载吲哚菁绿和液态氟碳的光致相变型纳米粒的制备及增强体内成像的实验研究

目的制备一种光致相变型液态氟碳纳米粒,研究其体外相变及体内增强光声、超声成像能力。方法采用三步乳化技术制备出以聚乳酸-羟基乙酸共聚物(PLGA)为载体,液态氟碳(PFH)和吲哚菁绿(ICG)为内核的纳米粒,检测该纳米粒的粒径和电位,然后体外激光辐照激发纳米粒相变,体内观察该纳米粒增强超声及光声成像的能力。结果成功制备出包裹PFH和ICG的光致相变型纳米粒,该纳米粒平均粒径(599.2±134.3)nm,平均电位(-24.10±4.09)m V。激光辐照后,纳米粒可发生相变转变成微米级的微泡,体内增强了裸鼠移植瘤的光声及超声信号。结论制备的光致相变型纳米粒在激光作用下发生相变,并可增强体内超声、光声成像,为临床疾病的诊断提供了新的思路。     

载ICG和PFH的光致相变型纳米粒—一种双模态分子探针宫玉萍 陈澄 孙阳 王志刚

目的 制备一种光致相变型液态氟碳纳米粒,研究其体外相变及体内增强光声、超声成像能力。方法 采用三步乳化技术制备出以PLGA为载体,液态氟碳(PFH)及吲哚菁绿(ICG)为内核的纳米粒,检测该纳米粒的的粒径、电位,然后体外激光辐照激发纳米粒相变,体内观察该纳米粒增强超声及光声成像的能力。结果 成功制备出包裹PFH和ICG的光致相变纳米粒,为球形,其平均粒径为599.2nm,平均电位为-24.1mv。激光辐照纳米粒时,纳米粒可发生相变转变成微米级的微泡,体内增强了裸鼠移植瘤的光声及超声信号。结论 制备的光致相变型纳米粒在激光作用下发生相变并增强体内超声、光声成像,为临床疾病的诊断提供新思路。     

载金纳米棒和液态氟碳纳米造影剂及其体外显影

目的制备一种载金纳米棒(Au)和液态氟碳全氟己烷(PFH)的纳米级造影剂,并对其进行体外双模态(光声/超声)显影研究,进一步实现体内显影。方法采用双乳化法制备包裹金纳米棒-液态氟碳的高分子聚合物(PLGA)纳米粒(GNPs)及只包裹双蒸水的纳米粒(WNPs)或只包裹金纳米棒的纳米粒(Au-NPs);MTT对不同浓度的GNPs行体外细胞毒性实验;分别对GNPs、W-NPs、A-NPs在激光辐照前后二维超声、造影强度和光声信号显影,并统计激光辐照前后二维超声灰度值、造影值及光声信号值。结果成功制备包裹金纳米棒-液态氟碳双模态纳米级造影剂,体外光声和造影效果好;GNPs对HUVECs的毒性,各个浓度抑制率较低,且各组间无统计学差异;在激光辐照前,GNPs、Au-NPs、W-NPs二维超声及造影模式下均为低回声;激光辐照后,GNPs超声灰度和造影强度明显增强,光声显影明显,W-NPs超声灰度和造影模式未见增强,光声未见显影,Au-NPs超声灰度造影强度未见明显增强,光声显影明显。结论成功制备包裹金纳米棒-液态氟碳的纳米级造影剂,实现了体外超声/光声双模态增强显影,为体内靶向显影提供实验基础。     

载10-羟基喜树碱液态氟碳纳米粒制备及其表征、体外增强超声显像效果观察

目的 研制一种包裹液态氟碳（PFP）的新型载药纳米级超声造影剂,考察其基本特性并观察其体外增强超声显像效果。方法 采用旋转蒸发和探头超声法制备载10-羟基喜树碱（10-HCPT）的液态氟碳（PFP）纳米粒,在光学显微镜和透射电镜下观察纳米粒形态,采用马尔文仪测量纳米粒粒径和电荷。采用紫外分光光度计测定纳米粒包封率,并应用低强度聚焦超声（LIFU）辐照载药液态氟碳纳米粒溶液,观察纳米粒相变情况及其增强超声显像效果。结果 制备的载药脂质纳米粒外观为乳白色混悬液,在油镜及透射电镜下观察,载药纳米粒形态规则,分布均一,平均粒径约（500.82±25.97）nm,表面平均电位为（-47.77±3.09）mV;在体外经LIFU辐照后,可见纳米粒发生液气相变形成微泡,在基波模式和谐波模式下,均可显著增强超声显影。结论 成功研制了包裹液态氟碳的载药脂质纳米粒,可望成为一种新型的多功能超声造影剂。     

