scholarly journals Activation Strategies in Image-Guided Nanotherapeutic Delivery

2020 ◽  
Vol 1 (1) ◽  
pp. 78-104
Author(s):  
Seok Choi
Keyword(s):  
Image Guidance ◽  
Controlled Drug Release ◽  
Review Article ◽  
Imaging Modalities ◽  
Tissue Penetration ◽  
External Stimulation ◽  
X Ray ◽  
Gate Opening ◽  
Design Characteristics ◽  
Ultrasound Hyperthermia

Therapeutic nanomaterials serve as an important platform for drug delivery under image guidance. Despite significant growth and broad applications, their design specifics remain a subject of continued interest primarily due to multifunctional factors involved, ranging from nanomaterial properties, imaging modalities, and therapeutic agents to activation strategies. This review article summarizes key findings on their design characteristics with a particular interest in strategies developed for therapeutic activation (release). First, their activation can be controlled using either an endogenous factor including low pH and glutathione or an external stimulation by light, ultrasound, or electromagnetic field. The former is passively controlled from a spatiotemporal aspect compared to the latter, which is otherwise actively controlled through drug linker photolysis, nanomaterial disassembly, or gate opening. Second, light stimulation serves a most notable strategy due to its essential role in controlled drug release, photothermal activation (hyperthermia), and photodynamic production of reactive oxygen species (ROS). Third, some of those activation strategies that rely on ultrasound, photothermal, photoacoustic, magnetic field, or X-ray radiation are dually functional due to their role in imaging modalities. In summary, this review article presents recent advances and new insights that pertain to nanotherapeutic delivery systems. It also addresses their technical limitations associated with tissue penetration (light), spatial resolution (ultrasound, hyperthermia), and occurrence of cellular resistance (ROS).

scholarly journals Exceptional adsorption-induced cluster and network deformation in the flexible metal–organic framework DUT-8(Ni) observed by in situ X-ray diffraction and EXAFS

2015 ◽  
Vol 17 (26) ◽  
pp. 17471-17479 ◽  
Author(s):  
Volodymyr Bon ◽  
Nicole Klein ◽  
Irena Senkovska ◽  
Andreas Heerwig ◽  
Jürgen Getzschmann ◽  
...  
Keyword(s):  
Metal Organic Framework ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gate Opening ◽  
Metal Organic ◽  
Flexible Metal ◽  
Organic Framework

The “gate opening” mechanism in flexible MOF Ni2(2,6-ndc)2dabco was elucidated in detail.

scholarly journals Chemiluminescence-initiated and in situ-enhanced photoisomerization for tissue-depth-independent photo-controlled drug release

2019 ◽  
Vol 10 (5) ◽  
pp. 1401-1409 ◽  
Author(s):  
Yufu Tang ◽  
Xiaomei Lu ◽  
Chao Yin ◽  
Hui Zhao ◽  
Wenbo Hu ◽  
...  
Keyword(s):  
Drug Release ◽  
Penetration Depth ◽  
Controlled Drug Release ◽  
Tissue Penetration

Tissue-penetration-depth-independent self-luminescence is highly expected to perform photoisomerization-related bioapplications in vivo to overcome the limitation of shallow tissue-penetration from external photoexcitation.

scholarly journals Role of Imaging in Diagnosis and Management of COVID-19: A Multiorgan Multimodality Imaging Review

2021 ◽  
Vol 8 ◽  
Author(s):  
Vinithra Varadarajan ◽  
Mahsima Shabani ◽  
Bharath Ambale Venkatesh ◽  
Joao A. C. Lima
Keyword(s):  
Multimodality Imaging ◽  
Imaging Techniques ◽  
Standard Of Care ◽  
Review Article ◽  
Health Centers ◽  
Imaging Modalities ◽  
Imaging Protocol ◽  
Diagnosis And Management ◽  
Radiologic Findings

In this pandemic of Coronavirus disease 2019 (COVID-19), a vast proportion of healthcare resources, including imaging tools, have been dedicated to the management of affected patients; yet, the frequent reports of unknown presentations and complications of disease over time have been changing the usual standard of care and resource allocation in health centers. As of now, we have witnessed multisystemic symptoms requiring the collaboration of different clinical teams in COVID-19 patients' care. Compared to previous viral pandemics, imaging modalities are now playing an essential role in the diagnosis and management of patients. This widespread utility of imaging modalities calls for a deeper understanding of potential radiologic findings in this disease and identifying the most compatible imaging protocol with safety precautions. Although initially used for respiratory tract evaluation, imaging modalities have also been used for cardiovascular, neurologic, and gastrointestinal evaluation of patients with COVID-19. In this narrative review article, we provide multimodality and multisystemic review of imaging techniques and features that can aid in the diagnosis and management of COVID-19 patients.

scholarly journals Recent Advances in Ultrafast Structural Techniques

2019 ◽  
Vol 9 (7) ◽  
pp. 1427 ◽  
Author(s):  
Germán Sciaini
Keyword(s):  
Structural Dynamics ◽  
Free Electron Laser ◽  
Review Article ◽  
Chemical Processes ◽  
Plasma Sources ◽  
X Ray ◽  
Recent Advances ◽  
Technological Developments ◽  
Computer Simulators ◽  
Electron Pulses

A review that summarizes the most recent technological developments in the field of ultrafast structural dynamics with focus on the use of ultrashort X-ray and electron pulses follows. Atomistic views of chemical processes and phase transformations have long been the exclusive domain of computer simulators. The advent of femtosecond (fs) hard X-ray and fs-electron diffraction techniques made it possible to bring such a level of scrutiny to the experimental area. The following review article provides a summary of the main ultrafast techniques that enabled the generation of atomically resolved movies utilizing ultrashort X-ray and electron pulses. Recent advances are discussed with emphasis on synchrotron-based methods, tabletop fs-X-ray plasma sources, ultrabright fs-electron diffractometers, and timing techniques developed to further improve the temporal resolution and fully exploit the use of intense and ultrashort X-ray free electron laser (XFEL) pulses.

Contrast Agents

2018 ◽  
Author(s):  
Resmi A. Charalel ◽  
Martin R. Prince
Keyword(s):  
Interventional Radiology ◽  
Contrast Agents ◽  
Image Guidance ◽  
Daily Basis ◽  
Imaging Modalities ◽  
Treatment Algorithms ◽  
Vital Part ◽  
Diagnostic Potential ◽  
Multiple Imaging ◽  
Basic Understanding

Imaging is reliant upon the contrast between different body elements, which may be present naturally or may require the introduction of extrinsic contrast agents. Since the 1920s, the use of contrast agents has been refined to enhance the diagnostic potential of multiple imaging modalities. Contrast agents are a vital part of diagnosis and treatment algorithms involving image guidance. Given the wealth of contrast agents on the market, a basic understanding of the various types is critical for budding interventional radiologists who need to use such agents judiciously on a daily basis. Such contrast agents may be administered intravenously, intraarterially, intrathecally, orally, via inhalation, transrectally, or via indwelling tubes or catheters cannulating a specific viscus. In this chapter, we review the key categories, contraindications, and alternatives for such agents, with special attention to their use in an interventional radiology (IR) practice.

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