NIR-emitting semiconducting polymer nanoparticles for in vivo two-photon vascular imaging

2020 ◽  
Vol 8 (9) ◽  
pp. 2666-2672
Author(s):  
Xiao-Ting Gong ◽  
Wenguang Xie ◽  
Jing-Jing Cao ◽  
Shengxiang Zhang ◽  
Kanyi Pu ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Vascular Diseases ◽  
Polymer Nanoparticles ◽  
Semiconducting Polymers ◽  
Vascular Imaging ◽  
Semiconducting Polymer ◽  
Two Photon ◽  
Whole Process ◽  
Versatile Tool

A NIR-emitting TPF probe (NESPN) was prepared using semiconducting polymers and used for continuously monitoring the whole process of ischemic stroke and subsequent reperfusion. This work provides a new and versatile tool for vascular research and diagnosis of vascular diseases.

scholarly journals Ultrabright red AIEgens for two-photon vascular imaging with high resolution and deep penetration

2018 ◽  
Vol 9 (10) ◽  
pp. 2705-2710 ◽  
Author(s):  
Wei Qin ◽  
Pengfei Zhang ◽  
Hui Li ◽  
Jacky W. Y. Lam ◽  
Yuanjing Cai ◽  
...  
Keyword(s):  
High Resolution ◽  
Vascular Imaging ◽  
Tissue Imaging ◽  
Deep Penetration ◽  
High Contrast ◽  
Deep Tissue ◽  
Two Photon ◽  
High Penetration ◽  
Deep Tissue Imaging

A successful strategy for the design of ultrabright red luminogens with aggregation-induced emission (AIE) features is reported. The AIE dots can be utilized as efficient fluorescent probes for in vivo deep-tissue imaging with high penetration depth and high contrast.

scholarly journals In vivo multiphoton fluorescence imaging with polymer dots

2017 ◽  
Author(s):  
Ahmed M. Hassan ◽  
Xu Wu ◽  
Jeremy W. Jarrett ◽  
Shihan Xu ◽  
David R. Miller ◽  
...  
Keyword(s):  
Multiphoton Microscopy ◽  
Multiphoton Imaging ◽  
Two Photon ◽  
Photon Excitation ◽  
Deep Imaging ◽  
Polymer Dots ◽  
Versatile Tool ◽  
Cortical Imaging ◽  
Semiconducting Polymer Dots

AbstractDeep in vivo imaging of vasculature requires small, bright, and photostable fluorophores suitable for multiphoton microscopy (MPM). Although semiconducting polymer dots (pdots) are an emerging class of highly fluorescent contrast agents with favorable advantages for the next generation of in vivo imaging, their use for deep multiphoton imaging has never before been demonstrated. Here we characterize the multiphoton properties of three pdot variants (CNPPV, PFBT, and PFPV) and demonstrate deep imaging of cortical microvasculature in C57 mice. Specifically, we measure the two-versus three-photon power dependence of these pdots and observe a clear three-photon excitation signature at wavelengths longer than 1300 nm, and a transition from two-photon to three-photon excitation within a 1060 – 1300 nm excitation range. Furthermore, we show that pdots enable in vivo two-photon imaging of cerebrovascular architecture in mice up to 850 μm beneath the pial surface using 800 nm excitation. In contrast with traditional multiphoton probes, we also demonstrate that the broad multiphoton absorption spectrum of pdots permits imaging at longer wavelengths (λex = 1,060 and 1225 nm). These wavelengths approach an ideal biological imaging wavelength near 1,300 nm and confer compatibility with a high-power ytterbium-fiber laser and a high pulse energy optical parametric amplifier, resulting in substantial improvements in signal-to-background ratio (>3.5-fold) and greater cortical imaging depths of 900 μm and 1300 μm. Ultimately, pdots are a versatile tool for MPM due to their extraordinary brightness and broad absorption, which will undoubtedly unlock the ability to interrogate deep structures in vivo.

Abstract 66: No Evidence of Functional Peri-Infarct Circuit Remapping in Mouse Somatosensory Cortex After Ischemic Stroke

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
William Zeiger ◽  
Mate Marosi ◽  
Satvir Saggi ◽  
Natalie Noble ◽  
Isa Samad ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Somatosensory Cortex ◽  
Single Neuron ◽  
Direct Evidence ◽  
Individual Layer ◽  
Two Photon ◽  
Whisker Stimulation ◽  
Transcriptomic Changes ◽  
The Brain

