Destruction of Recombinant Tissue Plasminogen Activator (rtPA) -Loaded Echogenic Liposomes under Dual Frequency Sonication
Authors
Abstract:
Background:Echogenic liposomes (ELIPs) encapsulate drugs and gas bubbles within lipid vesicles. The destruction of ELIPs in response to MHz and kHz ultrasound waves has been studied previously. Applying ultrasound above a certain threshold causes encapsulated gas bubbles destruct rapidly by fragmentation or more slowly by acoustically driven diffusion. This study compares the destruction of recombinant tissue plasminogen activator (rtPA) -loaded echogenic liposomes using three frequency protocols: 130 kHz, 1 MHz and dual (130 kHz + 1 MHz). Method:In gel phantom, ELIPs were imaged by diagnostic ultrasound system and simultaneously destructive ultrasonic fields were applied at different intensities in each protocol. Images were analyzed. Results:According to the results, 80% decline in MGV (mean of gray value) relative to initial MGV was associated with ELIPs fragmentation. At 130 kHz, results showed an 80% decline in MGV and fragmentation happened at all applied ultrasound intensities (0.01 W/cm2 as fragmentation threshold). In MHz and dual protocols, on average, less than 50% decline in MGV was observed which indicated an acoustically driven diffusion. Conclusion:Our study shows that kHz protocol fragments ELIPs more effectively than other two protocols. For better results, dual frequency protocols need optimized combination of frequencies and phases.
similar resources
Dual frequency ultrasound-enhanced tissue plasminogen activator thrombolysis in an in vitro human clot model
Introduction: Stroke causes death and disability in patients throughout the world. At present, the only FDA- approved drug for ischemic stroke is recombinant tissue plasminogen activator (rt- PA). Unfortunately, rtPA can cause intracerebral hemorrhage and must use within limited time window (within 3-4.5 hour after onset of stroke). Ultrasound with rtPA loaded liposomes (rtPA_L...
full textOptimizing refolding condition for recombinant tissue plasminogen activator
Low molecular size additives such as L-arginine and the redox compounds have been used both in the culturemedium and in vitro refolding to increase recombinant proteins production. Additives increase proteinrefolding and yield of active proteins by suppressing aggregate formation or enhancing refolding process.In this work, a comparative study was performed on refolding of rec...
full textThe Outcome of Treatment With Recombinant Tissue Plasminogen Activator in Acute Ischemic Stroke
Background: Thrombolytic therapy is the recommended treatment of acute ischemic stroke. It is crucial to evaluate the treatment results with recombinant Tissue Plasminogen Activator (r-TPA) in patients with acute stroke. Objectives: This study aimed to evaluate treatment outcomes with r-TPA in patients with acute stroke in a referral stroke center in Iran. Materials & Methods: In this retrosp...
full textAccelerated ST-segment reduction after thrombolytic therapy with recombinant tissue plasminogen activator (rtPA) compared to urokinase.
Effects of therapy with urokinase (UK) and with recombinant tissue plasminogen activator (rtPA) were compared in patients with acute myocardial infarction (AMI). To achieve homogenous therapeutic conditions the comparison was restricted to patients having their first AMI and to cases of clinically successful thrombolytic therapy (defined by non-invasive criteria, such as a 50% decrease in eleva...
full textDestruction thresholds of echogenic liposomes with clinical diagnostic ultrasound.
Echogenic liposomes (ELIP) are submicron-sized phospholipid vesicles that contain both gas and fluid. With antibody conjugation and drug incorporation, these liposomes can be used as novel targeted diagnostic and therapeutic ultrasound contrast agents. The utility of liposomes for contrast depends upon their stability in an acoustic field, whereas the use of liposomes for drug delivery requires...
full textMy Resources
Journal title
volume 25 issue 3
pages 243- 254
publication date 2018-05-01
By following a journal you will be notified via email when a new issue of this journal is published.
Hosted on Doprax cloud platform doprax.com
copyright © 2015-2023