic resonance/ultrasound imaging capabilities and thermal/ultrasound-mediated drug release. The Fe-Cur-NDs showed excellent anti-tumor efficacy for the MCF-7 cells under low-intensity focused ultrasound (LIFU) guidance in vitro. Therefore, Fe-Cur-NDs represent a promising smart responsive theranostic integrated micro/nano drug delivery system.
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Affiliation(s)
- Jieying Chen
- Department of Biomedical Engineering, School of Biomedical Engineering and Informatics, Nanjing Medical University, Nanjing, China
| | - Chan Zhao
- Department of Clinical Medical Engineering, First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Hao Liu
- Department of Biomedical Engineering, School of Biomedical Engineering and Informatics, Nanjing Medical University, Nanjing, China
| | - Zhangchao Wang
- Stomatological College, Nanjing Medical University, Nanjing, China
| | - Luyao Ma
- Department of Biomedical Engineering, School of Biomedical Engineering and Informatics, Nanjing Medical University, Nanjing, China
| | - Jiamin Zhang
- Department of Biomedical Engineering, School of Biomedical Engineering and Informatics, Nanjing Medical University, Nanjing, China
| | - Ning Xu
- School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Ke Hu
- Department of Biomedical Engineering, School of Biomedical Engineering and Informatics, Nanjing Medical University, Nanjing, China
| | - Lei Duan
- Department of Biomedical Engineering, School of Biomedical Engineering and Informatics, Nanjing Medical University, Nanjing, China
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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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5
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Honari A, Sirsi SR. The Evolution and Recent Trends in Acoustic Targeting of Encapsulated Drugs to Solid Tumors: Strategies beyond Sonoporation. Pharmaceutics 2023; 15:1705. [PMID: 37376152 DOI: 10.3390/pharmaceutics15061705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 05/29/2023] [Accepted: 06/02/2023] [Indexed: 06/29/2023] Open
Abstract
Despite recent advancements in ultrasound-mediated drug delivery and the remarkable success observed in pre-clinical studies, no delivery platform utilizing ultrasound contrast agents has yet received FDA approval. The sonoporation effect was a game-changing discovery with a promising future in clinical settings. Various clinical trials are underway to assess sonoporation's efficacy in treating solid tumors; however, there are disagreements on its applicability to the broader population due to long-term safety issues. In this review, we first discuss how acoustic targeting of drugs gained importance in cancer pharmaceutics. Then, we discuss ultrasound-targeting strategies that have been less explored yet hold a promising future. We aim to shed light on recent innovations in ultrasound-based drug delivery including newer designs of ultrasound-sensitive particles specifically tailored for pharmaceutical usage.
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Affiliation(s)
- Arvin Honari
- Department of Bioengineering, Erik Johnson School of Engineering, The University of Texas at Dallas, Richardson, TX 75080, USA
| | - Shashank R Sirsi
- Department of Bioengineering, Erik Johnson School of Engineering, The University of Texas at Dallas, Richardson, TX 75080, USA
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6
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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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7
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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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8
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Heymans SV, Collado-Lara G, Rovituso M, Vos HJ, D'hooge J, de Jong N, Van Abeele KD. Acoustic Modulation Enables Proton Detection With Nanodroplets at Body Temperature. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2022; 69:2028-2038. [PMID: 35385380 DOI: 10.1109/tuffc.2022.3164805] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Superheated nanodroplet (ND) vaporization by proton radiation was recently demonstrated, opening the door to ultrasound-based in vivo proton range verification. However, at body temperature and physiological pressures, perfluorobutane nanodroplets (PFB-NDs), which offer a good compromise between stability and radiation sensitivity, are not directly sensitive to primary protons. Instead, they are vaporized by infrequent secondary particles, which limits the precision for range verification. The radiation-induced vaporization threshold (i.e., sensitization threshold) can be reduced by lowering the pressure in the droplet such that ND vaporization by primary protons can occur. Here, we propose to use an acoustic field to modulate the pressure, intermittently lowering the proton sensitization threshold of PFB-NDs during the rarefactional phase of the ultrasound wave. Simultaneous proton irradiation and sonication with a 1.1 MHz focused transducer, using increasing peak negative pressures (PNPs), were applied on a dilution of PFB-NDs flowing in a tube, while vaporization was acoustically monitored with a linear array. Sensitization to primary protons was achieved at temperatures between [Formula: see text] and 40 °C using acoustic PNPs of relatively low amplitude (from 800 to 200 kPa, respectively), while sonication alone did not lead to ND vaporization at those PNPs. Sensitization was also measured at the clinically relevant body temperature (i.e., 37 °C) using a PNP of 400 kPa. These findings confirm that acoustic modulation lowers the sensitization threshold of superheated NDs, enabling a direct proton response at body temperature.
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9
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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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Schoen S, Kilinc MS, Lee H, Guo Y, Degertekin FL, Woodworth GF, Arvanitis C. Towards controlled drug delivery in brain tumors with microbubble-enhanced focused ultrasound. Adv Drug Deliv Rev 2022; 180:114043. [PMID: 34801617 PMCID: PMC8724442 DOI: 10.1016/j.addr.2021.114043] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 09/27/2021] [Accepted: 11/04/2021] [Indexed: 02/06/2023]
Abstract
Brain tumors are particularly challenging malignancies, due to their location in a structurally and functionally distinct part of the human body - the central nervous system (CNS). The CNS is separated and protected by a unique system of brain and blood vessel cells which together prevent most bloodborne therapeutics from entering the brain tumor microenvironment (TME). Recently, great strides have been made through microbubble (MB) ultrasound contrast agents in conjunction with ultrasound energy to locally increase the permeability of brain vessels and modulate the brain TME. As we elaborate in this review, this physical method can effectively deliver a wide range of anticancer agents, including chemotherapeutics, antibodies, and nanoparticle drug conjugates across a range of preclinical brain tumors, including high grade glioma (glioblastoma), diffuse intrinsic pontine gliomas, and brain metastasis. Moreover, recent evidence suggests that this technology can promote the effective delivery of novel immunotherapeutic agents, including immune check-point inhibitors and chimeric antigen receptor T cells, among others. With early clinical studies demonstrating safety, and several Phase I/II trials testing the preclinical findings underway, this technology is making firm steps towards shaping the future treatments of primary and metastatic brain cancer. By elaborating on its key components, including ultrasound systems and MB technology, along with methods for closed-loop spatial and temporal control of MB activity, we highlight how this technology can be tuned to enable new, personalized treatment strategies for primary brain malignancies and brain metastases.
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Affiliation(s)
- Scott Schoen
- Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - M. Sait Kilinc
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Hohyun Lee
- Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Yutong Guo
- Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - F. Levent Degertekin
- Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Graeme F. Woodworth
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA,Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, College Park, MD 20742, USA,Fischell Department of Bioengineering A. James Clarke School of Engineering, University of Maryland
| | - Costas Arvanitis
- Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA,Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30332, USA
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11
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Durham PG, Dayton PA. Applications of sub-micron low-boiling point phase change contrast agents for ultrasound imaging and therapy. Curr Opin Colloid Interface Sci 2021. [DOI: 10.1016/j.cocis.2021.101498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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12
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Dong F, An J, Zhang J, Yin J, Guo W, Wang D, Feng F, Huang S, Zhang J, Cheng H. Blinking Acoustic Nanodroplets Enable Fast Super-resolution Ultrasound Imaging. ACS NANO 2021; 15:16913-16923. [PMID: 34647449 DOI: 10.1021/acsnano.1c07896] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The advent of localization-based super-resolution ultrasound (SRUS) imaging creates a vista for precision vasculature and hemodynamic measurements in brain science, cardiovascular diseases, and cancer. As blinking fluorophores are crucial to super-resolution optical imaging, blinking acoustic contrast agents enabling ultrasound localization microscopy have been highly sought, but only with limited success. Here we report on the discovery and characterization of a type of blinking acoustic nanodroplets (BANDs) ideal for SRUS. BANDs of 200-500 nm diameters comprise a perfluorocarbon-filled core and a shell of DSPC, Pluronic F68, and DSPE-PEG2000. When driven by clinically safe acoustic pulses (MI < 1.9) provided by a diagnostic ultrasound transducer, BANDs underwent reversible vaporization and reliquefaction, manifesting as "blinks", at rates of up to 5 kHz. By sparse activation of perfluorohexane-filled BANDs-C6 at high concentrations, only 100 frames of ultrasound imaging were sufficient to reconstruct super-resolution images of a no-flow tube through either cumulative localization or temporal radiality autocorrelation. Furthermore, the use of high-density BANDs-C6-4 (1 × 108/mL) with a 1:9 admixture of perfluorohexane and perfluorobutane supported the fast SRUS imaging of muscle vasculature in live animals, at 64 μm resolution requiring only 100 frames per layer. We anticipate that the BANDs developed here will greatly boost the application of SRUS in both basic science and clinical settings.
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Affiliation(s)
- Feihong Dong
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
- State Key Laboratory of Membrane Biology, National Biomedical Imaging Center, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China
| | - Jian An
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Jiabin Zhang
- State Key Laboratory of Membrane Biology, National Biomedical Imaging Center, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China
| | - Jingyi Yin
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Wenyu Guo
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Di Wang
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Feng Feng
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Shuo Huang
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Jue Zhang
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
- College of Engineering, Peking University, Beijing 100871, China
- National Biomedical Imaging Center, Peking University, Beijing 100871, China
| | - Heping Cheng
- State Key Laboratory of Membrane Biology, National Biomedical Imaging Center, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China
- National Biomedical Imaging Center, Peking University, Beijing 100871, China
- Research Unit of Mitochondria in Brain Diseases, Chinese Academy of Medical Sciences, PKU-Nanjing Institute of Translational Medicine, Nanjing 211899, China
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Kuriakose M, Borden MA. Microbubbles and Nanodrops for photoacoustic tomography. Curr Opin Colloid Interface Sci 2021. [DOI: 10.1016/j.cocis.2021.101464] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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14
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Ho YJ, Huang CC, Fan CH, Liu HL, Yeh CK. Ultrasonic technologies in imaging and drug delivery. Cell Mol Life Sci 2021; 78:6119-6141. [PMID: 34297166 PMCID: PMC11072106 DOI: 10.1007/s00018-021-03904-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 07/13/2021] [Accepted: 07/19/2021] [Indexed: 12/14/2022]
Abstract
Ultrasonic technologies show great promise for diagnostic imaging and drug delivery in theranostic applications. The development of functional and molecular ultrasound imaging is based on the technical breakthrough of high frame-rate ultrasound. The evolution of shear wave elastography, high-frequency ultrasound imaging, ultrasound contrast imaging, and super-resolution blood flow imaging are described in this review. Recently, the therapeutic potential of the interaction of ultrasound with microbubble cavitation or droplet vaporization has become recognized. Microbubbles and phase-change droplets not only provide effective contrast media, but also show great therapeutic potential. Interaction with ultrasound induces unique and distinguishable biophysical features in microbubbles and droplets that promote drug loading and delivery. In particular, this approach demonstrates potential for central nervous system applications. Here, we systemically review the technological developments of theranostic ultrasound including novel ultrasound imaging techniques, the synergetic use of ultrasound with microbubbles and droplets, and microbubble/droplet drug-loading strategies for anticancer applications and disease modulation. These advancements have transformed ultrasound from a purely diagnostic utility into a promising theranostic tool.