携IR780碘化物液态氟碳纳米粒造影剂的制备及体外双模态成像

目的 制备携带IR780碘化物的液态氟碳纳米粒（IFNPs）,观察其体外超声/光声双模态成像效果。方法 以羟基端乳酸/羟基乙酸共聚物（PLGA-COOH）、IR780碘化物和全氟戊烷（PFP）为原料,采用双乳化法制备PLGA包裹的纳米粒IFNPs。以光学显微镜、共聚焦显微镜、透射电子显微镜及扫描电子显微镜检测其一般物理特性;以马尔文粒径分析仪分析其粒径大小、分布及表面电位;以紫外分光光度计测定IFNPs中IR780的包封率;观察IFNPs体外光声成像和超声成像的能力。结果 成功制备出IFNPs,其形态规则,大小均一,透射电子显微镜下表现为外壳黑色、内部灰白色的球形结构,扫描电子显微镜显示纳米粒表面光滑。IFNPs粒径为（241.87±3.47）nm,电位为（-0.766±0.096）mV,IR780包封率为（90.38±0.48）%。随IFNPs浓度增加,体外光声成像及超声成像效果均显著增强。结论 携带IR780碘化物的液态氟碳纳米粒造影剂制备成功,可用于体外超声/光声双模态成像。     

VCAM-1靶向双模态光声/超声纳米级分子探针的制备及其体外寻靶实验

目的 制备一种靶向炎症内皮细胞的双模态纳米级分子探针,并对其进行体外寻靶研究。方法 采用双乳化法制备包裹金纳米棒(Gold nanorods)-液态氟碳全氟己烷(PFH)的高分子聚合物纳米粒(GNPs)、只包裹PFH的纳米粒(NPs)和只包裹金纳米棒的纳米粒(Au-NPs);采用碳二亚胺法制备靶向血管内皮粘附因子(VCAM-1)靶向连接的纳米粒(VCAM-1-GNPs);于光镜、电镜下对GNPs基本性质进行检测;用激光辐照仪进行辐照观察GNPs、NPs和Au-NPs的光致相变情况;采用光镜和流式细胞仪观察GNPs与靶向抗体连接情况;用不同浓度肿瘤坏死因子(TNF-α)作用于人脐静脉内皮细胞(HUVECs)后,采用蛋白质印迹法(Western Blot)测量HUVECs膜上VCAM-1的表达量;观察靶向组和非靶向组与VCAM-1-GNPs的结合情况。结果 成功制备包裹金纳米棒-液态氟碳双模态靶向纳米粒,平均粒径(463.67±8.23)nm;激光辐照GNPs相变明显,而NPs和Au-NPs未见明显相变;流式仪检测GNPs和VCAM-1抗体的连接率为99.87%;10 ng/ml浓度的TNF-α作用于细胞后可见VCAM-1明显表达;光镜下VCAM-1-GNPs特异性与靶向组HUVECs结合,非靶向组则未见明显结合。结论 成功制备包裹金纳米棒-液态氟碳双模态靶向纳米粒,GNPs光致相变效果明显,靶向性好。     

靶向相变型载药纳米造影剂的制备及其基本性能检测刘建新1 柳阳1彭万宏2*(1. 华科科技大学同济医学院附属武汉中心医院超声诊断科,武汉,430014； 2.湖北省中西医结合医院放射科,武汉,430015 )

目的 制备一种叶酸靶向相变型载羟基喜树碱的纳米粒FA-HCPT-Fe3O4-PFP NDs,考察其理化性能和多模态显像特性。 方法 采用旋转蒸发-超声法制备叶酸靶向相变型载药液态氟碳纳米粒。检测纳米粒的稳定性及相变特性。使用高效液相色谱法检测纳米粒内药物羟基喜树碱的含量,用细胞实验来检测纳米粒寻靶能力。体外实验验证纳米乳液来进行增强超声、光声和磁共振成像。 结果 制备的纳米粒性质稳定,可以发生液气相变。体外实验中,纳米乳液可以明显增强超声、光声及磁共振成像。 结论 本研究所制备的纳米粒具备多模态造影剂的功能,是一种极具潜力的分子探针。     