Following ischemic stroke, many patients exhibit partial spontaneous recovery, suggesting that the brain has endogenous mechanisms to recover lost functions. Evidence supports a role for peri-infarct cortex in recovery as this area undergoes structural, physiologic, and transcriptomic changes following stroke. It has been hypothesized that these changes promote circuit rewiring, leading spared neurons in the peri-infarct cortex to “remap” and subsume the function previously performed by neurons in the ischemic core. However, direct evidence for remapping at the single neuron level is lacking. To test this, we targeted photothrombotic (PT) strokes to an individual barrel (C1) in the barrel field of mouse primary somatosensory cortex (S1BF). We then performed longitudinal in vivo two-photon (2P) calcium imaging in Thy1 -GCaMP6s transgenic mice and recorded whisker-evoked responses of individual layer 2/3 neurons in the adjacent D3 barrel. Before stroke, ~30% of active neurons in the D3 barrel respond to stimulation of the D3 whisker and ~8% of neurons respond to the C1 whisker. Based on the remapping hypothesis, we predicted that the percentage of C1 whisker-responsive neurons in the spared D3 barrel would increase after stroke; however, we found that only ~2% of neurons in the D3 barrel responded to C1 whisker stimulation one month after stroke. We also tested the effect of forced-use therapy on recovery by plucking all whiskers, except the C1 whisker corresponding to the infarcted barrel, following stroke. Still, we found that forced-use therapy did not lead to an increased percentage of C1 whisker-responsive neurons, but it did enhance the responses to C1 whisker stimulation in surviving C1-responsive neurons in the peri-infarct cortex. These results suggest that at the circuit level recovery may occur through potentiation of spared homotopic neurons rather than remapping of neurons to perform new functions.

Abstract 310: Do Biologic Variations in Plasminogen Levels Affect Endogenous Fibrinolysis and Outcomes in Acute Thrombotic Disease Such as Ischemic Stroke?

2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Satish Singh ◽  
Aiilyan Houng ◽  
Guy L Reed
Keyword(s):  
Ischemic Stroke ◽  
Brain Injury ◽  
Brain Infarction ◽  
Vascular Diseases ◽  
Dose Dependence ◽  
Thromboembolic Stroke ◽  
Plasma Clot ◽  
Dose Response Effect ◽  
Endogenous Fibrinolysis

Introduction: After activation of plasminogen (Pg), plasmin is the key enzyme that acutely dissolves thrombi. Yet, despite significant biologic variation in Pg levels between humans, there is no clear link between Pg levels (or Pg deficiency) and the development or resolution of acute thrombotic vascular diseases such as stroke. Hypothesis: We tested the hypothesis that plasma levels of Pg affect endogenous fibrinolysis, brain injury, hemorrhage and swelling after thromboembolic stroke. Methods and results: We examined male and female Pg +/+ ([Pg] =84±4.8 μg/ml), Pg +/- ([Pg] =37±5.2 μg/ml) and Pg -/- ([Pg] =1.3±3 μg/ml) mice, n= 10-13 per group. Ischemic stroke was induced by endovascular placement of an autologous 125 I-fibrin plasma clot at the origin of middle cerebral artery (MCA) that reduced hemispheric blood flow by ≥80%. After 6 hours of stroke, the dissolution of the culprit MCA thrombus was determined and the effects on brain injury were assessed. Data was analyzed by a two-way ANOVA with Neumann-Keul’s correction. There was a dose-dependent relationship between Pg levels and endogenous dissolution of the MCA thrombus (p=0.0019) with Pg +/+ mice showing greater lysis (20.7±6.6%) than Pg +/- mice (19.0±3.8%) and Pg -/- mice (12.6±6.4%). There was a significant, inverse dose-response effect on brain infarction with higher Pg levels associated with less severe infarction: Pg +/+ (24.8±4.3%) <Pg +/- (27.3±9.4%) <Pg -/- (37.4±8.9%) mice. No significant sex based differences were found in fibrinolysis and brain injury. Brain swelling showed a significant, but non-linear dose-dependence on Pg levels (p<0.01) which was affected by sex (p<0.01). There was no significant association between brain hemorrhage and Pg levels. Conclusions: In vivo, Pg levels have concentration-dependent effects on endogenous fibrinolysis, brain infarction and swelling after thromboembolic stroke. Further studies should be done to assess how Pg levels may affect outcomes in human thrombotic diseases.

scholarly journals Phosphorylcholine-Coated Semiconducting Polymer Nanoparticles as Rapid and Efficient Labeling Agents for In Vivo Cell Tracking

2014 ◽  
Vol 3 (8) ◽  
pp. 1292-1298 ◽  
Author(s):  
Kanyi Pu ◽  
Adam J. Shuhendler ◽  
Maija P. Valta ◽  
Lina Cui ◽  
Matthias Saar ◽  
...  
Keyword(s):  
Cell Tracking ◽  
Polymer Nanoparticles ◽  
Semiconducting Polymer ◽  
Semiconducting Polymer Nanoparticles

scholarly journals Self-quenched semiconducting polymer nanoparticles for amplified in vivo photoacoustic imaging

Biomaterials ◽  
2017 ◽  
Vol 119 ◽  
pp. 1-8 ◽  
Author(s):  
Chen Xie ◽  
Paul Kumar Upputuri ◽  
Xu Zhen ◽  
Manojit Pramanik ◽  
Kanyi Pu
Keyword(s):  
Photoacoustic Imaging ◽  
Polymer Nanoparticles ◽  
Semiconducting Polymer ◽  
Semiconducting Polymer Nanoparticles
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