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Affiliation(s)
- Yi-Ju Ho
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | - Chih-Chung Huang
- Department of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan
- Medical Device Innovation Center, National Cheng Kung University, Tainan, Taiwan
| | - Ching-Hsiang Fan
- Department of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan
- Medical Device Innovation Center, National Cheng Kung University, Tainan, Taiwan
| | - Hao-Li Liu
- Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan.
| | - Chih-Kuang Yeh
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan.
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15
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Krafft MP, Riess JG. Therapeutic oxygen delivery by perfluorocarbon-based colloids. Adv Colloid Interface Sci 2021; 294:102407. [PMID: 34120037 DOI: 10.1016/j.cis.2021.102407] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 03/18/2021] [Accepted: 03/25/2021] [Indexed: 02/06/2023]
Abstract
After the protocol-related indecisive clinical trial of Oxygent, a perfluorooctylbromide/phospholipid nanoemulsion, in cardiac surgery, that often unduly assigned the observed untoward effects to the product, the development of perfluorocarbon (PFC)-based O2 nanoemulsions ("blood substitutes") has come to a low. Yet, significant further demonstrations of PFC O2-delivery efficacy have continuously been reported, such as relief of hypoxia after myocardial infarction or stroke; protection of vital organs during surgery; potentiation of O2-dependent cancer therapies, including radio-, photodynamic-, chemo- and immunotherapies; regeneration of damaged nerve, bone or cartilage; preservation of organ grafts destined for transplantation; and control of gas supply in tissue engineering and biotechnological productions. PFC colloids capable of augmenting O2 delivery include primarily injectable PFC nanoemulsions, microbubbles and phase-shift nanoemulsions. Careful selection of PFC and other colloid components is critical. The basics of O2 delivery by PFC nanoemulsions will be briefly reminded. Improved knowledge of O2 delivery mechanisms has been acquired. Advanced, size-adjustable O2-delivering nanoemulsions have been designed that have extended room-temperature shelf-stability. Alternate O2 delivery options are being investigated that rely on injectable PFC-stabilized microbubbles or phase-shift PFC nanoemulsions. The latter combine prolonged circulation in the vasculature, capacity for penetrating tumor tissues, and acute responsiveness to ultrasound and other external stimuli. Progress in microbubble and phase-shift emulsion engineering, control of phase-shift activation (vaporization), understanding and control of bubble/ultrasound/tissue interactions is discussed. Control of the phase-shift event and of microbubble size require utmost attention. Further PFC-based colloidal systems, including polymeric micelles, PFC-loaded organic or inorganic nanoparticles and scaffolds, have been devised that also carry substantial amounts of O2. Local, on-demand O2 delivery can be triggered by external stimuli, including focused ultrasound irradiation or tumor microenvironment. PFC colloid functionalization and targeting can help adjust their properties for specific indications, augment their efficacy, improve safety profiles, and expand the range of their indications. Many new medical and biotechnological applications involving fluorinated colloids are being assessed, including in the clinic. Further uses of PFC-based colloidal nanotherapeutics will be briefly mentioned that concern contrast diagnostic imaging, including molecular imaging and immune cell tracking; controlled delivery of therapeutic energy, as for noninvasive surgical ablation and sonothrombolysis; and delivery of drugs and genes, including across the blood-brain barrier. Even when the fluorinated colloids investigated are designed for other purposes than O2 supply, they will inevitably also carry and deliver a certain amount of O2, and may thus be considered for O2 delivery or co-delivery applications. Conversely, O2-carrying PFC nanoemulsions possess by nature a unique aptitude for 19F MR imaging, and hence, cell tracking, while PFC-stabilized microbubbles are ideal resonators for ultrasound contrast imaging and can undergo precise manipulation and on-demand destruction by ultrasound waves, thereby opening multiple theranostic opportunities.
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Affiliation(s)
- Marie Pierre Krafft
- University of Strasbourg, Institut Charles Sadron (CNRS), 23 rue du Loess, 67034 Strasbourg, France.
| | - Jean G Riess
- Harangoutte Institute, 68160 Ste Croix-aux-Mines, France
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Zhou H, Fu J, Fu Q, Feng Y, Hong R, Li P, Wang Z, Huang X, Li F. Biotin-streptavidin-guided two-step pretargeting approach using PLGA for molecular ultrasound imaging and chemotherapy for ovarian cancer. PeerJ 2021; 9:e11486. [PMID: 34113492 PMCID: PMC8162236 DOI: 10.7717/peerj.11486] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 04/27/2021] [Indexed: 01/18/2023] Open
Abstract
Background Ovarian cancer seriously threatens the lives and health of women, and early diagnosis and treatment are still challenging. Pre-targeting is a promising strategy to improve the treatment efficacy of ovarian cancer and the results of ultrasound imaging. Purpose To explore the effects of a pre-targeting strategy using streptavidin (SA) and paclitaxel (PTX)-loaded phase-shifting poly lactic-co-glycolic acid (PLGA) nanoparticles with perfluoro-n-pentane (PTX-PLGA-SA/PFPs) on the treatment and ultrasound imaging of ovarian cancer. Methods PTX-PLGA/PFPs were prepared with a single emulsion (O/W) solvent evaporation method and SA was attached using carbodiimide. The encapsulation efficiency of PTX and the release characteristics were assessed with high performance liquid chromatography. The phase-change characteristics of the PTX-PLGA-SA/PFPs were investigated. The anti-carcinoembryonic antigen (CEA) antibody (Ab) was covalently attached to PTX-PLGA/PFPs via carbodiimide to create PTX-PLGA-Ab/PFPs. The targeting efficiency of the nanoparticles and the viability of ovarian cancer SKOV3 cells were evaluated in each group using a microscope, flow cytometry, and cell counting kit 8 assays. Results THE PTX-PLGA-SA/PFPs were spheres with a size of 383.0 ± 75.59 nm. The encapsulation efficiency and loading capability of the nanoparticles for PTX were 71.56 ± 6.51% and 6.57 ± 0.61%, respectively. PTX was burst-released up to 70% in 2–3 d. When irradiated at 7.5 W for 3 min, the PTX-PLGA-SA/PFPs visibly enhanced the ultrasonography images (P < 0.05). At temperatures of 45°C and 60°C the nanoparticles phase-shifted into micro-bubbles and the sizes increased. The binding efficiencies of SA and Ab to the PTX-PLGA/PFPs were 97.16 ± 1.20% and 92.74 ± 5.75%, respectively. Pre-targeting resulted in a high binding efficacy and killing effect on SKOV3 cells (P < 0.05). Conclusions The two-step pre-targeting process can significantly enhance the targeting ability of PTX-loaded PLGA nanoparticles for ovarian cancer cells and substantially improve the therapeutic efficacy. This technique provides a new method for ultrasonic imaging and precise chemotherapy for ovarian cancer.
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Affiliation(s)
- Hang Zhou
- Ultrasound Medicine Department, Chongqing Key Laboratory of Translational Research for Cancer Metastasis and Individualized Treatment, Chongqing University Cancer Hospital, Chongqing, Shapingba District, China
| | - Jing Fu
- Ultrasound Medicine Department, Chongqing Key Laboratory of Translational Research for Cancer Metastasis and Individualized Treatment, Chongqing University Cancer Hospital, Chongqing, Shapingba District, China
| | - Qihuan Fu
- Ultrasound Medicine Department, Chongqing Key Laboratory of Translational Research for Cancer Metastasis and Individualized Treatment, Chongqing University Cancer Hospital, Chongqing, Shapingba District, China
| | - Yujie Feng
- Ultrasound Medicine Department, Chongqing Key Laboratory of Translational Research for Cancer Metastasis and Individualized Treatment, Chongqing University Cancer Hospital, Chongqing, Shapingba District, China
| | - Ruixia Hong
- Ultrasound Medicine Department, Chongqing Key Laboratory of Translational Research for Cancer Metastasis and Individualized Treatment, Chongqing University Cancer Hospital, Chongqing, Shapingba District, China
| | - Pan Li
- Ultrasound Department, Chongqing Key Laboratory of Ultrasound Molecular Imaging, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, Yuzhong District, China
| | - Zhigang Wang
- Ultrasound Department, Chongqing Key Laboratory of Ultrasound Molecular Imaging, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, Yuzhong District, China
| | - Xiaoling Huang
- Department of Ultrasound, the First Affiliated Hospital of Chongqing Medical University, Chongqing, Yuzhong District, China
| | - Fang Li
- Ultrasound Medicine Department, Chongqing Key Laboratory of Translational Research for Cancer Metastasis and Individualized Treatment, Chongqing University Cancer Hospital, Chongqing, Shapingba District, China
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Phase-Conversion Nanodroplets: Good Things Coming in Small Packages. J Am Soc Echocardiogr 2021; 34:910-912. [PMID: 33962004 DOI: 10.1016/j.echo.2021.04.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 04/30/2021] [Indexed: 11/24/2022]
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18
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Improving Release of Liposome-Encapsulated Drugs with Focused Ultrasound and Vaporizable Droplet-Liposome Nanoclusters. Pharmaceutics 2021; 13:pharmaceutics13050609. [PMID: 33922219 PMCID: PMC8145150 DOI: 10.3390/pharmaceutics13050609] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 04/14/2021] [Accepted: 04/18/2021] [Indexed: 12/13/2022] Open
Abstract
Active targeted delivery of small molecule drugs is becoming increasingly important in personalized therapies, especially in cancer, brain disorders, and a wide variety of other diseases. However, effective means of spatial targeting and delivering high drug payloads in vivo are still lacking. Focused ultrasound combined with superheated phase-shift nanodroplets, which vaporize into microbubbles using heat and sound, are rapidly becoming a popular strategy for targeted drug delivery. Focused ultrasound can target deep tissue with excellent spatial precision and without using ionizing energy, thus can activate nanodroplets in circulation. One of the main limitations of this technology has been poor drug loading in the droplet core or the shell material. To address this need, we have developed a strategy to combine low-boiling point decafluorabutane and octafluoropropane (DFB and OFP) nanodroplets with drug-loaded liposomes, creating phase-changeable droplet-liposome clusters (PDLCs). We demonstrate a facile method of assembling submicron PDLCs with high drug-loading capacity on the droplet surface. Furthermore, we demonstrate that chemical tethering of liposomes in PDLCs enables a rapid release of their encapsulated cargo upon acoustic activation (>60% using OFP-based PDLCs). Rapid uncaging of small molecule drugs would make them immediately bioavailable in target tissue or promote better penetration in local tissue following intravascular release. PDLCs developed in this study can be used to deliver a wide variety of liposome-encapsulated therapeutics or imaging agents for multi-modal imaging applications. We also outline a strategy to deliver a surrogate encapsulated drug, fluorescein, to tumors in vivo using focused ultrasound energy and PDLCs.