"适配子-PLGA纳米粒"靶向超声/光声相变造影剂的制备

目的 研制一种适配子偶联的包裹纳米金棒和液态氟碳的PLGA纳米粒。方法 采用双乳化法制备包裹纳米金棒及全氟己烷(PFH)的PLGA纳米粒(GNP);用碳二亚胺法将适配子与PLGA纳米粒连接获得"适配子-PLGA纳米粒"靶向相变造影剂(AP-GNP)。光镜、激光共聚焦显微镜及电镜下观察及检测AP-GNP基本性质;激光共聚焦显微镜下及流式细胞术观察及检测适配子与纳米粒连接情况;以激光仪辐照AP-GNP观察其光致相变情况;观察AP-GNP与乳腺癌细胞MCF-7特异性结合情况。结果 成功制备适配子修饰的包裹纳米金棒和PFH的PLGA纳米粒, 其平均粒径为(472.43±25.82)nm, 适配子与纳米粒的连接率为达97.98%;激光辐照AP-GNP后, 光致相变效果明显;AP-GNP粘附于MCF-7细胞周围, 未修饰适配子GNP未见明显特异性结合。结论 成功制备偶联的包裹纳米金棒和PFH的PLGA纳米粒, 其光致相变效果明显, 靶向性能良好。     

对比液态氟碳脂质纳米粒与全氟丙烷脂质微泡体外显影及耐声压性

目的 与全氟丙烷（C₃F₈）脂质微泡造影剂比较,分析自制液态氟碳（PFOB）脂质纳米粒体外显影及耐声压性的优劣。方法 分别制备生物素化PFOB脂质纳米粒及生物素化C₃F₈脂质微泡,评估其稳定性,并观察其加入亲和素前后的体外显影效果。对2种造影剂在低声压（MI=0.28）及高声压（MI=0.56）环境下进行超声辐照,于辐照前及辐照10、20、30 s后观察显影情况及其差异。结果 2种造影剂加入亲和素后均发生聚集现象,粒径均较加入亲和素前明显增大（P均<0.05）;且加入亲和素前（t=16.225,P<0.001）、后2种造影剂间粒径差异均有统计学意义（t=-5.046,P<0.001）。稳定性观察期间PFOB脂质微粒内浓度无明显改变,而C₃F₈脂质微泡随放置时间延长浓度呈减低趋势。加入亲和素后,PFOB脂质纳米粒回声明显增强;C₃F₈脂质微泡加入亲和素前后显影效果均较好。低声压（MI=0.28）及高声压（MI=0.56）环境下,PFOB脂质纳米粒造影剂显影强度无明显改变,而C₃F₈脂质微泡显影强度随辐照时间延长呈减低趋势。结论 相较于C₃F₈脂质微泡,PFOB纳米脂质纳米粒造影剂粒径小、耐声压性好,更符合靶向超声造影剂的要求。     

一种产气超声/光声双模态纳米粒的制备及性质检测

目的 研制一种包碳酸氢铵溶液的脂质纳米粒,并观察其超声/光声成像效果。方法 采用薄膜水化法加挤出法制备脂质包裹碳酸氢铵溶液的纳米粒,光镜、电镜、激光粒径仪和电位检测仪检测纳米粒一般物理特性,并通过光声成像仪观察其超声/光声成像效果。结果 制备的纳米粒呈圆球形,形态规则,大小分布均匀,无明显聚集,平均粒径为(230.90±54.58)nm,电位为(-22.81±5.75)mV。碳酸氢铵纳米粒有超声/光声信号,双蒸水纳米粒无超声/光声信号。结论 成功制备包碳酸氢铵溶液脂质纳米粒,可用于超声及光声成像,为进一步体外、体内成像实验奠定了基础。     

Vaporization of perfluorocarbon droplets using optical irradiation

Micron-sized liquid perfluorocarbon (PFC) droplets are currently being investigated as activatable agents for medical imaging and cancer therapy. After injection into the bloodstream, superheated PFC droplets can be vaporized to a gas phase for ultrasound imaging, or for cancer therapy via targeted drug delivery and vessel occlusion. Droplet vaporization has been previously demonstrated using acoustic methods. We propose using laser irradiation as a means to induce PFC droplet vaporization using a method we term optical droplet vaporization (ODV). In order to facilitate ODV of PFC droplets which have negligible absorption in the infrared spectrum, optical absorbing nanoparticles were incorporated into the droplet. In this study, micron-sized PFC droplets loaded with silica-coated lead sulfide (PbS) nanoparticles were evaluated using a 1064 nm laser and ultra-high frequency photoacoustic ultrasound (at 200 and 375 MHz). The photoacoustic response was proportional to nanoparticle loading and successful optical droplet vaporization of individual PFC droplets was confirmed using photoacoustic, acoustic, and optical measurements. A minimum laser fluence of 1.4 J/cm(2) was required to vaporize the droplets. The vaporization of PFC droplets via laser irradiation can lead to the activation of PFC agents in tissues previously not accessible using standard ultrasound-based techniques.     