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19
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Thomas AN, Song KH, Upadhyay A, Papadopoulou V, Ramirez D, Benninger RKP, Lowerison M, Song P, Murray TW, Borden MA. Contrast-Enhanced Sonography with Biomimetic Lung Surfactant Nanodrops. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:2386-2396. [PMID: 33566623 PMCID: PMC8988746 DOI: 10.1021/acs.langmuir.0c03349] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Nanodrops comprising a perfluorocarbon liquid core can be acoustically vaporized into echogenic microbubbles for ultrasound imaging. Packaging the microbubble in its condensed liquid state provides some advantages, including in situ activation of the acoustic signal, longer circulation persistence, and the advent of expanded diagnostic and therapeutic applications in pathologies which exhibit compromised vasculature. One obstacle to clinical translation is the inability of the limited surfactant present on the nanodrop to encapsulate the greatly expanded microbubble interface, resulting in ephemeral microbubbles with limited utility. In this study, we examine a biomimetic approach to stabilize an expanding gas surface by employing the lung surfactant replacement, beractant. Lung surfactant contains a suite of lipids and proteins that provide efficient shuttling of material from bilayer folds to the monolayer surface. We hypothesized that beractant would improve stability of acoustically vaporized microbubbles. To test this hypothesis, we characterized beractant surface dilation mechanics and revealed a novel biophysical phenomenon of rapid interfacial melting, spreading, and resolidification. We then harnessed this unique functionality to increase the stability and echogenicity of microbubbles produced after acoustic droplet vaporization for in vivo ultrasound imaging. Such biomimetic lung surfactant-stabilized nanodrops may be useful for applications in ultrasound imaging and therapy.
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Affiliation(s)
- Alec N Thomas
- Department of Mechanical Engineering, University of Colorado, Boulder 80309, Colorado, United States
- Institute of Biomedical Engineering, Oxford University, Oxford OX3 7DQ, U.K
| | - Kang-Ho Song
- Department of Mechanical Engineering, University of Colorado, Boulder 80309, Colorado, United States
| | - Awaneesh Upadhyay
- Department of Mechanical Engineering, University of Colorado, Boulder 80309, Colorado, United States
| | - Virginie Papadopoulou
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill & North Carolina State University, Chapel Hill 27514, North Carolina, United States
| | - David Ramirez
- Department of Bioengineering, University of Colorado, Anschutz Medical Campus, Boulder 80045, Colorado, United States
| | - Richard K P Benninger
- Department of Bioengineering, University of Colorado, Anschutz Medical Campus, Boulder 80045, Colorado, United States
| | - Matthew Lowerison
- Department of Electrical and Computer Engineering, University of Illinois, Urbana-Champaign 61801, Colorado, United States
- Beckman Institute for Advanced Science and Technology, University of Illinois, Urbana-Champaign 61801, Colorado, United States
| | - Pengfei Song
- Department of Electrical and Computer Engineering, University of Illinois, Urbana-Champaign 61801, Colorado, United States
- Beckman Institute for Advanced Science and Technology, University of Illinois, Urbana-Champaign 61801, Colorado, United States
| | - Todd W Murray
- Department of Mechanical Engineering, University of Colorado, Boulder 80309, Colorado, United States
- Department of Biomedical Engineering, University of Colorado, Boulder 80309, Colorado, United States
| | - Mark A Borden
- Department of Mechanical Engineering, University of Colorado, Boulder 80309, Colorado, United States
- Department of Biomedical Engineering, University of Colorado, Boulder 80309, Colorado, United States
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20
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Sheng D, Deng L, Li P, Wang Z, Zhang Q. Perfluorocarbon Nanodroplets with Deep Tumor Penetration and Controlled Drug Delivery for Ultrasound/Fluorescence Imaging Guided Breast Cancer Therapy. ACS Biomater Sci Eng 2021; 7:605-616. [PMID: 33464814 DOI: 10.1021/acsbiomaterials.0c01333] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Danli Sheng
- Institute of Ultrasound Imaging, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P. R. China
- Department of Ultrasound, Fudan University, Shanghai Cancer Center, Shanghai 200032, China
| | - Liming Deng
- Institute of Ultrasound Imaging, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P. R. China
| | - Pan Li
- Institute of Ultrasound Imaging, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P. R. China
| | - Zhigang Wang
- Institute of Ultrasound Imaging, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P. R. China
| | - Qunxia Zhang
- Institute of Ultrasound Imaging, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P. R. China
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21
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Borden MA, Shakya G, Upadhyay A, Song KH. Acoustic Nanodrops for Biomedical Applications. Curr Opin Colloid Interface Sci 2020; 50:101383. [PMID: 33100885 PMCID: PMC7581261 DOI: 10.1016/j.cocis.2020.08.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Acoustic nanodrops are designed to vaporize into ultrasound-responsive microbubbles, which presents certain challenges nonexistent for conventional nano-emulsions. The requirements of biocompatibility, vaporizability and colloidal stability has focused research on perfluorocarbons (PFCs). Shorter PFCs yield better vaporizability via their lower critical temperature, but they also dissolve more easily owing to their higher vapor pressure and solubility. Thus, acoustic nanodrops have required a tradeoff between vaporizability and colloidal stability in vivo. The recent advent of vaporizable endoskeletal droplets, which are both stable and vaporizable, may have solved this problem. The purpose of this review is to justify this premise by pointing out the beneficial properties of acoustic nanodrops, providing an analysis of vaporization and dissolution mechanisms, and reviewing current biomedical applications.
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Affiliation(s)
- Mark A. Borden
- Biomedical Engineering, Mechanical Engineering, University of Colorado, Boulder, USA
| | - Gazendra Shakya
- Biomedical Engineering, Mechanical Engineering, University of Colorado, Boulder, USA
| | - Awaneesh Upadhyay
- Biomedical Engineering, Mechanical Engineering, University of Colorado, Boulder, USA
| | - Kang-Ho Song
- Biomedical Engineering, Mechanical Engineering, University of Colorado, Boulder, USA
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22
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DeRuiter RM, Markley EN, Rojas JD, Pinton GF, Dayton PA. Transient acoustic vaporization signatures unique to low boiling point phase change contrast agents enable super-resolution ultrasound imaging without spatiotemporal filtering. AIP ADVANCES 2020; 10:105124. [PMID: 33094029 PMCID: PMC7575328 DOI: 10.1063/5.0029207] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 09/21/2020] [Indexed: 05/18/2023]
Abstract
The unique activation signal of phase-change contrast agents (PCCAs or droplets) can be separated from the tissue signal and localized to generate super-resolution (SR) ultrasound (US) images. Lipid-shelled, perfluorocarbon PCCAs can be stochastically vaporized (activated) by a plane wave US transmission thereby enabling them to be used as separable targets for ultrasound localization microscopy. The unique signature of droplet vaporization imaging and the transient inherent nature of this signature increases signal contrast and therefore localization confidence, while the poor resolution of the low-frequency vaporization signal is overcome by the super-resolution result. Furthermore, our proposed PCCA SR technique does not require the use of user-dependent and flow-dependent spatio-temporal filtering via singular-value decomposition. Rather, matched filters selected by Fourier-domain analysis are able to identify and localize PCCA activations. Droplet SR was demonstrated in a crossed-microtube water phantom by localizing the activation signals of octafluoropropane nanodroplets (OFP, C3F8, -37 °C boiling point) to resolve 100 µm diameter fluorinated ethylene propylene tubes, which are ordinarily 35% smaller than the native diffraction-limited resolution of the imaging system utilized.
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Affiliation(s)
| | | | | | | | - P. A. Dayton
- Author to whom correspondence should be addressed:
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23
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Jing B, Kashyap EP, Lindsey BD. Transcranial activation and imaging of low boiling point phase-change contrast agents through the temporal bone using an ultrafast interframe activation ultrasound sequence. Med Phys 2020; 47:4450-4464. [PMID: 32657429 DOI: 10.1002/mp.14390] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 06/08/2020] [Accepted: 07/07/2020] [Indexed: 12/14/2022] Open
Abstract
PURPOSE As a cavitation enhancer, low boiling point phase-change contrast agents (PCCA) offer potential for ultrasound-mediated drug delivery in applications including intracerebral hemorrhage or brain tumors. In addition to introducing cavitation, ultrasound imaging also has the ability to provide guidance and monitoring of the therapeutic process by localizing delivery events. However, the highly attenuating skull poses a challenge for achieving an image with useful contrast. In this study, the feasibility of transcranial activation and imaging of low boiling point PCCAs through the human temporal bone was investigated by using a low frequency ultrafast interframe activation ultrasound (UIAU) imaging sequence with singular value decomposition-based denoising. METHODS Lipid-shelled PCCAs filled with decafluorobutane were activated and imaged at 37°C in tissue-mimicking phantoms both without and with an ex vivo human skull using the new UIAU sequence and a low frequency diagnostic transducer array at frequencies from 1.5 to 3.5 MHz. A singular value decomposition-based denoising filter was developed and used to further enhance transcranial image contrast. The contrast-to-tissue ratio (CTR) and contrast enhancement (CE) of UIAU was quantitatively evaluated and compared with the amplitude modulation pulse inversion (AMPI) and vaporization detection imaging (VDI) approaches. RESULTS Image results demonstrate enhanced contrast in the phantom channel with suppressed background when the low boiling point PCCA was activated both without and with an ex vivo human skull using the UIAU sequence. Quantitative results show that without the skull, low frequency UIAU imaging provided significantly higher image contrast (CTR ≥ 18.56 dB and CE ≥ 18.66 dB) than that of AMPI and VDI (P < 0.05). Transcranial imaging results indicated that the CE of UIAU (≥18.80 dB) was significantly higher than AMPI for free-field activation pressures of 5 and 6 MPa. The CE of UIAU is also significantly higher than that of VDI when PCCAs were activated at 2.5 MHz and 3 MHz (P < 0.05). The CTR (23.30 [20.07-25.56] dB) of denoised UIAU increased by 12.58 dB relative to the non-denoised case and was significantly higher than that of AMPI at an activation pressure of 4 MPa (P < 0.05). CONCLUSIONS Results indicate that low boiling point PCCAs can be activated and imaged at low frequencies including imaging through the temporal bone using the UIAU sequence. The UIAU imaging approach provides higher contrast than AMPI and VDI, especially at lower activation pressures with additional removal of electronic noise.
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Affiliation(s)
- Bowen Jing
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30332, USA
| | - Esha P Kashyap
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30332, USA
| | - Brooks D Lindsey
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30332, USA.,School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
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Xu T, Cui Z, Li D, Cao F, Xu J, Zong Y, Wang S, Bouakaz A, Wan M, Zhang S. Cavitation characteristics of flowing low and high boiling-point perfluorocarbon phase-shift nanodroplets during focused ultrasound exposures. ULTRASONICS SONOCHEMISTRY 2020; 65:105060. [PMID: 32199255 DOI: 10.1016/j.ultsonch.2020.105060] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 01/15/2020] [Accepted: 03/07/2020] [Indexed: 06/10/2023]
Abstract
This work investigated and compared the dynamic cavitation characteristics between low and high boiling-point phase-shift nanodroplets (NDs) under physiologically relevant flow conditions during focused ultrasound (FUS) exposures at different peak rarefactional pressures. A passive cavitation detection (PCD) system was used to monitor cavitation activity during FUS exposure at various acoustic pressure levels. Root mean square (RMS) amplitudes of broadband noise, spectrograms of the passive cavitation detection signals, and normalized inertial cavitation dose (ICD) values were calculated. Cavitation activity of low-boiling-point perfluoropentane (PFP) NDs and high boiling-point perfluorohexane (PFH) NDs flowing at in vitro mean velocities of 0-15 cm/s were compared in a 4-mm diameter wall-less vessel in a transparent tissue-mimicking phantom. In the static state, both types of phase-shift NDs exhibit a sharp rise in cavitation intensity during initial FUS exposure. Under flow conditions, cavitation activity of the PFH NDs reached the steady state less rapidly compared to PFP NDs under the lower acoustic pressure (1.35 MPa); at the higher acoustic pressure (1.65 MPa), the RMS amplitude increased more sharply during the initial FUS exposure period. In particular, the RMS-time curves of the PFP NDs shifted upward as the mean flow velocity increased from 0 to 15 cm/s; the RMS amplitude of the PFH ND solution increased from 0 to 10 cm/s and decreased at 15 cm/s. Moreover, amplitudes of the echo signal for the low boiling-point PFP NDs were higher compared to the high boiling-point PFH NDs in the lower frequency range, whereas the inverse occurred in the higher frequency range. Both PFP and PFH NDs showed increased cavitation activity in the higher frequency under the flow condition compared to the static state, especially PFH NDs. At 1.65 MPa, normalized ICD values for PFH increased from 0.93 ± 0.03 to 0.96 ± 0.04 and from 0 to 10 cm/s, then decreased to 0.86 ± 0.05 at 15 cm/s. This work contributes to our further understanding of cavitation characteristics of phase-shift NDs under physiologically relevant flow conditions during FUS exposure. In addition, the results provide a reference for selecting suitable phase-shift NDs to enhance the efficiency of cavitation-mediated ultrasonic applications.
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Affiliation(s)
- Tianqi Xu
- The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Zhiwei Cui
- The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Dapeng Li
- The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Fangyuan Cao
- The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Jichen Xu
- Institute of Artificial Intelligence and Robotics, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China; National Engineering Laboratory for Visual Information Processing and Applications, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Yujin Zong
- The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Supin Wang
- The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | | | - Mingxi Wan
- The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China.
| | - Siyuan Zhang
- The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China.
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Shakya G, Hoff SE, Wang S, Heinz H, Ding X, Borden MA. Vaporizable endoskeletal droplets via tunable interfacial melting transitions. SCIENCE ADVANCES 2020; 6:eaaz7188. [PMID: 32284985 PMCID: PMC7124936 DOI: 10.1126/sciadv.aaz7188] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 01/08/2020] [Indexed: 05/08/2023]
Abstract
Liquid emulsion droplet evaporation is of importance for various sensing and imaging applications. The liquid-to-gas phase transformation is typically triggered thermally or acoustically by low-boiling point liquids, or by inclusion of solid structures that pin the vapor/liquid contact line to facilitate heterogeneous nucleation. However, these approaches lack precise tunability in vaporization behavior. Here, we describe a previously unused approach to control vaporization behavior through an endoskeleton that can melt and blend into the liquid core to either enhance or disrupt cohesive intermolecular forces. This effect is demonstrated using perfluoropentane (C5F12) droplets encapsulating a fluorocarbon (FC) or hydrocarbon (HC) endoskeleton. FC skeletons inhibit vaporization, whereas HC skeletons trigger vaporization near the rotator melting transition. Our findings highlight the importance of skeletal interfacial mixing for initiating droplet vaporization. Tuning molecular interactions between the endoskeleton and droplet phase is generalizable for achieving emulsion or other secondary phase transitions, in emulsions.
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Affiliation(s)
- Gazendra Shakya
- Department of Mechanical Engineering, University of Colorado, 1111 Engineering Dr., Boulder, CO 80309, USA
| | - Samuel E. Hoff
- Department of Chemical and Biological Engineering, 596 UCB, Boulder, CO 80309, USA
| | - Shiyi Wang
- Department of Chemical and Biological Engineering, 596 UCB, Boulder, CO 80309, USA
| | - Hendrik Heinz
- Department of Chemical and Biological Engineering, 596 UCB, Boulder, CO 80309, USA
- Materials Science and Engineering Program, 027 UCB, University of Colorado, Boulder, CO 80309, USA
| | - Xiaoyun Ding
- Department of Mechanical Engineering, University of Colorado, 1111 Engineering Dr., Boulder, CO 80309, USA
| | - Mark A. Borden
- Department of Mechanical Engineering, University of Colorado, 1111 Engineering Dr., Boulder, CO 80309, USA
- Materials Science and Engineering Program, 027 UCB, University of Colorado, Boulder, CO 80309, USA
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26
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Brambila CJ, Lux J, Mattrey RF, Boyd D, Borden MA, de Gracia Lux C. Bubble Inflation Using Phase-Change Perfluorocarbon Nanodroplets as a Strategy for Enhanced Ultrasound Imaging and Therapy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:2954-2965. [PMID: 32090572 DOI: 10.1021/acs.langmuir.9b03647] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Phase-change perfluorocarbon microdroplets were introduced over 2 decades ago to occlude downstream vessels in vivo. Interest in perfluorocarbon nanodroplets has recently increased to enable extravascular targeting, to rescue the weak ultrasound signal of perfluorocarbon droplets by converting them to microbubbles and to improve ultrasound-based therapy. Despite great scientific interest and advances, applications of phase-change perfluorocarbon agents have not reached clinical testing because of efficacy and safety concerns, some of which remain unexplained. Here, we report that the coexistence of perfluorocarbon droplets and microbubbles in blood, which is inevitable when droplets spontaneously or intentionally vaporize to form microbubbles, is a major contributor to the observed side effects. We develop the theory to explain why the coexistence of droplets and microbubbles results in microbubble inflation induced by perfluorocarbon transfer from droplets to adjacent microbubbles. We also present the experimental data showing up to 6 orders of magnitude microbubble volume expansion, which occludes a 200 μm tubing in the presence of perfluorocarbon nanodroplets. More importantly, we demonstrate that the rate of microbubble inflation and ultimate size can be controlled by manipulating formulation parameters to tailor the agent's design for the potential theranostic application while minimizing the risk to benefit ratio.
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Affiliation(s)
- Carlos J Brambila
- Translational Research in Ultrasound Theranostics (TRUST) Program, Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
- Biomedical Engineering Graduate Program, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Jacques Lux
- Translational Research in Ultrasound Theranostics (TRUST) Program, Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
- Biomedical Engineering Graduate Program, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
- Organic Chemistry Graduate Program, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Robert F Mattrey
- Translational Research in Ultrasound Theranostics (TRUST) Program, Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
- Biomedical Engineering Graduate Program, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Dustin Boyd
- Translational Research in Ultrasound Theranostics (TRUST) Program, Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Mark A Borden
- Department of Mechanical Engineering, University of Colorado, Boulder, Colorado 80309, United States
| | - Caroline de Gracia Lux
- Translational Research in Ultrasound Theranostics (TRUST) Program, Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
- Biomedical Engineering Graduate Program, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
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27
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Wang X, Zhou Y, Palacio-Betancur V, Kim YK, Delalande L, Tsuei M, Yang Y, de Pablo JJ, Abbott NL. Reconfigurable Multicompartment Emulsion Drops Formed by Nematic Liquid Crystals and Immiscible Perfluorocarbon Oils. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:16312-16323. [PMID: 31652070 DOI: 10.1021/acs.langmuir.9b02864] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Liquid crystalline (LC) oils offer the basis of stimuli-responsive LC-in-water emulsions. Although past studies have explored the properties of single-phase LC emulsions, few studies have focused on complex multicompartment emulsions containing co-existing isotropic and LC domains. In this paper, we report a study of multiphase emulsions using LCs and immiscible perfluoroalkanes dispersed in water or glycerol (the latter continuous phase is used to enable characterization). We found that the nematogen 4'-pentyl-4-biphenylcarbonitrile (5CB) anchors homeotropically (perpendicularly) and weakly at liquid perfluorononane (F9) interfaces, consistent with the smectic layering of 5CB molecules. The proposed role of smectic layering is supported by experiments performed with 4-(trans-4-pentylcyclohexyl)benzonitrile, a nematogen that possesses a cyclohexyl group that frustrates the smectic packing and leads to tilted orientations at the F9 interface. By employing perfluorocarbon and hydrocarbon surfactants in combination with multiphase 5CB and F9 emulsion droplets dispersed in a continuous water or glycerol phase, we observe a range of emulsion droplet morphologies to form, including core-shell and Janus structures, with internal organizations that reflect an interplay of interfacial (anchoring energies; F9 and glycerol) and elastic energies within the confines of the geometry of the emulsion droplet. By comparing experimental observations to simulations of the LC-perfluorocarbon droplets based on a Landau-de Gennes model of the free energy, we place bounds on the orientation-dependent interfacial energies that underlie the internal ordering of these complex emulsions. Additionally, by forming core-shells emulsion droplets from 5CB (shell) and perfluoroheptane (cores), we demonstrate how a liquid-to-vapor phase transition in the perfluorocarbon core can be used to actuate the droplet and rapidly thin the nematic shell. Overall, the results reported in this paper demonstrate that multiphase LC emulsions formed from mixtures of perfluoroalkanes and LCs provide new opportunities to engineer hierarchical and stimuli-responsive emulsion systems.