Photoacoustic and ultrasound imaging using dual contrast perfluorocarbon nanodroplets triggered by laser pulses at 1064 nm

Recently, a dual photoacoustic and ultrasound contrast agent—named photoacoustic nanodroplet—has been introduced. Photoacoustic nanodroplets consist of a perfluorocarbon core, surfactant shell, and encapsulated photoabsorber. Upon pulsed laser irradiation the perfluorocarbon converts to gas, inducing a photoacoustic signal from vaporization and subsequent ultrasound contrast from the resulting gas microbubbles. In this work we synthesize nanodroplets which encapsulate gold nanorods with a peak absorption near 1064 nm. Such nanodroplets are optimal for extended photoacoustic imaging depth and contrast, safety and system cost. We characterized the nanodroplets for optical absorption, image contrast and vaporization threshold. We then imaged the particles in an ex vivo porcine tissue sample, reporting contrast enhancement in a biological environment. These 1064 nm triggerable photoacoustic nanodroplets are a robust biomedical tool to enhance image contrast at clinically relevant depths.OCIS codes: (110.5120) Photoacoustic imaging, (170.7170) Ultrasound, (160.4236) Nanomaterials, (170.3880) Medical and biological imaging, (170.7180) Ultrasound diagnostics     

Engineering optically triggered droplets for photoacoustic imaging and therapy

Liquid perfluorocarbon (PFC) droplets incorporating optical absorbers can be vaporized through photothermal heating using a pulsed laser source. Here, we report on the effect of droplet core material on the optical fluence required to produce droplet vaporization. We fabricate gold nanoparticle templated microbubbles filled with various PFC gases (C₃F₈, C₄F_10, and C₅F₁₂) and apply pressure to condense them into droplets. The core material is found to have a strong effect on the threshold optical fluence, with lower boiling point droplets allowing for vaporization at lower laser fluence. The impact of droplet size on vaporization threshold is discussed, as well as a proposed mechanism for the relatively broad distribution of vaporization thresholds observed within a droplet population with the same core material. We propose that the control of optical vaporization threshold enabled by engineering the droplet core may find application in contrast enhanced photoacoustic imaging and therapy.OCIS codes: (170.0170) Medical optics and biotechnology, (190.4870) Photothermal effects, (170.5120) Photoacoustic imaging, (160.1435) Biomaterials     

Biodegradable polymeric nanoparticles containing gold nanoparticles and Paclitaxel for cancer imaging and drug delivery using photoacoustic methods

In this study, optical-triggered multifunctional theranostic agents for photoacoustic/fluorescent imaging and cancer therapy have been developed. This system consists of a perfluorohexane liquid and gold nanoparticles (GNPs) in the core, stabilized by a Poly (lactide-co-glycolic acid) (PLGA) polymer shell. When cancer cells containing PLGA-GNPs were exposed to laser pulses, cell viability decreased due to the vaporization of the particles in and around the cells. The particle chemo drug loading and delivery capacity was also investigated in vitro experiments. These particles show potential as photoacoustic imaging and therapy agents for future clinical translation in cancer therapy.OCIS codes: (160.4236) Nanomaterials, (160.1435) Biomaterials, (170.5120) Photoacoustic imaging, (170.3880) Medical and biological imaging, (170.2520) Fluorescence microscopy     