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Affiliation(s)
- Xin Wang
- Smith School of Chemical and Biomolecular Engineering , Cornell University , Ithaca , New York 14850 , United States
| | - Ye Zhou
- Pritzker School of Molecular Engineering , University of Chicago , Chicago , Illinois 60637 , United States
| | - Viviana Palacio-Betancur
- Pritzker School of Molecular Engineering , University of Chicago , Chicago , Illinois 60637 , United States
| | - Young-Ki Kim
- Smith School of Chemical and Biomolecular Engineering , Cornell University , Ithaca , New York 14850 , United States
- Department of Chemical Engineering , Pohang University of Science and Technology , Pohang , Gyengbuk 37673 , Korea
| | - Lily Delalande
- Pritzker School of Molecular Engineering , University of Chicago , Chicago , Illinois 60637 , United States
| | - Michael Tsuei
- Smith School of Chemical and Biomolecular Engineering , Cornell University , Ithaca , New York 14850 , United States
| | - Yu Yang
- Department of Chemical and Biological Engineering , University of Wisconsin-Madison , Madison , Wisconsin 53706 , United States
| | - Juan J de Pablo
- Pritzker School of Molecular Engineering , University of Chicago , Chicago , Illinois 60637 , United States
- Center for Molecular Engineering , Argonne National Laboratory , Lemont , Illinois 60439 , United States
| | - Nicholas L Abbott
- Smith School of Chemical and Biomolecular Engineering , Cornell University , Ithaca , New York 14850 , United States
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28
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Yuan Z, Demith A, Stoffel R, Zhang Z, Park YC. Light-activated doxorubicin-encapsulated perfluorocarbon nanodroplets for on-demand drug delivery in an in vitro angiogenesis model: Comparison between perfluoropentane and perfluorohexane. Colloids Surf B Biointerfaces 2019; 184:110484. [PMID: 31522023 DOI: 10.1016/j.colsurfb.2019.110484] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Revised: 08/30/2019] [Accepted: 08/31/2019] [Indexed: 10/26/2022]
Abstract
Phase-transition perfluorocarbon (PFC) nanodroplets have been developed for on-demand drug delivery carriers with external triggers such as ultrasound or laser irradiation techniques. Although various perfluorocarbons, including perfluoropentane (C5F12) and perfluorohexane (C6F14), have been investigated for their theranostic use, comparison of the phase-transition efficiency, the drug delivery efficacy by light activation, and physical properties of the PFC nanodroplets have not been reported. We have synthesized gold nanorod-coated doxorubicin-encapsulated perfluorocarbon nanodroplets using perfluoropentane and perfluorohexane as light-activated on-demand drug delivery carriers, called PF5 and PF6, respectively. When gold nanorods on the perfluorocarbon nanodroplets resonate with a laser wavelength, plasmonic heat generated on the gold nanorods vaporizes the nanodroplets to gas bubbles (phase-transition), and releases the encapsulated drug from the nanodroplet core. Overall, the nanodroplet size, drug encapsulation efficiency, number density, and cytotoxicity were similar between PF5 and PF6. However, the long-term stability against passive phase-transition or coalescence in physiological conditions and the phase-transition efficiency were different from each other. PF6 was better in long-term stability but showed lower phase-transition than PF5. The lower phase-transition of PF6 might have led to lower drug delivery efficiency compared to PF5. This is probably because PF6 has higher temperature thresholds required for phase-transition due to its higher boiling point. The study demonstrated feasibility of the light-activated nanodroplets for on-demand targeted nanotherapy, which suppresses the development of angiogenesis.
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Affiliation(s)
- Zheng Yuan
- Department of Chemical & Environmental Engineering, College of Engineering & Applied Sciences, USA
| | - Alec Demith
- Medical Sciences Program, College of Medicine, University of Cincinnati, Cincinnati, OH, USA
| | - Ryan Stoffel
- Department of Chemical & Environmental Engineering, College of Engineering & Applied Sciences, USA
| | - Zhe Zhang
- Department of Chemical & Environmental Engineering, College of Engineering & Applied Sciences, USA
| | - Yoonjee C Park
- Department of Chemical & Environmental Engineering, College of Engineering & Applied Sciences, USA.
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29
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Borden MA. Intermolecular Forces Model for Lipid Microbubble Shells. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:10042-10051. [PMID: 30543753 DOI: 10.1021/acs.langmuir.8b03641] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Lipid-coated microbubbles are currently used clinically as ultrasound contrast agents for echocardiography and radiology and are being developed for many new diagnostic and therapeutic applications. Accordingly, there is a growing need to engineer specific formulations by employing rational design to guide lipid selection and processing. This approach requires a quantitative relationship between lipid chemistry and interfacial properties of the microbubble shell. Just such a model is proposed here on the basis of lateral Coulomb and van der Waals interactions between lipid head- and tailgroups, using previous coarse graining and force fields developed for molecular dynamics simulations. The model predicts with sufficient accuracy the monolayer permeability, the elasticity as a function of either lipid composition or temperature, and the equilibrium spreading surface tension of the lipid onto an air/water interface. In the future, the intermolecular forces model could be employed to elucidate more complex phenomena and to engineer novel microbubble formulations.
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Affiliation(s)
- Mark Andrew Borden
- Mechanical Engineering , University of Colorado , Boulder , Colorado 80309-0427 , United States
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30
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Zhang Z, Taylor M, Kaval N, Park YC. Phase-Transition Temperature of Gold-Nanorod-Coated Nanodroplets to Microbubbles by Pulsed Laser. J Phys Chem A 2019; 123:4844-4852. [PMID: 31117591 DOI: 10.1021/acs.jpca.9b02566] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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31
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Zhang G, Lin S, Leow CH, Pang KT, Hernández-Gil J, Long NJ, Eckersley R, Matsunaga T, Tang MX. Quantification of Vaporised Targeted Nanodroplets Using High-Frame-Rate Ultrasound and Optics. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:1131-1142. [PMID: 30827708 DOI: 10.1016/j.ultrasmedbio.2019.01.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 01/08/2019] [Accepted: 01/11/2019] [Indexed: 06/09/2023]
Abstract
Molecular targeted nanodroplets that can extravasate beyond the vascular space have great potential to improve tumor detection and characterisation. High-frame-rate ultrasound, on the other hand, is an emerging tool for imaging at a frame rate one to two orders of magnitude higher than those of existing ultrasound systems. In this study, we used high-frame-rate ultrasound combined with optics to study the acoustic response and size distribution of folate receptor (FR)-targeted versus non-targeted (NT)-nanodroplets in vitro with MDA-MB-231 breast cancer cells immediately after ultrasound activation. A flow velocity mapping technique, Stokes' theory and optical microscopy were used to estimate the size of both floating and attached vaporised nanodroplets immediately after activation. The floating vaporised nanodroplets were on average more than seven times larger than vaporised nanodroplets attached to the cells. The results also indicated that the acoustic signal of vaporised FR-targeted-nanodroplets persisted after activation, with 70% of the acoustic signals still present 1 s after activation, compared with the vaporised NT-nanodroplets, for which only 40% of the acoustic signal remained. The optical microscopic images revealed on average six times more vaporised FR-targeted-nanodroplets generated with a wider range of diameters (from 4 to 68 µm) that were still attached to the cells, compared with vaporised NT-nanodroplets (from 1 to 7 µm) with non-specific binding after activation. The mean size of attached vaporised FR-targeted-nanodroplets was on average about threefold larger than that of attached vaporised NT-nanodroplets. Taking advantage of high-frame-rate contrast-enhanced ultrasound and optical microscopy, this study offers an improved understanding of the vaporisation of the targeted nanodroplets in terms of their size and acoustic response in comparison with NT-nanodroplets. Such understanding would help in the design of optimised methodology for imaging and therapeutic applications.
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Affiliation(s)
- Ge Zhang
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Shengtao Lin
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Chee Hao Leow
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Kuin Tian Pang
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore
| | | | - Nicholas J Long
- Department of Chemistry, Imperial College London, London, United Kingdom
| | - Robert Eckersley
- Division of Imaging Sciences & Biomedical Engineering Department, King's College London, United Kingdom
| | - Terry Matsunaga
- Department of Medical Imaging, University of Arizona, Tucson, Arizona, USA
| | - Meng-Xing Tang
- Department of Bioengineering, Imperial College London, London, United Kingdom.
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32
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Rojas JD, Borden MA, Dayton PA. Effect of Hydrostatic Pressure, Boundary Constraints and Viscosity on the Vaporization Threshold of Low-Boiling-Point Phase-Change Contrast Agents. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:968-979. [PMID: 30658858 DOI: 10.1016/j.ultrasmedbio.2018.11.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 11/04/2018] [Accepted: 11/11/2018] [Indexed: 05/09/2023]
Abstract
The vaporization of low-boiling-point phase-change contrast agents (PCCAs) using ultrasound has been explored in vitro and in vivo. However, it has been reported that the pressure required for activation is higher in vivo, even after attenuation is accounted for. In this study, the effect of boundary constraints, hydrostatic pressure and viscosity on PCCA vaporization pressure threshold are evaluated to explore possible mechanisms for variations in in vivo vaporization behavior. Vaporization was measured in microtubes of varying inner diameter and a pressurized chamber under different hydrostatic pressures using a range of ultrasound pressures. Furthermore, the activation threshold was evaluated in the kidneys of rats. The results confirm that the vaporization threshold is higher in vivo and reveal an increasing activation threshold inversely proportional to constraining tube size and inversely proportional to surrounding viscosity in constrained environments. Counterintuitively, increased hydrostatic pressure had no significant effect experimentally on the PCCA vaporization threshold, although it was confirmed that this result was supported by homogeneous nucleation theory for liquid perfluorocarbon vaporization. These factors suggest that constraints caused by the surrounding tissue and capillary walls, as well as increased viscosity in vivo, contribute to the increased vaporization threshold compared with in vitro experiments, although more work is required to confirm all relevant factors.
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Affiliation(s)
- Juan D Rojas
- Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, North Carolina, USA
| | - Mark A Borden
- Department of Mechanical Engineering, University of Colorado, Boulder, Colorado, USA
| | - Paul A Dayton
- Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, North Carolina, USA.
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33
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Burgess MT, Porter TM. Control of Acoustic Cavitation for Efficient Sonoporation with Phase-Shift Nanoemulsions. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:846-858. [PMID: 30638968 PMCID: PMC8859868 DOI: 10.1016/j.ultrasmedbio.2018.12.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 11/20/2018] [Accepted: 12/03/2018] [Indexed: 05/18/2023]
Abstract
Acoustic cavitation can be used to temporarily disrupt cell membranes for intracellular delivery of large biomolecules. Termed sonoporation, the ability of this technique for efficient intracellular delivery (i.e., >50% of initial cell population showing uptake) while maintaining cell viability (i.e., >50% of initial cell population viable) has proven to be very difficult. Here, we report that phase-shift nanoemulsions (PSNEs) function as inertial cavitation nuclei for improvement of sonoporation efficiency. The interplay between ultrasound frequency, resultant microbubble dynamics and sonoporation efficiency was investigated experimentally. Acoustic emissions from individual microbubbles nucleated from PSNEs were captured using a broadband passive cavitation detector during and after acoustic droplet vaporization with short pulses of ultrasound at 1, 2.5 and 5 MHz. Time domain features of the passive cavitation detector signals were analyzed to estimate the maximum size (Rmax) of the microbubbles using the Rayleigh collapse model. These results were then applied to sonoporation experiments to test if uptake efficiency is dependent on maximum microbubble size before inertial collapse. Results indicated that at the acoustic droplet vaporization threshold, Rmax was approximately 61.7 ± 5.2, 24.9 ± 2.8, and 12.4 ± 2.1 μm at 1, 2.5 and 5 MHz, respectively. Sonoporation efficiency increased at higher frequencies, with efficiencies of 39.5 ± 13.7%, 46.6 ± 3.28% and 66.8 ± 5.5% at 1, 2.5 and 5 MHz, respectively. Excessive cellular damage was seen at lower frequencies because of the erosive effects of highly energetic inertial cavitation. These results highlight the importance of acoustic cavitation control in determining the outcome of sonoporation experiments. In addition, PSNEs may serve as tailorable inertial cavitation nuclei for other therapeutic ultrasound applications.
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Affiliation(s)
- Mark T Burgess
- Department of Mechanical Engineering, Boston University, Boston, Massachusetts, USA
| | - Tyrone M Porter
- Department of Mechanical Engineering, Boston University, Boston, Massachusetts, USA; Department of Biomedical Engineering, Boston University, Boston, Massachusetts, USA.
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34
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Lea-Banks H, O'Reilly MA, Hynynen K. Ultrasound-responsive droplets for therapy: A review. J Control Release 2019; 293:144-154. [PMID: 30503398 PMCID: PMC6459400 DOI: 10.1016/j.jconrel.2018.11.028] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 11/26/2018] [Accepted: 11/27/2018] [Indexed: 12/21/2022]
Abstract
The last two decades have seen the development of acoustically activated droplets, also known as phase-change emulsions, from a diagnostic tool to a therapeutic agent. Through bubble effects and triggered drug release, these superheated agents have found potential applications from oncology to neuromodulation. The aim of this review is to summarise the key developments in therapeutic droplet design and use, to discuss the current challenges slowing clinical translation, and to highlight the new frontiers progressing towards clinical implementation. The literature is summarised by addressing the droplet design criteria and by carrying out a multiparametric study of a range of droplet formulations and their associated vaporisation thresholds.
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Affiliation(s)
- H Lea-Banks
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Canada.
| | - M A O'Reilly
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Canada
| | - K Hynynen
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Canada
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35
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Rojas JD, Dayton PA. Vaporization Detection Imaging: A Technique for Imaging Low-Boiling-Point Phase-Change Contrast Agents with a High Depth of Penetration and Contrast-to-Tissue Ratio. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:192-207. [PMID: 30482709 DOI: 10.1016/j.ultrasmedbio.2018.08.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 08/17/2018] [Accepted: 08/22/2018] [Indexed: 06/09/2023]
Abstract
Phase-change contrast agents (PCCAs) possess advantages over microbubble contrast agents, such as the ability to extravasate and circulate longer in the vasculature that could enhance the diagnostic capabilities of contrast-enhanced ultrasound. PCCAs typically have a liquid perfluorocarbon (PFC) core that can be vaporized into echogenic microbubbles. Vaporization of submicron agents filled with liquid PFCs at body temperature usually requires therapeutic pressures higher than typically used for diagnostic imaging, but low-boiling-point PCCAs using decafluorobutane or octafluoropropane can be vaporized using pressures in the diagnostic imaging regime. Low-boiling-point PCCAs produce a unique acoustic signature that can be separated from tissue and bubble signals to make images with high contrast-to-tissue ratios. In this work, we explore the effect of pulse length and concentration on the vaporization signal of PCCAs and a new technique to capture and use the signals to make high contrast-to-tissue ratio images in vivo. The results indicate that using a short pulse may be ideal for imaging because it does not interact with created bubbles but still produces strong signals for making images. Furthermore, it was found that capturing PCCA vaporization signals produced higher contrast-to-tissue ratio values and better depth of penetration than imaging the bubbles generated by droplet activation using conventional contrast imaging techniques. The resolution of the vaporization signal images is poor because of the low frequency of the signals, but their high sensitivity may be used for applications such as molecular imaging, where the detection of small numbers of contrast agents is important.
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Affiliation(s)
- Juan D Rojas
- Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, North Carolina, USA
| | - Paul A Dayton
- Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, North Carolina, USA.
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36
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Nguyen K, Pan HY, Haworth K, Mahoney E, Mercado-Shekhar KP, Lin CY, Zhang Z, C Park Y. Multiple-Exposure Drug Release from Stable Nanodroplets by High-Intensity Focused Ultrasound for a Potential Degenerative Disc Disease Treatment. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:160-169. [PMID: 30482711 PMCID: PMC6290355 DOI: 10.1016/j.ultrasmedbio.2018.09.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 09/10/2018] [Accepted: 09/17/2018] [Indexed: 06/09/2023]
Abstract
The combination of simvastatin and CF680 dye encapsulated by stable nanodroplets has been developed as a drug delivery carrier. Simvastatin has previously been found to be a potential degenerative disc disease treatment. Multiple exposures of the nanodroplets to high-intensity focused ultrasound induced release of simvastatin. Each ultrasound exposure yielded a consistent concentration of the drug and dye released. B-mode ultrasound image analysis data and cavitation data clearly indicated the release mechanism is phase transition of the liquid nanodroplets into gas bubbles. The nanodroplets were stably stored in ex vivo rabbit spinal discs for at least 14 days, and the contents responded to ultrasound exposure on demand. Lastly, nucleus pulposus cells harvested from rabbit spine discs and exposed to media with nanodroplets exhibited a decrease in cell viability (85%) relative to the cells only (96.7%) at 24 h, but no difference at 48 h. Thus, the system may be a potential degenerative disc disease treatment.
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Affiliation(s)
- Khoi Nguyen
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, USA
| | - Hsuan-Yeh Pan
- Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Kevin Haworth
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, USA; Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Eric Mahoney
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, USA
| | | | - Chia-Ying Lin
- Department of Orthopaedic Surgery, University of Cincinnati, Cincinnati, Ohio, USA
| | - Zhe Zhang
- Department of Chemical & Environmental Engineering, University of Cincinnati, Cincinnati, Ohio, USA
| | - Yoonjee C Park
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, USA; Department of Chemical & Environmental Engineering, University of Cincinnati, Cincinnati, Ohio, USA.
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37
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Yoo K, Walker WR, Williams R, Tremblay-Darveau C, Burns PN, Sheeran PS. Impact of Encapsulation on in vitro and in vivo Performance of Volatile Nanoscale Phase-Shift Perfluorocarbon Droplets. ULTRASOUND IN MEDICINE & BIOLOGY 2018; 44:1836-1852. [PMID: 29908752 DOI: 10.1016/j.ultrasmedbio.2018.04.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 04/17/2018] [Accepted: 04/17/2018] [Indexed: 05/15/2023]
Abstract
Phase-shift droplets can be converted by sound from low-echogenicity, liquid-core agents into highly echogenic microbubbles. Many proposed applications in imaging and therapy take advantage of the high spatiotemporal control over this dynamic transition. Although some studies have reported increased circulation time of the droplets compared with microbubbles, few have directly explored the impact of encapsulation on droplet performance. With the goal of developing nanoscale droplets with increased circulatory persistence, we first evaluate the half-life of several candidate phospholipid encapsulations in vitro at clinical frequencies. To evaluate in vivo circulatory persistence, we develop a technique to periodically measure droplet vaporization from high-frequency B-mode scans of a mouse kidney. Results show that longer acyl chain phospholipids can dramatically reduce droplet degradation, increasing median half-life in vitro to 25.6 min-a 50-fold increase over droplets formed from phospholipids commonly used for clinical microbubbles. In vivo, the best-performing droplet formulations showed a median half-life of 18.4 min, more than a 35-fold increase in circulatory half-life compared with microbubbles with the same encapsulation in vivo. These findings also point to possible refinements that may improve nanoscale phase-shift droplet performance beyond those measured here.
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Affiliation(s)
- Kimoon Yoo
- Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Wesley R Walker
- Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Ross Williams
- Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Charles Tremblay-Darveau
- Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Peter N Burns
- Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Paul S Sheeran
- Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada.
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38
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Ho YJ, Chiang YJ, Kang ST, Fan CH, Yeh CK. Camptothecin-loaded fusogenic nanodroplets as ultrasound theranostic agent in stem cell-mediated drug-delivery system. J Control Release 2018; 278:100-109. [PMID: 29630986 DOI: 10.1016/j.jconrel.2018.04.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Revised: 03/15/2018] [Accepted: 04/02/2018] [Indexed: 12/22/2022]
Abstract
Adipose-derived stem cells (ADSCs) have been utilized in cellular delivery systems to carry therapeutic agents into tumors by migration. Drug-loaded nanodroplets release drugs and form bubbles after acoustic droplet vaporization (ADV) triggered by ultrasound stimulation, providing a system for ultrasound-induced cellular delivery of theranostic agents. In order to improve the efficiency of drug release, fusogenic nanodroplets were designed to go from nano to micron size upon uptake by ADSCs for reducing ADV threshold. The purpose of our study was to demonstrate the utility of camptothecin-loaded fusogenic nanodroplets (CPT-FNDs) as ultrasound theranostic agents in an ADSCs delivery system. CPT-FNDs showed an increase in size from 81.6 ± 3.5 to 1043.5 ± 28.3 nm and improved CPT release from 22.0 ± 1.8% to 37.6 ± 2.1%, demonstrating the fusion ability of CPT-FNDs. CPT-FNDs-loaded ADSCs demonstrated a cell viability of 77 ± 4%, and the in vitro migration ability was 3.2 ± 1.2-fold for the tumor condition compared to the cell growth condition. Ultrasound enhancement imaging showed intratumoral ADV-generated bubble formation (increasing 3.24 ± 0.47 dB) triggered by ultrasound after CPT-FNDs-loaded ADSCs migration into B16F0 tumors. Histological images revealed intratumoral distribution of CPT-FNDs-loaded ADSCs and tissue damage due to the ADV. The CPT-FNDs can be used as theranostic agents in an ADSCs delivery system to provide the ultrasound contrast imaging and deliver combination therapy of drug release and physical damage after ADV.
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Affiliation(s)
- Yi-Ju Ho
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | - Yu-Jung Chiang
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | - Shih-Tsung Kang
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | - Ching-Hsiang Fan
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | - Chih-Kuang Yeh
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan.
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39
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Lin S, Zhang G, Jamburidze A, Chee M, Leow CH, Garbin V, Tang MX. Imaging of vaporised sub-micron phase change contrast agents with high frame rate ultrasound and optics. Phys Med Biol 2018; 63:065002. [PMID: 29384498 DOI: 10.1088/1361-6560/aaac05] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Phase-change ultrasound contrast agent (PCCA), or nanodroplet, shows promise as an alternative to the conventional microbubble agent over a wide range of diagnostic applications. Meanwhile, high-frame-rate (HFR) ultrasound imaging with microbubbles enables unprecedented temporal resolution compared to traditional contrast-enhanced ultrasound imaging. The combination of HFR ultrasound imaging and PCCAs can offer the opportunity to observe and better understand PCCA behaviour after vaporisation captures the fast phenomenon at a high temporal resolution. In this study, we utilised HFR ultrasound at frame rates in the kilohertz range (5-20 kHz) to image native and size-selected PCCA populations immediately after vaporisation in vitro within clinical acoustic parameters. The size-selected PCCAs through filtration are shown to preserve a sub-micron-sized (mean diameter < 200 nm) population without micron-sized outliers (>1 µm) that originate from native PCCA emulsion. The results demonstrate imaging signals with different amplitudes and temporal features compared to that of microbubbles. Compared with the microbubbles, both the B-mode and pulse-inversion (PI) signals from the vaporised PCCA populations were reduced significantly in the first tens of milliseconds, while only the B-mode signals from the PCCAs were recovered during the next 400 ms, suggesting significant changes to the size distribution of the PCCAs after vaporisation. It is also shown that such recovery in signal over time is not evident when using size-selective PCCAs. Furthermore, it was found that signals from the vaporised PCCA populations are affected by the amplitude and frame rate of the HFR ultrasound imaging. Using high-speed optical camera observation (30 kHz), we observed a change in particle size in the vaporised PCCA populations exposed to the HFR ultrasound imaging pulses. These findings can further the understanding of PCCA behaviour under HFR ultrasound imaging.