诊疗一体化胶质瘤靶向纳米粒增效声动力治疗及多模态显像：体外实验研究

目的 制备胶质瘤靶向诊疗一体化纳米粒,观察体外多模态显像及对U87细胞主动靶向能力和增效声动力治疗（SDT）效果。方法 以双乳化法制备载IR780和全氟戊烷（PFP）纳米粒（IR780-PFP@PLGA）,验证其体外光声（PA）/超声（US）/荧光（FL）多模态显像能力;以细胞计数试剂盒（CCK-8）检测细胞毒性,激光共聚焦显微镜观察其主动靶向能力,通过单线氧荧光探针（SOSG）检测法、JC-1染色法、2'',7''-二氯荧光黄双乙酸盐（DCFH-DA）染色法、钙黄绿素/碘化丙啶（Calcein-AM/PI）双染及CCK-8评价其增效SDT效果。结果 所制备IR780-PFP@PLGA呈圆形,形态规则,粒径均匀,平均（240.67±1.30） nm,表面电位（-9.50±0.06） mV,IR780包封率（92.03±0.42）%;经激光辐照后其PA和FL信号强度呈浓度依赖性,经低强度聚焦超声（LIFU）辐照后表现出良好US对比度成像能力和较强U87细胞靶向能力,并呈活性氧（ROS）浓度依赖。于U87细胞中检出大量ROS,线粒体膜电位明显降低,细胞毒作用明显。结论 成功构建的IR780-PFP@PLGA不仅可用于PA/US/FL多模态显像并具有良好体外寻靶能力,还可通过声致相变（ADV）增强SDT疗效,有望用于多模态成像指导下早期诊断和靶向精准治疗脑胶质瘤并评估疗效。     

High frame rate photoacoustic imaging at 7000 frames per second using clinical ultrasound system

Photoacoustic tomography, a hybrid imaging modality combining optical and ultrasound imaging, is gaining attention in the field of medical imaging. Typically, a Q-switched Nd:YAG laser is used to excite the tissue and generate photoacoustic signals. But, such photoacoustic imaging systems are difficult to translate into clinical applications owing to their high cost, bulky size often requiring an optical table to house such lasers. Moreover, the low pulse repetition rate of few tens of hertz prevents them from being used in high frame rate photoacoustic imaging. In this work, we have demonstrated up to 7000 Hz photoacoustic imaging (B-mode) and measured the flow rate of a fast moving object. We used a ~140 nanosecond pulsed laser diode as an excitation source and a clinical ultrasound imaging system to capture and display the photoacoustic images. The excitation laser is ~803 nm in wavelength with ~1.4 mJ energy per pulse. So far, the reported 2-dimensional photoacoustic B-scan imaging is only a few tens of frames per second using a clinical ultrasound system. Therefore, this is the first report on 2-dimensional photoacoustic B-scan imaging with 7000 frames per second. We have demonstrated phantom imaging to view and measure the flow rate of ink solution inside a tube. This fast photoacoustic imaging can be useful for various clinical applications including cardiac related problems, where the blood flow rate is quite high, or other dynamic studies.OCIS codes: (110.5120) Photoacoustic imaging, (110.0110) Imaging systems, (140.2010) Diode laser arrays     

Laser activatable perfluorocarbon bubbles for imaging and therapy through enhanced absorption from coupled silica coated gold nanoparticles

Nanoparticles have extensively been used for cancer therapy and imaging (i.e., theranostics) using various imaging modalities. Due to their physical and chemical properties (e.g., absorption, fluorescence, and magnetic properties) they have been used for image guided therapy for cancer treatment monitoring. There are various limitations that make many theranostic agents unable to be used for the extended periods of time required for enhancing theranostic capabilities. Some of these are due to inherent characteristics (e.g., change and/or breakdown of structure) present upon continuous irradiation and others are due to environmental (i.e., physiological) conditions that can lead to physical instability (i.e., in terms of size) affecting the amount of particles that can accumulate at the target site and the overall contrast that can be achieved. In this study, perfluorohexane (PFH) nanoemulsions (NEs) were synthesized with silica coated gold nanoparticles (PFH-NEs-scAuNPs) in order to give both stable and enhanced signals for cancer imaging by increasing vaporization of the emulsions into bubbles through the process of optical droplet vaporization (ODV). The resulting perfluorohexane bubbles could be imaged using nonlinear ultrasound (NL US) which significantly increases the signal to noise ratio due to the nonlinear scattering properties of oscillating bubbles. The NL US signals from PFH bubbles were found to be more stable compared to conventional bubbles used for contrast imaging. In addition, the vaporization of PFH NEs into bubbles was shown to cause significant cancer cell death reflecting the theranostic capabilities of the formed PFH bubbles. Since cell death is initiated with laser excitation of PFH-NEs-scAuNPs, these nanoparticles can specifically target cancer cells once they have accumulated at the tumor region. Due to the type of theranostic agent and imaging modality used, the PFH-NEs-scAuNPs can be used to provide higher specificity compared to other agents for locating the tumor region by minimizing tissue specific signals while at the same time being used to treat cancer.

PFH-NEs from PFH-NEs-scAuNPs can vaporize upon laser excitation leading to formation of PFH bubbles that can be used for contrast enhanced US imaging and therapy.