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Affiliation(s)
- Shengtao Lin
- Department of Bioengineering, Imperial College London, London, United Kingdom
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40
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Wu SY, Fix SM, Arena CB, Chen CC, Zheng W, Olumolade OO, Papadopoulou V, Novell A, Dayton PA, Konofagou EE. Focused ultrasound-facilitated brain drug delivery using optimized nanodroplets: vaporization efficiency dictates large molecular delivery. Phys Med Biol 2018; 63:035002. [PMID: 29260735 DOI: 10.1088/1361-6560/aaa30d] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Focused ultrasound with nanodroplets could facilitate localized drug delivery after vaporization with potentially improved in vivo stability, drug payload, and minimal interference outside of the focal zone compared with microbubbles. While the feasibility of blood-brain barrier (BBB) opening using nanodroplets has been previously reported, characterization of the associated delivery has not been achieved. It was hypothesized that the outcome of drug delivery was associated with the droplet's sensitivity to acoustic energy, and can be modulated with the boiling point of the liquid core. Therefore, in this study, octafluoropropane (OFP) and decafluorobutane (DFB) nanodroplets were used both in vitro for assessing their relative vaporization efficiency with high-speed microscopy, and in vivo for delivering molecules with a size relevant to proteins (40 kDa dextran) to the murine brain. It was found that at low pressures (300-450 kPa), OFP droplets vaporized into a greater number of microbubbles compared to DFB droplets at higher pressures (750-900 kPa) in the in vitro study. In the in vivo study, successful delivery was achieved with OFP droplets at 300 kPa and 450 kPa without evidence of cavitation damage using ¼ dosage, compared to DFB droplets at 900 kPa where histology indicated tissue damage due to inertial cavitation. In conclusion, the vaporization efficiency of nanodroplets positively impacted the amount of molecules delivered to the brain. The OFP droplets due to the higher vaporization efficiency served as better acoustic agents to deliver large molecules efficiently to the brain compared with the DFB droplets.
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Affiliation(s)
- Shih-Ying Wu
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, United States of America
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41
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Zullino S, Argenziano M, Stura I, Guiot C, Cavalli R. From Micro- to Nano-Multifunctional Theranostic Platform: Effective Ultrasound Imaging Is Not Just a Matter of Scale. Mol Imaging 2018; 17:1536012118778216. [PMID: 30213222 PMCID: PMC6144578 DOI: 10.1177/1536012118778216] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 03/20/2018] [Accepted: 04/08/2018] [Indexed: 12/20/2022] Open
Abstract
Ultrasound Contrast Agents (UCAs) consisting of gas-filled-coated Microbubbles (MBs) with diameters between 1 and 10 µm have been used for a number of decades in diagnostic imaging. In recent years, submicron contrast agents have proven to be a viable alternative to MBs for ultrasound (US)-based applications for their capability to extravasate and accumulate in the tumor tissue via the enhanced permeability and retention effect. After a short overview of the more recent approaches to ultrasound-mediated imaging and therapeutics at the nanoscale, phase-change contrast agents (PCCAs), which can be phase-transitioned into highly echogenic MBs by means of US, are here presented. The phenomenon of acoustic droplet vaporization (ADV) to produce bubbles is widely investigated for both imaging and therapeutic applications to develop promising theranostic platforms.
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Affiliation(s)
- Sara Zullino
- Department of Neuroscience, University of Turin, Turin, Italy
| | - Monica Argenziano
- Department of Drug Science and Technology, University of Turin, Turin, Italy
| | - Ilaria Stura
- Department of Clinical and Biological Science, University of Turin, Turin, Italy
| | - Caterina Guiot
- Department of Neuroscience, University of Turin, Turin, Italy
| | - Roberta Cavalli
- Department of Drug Science and Technology, University of Turin, Turin, Italy
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42
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Lin S, Zhang G, Leow CH, Tang MX. Effects of microchannel confinement on acoustic vaporisation of ultrasound phase change contrast agents. Phys Med Biol 2017; 62:6884-6898. [PMID: 28718774 DOI: 10.1088/1361-6560/aa8076] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The sub-micron phase change contrast agent (PCCA) composed of a perfluorocarbon liquid core can be activated into gaseous state and form stable echogenic microbubbles for contrast-enhanced ultrasound imaging. It has shown great promise in imaging microvasculature, tumour microenvironment, and cancer cells. Although PCCAs have been extensively studied for different diagnostic and therapeutic applications, the effect of biologically geometrical confinement on the acoustic vaporisation of PCCAs is still not clear. We have investigated the difference in PCCA-produced ultrasound contrast enhancement after acoustic activation with and without a microvessel confinement on a microchannel phantom. The experimental results indicated more than one-order of magnitude less acoustic vaporisation in a microchannel than that in a free environment taking into account the attenuation effect of the vessel on the microbubble scattering. This may provide an improved understanding in the applications of PCCAs in vivo.
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Affiliation(s)
- Shengtao Lin
- Department of Bioengineering, Imperial College London, London, United Kingdom
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43
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Lin S, Shah A, Hernández-Gil J, Stanziola A, Harriss BI, Matsunaga TO, Long N, Bamber J, Tang MX. Optically and acoustically triggerable sub-micron phase-change contrast agents for enhanced photoacoustic and ultrasound imaging. PHOTOACOUSTICS 2017; 6:26-36. [PMID: 28507898 PMCID: PMC5423321 DOI: 10.1016/j.pacs.2017.04.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 03/10/2017] [Accepted: 04/08/2017] [Indexed: 05/20/2023]
Abstract
We demonstrate a versatile phase-change sub-micron contrast agent providing three modes of contrast enhancement: 1) photoacoustic imaging contrast, 2) ultrasound contrast with optical activation, and 3) ultrasound contrast with acoustic activation. This agent, which we name 'Cy-droplet', has the following novel features. It comprises a highly volatile perfluorocarbon for easy versatile activation, and a near-infrared optically absorbing dye chosen to absorb light at a wavelength with good tissue penetration. It is manufactured via a 'microbubble condensation' method. The phase-transition of Cy-droplets can be optically triggered by pulsed-laser illumination, inducing photoacoustic signal and forming stable gas bubbles that are visible with echo-ultrasound in situ. Alternatively, Cy-droplets can be converted to microbubble contrast agents upon acoustic activation with clinical ultrasound. Potentially all modes offer extravascular contrast enhancement because of the sub-micron initial size. Such versatility of acoustic and optical 'triggerability' can potentially improve multi-modality imaging, molecularly targeted imaging and controlled drug release.
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Affiliation(s)
- Shengtao Lin
- Department of Bioengineering, Imperial College London, London, UK
| | - Anant Shah
- Joint Department of Physics and CRUK Cancer Imaging Centre, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, England, UK
| | | | | | | | | | - Nicholas Long
- Department of Chemistry, Imperial College London, London, UK
| | - Jeffrey Bamber
- Joint Department of Physics and CRUK Cancer Imaging Centre, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, England, UK
| | - Meng-Xing Tang
- Department of Bioengineering, Imperial College London, London, UK
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44
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Sheeran PS, Yoo K, Williams R, Yin M, Foster FS, Burns PN. More Than Bubbles: Creating Phase-Shift Droplets from Commercially Available Ultrasound Contrast Agents. ULTRASOUND IN MEDICINE & BIOLOGY 2017; 43:531-540. [PMID: 27727022 DOI: 10.1016/j.ultrasmedbio.2016.09.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Revised: 08/30/2016] [Accepted: 09/06/2016] [Indexed: 05/09/2023]
Abstract
Phase-shift perfluorocarbon droplets have been investigated for over 20 years as pre-clinical ultrasound contrast agents with distinctive advantages in imaging and therapy. A number of formulation strategies exist, each with inherent advantages and limitations. In this note, we demonstrate a unique opportunity: that phase-shift droplets can be generated directly from commercially available microbubbles. This may facilitate pre-clinical and translational development by reducing the in-house synthesis expertise and resources required to generate high concentration droplet emulsions. Proof-of-principle in vitro and in vivo is given using droplets created from Definity and MicroMarker. The results demonstrate the role of perfluorocarbon choice in the trade-off between thermal stability and vaporization threshold, and suggest that commercial microbubbles with decafluorobutane cores may be ideal for this approach.
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Affiliation(s)
- Paul S Sheeran
- Physical Sciences Department, Sunnybrook Research Institute, Toronto, ON, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Canada.
| | - Kimoon Yoo
- Physical Sciences Department, Sunnybrook Research Institute, Toronto, ON, Canada
| | - Ross Williams
- Physical Sciences Department, Sunnybrook Research Institute, Toronto, ON, Canada
| | - Melissa Yin
- Physical Sciences Department, Sunnybrook Research Institute, Toronto, ON, Canada
| | - F Stuart Foster
- Physical Sciences Department, Sunnybrook Research Institute, Toronto, ON, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Canada
| | - Peter N Burns
- Physical Sciences Department, Sunnybrook Research Institute, Toronto, ON, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Canada
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45
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Capece S, Domenici F, Brasili F, Oddo L, Cerroni B, Bedini A, Bordi F, Chiessi E, Paradossi G. Complex interfaces in "phase-change" contrast agents. Phys Chem Chem Phys 2017; 18:8378-88. [PMID: 26931337 DOI: 10.1039/c5cp07538f] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this paper we report on the study of the interface of hybrid shell droplets encapsulating decafluoropentane (DFP), which exhibit interesting potentialities for ultrasound (US) imaging. The fabrication of the droplets is based on the deposition of a dextran methacrylate layer onto the surface of surfactants. The droplets have been stabilized against coalescence by UV curing, introducing crosslinks in the polymer layer and transforming the shell into an elastomeric membrane with a thickness of about 300 nm with viscoelastic behaviour. US irradiation induces the evaporation of the DFP core of the droplets transforming the particles into microbubbles (MBs). The presence of a robust crosslinked polymer shell introduces an unusual stability of the droplets also during the core phase transition and allows the recovery of the initial droplet state after a few minutes from switching off US. The interfacial tension of the droplets has been investigated by two approaches, the pendant drop method and an indirect method, based on the determination of the liquid ↔ gas transition point of DFP confined in the droplet core. The re-condensation process has been followed by capturing images of single MBs by confocal microscopy. The time evolution of MB relaxation to droplets was analysed in terms of a modified Church model to account for the structural complexity of the MB shell, i.e. a crosslinked polymer layer over a layer of surfactants. In this way the microrheology parameters of the shell were determined. In a previous paper (Chem. Commun., 2013, 49, 5763-5765) we showed that these systems could be used as ultrasound contrast agents (UCAs). In this work we substantiate this view assessing some key features offered by the viscoelastic nature of the droplet shell.
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Affiliation(s)
- Sabrina Capece
- Dipartimento di Scienze e Tecnologie Chimiche, Università di Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy.
| | - Fabio Domenici
- Dipartimento di Scienze e Tecnologie Chimiche, Università di Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy. and Dipartimento di Fisica, Università di Roma Sapienza, P.le Aldo Moro 5, 00185 Rome, Italy
| | - Francesco Brasili
- Dipartimento di Fisica, Università di Roma Sapienza, P.le Aldo Moro 5, 00185 Rome, Italy
| | - Letizia Oddo
- Dipartimento di Scienze e Tecnologie Chimiche, Università di Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy.
| | - Barbara Cerroni
- Dipartimento di Scienze e Tecnologie Chimiche, Università di Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy.
| | - Angelico Bedini
- INAIL - Settore Ricerca Certificazione e Verifica - DITSIPIA, Via Fontana Candida, 1 Monteporzio Catone, 00040 Italy
| | - Federico Bordi
- Dipartimento di Fisica, Università di Roma Sapienza, P.le Aldo Moro 5, 00185 Rome, Italy
| | - Ester Chiessi
- Dipartimento di Scienze e Tecnologie Chimiche, Università di Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy.
| | - Gaio Paradossi
- Dipartimento di Scienze e Tecnologie Chimiche, Università di Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy.
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46
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Sheeran PS, Matsuura N, Borden MA, Williams R, Matsunaga TO, Burns PN, Dayton PA. Methods of Generating Submicrometer Phase-Shift Perfluorocarbon Droplets for Applications in Medical Ultrasonography. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2017; 64:252-263. [PMID: 27775902 PMCID: PMC5706463 DOI: 10.1109/tuffc.2016.2619685] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Continued advances in the field of ultrasound and ultrasound contrast agents have created new approaches to imaging and medical intervention. Phase-shift perfluorocarbon droplets, which can be vaporized by ultrasound energy to transition from the liquid to the vapor state, are one of the most highly researched alternatives to clinical ultrasound contrast agents (i.e., microbubbles). In this paper, part of a special issue on methods in biomedical ultrasonics, we survey current techniques to prepare ultrasound-activated nanoscale phase-shift perfluorocarbon droplets, including sonication, extrusion, homogenization, microfluidics, and microbubble condensation. We provide example protocols and discuss advantages and limitations of each approach. Finally, we discuss best practice in characterization of this class of contrast agents with respect to size distribution and ultrasound activation.
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47
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Rojas JD, Dayton PA. Optimizing Acoustic Activation of Phase Change Contrast Agents With the Activation Pressure Matching Method: A Review. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2017; 64:264-272. [PMID: 27740481 PMCID: PMC5270505 DOI: 10.1109/tuffc.2016.2616304] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Submicrometer phase-change contrast agents (PCCAs) consist of a liquid perfluorocarbon (PFC) core that can be vaporized by ultrasound (acoustic droplet vaporization) to generate contrast with excellent spatial and temporal control. When these agents, commonly referred to as nanodroplets, are formulated with cores of low boiling-point PFCs such as decafluorobutane and octafluoropropane, they can be activated with low-mechanical-index (MI) imaging pulses for diagnostic applications. Since the utilization of minimum MI is often desirable to avoid unnecessary biological effects, enabling consistent activation of these agents in an acoustic field is a challenge because the energy that must be delivered to achieve the vaporization threshold increases with depth due to attenuation. A novel vaporization approach called activation pressure matching (APM) has been developed to deliver the same pressure throughout a field of view in order to produce uniform nanodroplet vaporization and to limit the amount of energy that is delivered. In this paper, we discuss the application of this method with a Verasonics V1 Research Ultrasound System to modulate the output pressure from an ATL L11-5 transducer. Vaporization-pulse spacing optimization can be used in addition to matching the activation pressure through depth, and we demonstrate the feasibility of this approach both in vivo and in vitro. The use of optimized vaporization parameters increases the amount of time a single bolus of nanodroplets can generate useful contrast and provides consistent image enhancement in vivo. Therefore, APM is a useful technique for maximizing the efficacy of PCCA while minimizing delivered acoustic energy.
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48
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Chattaraj R, Goldscheitter GM, Yildirim A, Goodwin AP. Phase Behavior of Mixed Lipid Monolayers on Perfluorocarbon Nanoemulsions and its Effect on Acoustic Contrast. RSC Adv 2016; 6:111318-111325. [PMID: 28603605 DOI: 10.1039/c6ra20328k] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Lipid-stabilized nanoemulsions containing a volatile liquid perfluorocarbon core have been studied as ultrasound contrast agents owing to their ability to transform into high-contrast microbubbles when subjected to high intensity focused ultrasound (HIFU). However, while there have been several studies on the effect of acoustic parameters on contrast, the effect of the droplet's stabilizing shell has not been studied as extensively. Inspired by previous studies showing lateral phase separation in microbubbles and vesicles, nanodroplets were formulated with a perfluorohexane core and a shell composed of varying amounts of saturated (DPPC) phospholipids, unsaturated (DOPC) phospholipids, and cholesterol, which were fractionated to obtain nanodroplets of mean diameter 300-400 nm and were stable over one week. When the DOPC content was increased to 40 mol%, ultrasound contrast increased by about one order of magnitude over DPPC-only droplets. Based on fluorescence microscopy results of lateral lipid phase separation on the droplet surface, the various combinations of DPPC, DOPC, and cholesterol were assigned to three regimes on the ternary phase diagram: solid-liquid ordered (low contrast), liquid ordered-liquid disordered (medium contrast), and solid-liquid disordered (high contrast). These regimes were confirmed by TEM analysis of nanoscale droplets. Droplets containing mixed lipid monolayers were also found to produce a significantly greater yield than single-component droplets. The discovery of the dependence of acoustic response on lipid phase separation will help to understand the formulation, behavior, and vaporization mechanism of acoustically-responsive nanoemulsions.
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Affiliation(s)
- Rajarshi Chattaraj
- Department of Mechanical Engineering, University of Colorado Boulder. Boulder, CO 80309
| | - Galen M Goldscheitter
- Department of Chemical and Biological Engineering. University of Colorado Boulder. Boulder, CO 80303
| | - Adem Yildirim
- Department of Chemical and Biological Engineering. University of Colorado Boulder. Boulder, CO 80303
| | - Andrew P Goodwin
- Department of Chemical and Biological Engineering. University of Colorado Boulder. Boulder, CO 80303
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49
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Mountford PA, Borden MA. On the thermodynamics and kinetics of superheated fluorocarbon phase-change agents. Adv Colloid Interface Sci 2016; 237:15-27. [PMID: 27574721 DOI: 10.1016/j.cis.2016.08.007] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Revised: 08/08/2016] [Accepted: 08/12/2016] [Indexed: 11/24/2022]
Abstract
Superheated nanodrops are a new class of submicron-diameter liquid emulsion particles comprising perfluoropropane (C3F8), perfluorobutane (C4F10) and perfluoropentane (C5F12) that are being developed for ultrasound imaging and therapy. They can be formed by condensation of precursor lipid-coated, gas-filled microbubbles. Application of ultrasound or laser energy triggers the phase transformation back to a vapor bubble, and this process can be exploited for certain biomedical applications. The nanodrops are remarkably metastable in the liquid state under physiological conditions, even though they are highly superheated. In prior work, it was suggested that a high Laplace pressure in the lipid-coated nanodrop is responsible for its stability in the superheated state. Recent work by our group, however, points to the energy barrier for homogeneous nucleation as a more likely explanation. The purpose of this article is to review and discuss this mechanism in greater detail. We start with a brief description of basic fluorocarbon intermolecular forces. We then use the van der Waals equation of state to construct equilibrium phase diagrams and saturation curves. The effect of droplet Laplace pressure is superimposed onto these curves and compared to experimental data, where a poor correlation is observed. It is also shown that nanodrops with Laplace pressure are unstable to dissolution. The mechanism of homogeneous nucleation is then offered as an alternative explanation for the metastability of superheated nanodrops, with calculations that show good agreement with experimental data.
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50
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Marshalek JP, Sheeran PS, Ingram P, Dayton PA, Witte RS, Matsunaga TO. Intracellular delivery and ultrasonic activation of folate receptor-targeted phase-change contrast agents in breast cancer cells in vitro. J Control Release 2016; 243:69-77. [PMID: 27686582 DOI: 10.1016/j.jconrel.2016.09.010] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 08/01/2016] [Accepted: 09/12/2016] [Indexed: 12/22/2022]
Abstract
Breast cancer is a diverse and complex disease that remains one of the leading causes of death among women. Novel, outside-of-the-box imaging and treatment methods are needed to supplement currently available technologies. In this study, we present evidence for the intracellular delivery and ultrasound-stimulated activation of folate receptor (FR)-targeted phase-change contrast agents (PCCAs) in MDA-MB-231 and MCF-7 breast cancer cells in vitro. PCCAs are lipid-coated, perfluorocarbon-filled particles formulated as nanoscale liquid droplets capable of vaporization into gaseous microbubbles for imaging or therapy. Cells were incubated with 1:1 decafluorobutane (DFB)/octafluoropropane (OFP) PCCAs for 1h, imaged via confocal microscopy, exposed to ultrasound (9MHz, MI=1.0 or 1.5), and imaged again after insonation. FR-targeted PCCAs were observed intracellularly in both cell lines, but uptake was significantly greater (p<0.001) in MDA-MB-231 cells (93.0% internalization at MI=1.0, 79.5% at MI=1.5) than MCF-7 cells (42.4% internalization at MI=1.0, 35.7% at MI=1.5). Folate incorporation increased the frequency of intracellular PCCA detection 45-fold for MDA-MB-231 cells and 7-fold for MCF-7 cells, relative to untargeted PCCAs. Intracellularly activated PCCAs ranged from 500nm to 6μm (IQR=800nm-1.5μm) with a mean diameter of 1.15±0.59 (SD) microns. The work presented herein demonstrates the feasibility of PCCA intracellular delivery and activation using breast cancer cells, illuminating a new platform toward intracellular imaging or therapeutic delivery with ultrasound.
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Affiliation(s)
| | - Paul S Sheeran
- Physical Sciences Department, Sunnybrook Research Institute, Toronto, ON, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - Pier Ingram
- Department of Medical Imaging, University of Arizona, Tucson, AZ, USA
| | - Paul A Dayton
- Joint Department of Biomedical Engineering, The University of North Carolina and North Carolina State University, Chapel Hill, NC, USA
| | - Russell S Witte
- Department of Medical Imaging, University of Arizona, Tucson, AZ, USA
| | - Terry O Matsunaga
- Department of Medical Imaging, University of Arizona, Tucson, AZ, USA.
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